{"1": {"fulltext": "SfiS*\\nRn\\nH9s\\nn^luu^iSttB 1PMB\\nBHHHHEmHEB\\nJ| HHSl Um\\n59PH Bfp wft BB S\\nHHhHRSH\\nIWffiffltW ffi\\nw\\nWSSm\\nEsHB\\nWmam\\nmHBBBI\\n\u00e2\u0096\u00a0MMBOn\\nH\\nrowMufTifyjcD\\nJBfflmil g\\nWHHHB\\n\u00e2\u0096\u00a0Mb\\naKgU?", "height": "2944", "width": "1837", "jp2-path": "ropersquestions00rope_0001.jp2"}, "2": {"fulltext": "", "height": "2869", "width": "1756", "jp2-path": "ropersquestions00rope_0002.jp2"}, "3": {"fulltext": "", "height": "2907", "width": "1781", "jp2-path": "ropersquestions00rope_0003.jp2"}, "4": {"fulltext": "", "height": "2897", "width": "1662", "jp2-path": "ropersquestions00rope_0004.jp2"}, "5": {"fulltext": "", "height": "2901", "width": "1749", "jp2-path": "ropersquestions00rope_0005.jp2"}, "6": {"fulltext": "ROPER S\\nPractical Hand -Books\\nFor Engineers and Firemen*\\nNEW REVISED AND ENLARGED EDITION.\\nHANDY-BOOK FOR STEAM ENGINEERS\\nAND ELECTRICIANS.\\nPRICE, $3.50.\\nPRICE.\\nRoper s Catechism for Steam Engineers and Electric-\\nians, $2.00\\nRoper s Questions and Answers for Steam Engineers\\nand Electricians, 2.00\\nRoper s Hand-Book of Land and Marine Engines, 3.50\\nRoper s Care and Management of the Steam Boiler, 2.00\\nRoper s Use and Abuse of the Steam Boiler, 2.00\\nRoper s Young Engineers Own Book, 2.50\\nRoper s Hand-Book of the Locomotive, 2.50\\nRoper s Instructions and Suggestions for Engineers\\nand Firemen, 2.00\\nRoper s Hand-Book of Modern Steam Fire Engines, 3.50\\nDAVID MCKAY, Publisher,\\n1022 Market Street, Philadelphia, Pa.", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0006.jp2"}, "7": {"fulltext": "ROPERS\\nQUESTIONS AND ANSWERS\\nFOR\\nSTATIONARY AND MARINE\\nENGINEERS\\nAND\\nELECTRICIANS\\nWITH A CHAPTER ON\\nWHAT TO DO IN CASE OF ACCIDENTS\\nJR\\\\th (gtUtion, llctmtten and 6r*athj\\n(ftnlarfled by\\nEDWIN R. KELLER, M.E.\\nAND\\nCLAYTOX \\\\V. PIKE. B.S.\\nEx-President of the Electrical Section of the Franklin Institute\\nPHILADELPHIA\\nDAVID McKAY, Publisher,\\n1022 Market Street", "height": "2901", "width": "1749", "jp2-path": "ropersquestions00rope_0007.jp2"}, "8": {"fulltext": "42274\\nLibrary of Conqrese\\nTWO COWS RfCf\u00c2\u00abV\u00e2\u0082\u00ac0\\nSEP 1 1900\\nCopyright antry\\n9lAm /3, l f 4\\nSECOND COPY.\\nO MHH DIVISION.\\nSEP 6 19d0\\nEntered, according to Act of Congress, in the year 1880, by\\nSTEPHEN ROPER,\\nIn the Office of the Librarian of Congress, at Washington.\\nCopyright by DAVID McKAY, 1897.\\nCopyright by DAVID McKAY, 1900.\\n\u00c2\u00a34289\\nd- 5\\nbO", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0008.jp2"}, "9": {"fulltext": "PREFACE TO THE REVISED EDITION.\\nLike the early editions of the Questions and\\nAnswers for Engineers, the present revision is in-\\ntended for stationary engineers as well as those in\\nthe Mercantile Marine. At the time when this\\nbook was first written there were no published\\nrequirements for either of these two classes of ser-\\nvice, and even at the present time it would\\nbe difficult to say just what should be the\\nqualifications of stationary engineers. Some of the\\nStates have attempted to formulate the require-\\nments, but there has been nothing evolved as yet\\nwhich specifically states them. It would, in fact,\\nbe a difficult matter to comprise in one formula\\nall branches of this service, but it is to be hoped that\\nsomething in this direction will be accomplished\\nin the near future by the co-operation of the\\nvarious States and subsequent legislation.\\nFor Marine Engineers the only requirements\\nestablished by law are contained in the Regulations\\nv", "height": "2933", "width": "1813", "jp2-path": "ropersquestions00rope_0009.jp2"}, "10": {"fulltext": "VI PREFACE TO THE REVISED EDITION.\\nof the Steamboat Inspection Service of the Treas-\\nury Department. These, however, are stated in\\nsuch a general way as to be of little service to\\nan applicant in fitting himself for this service.\\nAs the requirements of the Mercantile Marine are\\nvery fully stated in the Frye Bill, introduced at\\nWashington in January, 1892, the authors have\\ndeemed it advisable to make it a basis for the\\nquestions even though it did not become a\\nlaw.\\nThis bill is the result of certain recommenda-\\ntions from theU. S. delegates to the International\\nMarine Conference and is based largely on the re-\\nquirements in other countries. It contains not\\nonly rules governing the inspection of steamboats,\\nbut it states in a specific way just what shall be\\nthe qualifications of engineers. According to this\\nbill, those in charge of the machinery on steam-\\nboats are divided into Chief Engineers and First.\\nSecond and Third Assistants. Such portions\\nas have a direct bearing on the qualifications of\\nthese are here printed in full, but the subsequent\\nquestions and answers are confined to the first,\\nsecond and third assistants requirements. The", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0010.jp2"}, "11": {"fulltext": "PREFACE TO THE REVISED EDITION. Yll\\nauthors have purposely omitted a detailed con-\\nsideration of the requirements for chief engineer,\\nnot only because they are beyond the scope of\\nRoper s series of books for practical engineers, but\\nalso because the chief engineer s qualifications are\\nlargely covered by the requirements of the assist-\\nants, excepting in so far as they relate to electrical\\nmatters.\\nA series of electrical questions and answers has\\nbeen added for Dynamo Tenders and Wiremen.\\nAs the greater part of their work is confined to\\nlow pressure direct currents, it has been consid-\\nered advisable to confine these questions to that\\nclass of work.\\nOf course, it would be impossible in a book of\\nthis kind to cover all of the questions that might\\nconfront an applicant on examination, and the\\nauthors have confined themselves to the more im-\\nportant subjects and selected such questions as in\\ntheir judgment would on the one hand give a fair\\ntest of the knowledge of the applicant and, on\\nthe other, a well prepared engineer should be\\ncapable of answering.\\nThe authors desire to express their obligations", "height": "2933", "width": "1813", "jp2-path": "ropersquestions00rope_0011.jp2"}, "12": {"fulltext": "Vlll PREFACE TO THE REVISED EDITION.\\nto the following gentlemen who have so kindly\\nassisted them in the preparation of various parts\\nof the book. To Mr. Samuel B. Locke, for prac-\\ntical questions for Firemen and Stationary Engi-\\nneers to Mr. W. H. Thorne, for questions for\\nMarine Engineers; to Augustus Koenig, M. D.,\\nfor the chapter on What to do in Case of Acci-\\ndents.\\nEdwin R. Keller.\\nClayton W. Pike.\\nPhiladelphia, August, 1900.", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0012.jp2"}, "13": {"fulltext": "CONTENTS.\\nQuestions foe Fieemen. page\\nBoilers, Different Classes of, 1\\nCare and Management of, 10\\nFormation of Scale in, 18\\nFoaming in, 20\\nSafety Valves, 21\\nGauges, 22\\nPumps, 23\\nInjectors, 25\\nFeed-water Heaters, 27\\nGrates, 28\\nStokers, 30\\nDamper Eegulators, 33\\nQuestions foe Stationary Engineees.\\nHorse-power of Boilers, 35\\nEvaporative Efficiency of Boilers, 37\\nHeating Surface of Boilers, 38\\nConstruction of Boilers, 41\\nBoiler Setting, 45\\nScale, 46\\nFoaming, 48\\nSafety Valves, 49\\nGauges, 51\\nix", "height": "2933", "width": "1813", "jp2-path": "ropersquestions00rope_0013.jp2"}, "14": {"fulltext": "X CONTENTS.\\nPAGE\\nPumps, 54\\nInjectors, 57\\nFeed water Heaters, 59\\nBoiler Flues, 62\\nGrates, 63\\nStokers, 65\\nChimneys, 06\\nSteam Traps, 68\\nBoiler Eepairs, 71\\nSteam Engines, Power of, 72\\nTypes of, 78\\nValve Gears for, 85\\nGovernors, 97\\nFoundations for, 98\\nCare and Management of, 99\\nThe Steam Engine Indicator, 105\\nCondensers, 10S\\nLess Practical Questions, 109\\nSteam Heating, 123\\nQuestions for Marine Engineers.\\nRules of Supervising Steam Inspectors, 132\\nThe Frye Bill, 140\\nClassification of Engineers, 144\\nQualifications of 3d Assistant Engineers, laO\\n2d 151\\n1st 152\\nChief Engineers, 153\\nQuestions for 3d Assistant Engineers, 159\\n11 2d 172\\n1st 192\\nRequirements for the Revenue Marine, 223", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0014.jp2"}, "15": {"fulltext": "CONTENTS. XI\\nELECTPJCAL QUESTIONS.\\nQuestions foe Dynamo Tenders.\\nPAGE\\nThe Dynamo and its Parts, 227\\nElectrical Distribution, 239\\nSwitchboard and Apparatus, 240\\nDynamos in Multiple, 247\\nRheostats, 249\\nInstruments, 250\\nMotors, 252\\nWiring Systems, 256\\nQuestions for Electricians oe Wiremen.\\nSystems of Distribution, 258\\nDetermination of Sizes of Wire, 260\\nVarieties of Wiring, 261\\nArc Lamps, 269\\nElectric Bells and Annunciators, 273\\nWatchmen s Clock Systems, 276\\nBatteries, 278\\nTelephones, 282\\nElecteical Units, Properties and Measurement.\\nElectric Pressure, 288\\nCurrent, 289\\nEesistance, 290\\nOhm s Law, 293\\nMeasurement, 296", "height": "2933", "width": "1813", "jp2-path": "ropersquestions00rope_0015.jp2"}, "16": {"fulltext": "", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0016.jp2"}, "17": {"fulltext": "QUESTIONS AND ANSWERS\\nFOR\\nSTEAM ENGINEERS\\nAND\\nELECTRICIANS.\\nQUESTIONS FOR FIREMEN.\\nQ. How would you classify steam boilers\\nA. Into cylindrical, flue, fire tubular, and water\\ntubular.\\nQ. What advantages does the plain cylinder\\nboiler possess over other types\\nA. It is simple, inexpensive, easy to clean and\\nrepair.\\nQ. Are plain cylinder boilers much used at the\\npresent time\\nA. No; they have disappeared almost entirely,\\nmainly on account of their inefficiency. They\\nare found occasionally in localities where the cost\\nof fuel is very low.\\nQ. Name the principal varieties of flue boilers\\nand briefly describe their characteristics.\\n1 1", "height": "2933", "width": "1813", "jp2-path": "ropersquestions00rope_0017.jp2"}, "18": {"fulltext": "A QUESTIONS AND ANSWERS FOR\\nA. The Cornish, Lancashire, and Galloway\\nboilers are the principal varieties of flue boilers.\\nIn the Cornish type an internal cylindrical flue\\nextends the whole length of the boiler, and the\\nfurnace is usually contained in the tlue. The\\nLancashire boiler has two internal flues with a\\nfurnace in each, the two flues uniting into one\\nbehind the bridge wall. The Galloway is similar\\nto the Lancashire, but has a number of conical\\ntubes, called Galloway tubes, inside and across\\nthe flues, through which the water circulates.\\nThe furnaces are either within the flues or ex-\\nternal.\\nQ. What are the relative advantages and dis-\\nadvantages of the above-named boilers?\\nA. The Cornish boiler has a greater heating\\nsurface than the plain cylindrical boiler, and it\\nhas the further advantage that that portion of the\\nshell on which the scale is deposited is the coolest\\ninstead of the hottest point. It has the disad-\\nvantage that for the same water capacity it must\\nhave a greater diameter.\\nThe Galloway boiler, being virtually a modified\\nLancashire boiler, possesses all of its advantages;\\nand, additionally, on account of the conical tubes,\\nwhich are placed transversely in the flues, it has a\\ngreater heating surface and better circulation.\\nFurthermore, the flues are much less liable to", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0018.jp2"}, "19": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 6\\ncollapse. All of this is accomplished by the\\nGalloway tubes. Of the three boilers mentioned,\\nthe Galloway type is the safest and most economi-\\ncal in the use of fuel.\\nQ. What methods are employed to stiffen the\\nflues of boilers and to provide for linear expansion\\nand contraction\\nA. This end was formerly accomplished by\\nmaking the flues in short lengths and connecting\\nthem by U-shaped rings, riveted on each section\\nof flue. The stiffening of the flue alone is also\\naccomplished by placing (J -shaped rings within\\nthe flues, at intervals, and by the use of Galloway\\ntubes. This, however, does not take care of\\nexpansion and contraction. The best way of\\naccomplishing both ends is by corrugating the flue,\\nwhich has the further advantage of increasing the\\nheating surface without taking up any more space\\nin the boiler.\\nQ. What is meant by fire-tube or tubular\\nboilers\\nA. Fire-tube or tubular boilers are those in\\nwhich the combustion gases pass, not only around\\nthe outside shell, but also through tubes which are\\nsurrounded by water.\\nQ. In what respect do they differ from flue\\nboilers\\nA. In no essential feature, except that instead", "height": "2933", "width": "1813", "jp2-path": "ropersquestions00rope_0019.jp2"}, "20": {"fulltext": "4 QUESTIONS AND ANSWERS FOR\\nof one flue of large diameter there are a number\\nof small flues or tubes.\\nQ. What is the difference between internally\\nand externally fired tubular boilers?\\nA. The internally fired type consists of an ex-\\nternal cylindrical shell containing a furnace extend-\\ning from the front of the boiler to a point about\\nmidway in the length of the boiler. From this\\npoint, and extending to the rear end of the boiler,\\nthere are a number of tubes which lead the gases\\nof combustion to the back, whence they pass\\nunder the outside shell to the front and into the\\nstack. In the externally fired type the tubes\\nextend the whole length of the boiler, and the\\nfurnace is outside and under the front end of the\\nboiler. The products of combustion pass along\\nthe bottom of the shell to the back of the boiler,\\nand then return through the tubes to the front\\nwhere they enter the stack connection. This latter\\ntype is frequently called the Return Tubular.\\nQ. What advantages does a tubular boiler pos-\\nsess over the cylinder and flue boilers\\nA. The tubular takes up less room, generates\\nsteam more rapidly, and requires less fuel more-\\nover, tubes are less dangerous than flues, on\\naccount of their small diameter and great strength.\\nQ. Why are tubular boilers more economical\\nthan plain cylinder and flue boilers", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0020.jp2"}, "21": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. D\\nA. Because their heating surface is much\\ngreater, and consequently the greater portion of\\nthe heat contained in the combustion gases is\\nimparted to the water.\\nQ. What are their disadvantages as compared\\nto the above-mentioned types Are they impor-\\ntant\\nA. The disadvantages are that the first cost is\\ngreater, and that they are more difficult to clean\\nand repair, because they are less accessible. These\\ndisadvantages are unimportant compared to the\\ngreat gain in economy.\\nQ. What may be said about the tubular boiler\\nin regard to safety\\nA. The tubular boiler is just as safe as the\\ncylindrical boiler, and more so than the flue boiler,\\nbecause the parts subjected to internal pressure\\nhave the same strength, while those subjected to\\nexternal pressure, being smaller in diameter, are\\nmuch stronger.\\nQ. What is a water- tube boiler?\\nA. It is one in which the water circulates\\nthrough a series of tubes, which are surrounded\\nby the combustion gases.\\nQ. What is the position of the tubes in this\\nclass of boilers\\nA. Different makers place the tubes in different\\npositions. In the most common type, such as the", "height": "2933", "width": "1813", "jp2-path": "ropersquestions00rope_0021.jp2"}, "22": {"fulltext": "6 QUESTIONS AND ANSWERS FOR\\nBabcock and Wilcox, Heine, Gill, and Root, the\\ntubes are inclined in others, such as the Cahall,\\nthey are vertical, and occasionally they may even\\nbe found curved spirally.\\nQ. What are the principal advantages of the\\nwater-tube boiler as compared with other types\\nA. Its advantages are that it is safer, more\\neconomical, steams more rapidly, is easily repaired,\\nmore durable its form may be adapted to almost\\nany existing conditions, and it may be easily\\ntaken apart and transported. Its only disadvan-\\ntages are that it is heavy and expensive.\\nQ. Why is it durable?\\nA. Because it is easily accessible, and because,\\nas already stated, it adapts itself to the varying\\nexpansion and contraction without producing\\nundue strains further, the circulation is good,\\nand consequently the temperature of the different\\nparts is fairly uniform.\\nQ. To what class do locomotive and marine\\nboilers belong?\\nA. They may be said to belong to the tubular\\ntype, but they have certain characteristics not\\nfound in the ordinary tubular boiler, which\\nreally place them in separate classes by them-\\nselves.\\nQ. Give a. brief description of a modern marine\\nboiler.", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0022.jp2"}, "23": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 7\\nA. It usually consists of a short, circular shell\\nof large diameter, with an internal corrugated\\nfurnace. At the back of the furnace is a chamber\\ninto which the gases pass from the furnace. This\\nis called the back up-take. A similar chamber in\\nthe front, called the front up-take, connects with\\nthe stack. The tubes are placed above and around\\nthe furnace, and extend from the front to the back\\nup-take.\\nQ. What, then, is the essential difference be-\\ntween a marine boiler and an internally fired\\ntubular boiler\\nA. The principal difference is that while in the\\nordinary internally fired tubular boiler the gases\\npass from the furnaces through tubes to the back\\nand then along the outside to the front, in the\\nmarine boiler the gases do not pass around the\\noutside at all, but go from the furnace directly\\ninto the back up-take, thence through the tubes\\nto the front up-take and into the stack.\\nQ. What conditions have brought about this\\ndesign of boiler for marine purposes\\nA. For marine purposes a boiler must be short,\\nas otherwise it could not be set and operated in\\nthe available space and it must be self-contained,\\nbecause brick setting, on account of its great\\nweight and the motion of the ship, would be out\\nof the question. It must also make steam rapidly.", "height": "2933", "width": "1813", "jp2-path": "ropersquestions00rope_0023.jp2"}, "24": {"fulltext": "c5 QUESTIONS AND ANSWERS FOR\\nQ. Are marine-type boilers ever used for sta-\\ntionary purposes\\nA. Yes; where the vibration is so great as to\\nmake it impossible to make use of a brick setting.\\nQ. Describe briefly a locomotive boiler.\\nA. A locomotive boiler consists of a lon\u00c2\u00ab: cylin-\\nder that contains a large number of tubes, at\\none end of which is the fire-box or furnace, fre-\\nquently made of copper, in which the grate bars\\nare contained. The shape of the fire-box and\\nthe end of the boiler shell which incloses it is\\nrectangular.\\nQ. What is the path followed by the products\\nof combustion\\nA. They first strike a fire-brick arch, which\\ndeflects them into the tubes through which they\\npass into the funnel or smoke-stack placed at the\\nfront end.\\nQ. How is sufficient draft obtained\\nA. In the case of the actual locomotive, by\\nexhausting steam from the cylinders into the fun-\\nnel. When this type of boiler is used for station-\\nary work, a sufficiently high stack is employed to\\ngive the necessary draft.\\nQ. How are the flat surfaces of the fire-boxes\\nmade sufficiently strong in this type of boiler\\nA. By short stay-bolts that are connected with\\nthe outside shell of the boiler.", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0024.jp2"}, "25": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 9\\nQ. How is steam taken from locomotive boilers\\nA. Usually from a steam dome that is placed\\non top of the boiler shell.\\nQ. Why is this steam dome used\\nA. To make sure of obtaining dry steam.\\nQ. Is any other arrangement used\\nA. Yes dry pipes.\\nQ. What do you mean by a one horse-power\\nboiler\\nA. One which evaporates 30 pounds of water\\nper hour from a temperature of 100\u00c2\u00b0 Fahr. to\\nsteam at a pressure of 70 pounds.\\nQ. What materials are used for boiler shells\\nA. Wrought iron and steel, mostly the latter.\\nQ. Why is steel better\\nA. Because it is lighter for the same strength,\\nand therefore a thinner plate may be used which\\nmakes the heating surface more efficient.\\nQ. What is the difference between longitudinal\\nand curvilinear rivets\\nA. The longitudinal rivets are those that run\\nlengthwise of the boiler, and the curvilinear are\\nthose that run around the circumference of the\\nshell.\\nQ. What is the first duty of a fireman in taking\\ncharge of a boiler\\nA. He should examine the water and see if it\\nis at a proper level.", "height": "2933", "width": "1813", "jp2-path": "ropersquestions00rope_0025.jp2"}, "26": {"fulltext": "10 QUESTIONS AND ANSWERS FOR\\nQ. At what level should the water stand in a\\ngauge-glass\\nA. It should be kept up to the second gauge\\nwhile working, and at night should be raised to\\nthe third gauge.\\nQ. Why should the level of the water be raised\\nat night?\\nA. To insure against the water becoming too low\\nfrom leakage or evaporation.\\nQ. Suppose the water should become danger-\\nously low, what should the fireman do\\nA. He should at once draw the fire and allow\\nthe boiler to cool.\\nQ. Should he admit any cold water to the boiler\\nA. On no account.\\nQ. Should he attempt to raise the safety valve\\nin order to diminish the steam pressure?\\nA. Never as this would be positively danger-\\nous.\\nQ. Why is it dangerous to raise the safety\\nvalve\\nA. Because this would suddenly lessen the\\npressure in a boiler, and the water would be per-\\nmitted to rise and perhaps come in contact with\\nthe overheated iron, which might cause an ex-\\nplosion.\\nQ. Suppose the water supply should be cut off\\nfor a short time, how should the fireman proceed", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0026.jp2"}, "27": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 11\\nA. He should cover his fire with fresh coal, and\\nshut off all steam engines or other steam-using\\ndevices.\\nQ. In getting up steam, how should the fire-\\nman proceed\\nA. First, he should find out if the water is at a\\nproper lev^el, trying the gauge-cocks for this pur-\\npose, remove all ashes and cinders from the fur-\\nnace, and then cover the grate with a thin layer\\nof coal. He should then place wood and shavings\\non the coal, after which he can start the fire.\\nQ. Why is it advantageous to place a little cov-\\nering of coal on the grate before putting on the\\nwood and the shavings\\nA. It protects the cold grate bars from the heat\\nof the fire and it also saves fuel, since the heat\\nthat would be transmitted to the bars is absorbed\\nby the coal.\\nQ. Is there any advantage in starting the fire\\ngradually and slowly when commencing to get up\\nsteam from cold water\\nA. Yes; it allows the parts of the boiler to ex-\\npand equally, and therefore it throws less strain\\non these parts.\\nQ. How should a fireman regulate his fire\\nA. He should keep the fire at a uniform thick-\\nness over all parts of the grate, not allowing any\\nbare spots or any accumulations of ashes or dead", "height": "2933", "width": "1813", "jp2-path": "ropersquestions00rope_0027.jp2"}, "28": {"fulltext": "12 QUESTIONS AND ANSWERS FOR\\ncoals at any part of the furnace; he should supply\\nthe coal in small quantities at frequent intervals;\\nhe should avoid excessive firing as much as pos-\\nsible, as it is always attended with more or less\\ndanger, since the intense heat repels the water\\nfrom the surface of the iron and this causes the\\nplates to burn.\\nQ. How thick should the fire be\\nA. This depends upon the capacity of the\\nboiler relative to the engine and upon the coal\\nused. If anthracite coal be used, the thickness of\\nabout 3 inches is proper, and for soft coal about 5\\ninches. If the boiler is too small for the work,\\nit will be necessary to keep the fire thin; if, how-\\never, the boiler is extra large, the thickness of the\\nfire makes little difference.\\nQ. Suppose from any cause the fire becomes\\nvery low, what should the fireman do\\nA. He should place shavings, sawdust, wood,\\nor other very combustible substances on the bare\\nspot with a thin covering of coal and then open\\nthe draft to its full extent. He should not poke\\nor disturb the fire, as this is likely to put it out.\\nQ. Is the regulation of the draft of a furnace of\\nmuch importance\\nA. Yes; it is next in importance to the regula-\\ntion of water, because by poor regulation of the\\ndraft enormous quantities of coal are wasted.", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0028.jp2"}, "29": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 13\\nQ. How should the draft be regulated in order\\nto obtain best results from the fuel\\n.4. There should be no more draft at any time\\nthan would produce sufficient combustion to keep\\nthe steam at the working pressure; any greater\\nsupply of air than this carries great quantities of\\nheat into the chimney, which is lost.\\nQ. Can this principle of regulation be carried\\nout always?\\nA. Not unless the furnace and the boilers are\\nsufficiently large to do their work without forcing;\\nif the boiler is too small, it is impossible to use\\nthe fuel economically.\\nQ. Why should the ashpit be kept clean\\nA. Because if it is filled with ashes and cinders,\\nthe grate bars become overheated and may be\\neither badly warped or melted.\\nQ. Is it objectionable to throw steam or water\\nunder the grate bars of boilers\\nA. Yes; because water forms with the ashes a\\nlye that corrodes the iron.\\nQ. What care should the fireman give to the\\nsafety valve\\nA. He should keep it at all times in good work-\\ning order and should try it at least once a day,\\npreferably in the morning, so as to see that all the\\nparts are in good working order before getting up\\nsteam.", "height": "2933", "width": "1813", "jp2-path": "ropersquestions00rope_0029.jp2"}, "30": {"fulltext": "14 QUESTIONS AND ANSWERS FOR\\nQ. In filling boilers, why is a cock or valve in\\nthe steam room of the boiler often open\\nA. In order to allow the air to escape so that it\\nmay not collect in the steam room, thus retarding\\nthe entrance of the water and preventing the reg-\\nular expansion of the iron after the fire is started.\\nQ. Explain what you mean by the steam room\\nof the boiler.\\nA. That portion of the boiler occupied by steam\\nabove the water.\\nQ. What do you mean by the fire line of the\\nboiler?\\nA. The line above which the fire cannot rise\\nbecause of the masonry which surrounds the\\nboiler.\\nQ. How often should boiler flues and tubes be\\ncleaned\\nA. At least once a week.\\nQ. Should the outside shell of the boiler also\\nbe cleaned?\\nA. Yes.\\nQ. What is the advantage gained by cleaning\\nthe flues frequently and the removing of soot and\\nashes from the boiler shell and tubes\\nA. It saves fuel it also saves the burning of\\nthe tubes or plates.\\nQ. How often should the fireman clean his\\nboilers", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0030.jp2"}, "31": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 15\\nA. This depends upon the kind of water used\\nbut no matter how good the water, he should\\nclean his boiler at least every three months.\\nQ. What is the duty of a fireman in regard to\\nblowing out his boilers\\nA. He should 1 blow them out regularly and\\ncarefully; the condition of the feed water being\\nwhat determines how often this should be done.\\nIn blowing them out the dampers should be closed\\nand the fire drawn. Then as much time as pos-\\nsible should be allowed the boiler to cool off\\nbefore opening the blow-off cock. An entire day\\nis not too much to allow for cooling.\\nQ. Why is it bad practice to blow off a boiler\\nwhile hot\\nA. Because in cooling without any water un-\\nequal strains are liable to be produced, and also\\nthe scale and mud become hardened by the heat\\nand stick to the boiler, thus defeating the object\\nfor which the boiler is blown off namely, the\\nremoval of scale and mud.\\nQ. What else should be done at the time of\\ncleaning the boilers\\nA. The fireman should examine all the seams\\nand stays and rivets, crown sheet, etc. and should\\nalso sound the shell of the boiler with a very\\nlight steel hammer, in order to determine the con-\\ndition of the iron.", "height": "2933", "width": "1813", "jp2-path": "ropersquestions00rope_0031.jp2"}, "32": {"fulltext": "16 QUESTIONS AND ANSWERS FOR\\nQ. How often should the steam gauge be tested\\nA. At least once a year.\\nQ. Can the fireman usually test the steam gauge\\nhimself\\nA. Not unless he has access to a test gauge,\\nwhich is not often the case.\\nQ. How can the fireman clean his water-gauge\\nglass inside?\\nA. Open the drip-cock and close the water valve\\nwhich will allow the steam to rush down the\\nglass and carry out any dirt that is in it. When\\nthe boiler is cool, the glass can also be swabbed\\nout with a piece of cloth on a stick.\\nQ. Is it advisable to use a piece of wire or iron\\ninstead of a stick\\nA. No as it is likely to crack the glass.\\nQ. What can you say about the care of the\\ngauge cocks\\nA. They should be examined several times a\\nday, to make sure that they are in good working\\norder they should be shut tight, and should be\\nground or repaired whenever necessary so as to\\nmake them tight.\\nQ. What Avould you do in cold weather if you\\nthought that your pumps, boiler connections, or\\nwater pipes were liable to be frozen\\nA. I would open all drip- or discharge-cocks\\nand allow the water to run out of them when I", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0032.jp2"}, "33": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 17\\nstopped work at night. In the morning I would\\nexamine all the steam- and water-connections be-\\nfore starting the fires.\\nQ. What would you do in case it becomes\\nnecessary to stop the engine and steam should\\ncommence to blow off at the safety valve\\nA. I would immediately start the pump or\\ninjector and cover the fire with fresh coal.\\nQ. Is it desirable to have the damper open at\\nthe same time as the fire door\\nA. No the door and damper should never be\\nopen at the same time, because the cold air would\\nrush through the open door above the fire and\\nstrike on the tube and crown sheets, which would\\nbe liable to contract the seams and cause leakage.\\nQ. How would you proceed if you wished to\\nexamine the check valve while the steam is on the\\nboiler\\nA. I would first close the stop-cock between the\\ncheck valve and boiler then I would unscrew\\nand remove the check.\\nQ. Describe how you would make a joint on\\nthe manhole or handhole of the boiler.\\nA. I would first remove all gum or other ma-\\nterial from the seat flange where the joint is to be\\nmade, and would then put on the gasket and\\ntighten the nut.\\nQ. How often should you consider that a good", "height": "2933", "width": "1813", "jp2-path": "ropersquestions00rope_0033.jp2"}, "34": {"fulltext": "18 QUESTIONS AND ANSWERS FOR\\nfireman should make a thorough examination of\\neverything under his charge\\nA. He should, at least once a day, make a\\nthorough examination of all safety valves, pumps,\\ninjectors, steam- and water-connections, etc.\\nQ. What is scale in a boiler\\nA. It is a deposit that forms on the inside of a\\nboiler shell or tubes.\\nQ. From what does this deposit come\\nA. From impurities in the feed water.\\nQ. What are the results of scale in boilers\\nA. It increases the coal consumption and causes\\nburning of the plates.\\nQ. Why does it increase the coal consumption\\nA. Because the scale being a poor conductor of\\nheat, the heat of the fire is not imparted to the\\nwater as completely as if the water was directly\\nin contact with the plate.\\nQ. Why does the deposition of scale increase\\nthe tendency of the plates to burn\\nA. The water, not being directly against the iron,\\ndoes not protect it from crystallization or burning.\\nQ. How can the formation of scale be guarded\\nagainst\\nA. In two ways first, by depositing the im-\\npurities in water in feed-water heaters of the open\\ntype before the water gets into the boiler second,\\nby the use of boiler compounds in the boiler.", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0034.jp2"}, "35": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 19\\nQ. Is there any boiler compound that will be\\neffective in all cases\\nA. No the composition of the compounds\\nshould be varied according to the nature of the\\nimpurities that are contained in the feed water.\\nQ. What is corrosion\\nA. Corrosion is the w r asting or pitting of iron in\\nthe boiler.\\nQ. To what is it generally due\\nA. Corrosion on the outside of a boiler is gener-\\nally due to the chemical action of sulphur or other\\nimpurities in the fuel or in the atmosphere. Cor-\\nrosion on the interior of the boiler is caused by\\nthe chemical action of acid or mineral substances\\nin the feed water.\\nQ. What remedies are employed to prevent\\ncorrosion\\nA. The interior of the boiler is often painted\\nwith a thin coating of Portland cement another\\nmethod is to allow a thin layer of scale to form;\\nstill another method is to suspend metallic zinc in\\nthe water and steam spaces.\\nQ. What is foaming, and w T here would it be\\nnoticed\\nA. Foaming is a violent movement of the\\nwater it is noticed at the gauge glass by the\\nrapid rise and fall of the w r ater level.\\nQ. What causes foaming in boilers", "height": "2933", "width": "1813", "jp2-path": "ropersquestions00rope_0035.jp2"}, "36": {"fulltext": "20 QUESTIONS AND ANSWERS FOR\\nA. Foaming may be clue to poor design of the\\nboiler that has provided an insufficient amount of\\nsteam space. If the boiler is properly designed\\nin this respect, foaming will be due to the foul\\ncondition of the boiler or to the presence of some\\nsoapy or greasy substance in the feed water.\\nQ. Is foaming a source of danger\\nA. Yes; when a boiler foams badly the water is\\nlifted from the fire surface of the boiler, which\\nallows the iron to be burned.\\nQ. Is there any danger to the engine in case of\\nfoaming\\nA. Yes mud and water from the boiler are\\nliable to be carried into the cylinder of the engine,\\nand either scratch the cylinder surface or perhaps\\ncause the breaking of the cylinder head.\\nQ. What steps should you take to prevent\\nfoaming\\nA. I would check the boiler and endeavor to\\nobtain pure feed water.\\nQ. What is priming?\\nA. Priming is the carrying over of water from\\nthe boiler to the engine in the form of spray.\\nQ. What causes priming?\\nA. Sometimes a lack of sufficient steam space\\nin the boiler, but if properly designed in this re-\\nspect it will be due to carrying the water at a too\\nhigh level.", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0036.jp2"}, "37": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 21\\nQ. For what is a safety valve used\\nA. It is intended to protect the boiler from ex-\\nplosion by relieving the pressure of the boiler\\nwhenever it gets beyond a certain amount.\\nQ. What is the general principle on which a\\nsafety valve works\\nA. The steam pressure in the boiler is balanced\\nagainst the pressure of a spring or weight in such\\na manner that when the pressure in the boiler ex-\\nceeds a safety limit it will overcome the action of\\nthe spring or weight and open the valve. This\\nallows the escape of steam and thus diminishes\\nthe pressure.\\nQ. What is the effect of the continual action of\\nthe steam on the safety valve\\nA. The valve becomes worn and leaky and must\\nbe occasionally ground on the seat.\\nQ. What material would you use for the grind-\\ning?\\nA. Powdered glass, grit from grindstones, or\\nfine emery.\\nQ. How often would you test a safety valve,\\nand when\\nA. At least once a day in the morning so as\\nto be sure that it is in good working order before\\nstarting the fire.\\nQ. What classes of safety valve are you familiar\\nwith?", "height": "2933", "width": "1813", "jp2-path": "ropersquestions00rope_0037.jp2"}, "38": {"fulltext": "22 QUESTIONS AND ANSWERS FOR\\nA. Three classes: first, the dead-weight safety\\nvalve, in which the weight that balances the pres-\\nsure of the steam is placed directly on the valve\\nspindle second, a spring safety valve, which is\\nlike the first except that the spring takes the place\\nof the weight third, the lever safety valve, in\\nwhich the weight or spring, instead of being\\nplaced directly on the valve spindle, is attached to\\na lever.\\nQ. How are the adjustments made with a lever\\nvalve\\nA. By altering the position of the weight or\\nspring on the lever.\\nQ. How many safety valves should a boiler\\nhave\\nA. At least two.\\nQ. What are the principal gauges used in con-\\nnection with steam boilers\\nA. The water gauge, pressure gauge, and vac-\\nuum gauge.\\nQ. When there is no steam on the boiler, where\\nshould the pointer of the pressure gauge stand\\nA. At zero.\\nQ. Suppose that it does not stand at zero\\nA. It should be adjusted by comparison with a\\nstandard gauge.\\nQ. What is a water gauge\\nA. An apparatus for showing the level at which", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0038.jp2"}, "39": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 23\\nwater stands in a boiler. It consists of the glass\\ntube placed on the outside of the boiler, the top\\nend being connected to the steam space and the\\nbottom end to the water space.\\nQ. What is a safety water column\\nA. A modification of the water gauge, consist-\\ning of floats so arranged that a signal is given\\nwhenever the water is too high or too low.\\nQ. Is it safe to depend upon the indications of\\nthe safety water column\\nA. No; while they are useful as an additional\\nsafeguard in maintaining the proper level of the\\nwater, a fireman must on no account neglect to\\nwatch the level in the water gauge.\\nQ. What other device is used for finding out\\nthe water level\\nA. Gauge cocks (usually three in number)\\nplaced at different levels.\\nQ. How often should these gauge cocks be\\ntried, and why\\nA. Several times a day, because the gauge-glass\\nconnections may become choked and cause the\\nglass to give incorrect indications of the level of\\nthe water.\\nQ. What are pumps, and how are they usually\\noperated\\nA. Pumps are machines for lifting or transfer-\\nring water or other liquids. They are operated", "height": "2933", "width": "1813", "jp2-path": "ropersquestions00rope_0039.jp2"}, "40": {"fulltext": "24 QUESTIONS AND ANSWERS FOR\\neither by belting, by steam, or by connection to\\nan electric motor.\\nQ. Which of the above types is usually em-\\nployed for boiler-feed pumps\\nA. The steam pump.\\nQ. What different kinds of steam pumps are\\nthere\\nA. Fty-wheel pumps, direct- acting pumps, and\\nduplex pumps.\\nQ. Which of these pumps is most commonly\\nused for a boiler-feed pump, and why\\nA. The duplex pump, because it is the simplest.\\nQ. What is a duplex pump\\nA. Duplex pumps consist of a combination of\\ntwo steam pumps so coupled together that the\\nsteam valve of one is operated by the piston of the\\nother.\\nQ. Explain the difference between a force pump\\nand a suction pump.\\nA. A force pump is one that forces the water\\nagainst some opposing pressure, such as the pressure\\nin the boiler; and a suction pump is one that takes\\nwater from a level below that of the pump and\\nraises it as, for example, an ordinary well pump.\\nQ. Is there any limit to the height to which a\\nsuction pump will draw water?\\nA. Yes; it cannot lift water more than 33 feet\\nvertically.", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0040.jp2"}, "41": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 25\\nQ. Is there any limit to the height to which a\\npump will force water\\nA. Xone, except the power of the pump.\\nQ. What is an injector\\nA. An apparatus for forcing water against a\\npressure by the direct action of a jet of steam\\non the water.\\nQ. Injectors frequently fail to operate. What\\nis the common cause of this failure\\nA. The presence of air in the suction pipe.\\nQ, How would you avoid this\\nA. I would make sure that the end of the suc-\\ntion pipe was entirely in the water, that the valve\\nstem was properly packed, and that there was no\\nsediment or dirt in the nozzle.\\nQ. If an injector was not getting water, where\\nwould you look for trouble\\nA. I would first examine the water pipe, then\\nsee if the strainer was clogged; then, if the trouble\\nwere due to neither of these, it might be due to too\\nhot water or too low a steam pressure.\\nQ. If after the injector has once started the jet\\nof water breaks, where would you look for the\\ndifficulty\\nA. It might be due to any of the above causes\\nor to a loose disc in the supply pipe valve.\\nQ. What are the principal precautions to be used\\nin setting up injectors", "height": "2933", "width": "1813", "jp2-path": "ropersquestions00rope_0041.jp2"}, "42": {"fulltext": "26 QUESTIONS AND ANSWERS FOR\\nA. All pipes must be at least as large as the\\nholes in the corresponding branch of the injector,\\nand must be as short and straight as possible. A\\nstrainer should be placed over the end of the\\nwater-supply pipe. The area of all holes in the\\nstrainer must be considerably greater than the area\\nof the water-supply pipe, so as to compensate for\\nthe closing of some of them by deposits of sticks\\nor other matter. Steam should be taken from the\\nhighest part of the boiler, so as to get it as dry as\\npossible, as wet steam cuts the steam spindle and\\nnozzle of the injector. It is not advisable to take\\nsteam from the engine supply pipe unless this pipe\\nis very large, as the sudden variations in pressure\\nmay break the jet. After the injector is properly\\nconnected it should be thoroughly washed out by\\nblowing steam through it, so as to take out all\\nthe red lead or any other solids that may be in the\\npipe.\\nQ. Should injectors be set high or low\\nA. As low as possible, since their capacity\\ndiminishes and also their reliability as to the\\nheight of the lift is increased.\\nQ. What is an ejector\\nA. An instrument similar to the injector, and\\ndesigned only to lift water without forcing it\\nagainst a pressure.\\nQ. What is an inspirator", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0042.jp2"}, "43": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 27\\nA. A double jet injector; one jet is used to lift\\nthe water, the other to force it into the boiler.\\nQ. Should a boiler plant have both a pump and\\nan injector?\\nA. Yes; because either one may at some time\\nrefuse to operate.\\nQ. What is the object in heating feed water\\nbefore it goes in the boiler\\nA. There are several reasons for doing so: first,\\nbecause if the water were fed into the boiler cold,\\nit would produce strains in the boiler which would\\ntend to shorten its life; second, because heating the\\nfeed water to a high temperature will cause a large\\nproportion of the salts contained in the solution to\\nseparate out and to be deposited in the heater\\ninstead of producing scale in the boiler; third, if\\nthe heater is supplied with exhaust steam or with\\nsome other source of heat which would otherwise\\nbe wasted, there is a considerable saving of fuel.\\nQ. What is the difference between open and\\nclosed heaters?\\nA. In closed heaters the exhaust steam passes\\nthrough a series of brass tubes and the feed water\\npasses through a space around the tubes and into\\nthe boiler; or, the opposite arrangement may be\\nused, the water passing through the tubes and the\\nsteam around the tubes. In open heaters the\\nsteam comes in actual contact with the water.", "height": "2933", "width": "1813", "jp2-path": "ropersquestions00rope_0043.jp2"}, "44": {"fulltext": "28 QUESTIONS AND ANSWERS FOR\\nQ. What is an economizer\\nA. An economizer is a device used for heating\\nfeed water which makes use of the products of\\ncomposition passing from the boiler furnace into\\nthe stack.\\nQ. How are economizers generally made\\nA. They are usually made of a series of iron or\\nsteel tubes connected at each end by headers like\\nthose used in water-tube boilers. The feed water\\ncirculates through the tubes and the products of\\ncomposition pass around the tubes.\\nQ. What is a grate, and for what purpose is it\\nused?\\nA. A grate consists usually of a series of cast-\\niron bars supported at either end and placed in the\\nfurnace chamber, its object being to support the\\nfuel in such a manner as to allow the free passage\\nof air through the fuel.\\nQ. What limits the length of the grate\\nA. The distance to which the fireman can throw\\nthe coal, which is about 6 feet.\\nQ. What is the object in inclining the bars\\ndownward toward the bridge wall\\nA. To make the distribution of fuel more easy.\\nQ. How much coal is generally consumed j)er\\nsquare foot of grate surface\\nA. This depends entirely upon the draft and the\\nkind of coal.", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0044.jp2"}, "45": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 29\\nQ. How much anthracite coal would you expect\\nto be burned in a good stationary boiler\\nA. About nine (9) pounds.\\nQ. Roughly, how much grate surface is allowed\\nper horse-power\\nA. In stationary boilers about J- of a square\\nfoot.\\nQ. What is a shaking grate\\nA. It is a grate operated mechanically, which\\nmoves in such a way as to clean the fire, break up\\nthe clinkers, and remove them without opening\\nthe fire door.\\nQ. What is the advantage of a shaking grate\\nA. It does away with the necessity of opening\\nthe fire doors frequently, and since the entrance\\nof cold air in the fire door tends to create strains\\nin the boiler the use of the shaking grate would\\nincrease the durability of the boiler. Also, it is\\nimpossible for a fireman to thoroughly stir up\\nwith the slicing bar every part of the grate; there-\\nfore, if the coal used had a tendency to form\\nclinkers, the shaking grate would be an advan-\\ntage, because all parts of the fire would be reached\\nby its action.\\nQ. What do you mean by automatic stoking\\nA. Feeding the coal and removing the ashes\\nfrom the furnace automatically without opening\\nthe furnace doors.", "height": "2933", "width": "1813", "jp2-path": "ropersquestions00rope_0045.jp2"}, "46": {"fulltext": "30 QUESTIONS AND ANSWERS FOR\\nQ. What advantages are claimed for mechanical\\nstokers\\nA. Saving of fuel, prevention of smoke, and\\nless hand labor.\\nQ. Why should a mechanical stoker save fuel\\nA. Because the coal is spread upon the grate\\nuniformly and frequently, whereas with hand\\ntiring coal is fed into the furnace at irregular\\nintervals, and usually more coal is put in than\\nis desirable to obtain a perfect combustion\\nmoreover, each time the boiler is fired by hand\\nthe furnace doors must be opened, which allows\\ncold air to rush in, and this current of cold air\\ndiminishes the effectiveness of the boiler.\\nQ. Why do mechanical stokers diminish the\\nproduction of smoke?\\nA. Because the fuel is fed in small quantities\\nand the motion of the grate keeps the air spaces\\nopen so that the combustion is at all times com-\\nplete. As smoke is the product of imperfect\\ncombustion, it is clear that any process which\\nmakes the combustion better will diminish the\\namount of smoke.\\nQ. Why do stokers save labor?\\nA. Because there is no cleaning of fires or shov-\\neling of coal or manual labor of any kind except\\nthe wheeling out of the ashes.\\nQ. What is the purpose of a chimney or stack", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0046.jp2"}, "47": {"fulltext": "STEAM ENGINEERS AXD ELECTRICIANS. 31\\nA. Its purpose is to produce a draft that will\\ntake away from the furnaces the products of com-\\nbustion and will furnish fresh air.\\nQ. What kinds of coal require the tallest\\nstacks\\nA. Those that do not burn very readily, such as\\nanthracites.\\nQ. For what is a steam separator used\\nA. In order to remove the moisture from steam\\nbefore it enters the engine cylinder.\\nQ. For what is a steam trap used\\nA. In order to remove condensed steam from\\nsteam pipes without allowing any of the steam\\nitself to escape.\\nQ. If a separator or trap or heater should re-\\nquire cleaning or repairing, will it be necessary to\\nshut down the plant in order to do this\\nA. In a properly designed system it would not\\nbe, for they should always be piped in such a way\\nthat steam or water may, by turning the valves,\\nbe made to pass temporarily through auxiliary\\npipes around the heater separator or trap.\\nQ. Give a brief description of the manner in\\nwhich a by-pass is usually constructed.\\nA. See Roper s Catechism, page 173.\\nQ. Explain how you would proceed in cleaning\\na fire.\\nA. Let one side of the fire burn down, keeping", "height": "2933", "width": "1813", "jp2-path": "ropersquestions00rope_0047.jp2"}, "48": {"fulltext": "32 QUESTIONS AND ANSWERS FOR\\nthe other side burning in good condition. Pull out\\nthe side that has burned down and knock off any\\nclinkers that may be on the walls. Turn the good\\npart of the fire over onto the grate bars and put on\\nas much new fuel as it needs allow a little time\\nfor the clinkers and ashes on the other side to cool\\nand then pull them out.\\nQ. What is the purpose of a fusible plug?\\nA. It is intended to melt if by any chance the\\nwater falls below the level of the plug. The\\nmelting of the plug opens a passage-way by which\\nwater flows into the fire-box and extinguishes the\\nfire.\\nQ. How is the plug made\\nA. It is made of a brass nipple having a hexa-\\ngon head on one end this nipple is hollow and is\\nfilled with a composition which remains solid as\\nlong as the water is in contact with it, but which\\nmelts at a fairty low temperature.\\nQ. Where is the fusible plug usually placed\\nA. In the top of a fire-box.\\nQ. How could you tell whether or not the\\nfusible plug were in proper condition\\nA. If it were covered with scale or soot I should\\nnot consider it were in good condition, but if free\\nfrom both, I should consider it to be all right.\\nQ. How can you tell a high pressure from a\\nlow pressure safety valve", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0048.jp2"}, "49": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS, 33\\nA. By looking at the figures stamped on the\\nvalve or on the lever. On low pressure valves\\nthe figures will not run higher than about 30\\npounds.\\nQ. In what way could you judge whether the\\nsafety valve of a boiler were in good condition or\\nnot?\\nA. If it opened always at the same pressure and\\nnever showed any indication of sticking, I should\\nassume that it were in good condition.\\nQ. What is a steam damper regulator and how\\ndoes it work\\nA. It is an apparatus for regulating the position\\nof the damper by the pressure of steam in the\\nboiler. The general arrangement is to have the\\ndamper connected with a water pressure. The\\nsteam pressure in the boiler controls a valve not\\nunlike a safety valve which admits or releases the\\nwater pressure according as the steam pressure is\\ntoo high or too low.\\nQ. What checks have you on the accuracy of\\nthe steam gauge\\nA. If the gauge reading corresponds with the\\nposition at which the safety valve blows off or\\nwith the position of the damper regulator it would\\nshow that the gauge were accurate.\\nQ. How can you tell whether the blow-off valve\\nis leaking or not\\n3", "height": "2933", "width": "1813", "jp2-path": "ropersquestions00rope_0049.jp2"}, "50": {"fulltext": "34 QUESTIONS AND ANSWERS FOR\\nA. If it is leaking, the pipe will be hot outside\\nof the valve.\\nQ. How is the feed water for a boiler regulated\\nwith a power pump\\nA. By means of the by-pass on the pump.\\nQ. How is the feed regulated with a steam\\npump\\nA. If the pump takes water from a water system,\\nit is regulated by means of the throttle valve of\\nthe pump. If it takes water from a receiver into\\nwhich the returns from a heating system flow\\ntogether with city water, it is controlled by the\\ncold-water valve on the receiver.", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0050.jp2"}, "51": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 35\\nQUESTIONS FOR STATIONARY\\nENGINEERS.\\nEngineers should also be prepared to answer any of the\\nQuestions for Firemen.\\nQ. What do you mean by the term a one\\nhorse-power steam boiler\\nA. A one horse-power boiler is one which\\nwould, under ordinary conditions, supply as\\nmuch steam as would be consumed in an aver-\\nage steam engine producing one horse-power.\\nQ. Is there no more definite rating than this\\nfor the horse-power of boilers\\nA. Yes; generally, the horse-power of boilers\\nis based on a capacity for evaporation of 30\\npounds of water per hour from feed water at a\\ntemperature of 100\u00c2\u00b0 Fahr. to steam at a pressure\\nof 70 pounds.\\nQ. What is this method of rating called\\nA. It is known as the Centennial Rating, be-\\ncause it was determined upon by the Committee\\nof Judges at the Centennial Exhibition in 1876.\\nQ. Does the horse-power of steam boilers cal-\\nculated according to this rule come near to the\\nactual consumption of steam in ordinary steam\\nengines\\nA. It is about right for an automatic cut-off,\\nhigh-speed, non-condensing engine. For plain", "height": "2933", "width": "1813", "jp2-path": "ropersquestions00rope_0051.jp2"}, "52": {"fulltext": "36 QUESTIONS AND ANSWERS FOR\\nslide valve engines using a throttling governor the\\nrating is much too low, while for compound and\\ncondensing engines it is too high.\\nQ. In choosing a boiler, how would you deter-\\nmine upon the proper size, assuming that the\\nhorse-power is based upon the Centennial Rating\\nA. I would in any case have the boiler capacity\\nsomewhat in excess of that of the engine, because\\nthe evaporative power of the boiler will diminish\\nwith use owing to the accumulation of scale.\\nQ. Is there any disadvantage in using a boiler\\nlarger than is strictly necessary to evaporate the\\nnecessary amount of steam\\nA. No; the efficiency of a boiler is not lessened\\nby operating it below its maximum capacity,\\nwherein the boiler differs materially from the\\nsteam engine.\\nQ. What horse-power boiler would you use for\\nan automatic cut-off, single expansion, and non-\\ncondensing engine of 100 horse-power?\\nA. I would use a boiler of 130 to 140 horse-\\npower based upon the Centennial Rating.\\nQ. Suppose the engine was used with a con-\\ndenser\\nA. Then a 100 horsepower boiler would be\\nsufficient.\\nQ. Suppose the engine were a plain slide valve\\nwith throttling governor?", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0052.jp2"}, "53": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 37\\nA. I would then use a boiler of 160 horse-\\npower.\\nQ. Suppose the engine used was a Corliss type,\\nnon-condensing\\nA. I would then use a boiler of about 100 horse-\\npower.\\nQ. What is the effect on the evaporative ca-\\npacity of a boiler of lowering the temperature of\\nthe feed water\\nA. It diminishes the capacity of the boiler.\\nQ. Can a boiler of given size evaporate as many\\npounds of water per hour to a pressure of 100\\npounds as to a pressure of 70 pounds\\nA. No; it will evaporate much less water.\\nQ. What is meant by the evaporative efficiency\\nof a boiler\\nA. The number of pounds of steam that it will\\ngenerate for each pound of fuel consumed.\\nQ. What evaporative efficiency would you\\nexpect from the various types of boilers\\nA. From flue boilers, from 6 to 8 J- pounds;\\nfrom tubular boilers, from 8 to 10 pounds; from\\nwater- tube boilers, from 10 to 11 pounds of w r ater\\nper pound of coal.\\nQ. Are the average results as good as these\\nA. No; they are probably 25 per cent, lower.\\nQ. Upon what does the grate surface in boilers\\ndepend", "height": "2933", "width": "1813", "jp2-path": "ropersquestions00rope_0053.jp2"}, "54": {"fulltext": "38 QUESTIONS AND ANSWERS FOR\\nA. Mostly upon the quality of coal and the\\ndraft.\\nQ. Is it well to have the grate surface too large\\nA. No; not so large that the air passing through\\nit will greatly exceed the amount necessary for the\\ncomplete combustion of the fuel.\\nQ. How many pounds of coal can be consumed\\nper square foot of grate surface\\nA. From 4 to 120 pounds, depending on the\\ncoal and the draft.\\nQ. What do you mean by heating surface\\nA. The total area of all those parts of the\\nboiler that come in contact on one side with the\\nflame or products of combustion, and on the other\\nside with water or steam; that is, it is all that part\\nof the surface through which the heat of the fire\\nis transmitted to the water or steam.\\nQ. Give a rule by which you could calculate the\\nheating surface of the cylinder boiler.\\nA. Multiply of the circumference of the shell\\nin inches by its length in inches, add the area of\\none end expressed in square inches and divide by\\n144; the quotient will be the number of square\\nfeet of heating surface.\\nQ. How would you calculate the heating surface\\nfor horizontal tubular boilers\\nA. Multiply of the circumference of the shell\\nin inches by its length in inches; multiply the", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0054.jp2"}, "55": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 39\\ncombined circumference of all the tubes in inches\\nby the length of one of them in inches; to the sum\\nof these two products add of the area of both\\ntube sheets; from this sum subtract the combined\\narea of the cross-section of all the tubes;, divide\\nthe remainder by 144, and the quotient will be\\nthe number of square feet of heating surface.\\nQ. How much heating surface per horse-power\\nis provided in fire- and water-tube boilers\\nA. From 12 to 15 square feet.\\nQ. Could you then calculate approximately the\\nhorse-power of any tube boiler\\nA. Yes; by calculating the heating surface in\\nsquare feet and dividing it by 12.\\nQ. What is the average ratio between the grate\\nsurface and heating surface in stationary boilers\\nA. About 35 feet of heating surface to 1 square\\nfoot of grate surface.\\nQ. How much good anthracite coal can be con-\\nsumed per square foot of grate under ordinary\\nconditions\\nA. About 11 pounds.\\nQ. How much coal per horse-power per hour\\nwould you expect to be consumed if the boiler\\nwere a good water-tube boiler and the engine were\\na simple, high-speed, automatic cut-off engine\\nused without a condenser and explain how you\\narrive at this figure.", "height": "2933", "width": "1813", "jp2-path": "ropersquestions00rope_0055.jp2"}, "56": {"fulltext": "40 QUESTIONS AND ANSWERS FOR\\nA. I should expect the water-tube boiler to\\nevaporate 10 pounds of water per pound of coal;\\nI should expect the engine, if of good size, to use\\nabout 45 pounds of water per horse-power per\\nhour; therefore, I should expect a coal consump-\\ntion of about 4^ pounds per horse-power per hour.\\nQ. What materials are principally used now for\\nmaking boiler shells\\nA. Wrought iron and steel, of which the latter\\nis more widely used.\\nQ. Why is steel replacing wrought iron\\nA. Because it is lighter for a given strength and\\ntherefore, since a thinner plate may be used, the\\nefficiency of the heating surface is better.\\nQ. What considerations would guide you in\\ndetermining upon the proper thickness of boiler\\nplate?\\nA. First, the question of safety; second, dura-\\nbility third, economy. As to safety, the thick-\\nness depends upon the quality of iron, diameter\\nof boiler, and pressure to be carried. As to dura-\\nbility, the thickest metal is not necessarily the\\nbest, since the outside of the sheet becomes burned\\nand crystallized, and in general gives less wear\\nand satisfaction than the thinner gauge. As to\\neconomy, obviously the thinner sheets are better.\\nQ. Give some figures as to the range of thick-\\nness of boiler iron or steel.", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0056.jp2"}, "57": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 41\\nA. The thickness should in general range be-\\ntween and T 3 g- of an inch.\\nQ. What special properties should a material\\npossess in order to make it suitable for use in\\nboiler plates\\nA. Whether it be of iron or steel, it should\\nhave a tensile strength of not less than 50,000\\npounds per square inch; it should elongate 25 per\\ncent, without breaking, and the contraction of\\narea of cross-section at the point where breaking\\ntakes place in the test-piece should be 50 per cent.\\nIt should also stand bending without injury\\naround a radius equal to the thickness of the plate.\\nQ. What do you mean by longitudinal and\\ncurvilinear rivets\\nA. By the first, I mean those that run length-\\nwise of the boiler by the second, those that run\\naround the circumference of the shell.\\nQ. Is the pressure on all seams the same\\nA. No; on the longitudinal it is nearly double\\nwhat it is on the curvilinear, and for this reason\\nthe longitudinal seams are double riveted.\\nQ. Does a boiler plate lose any of its strength\\nby riveting?\\nA. Yes; about 45 per cent, if single riveted,\\nand about 30 per cent, if double riveted.\\nQ. What determines the proper diameter for\\nrivets", "height": "2933", "width": "1813", "jp2-path": "ropersquestions00rope_0057.jp2"}, "58": {"fulltext": "42 QUESTIONS AND ANSWERS FOR\\nA. The diameter of the boiler, thickness of\\niron, and the pressure to be carried.\\nQ. Give some rough figures for the diameter of\\nrivets.\\nA. Rivets generally vary from to f of an inch\\nin diameter. The larger the diameter of the\\nboiler and the thicker the plate, the greater should\\nbe the diameter of the rivet.\\nQ. Which is the better method of riveting\\nboilers, by hand or by machine\\nA. If thick plates, machine work is much supe-\\nrior, as the power of the machine brings the work\\ntogether better than can be done by hand; if thin\\nboiler plates, hand riveting answers very well.\\nQ. Is it better to drill rivet holes in boilers in-\\nstead of punching them\\nA. Very much, as the punching of holes injures\\nthe strength of the plates much more than does\\nthe process of drilling them.\\nQ. What is a drift pin\\nA. It is a tapering steel pin, which is intro-\\nduced into the holes at the seams in order to\\nbring them into line.\\nQ. Is the use of the drift pin advisable\\nA. No; it should be dispensed with as much as\\npossible, as a reckless use of it often results in\\ngreat injury to the boiler plates.\\nQ. How can its use be avoided", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0058.jp2"}, "59": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 43\\nA. To a great extent b}^ the careful laying out\\nof the holes in the sheet and drilling or punching\\nthem with good judgment the holes will then\\ncome together so closely that they can be straight-\\nened by the use of the reamer without having\\nrecourse to the drift pin.\\nQ. What is the effect of hammering on the\\nquality of iron\\nA. It injures it, making it harder and more\\nbrittle.\\nQ. What is the effect of rolling\\nA. Rolling adds to the toughness of the iron.\\nQ. When a boiler is under steam, is the pressure\\nequal on all sides of the shell\\nA. No; the pressure on the lower side is greater\\nthan the upper side of the boiler by the weight of\\nthe water.\\nQ. Is there any danger of injuring boilers by\\napplication of the cold-water or hydrostatic\\ntest?\\nA. Yes; a reckless use of this test has often\\nresulted in injury to the boilers.\\nQ. Would the shell and flues be stronger under\\na cold-water pressure of, say, 80 pounds to the\\nsquare inch than under same steam pressure\\nA. No; because iron increases in strength with\\nthe increase of temperature up to about 550\u00c2\u00b0\\nFahr.", "height": "2933", "width": "1813", "jp2-path": "ropersquestions00rope_0059.jp2"}, "60": {"fulltext": "44 QUESTIONS AND ANSWERS FOR\\nQ. How would you calculate the safe working\\npressure\\nA. Multiply the thickness of the shell in inches\\nby the tensile strength in pounds per square inch\\nmultiply one-half the diameter by the factor of\\nsafety and divide the first product by the second.\\nand the quotient will be the safe working pressure.\\nQ. What factor of safety is usually employed\\nA. A factor varying from 3 to 5; a safe average\\nfor stationary boilers would be 4.\\nQ. What value of tensile strength would be\\nused in the rule for safe working strength\\nA. That would depend upon the riveting of the\\njoints. If single riveted, I would use about fifty-\\nfive hundredths (.55) of the ultimate breaking\\nstrength of the steel; if the joints were double\\njointed, I would take seventy hundredths (.70).\\nQ. If a boiler 48 inches in diameter were made\\nof steel having an ultimate tensile strength of\\n55,000 pounds per square inch with double-riveted\\njoints, Avhat would be the safe working pressure\\nif the thickness of the shell were of an inch and\\nthe factor of safety decided upon were 5\\n_ X 55, 000 X. 70 onn\\nA. P xx 4 8X 5 200 pounds per\\nsquare inch.\\nQ. What materials are best adapted for the set-\\nting of boilers", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0060.jp2"}, "61": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 45\\nA. The walls should be of hard-burned brick\\nlaid in Portland cement; all surfaces exposed to\\nthe action of the flame or heated gases should be\\nlined with the best quality of fire-brick laid in a\\nthin mortar of fire clay.\\nQ. What should be the distance between the\\ngrate bars and the bottom of the boiler shell\\nA. About 40 inches.\\nQ. What should be the distance between the\\nback tube sheet and the wall\\nA. For a 48-inch shell about 24 inches, and for\\na 72-inch shell about 36 inches.\\nQ. What are buckstaves\\nA. They are vertical braces of cast or wrought\\niron, which are placed on the outside of the boiler\\nwalls and are held together at the top and bottom\\nby tie rods. They are used to hold the boiler\\nwalls in place.\\nQ. What are the two styles of boiler fronts\\nA. A full-flush front, which consists of a cast-\\niron plate covering the entire front of the setting\\nand leaves no brickwork in sight; and the half-\\narch front, which covers only the furnace with an\\niron plate.\\nQ. Which of these two are the better\\nA. The full-flush front.\\nQ. When a number of boilers are set together,\\nis it desirable that each should be set indepen-", "height": "2933", "width": "1813", "jp2-path": "ropersquestions00rope_0061.jp2"}, "62": {"fulltext": "46 QUESTIONS AND ANSWERS FOR\\nclently from the others and that each should have\\nits separate stack connection\\nA. Yes; because each boiler can be operated and\\nshut down independently of the others, and be-\\ncause the draft of one is not affected by the others.\\nQ. Suppose that you were asked to choose a\\nboiler to be used where the vibration is excessive,\\nwhat type of boiler would you select\\nA. A locomotive or marine type of a boiler, be-\\ncause they require no brickwork.\\nQ. What are the results of the formation of\\nscale in boilers\\nA. The scale produces burning of the plates and\\nan increased coal consumption.\\nQ. Why is this?\\nA. Because the scale is a poor conductor of heat,\\nand therefore the water does not protect the plate\\nagainst crystallization and burning, and also the\\nheat of the fire is not imparted to the water as\\nadvantageously as if the scale were not present.\\nQ. Roughly, how does the conductivity of scale\\ncompare with that of iron\\nA. It is about -j^ of that of iron.\\nQ. What are the principal ingredients contained\\nin water that go to cause the formation of scale\\nA. They are sulphate of lime, phosphate of\\nlime, carbonate of lime, magnesia, silica, and\\nalumina.", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0062.jp2"}, "63": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 47\\nQ. Which is the most important of these exist-\\ning in sea- water\\nA. Sulphate of lime.\\nQ. What are boiler compounds\\nA. Boiler compounds are chemical substances\\nof various kinds that are employed in order to\\ncheck the formation of scale.\\nQ. Will any one boiler compound be effective\\nin all cases\\nA. No; to be effective the composition of the\\ncompound must be suited to the nature of the\\nimpurities.\\nQ. Suppose that the principal ingredient in the\\nwater tending to produce scale were sulphate of\\nlime, what substance would you use\\nA. Carbonate of soda.\\nQ. What would be the best thing to do if it\\nwere found that a large amount of scale formed in\\nboilers under your charge\\nA. It would be best to have an anatysis of the\\nfeed water made by a chemist, so that knowing\\nwhat scale-producing substances are present we\\ncould add sufficient quantities of proper materials\\nto change the scale producers into soluble salts.\\nQ. In what other way can formation of scale in\\nboilers be largely prevented\\nA. By the use of feed- water heaters and puri-\\nfiers of the open type.", "height": "2869", "width": "1825", "jp2-path": "ropersquestions00rope_0063.jp2"}, "64": {"fulltext": "48 QUESTIONS AND ANSWERS FOR\\nQ. How does this remedy the difficulty\\nA. By depositing the impurities in the heater\\nwhere they can do no harm, and from which they\\ncan be easily removed, instead of in the boiler\\nitself.\\nQ. What do you mean by foaming in a boiler\\nA. Foaming is a violent agitation of water in a\\nboiler, which is shown by the frequent change of\\nlevel of the water in the gauge glass.\\nQ. What are some of the causes of foaming?\\nA. Poor design of boiler, muddy water, foul\\ncondition of the boiler, and the presence of any\\nsoapy or greasy substance in the feed water.\\nQ. What injury could foaming produce on the\\nboiler\\nA. When a boiler foams badly the water is\\nlifted from the fire surface and this allows the\\nplates to burn.\\nQ. Is there any danger to the engine from foam-\\ning in the boiler\\nA. Yes; mud and water are liable to be carried\\nover with the steam into the cylinder and injure\\nthe surface of the cylinder and often cause the\\nbreaking of the cylinder head.\\nQ. What do you mean by priming?\\nA. The carrying over of water from the boiler\\nto the engine in the form of spray.\\nQ. How could you detect it?", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0064.jp2"}, "65": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 49\\nA. By noticing the exhaust from the engine; if\\nthis be white instead of colorless, it would show\\nthat moisture is present in the steam. In such\\ncases there is generally a clicking noise in the\\ncylinder.\\nQ. What causes priming\\nA. Generally it is due either to the water being\\ncarried at too high a level in the boiler or to the\\nlack of sufficient steam space.\\nQ. What is a safety valve\\nA. A valve designed to prevent explosion of\\nboilers by relieving them from excessive pressure.\\nQ. What is the general principle on which it is\\nconstructed\\nA. The steam pressure is balanced by a spring\\nor weight in such a manner that when the pres-\\nsure in the boiler gets too high it overcomes the\\naction of the spring or weight and opens a valve\\nthat allows the steam to escape.\\nQ. What are the most important points to be\\nlooked after in the construction of safety valves\\nA. Simplicity and freedom of action.\\nQ. Should the stems be loose or rigid\\nA, Loose, as the solid or rigid stem is liable to\\nbe jammed by the canting of the lever or weight,\\nand in this case the higher the pressure the more\\ndifficult it is for the valve to open.\\nQ. What three classes of safety valves are there\\n4", "height": "2869", "width": "1825", "jp2-path": "ropersquestions00rope_0065.jp2"}, "66": {"fulltext": "50 QUESTIONS AND ANSWERS FOR\\nA. The dead-weight, spring, and lever safety-\\nvalves.\\nQ. Which are the better to use, springs or\\nweights in safety valves\\nA. This depends upon the places in which they\\nare to be used. On vessels or locomotives, weights\\ncould not be used on account of the motion, but\\nfor stationary work, weights have the advantage\\nin that they do not change, while springs are\\nliable to alter their strength when under tension.\\nQ. How would you set a safety valve for any\\ndesired blow-off pressure in the dead-weight or\\nspring type?\\nA. By adjusting the weight or the tension of\\nthe spring until this weight becomes equal to the\\narea of the valve in square inches multiplied by\\nthe pressure in pounds per square inch.\\nQ. How would you calculate the weight which\\nit would be necessary to put on the end of a certain\\nlever safety valve for a desired blow-off pressure\\nA. I would first multiply the area of the valve\\nin square inches by the blow-off pressure in\\npounds per square inch and by the distance of\\nthe valve from the fulcrum in inches then I\\nwould multiply the weight of the lever in pounds\\nby the distance of its center of gravity from the\\nfulcrum then I would multiply the weight of\\nthe valve and stem by their distance from the ful-", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0066.jp2"}, "67": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 51\\ncrum after adding the last two products together\\nand subtracting their sum from the first product,\\nI would divide the remainder by the length of the\\nlever, and the quotient will be the weight in\\npounds required.\\nQ. How would you find the distance of the\\ncenter of gravity from the fulcrum\\nA. If the lever is of uniform cross-section, its\\ncenter of gravity is at its middle point.\\nQ. If the lever is tapering\\nA. See Roper s Catechism, page 134.\\nQ. What determines the proper area of safety\\nvalves for different sized boilers\\nA. They should be capable of discharging twice\\nas much steam as corresponds with their rate of\\nhorse-power. There are many rules given some\\nbasing it upon the heating surface, others upon the\\ngrate surface, and still others upon the coal con-\\nsumption.\\nQ. Is one safety valve sufficient for a boiler\\nA. No; it should have at least two.\\nQ. What do you mean by a gauge\\nA. Any instrument or device used for measure-\\nment.\\nQ. What are the principal gauges used in con-\\nnection with boilers\\nA. The pressure gauge, vacuum gauge, water\\ngauge, and salinometer gauge.", "height": "2869", "width": "1825", "jp2-path": "ropersquestions00rope_0067.jp2"}, "68": {"fulltext": "52 QUESTIONS AND ANSWERS FOR\\nQ. What two kinds of steam gauges are there\\nA. Indicating gauges and recording gauges.\\nQ. What is the general principle on which the\\nindicating gauge is constructed\\nA. It is usually constructed on the principle\\ninvented by Bourdon, and consists of a thin tube\\nof elliptical cross-section bent in the form of a\\ncurve. The steam, the pressure of which is to be\\nmeasured, is admitted into the tube, and its pres-\\nsure tends to make the cross-section circular,\\nwhich causes the tube to straighten itself par-\\ntially. The tube is so connected with a pointer\\nby gearing that the straightening moves the pointer\\nover a suitable dial that indicates the pressure.\\nQ. How does the recording gauge usually differ\\nfrom this?\\nA. It has in addition a clock that moves the\\ndial, giving it one revolution in 24 hours, and the\\npointer has a pen or stylus attached that makes a\\ncomplete record of the pressure during this time.\\nQ. Does the steam gauge register absolute pres-\\nsure?\\nA. No; as usually constructed, it stands at zero\\nunder atmospheric pressure therefore its pointer\\nindicates the pressure above the atmosphere, or\\nabout 15 pounds less than absolute pressure.\\nQ. Suppose the pointer does not stand exactly\\nat zero when there is no pressure in the boiler", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0068.jp2"}, "69": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 53\\nA. It should be adjusted by comparison with a\\nstandard gauge.\\nQ. How does a vacuum gauge differ from a\\npressure gauge\\nA. It is made in the same way, but made to\\nread pressure below the atmosphere instead of\\nabove.\\nQ. How are vacuum gauges generally marked\\nA. So as to read in inches of mercury instead\\nof pounds that is to say, the readings indicate to\\nhow many inches the vacuum would allow a col-\\numn of mercury to rise under atmospheric pres-\\nsure.\\nQ, To what vacuum does an inch of mercury\\nusually correspond\\nA. To a vacuum of about one-half pound.\\nQ. Why are the vacuum gauges marked in this\\nway and not in absolute pressure\\nA. Because the mechanism that operates the\\ngauge acts by virtue of the difference in pressure\\nof the atmosphere and the vacuum chamber\\ntherefore, as the atmospheric pressure is contin-\\nually varying, the pointer would not give accu-\\nrately the number of pounds of absolute pressure.\\nQ. What is a water gauge, and how is it usually\\narranged\\nA. It is a device for showing the level at which\\nthe water stands in the boiler, and usually con-", "height": "2869", "width": "1825", "jp2-path": "ropersquestions00rope_0069.jp2"}, "70": {"fulltext": "54 QUESTIONS AND ANSWERS FOR\\nsists of a glass tube placed on the outside of the\\nboiler with its upper end connected to the steam\\nspace and its lower end connected to the water\\nspace.\\nQ. What other devices are used for indicating\\nwater level?\\nA. Gauge cocks and safety water columns.\\nQ. What is a salinometer\\nA. An instrument or gauge for indicating the\\namount of salt contained in the water used in\\nmarine boilers.\\nQ. What is the effect of too great a supply of\\nair in the furnace of a boiler\\nA. It diminishes the economy of the boiler,\\nbecause a portion of the heat of combustion is\\nused in heating the excess of air and this amount\\nof heat is wasted.\\nQ. What are the three common methods of\\noperating pumps\\nA. By belting or gearing, by direct connection\\nwith a steam cylinder, and by electric motors.\\nQ. Which of these methods is usually em-\\nployed for boiler-feed water pumps\\nA. The second.\\nQ. What is a fly-wheel pump\\nA. One in which the reciprocating motion o\\\\\\nthe steam piston is first converted into rotary\\nmotion by means of the crank shaft, with a fly-", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0070.jp2"}, "71": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 55\\nwheel to help it over dead centers, and then con-\\nverted back into reciprocating motion for the\\nwater cylinder by another crank and rods.\\nQ. What is a direct-acting pump\\nA. One in which the water piston is mounted\\non the same rod as the steam piston.\\nQ. What is required in order to help such a\\npump over the dead centers\\nA. An auxiliary valve gear in addition to the\\nmain valve gear.\\nQ. What is a duplex pump\\nA. A duplex pump is a combination of two\\npumps coupled together so that the steam valve\\nof one is operated by the piston of the other, and\\nvice versa.\\nQ. What type of steam pump is most com-\\nmonly used as a boiler-feed pump, and why-?\\nA. The duplex pump, because it is the simplest\\nform.\\nQ. What is the limit beyond which a suction\\npump will not lift water\\nA. About 33 feet.\\nQ. What is the reason for this\\nA. Because the pump does not actually lift the\\nwater but only creates a vacuum, allowing the\\nwater to be lifted by the pressure of the atmos-\\nphere on its surface. As the atmospheric pressure\\nwill not support the column of water more than", "height": "2869", "width": "1825", "jp2-path": "ropersquestions00rope_0071.jp2"}, "72": {"fulltext": "56 QUESTIONS AXD ANSWERS FOR\\n33 feet in height, this is the limit to the lifting of\\nthe suction pump.\\nQ. Is there no limit to the distance to which\\nwater can be thrown horizontally\\nA. Practically none if the connections are tight.\\nQ. What limits the height to which a pump will\\nforce water?\\nA. Nothing except the power of the pump.\\nQ. How would you calculate the power required\\nto pump water?\\nA. Multiply the number of pounds to be\\npumped per minute by the vertical distance in\\nfeet between the level of supply and discharge,\\nand divide the product by 33,000. This result\\nwill be the theoretical horse-power. The actual\\nhorse-power will be obtained by adding the losses\\nin friction corresponding to the velocity of the\\nwater. (See Roper s Handy-Book, page 142.)\\nQ. Explain how you would choose the proper\\nsize of boiler-feed pump for a given boiler.\\nA. I would multiply the horse-power of the\\nboiler by 30, which would give the number of\\npounds of water that it will evaporate per hour.\\nI would divide this by 8.35, which gives the\\nnumber of gallons; I would then choose a pump\\ncapable of supplying double this quantity, so that\\nit would be large enough even when the boiler\\nwas being forced to its utmost.", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0072.jp2"}, "73": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 57\\nQ. When the water is hot, what precaution\\nmust be taken with the pump\\nA. It should be brass lined, so as not to corrode,\\nand must be placed below the level of the water\\nsupply, as otherwise the hot water will not follow\\nthe plunger. A valve should also be placed be-\\ntween the supply and the pump, so that any\\naccumulated vapor may be liberated.\\nQ. What is an injector?\\nA. An apparatus which forces water against a\\npressure by the direct action of a steam jet upon\\nthe mass of water.\\nQ. Give a description of an injector and how it\\nacts.\\nA. There is, first, a steam nozzle through which\\nthe steam enters second, a water-supply tube\\nthrough which the water enters; third, a combin-\\ning tube, beginning at the end of the steam nozzle\\nwhere the steam and water come in contact; fourth,\\na delivery tube, from which the mixture of steam\\nand water enters the discharge pipe. The action\\nof the apparatus is as follows The steam leaves\\nthe nozzle and enters the combining tube at a high\\nvelocity; owing to the friction between the steam\\njet and the air in the water-supply pipe, the air is\\nexhausted from the latter, and water consequently\\nrises owing to the pressure of the atmosphere on\\nits surface. It enters the combining tube where", "height": "2869", "width": "1825", "jp2-path": "ropersquestions00rope_0073.jp2"}, "74": {"fulltext": "58 QUESTIONS AND ANSWERS FOR\\nit meets the steam jet and condenses it. By con-\\ndensation the cross-section of the steam jet is made\\nvery small, and the entire energy due to its ve-\\nlocity is thus concentrated upon a very thin jet.\\nThis amount of energy is more than sufficient to\\nforce the steam into the boiler, and some of it\\nis imparted to the water it meets in the com-\\nbining tube, and the entire mixture of steam and\\nwater is carried into the delivery tube and then\\ninto the boiler by the acquired momentum.\\nQ. What advantages have injectors over pumps\\nA. The water enters the boiler in a steady\\nstream, and practically none of the energy of the\\nsteam used to operate it is wasted and the water\\nenters the boiler hot; they are also more compact\\nand have no moving parts.\\nQ. Is the injector more economical than a pump\\nas a boiler feeder\\nA. Not always; if the feed water used is cold,\\nthe injector is more economical, but in combina-\\ntion with a feed-water heater a pump is more\\neconomical.\\nQ. Is it desirable that a boiler plant should have\\nboth a pump and injector\\nA. Yes; in case one or the other should get out\\nof order.\\nQ. What is the advantage of heating feed water\\nbefore it enters the boiler", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0074.jp2"}, "75": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 59\\nA. It increases the durability of the boiler by\\ndoing away with the strains that would be pro-\\nduced by the entrance of cold water. It prevents,\\nto a large extent, the formation of scale by causing\\nthe deposition of scale-producing impurities in the\\nheater instead of in the boiler; it produces a\\nmarked economy in the consumption of fuel by\\nutilizing a portion of the heat in the exhaust\\nsteam that would otherwise be wasted.\\nQ. How much of a saving in the fuel con-\\nsumption might be expected from the use of feed-\\nwater heaters?\\nA. About 15 per cent.\\nQ. To how high a temperature can the feed\\nwater be raised by a good heater?\\nA. There is no trouble in raising the tempera-\\nture of feed water to 212\u00c2\u00b0 Fahr.\\nQ. What is the difference between open and\\nclosed feed- water heaters\\nA. In the closed type of heaters the exhaust\\nsteam is not brought in contact with the water to\\nbe heated, but is carried through a series of brass\\ntubes surrounded by the feed water; or the re-\\nverse arrangement may be used, the water being\\ncarried through the tubes and the steam passing\\naround them. In open feed-water heaters the\\nsteam mixes with the water, the latter usually\\npassing over a series of steel or iron pans placed", "height": "2837", "width": "1780", "jp2-path": "ropersquestions00rope_0075.jp2"}, "76": {"fulltext": "60 QUESTIONS AND ANSWERS FOR\\nin a chamber through which the exhaust steam\\nflows.\\nQ. How is the pump placed in relation to the\\nheater and boiler with open heaters\\nA. The pump is placed between the heater and\\nthe boiler, and since it takes hot water, it must\\ntherefore be placed below the level of the water in\\nthe heater.\\nQ. What is the arrangement with closed heaters\\nA. With closed heaters the water enters the\\npump cold and is forced through the heater into\\nthe boiler.\\nQ. Can an injector be used with an open heater\\nA. No; because the water would be raised to\\nsuch a high temperature by the heater that the\\ninjector will not work, since the injector requires\\nmoderately cold water in order to condense the\\nsteam in the combining tube.\\nQ. State what you consider to be the relative\\nadvantages of the two types.\\nA. The closed heater must be located in any\\nconvenient place, while the open heater must be\\nplaced higher than the pump that is to pump hot\\nwater. On the one hand, the open type not being\\nunder the strong steam pressure is lighter and\\ncheaper; it is more easily cleaned; heats the water\\nto a higher temperature; purifies it better and\\nproduces no back pressure on the engine on the", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0076.jp2"}, "77": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 61\\nother hand, the oil from the cylinder exhaust is\\nmixed with the feed water, and unless this is\\neliminated by a suitable oil separator this will\\ninjure the boiler.\\nQ. What is an economizer, and how is it usually\\nconstructed\\nA, It is a device for heating the feed water by\\nmaking use of the products of combustion after\\nthey leave the boiler and before they pass into the\\nstack. It is usually made somewhat like a water-\\ntube boiler out of a series of tubes connected\\nat each end by headers. The water circulates\\nthrough the tubes and the products of combus-\\ntion pass around the tube and out into the stack.\\nQ. What fittings should an economizer have\\nA. Like a water-tube boiler, it should have a\\nblow-off pipe and a safety valve.\\nQ. In what cases are economizers generally used\\nA. They are generally added to existing boiler\\nplants, so as to increase their efficiency.\\nQ. Are they generally desirable in new installa-\\ntions\\nA. Not if the boilers are properly designed.\\nQ. Can you name other methods of heating\\nfeed water than by injectors, feed- water heaters,\\nand economizers\\nA. It is sometimes heated by the use of con-\\ndensers.", "height": "2837", "width": "1780", "jp2-path": "ropersquestions00rope_0077.jp2"}, "78": {"fulltext": "62 QUESTIONS AND ANSWERS FOR\\nQ. Will the same rule that you use for calculat-\\ning the boiler shells apply to the calculating of the\\nstrength of boiler flues\\nA. No; because the effect of a given pressure\\nexerted on the interior of the cylinder is not the\\nsame as if it were exerted on the outside surface.\\nPressure exerted within a cylindrical tube tends\\nto make the tube assume a true cylindrical form\\npressure exerted on the outside of the tube tends\\nto crush the tube or flatten it. It is well known\\nthat iron formed into a tube would require a much\\ngreater force to tear it asunder than would be\\nnecessary to crush it.\\nQ. Does internal pressure cause a tearing strain\\nor a crushing strain\\nA. A tearing strain.\\nQ. What is a collapse\\nA. It is the crushing or flattening of a flue by\\noverpressure.\\nQ. How may long flues be strengthened\\nA. In various ways: An early method was to\\nrivet rings of angle- or tee-iron around the flue at\\nfixed intervals another method was to make the\\nflue in sections and join these sections together by\\nriveting on U-shaped .rings the more modern\\nmethod is to make the entire flue of corrugated iron.\\nQ. What is the advantage of corrugating the\\niron of boiler flues", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0078.jp2"}, "79": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 63\\nA. It adds strength, facilitates expansion, and\\nincreases the heating surface.\\nQ. What method of strengthening the flues is\\nemployed in Galloway boilers\\nA. Galloway tubes, conical in form, are placed\\nwithin and across the flues and riveted to the sides.\\nQ. What relation exists between the length of a\\ncylindrical tube and the pressure which will cause\\nit to collapse\\nA. The collapsing pressure is inversely propor-\\ntioned to the length of the tube that is, with a\\ntube of double length the pressure necessary to\\ncause collapse is only one-half.\\nQ. Describe the simplest form of grate.\\nA. A grate consists of a number of cast-iron\\nbars shaped like beams, which are supported at\\neach end; these bars are placed at a little distance\\napart, so as to allow space between them for the\\npassage of air, the distance being from about f to\\n-f of an inch the grate is placed from 2 to 2^-\\nfeet above the bottom of the ashpit, and is inclined\\ndownward toward the bridge wall so that the fuel\\ncan be more easily distributed. The length of the\\ngrate is about 6 feet, and its width varies with the\\nsize of the boiler.\\nQ. Is there any fixed relation between the\\namount of coal consumed and the number of\\nsquare feet of grate surface", "height": "2856", "width": "1768", "jp2-path": "ropersquestions00rope_0079.jp2"}, "80": {"fulltext": "64 QUESTIONS AND ANSWERS FOR\\nA. No; this depends entirely upon the kind of\\ndraft and the quality of coal; the consumption\\nmay be as low as 4 pounds, and in locomotive\\nboilers with an exceedingly strong draft may run\\nas high as 100 pounds.\\nQ. What would you consider a fair average for\\nstationary boilers using anthracite coal of good\\nquality\\nA. I should consider 9 pounds per square foot\\nper hour a fair average.\\nQ. Is there any rule between the grate surface\\nand the horse-power\\nA. In stationary boilers about J of a square\\nfoot per horse-power is allowed, although often\\nwith particular varieties of coal better results may\\nbe obtained by changing the area of the grate and\\nthe amount of draft.\\nQ. What is a shaking grate, and what are its\\nadvantages\\nA. It is a grate that is operated mechanically\\nin such a way that it cleans the fires, breaks up\\nclinkers, and removes the ashes, without the\\nnecessity of opening the fire door. As to its\\nadvantages, anything which does away with open-\\ning the fire door is desirable, since when it is open\\ncold air rushes in and injures the efficiency of the\\nboiler and also its durability. The shaking grate\\nis also advantageous, in that it prevents the forma-", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0080.jp2"}, "81": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 65\\ntion of clinkers and cleans every part of the grate,\\nwhich it is impossible for the fireman to do with\\nthe slicing bar.\\nQ. Why does the introduction of cold air\\nthrough the fire door diminish the durability of\\nthe boiler\\nA. Because the cold air striking against the\\nheated boiler plates sets up unequal strains that\\ntend to cause leakage.\\nQ. What is an automatic stoker\\nA. An apparatus for feeding coal into, and re-\\nmoving ashes from, a furnace automatically with-\\nout opening the furnace doors.\\nQ. What are the advantages to be claimed for\\nmechanical or automatic stokers\\nA. Economy of fuel and labor and prevention\\nof smoke.\\nQ. Why should stokers be productive of econ-\\nomy in the use of fuel?\\nA. Because by them the coal is spread upon the\\ngrate uniformly and in small quantities, whereas\\nwith hand firing coal is fed at irregular intervals,\\nand more is put on than would be necessary to\\nget the best combustion; moreover, with mechani-\\ncal stokers the furnace doors need not be opened.\\nQ. Why do stokers lessen the smoke pro-\\nduction\\nA. For practically the same reasons; the com-\\n5", "height": "2856", "width": "1768", "jp2-path": "ropersquestions00rope_0081.jp2"}, "82": {"fulltext": "66 QUESTIONS AND ANSWERS FOR\\nbustion being more complete than with the hand\\nfiring, less smoke is produced.\\nQ. AVould mechanical stokers pay in small\\nplants\\nA. No; because their additional cost and the\\npower consumed in operating them would more\\nthan offset the saving they would produce.\\nQ. For what is a chimney or stack used\\nA. To produce a draught that will take away\\nfrom the furnace the products of combustion and\\nwill draw in fresh air for keeping up combustion.\\nQ. Why does a chimney produce a draught\\nA. Because heated gases being less dense, the\\ntendency of the products of combustion is to rise,\\nand this produces a partial vacuum that is rilled\\nby the rushing of air through the furnace.\\nQ. On what does the amount of draught pro-\\nduced by a chimney depend\\nA. On the height of the chimney and the dif-\\nference in weight of the gases in the chimney and\\natmosphere.\\nQ. On what does this difference in weight de-\\npend\\nA. Upon the temperature at which the gases\\nleave the boiler.\\nQ. At what temperature do gases usually leave\\nthe boiler\\nA. From 500\u00c2\u00b0 to 600\u00c2\u00b0 Fahr.", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0082.jp2"}, "83": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS tW\\nQ. On what does the area of the chimney for a\\ngiven boiler depend\\nA. Upon the quantity of coal to be consumed.\\nQ. What is the relation between the quantity\\nof coal consumed per hour and the area of the\\nchimney\\nA. The area of the chimney in square inches\\nshould be about double the number of pounds of\\ncoal to be consumed per hour.\\nQ. What would be the proper area of a chimney\\nfor a 500 horse-power boiler of the water-tube\\ntype?\\nA. Assuming that 3 pounds of coal are used per\\nhour for each horse-power, the total consumption\\nof coal per hour would be 1500 pounds. The area\\nof chimney should then be about 3000 square\\ninches and its diameter about 60 inches.\\nQ. What determines the proper height for the\\nchimney\\nA. The strength of draught that is necessary for\\nthe kind of coal to be burned. Heights of chim-\\nneys based upon practical experience are given in\\ntables in Roper s Engineers Handy-Book.\\nQ. What is a steam separator\\nA. An arrangement for removing moisture from\\nsteam before it enters the engine cylinder.\\nQ. Why is their use desirable\\nA. Because an accumulation of water in the", "height": "2856", "width": "1768", "jp2-path": "ropersquestions00rope_0083.jp2"}, "84": {"fulltext": "65 QUESTIONS AND ANSWERS FOR\\ncylinder from priming or any other cause often\\nresults in blowing out the cylinder head or steam-\\nchest cover. Also, the presence of moisture in\\nsteam diminishes the economy in the engine.\\nQ. What is the general principle on which\\nsteam separators are constructed\\nA. Steam enters the apparatus at a high velocity,\\nand has its direction of flow altered or reversed so\\nas to destroy the momentum of the particles of\\nwater in the steam. Gravity then causes these\\nparticles to fall into a passage that is provided for\\nthe purpose of receiving them. The steam freed\\nfrom the water particles continues into the pipe\\nleading to the engine.\\nQ. For what other purposes are separators often\\nused?\\nA. To extract the oil from feed water in open\\nheaters.\\nQ. What is a steam trap\\nA. An apparatus for removing condensed steam\\nfrom steam piping without allowing any live steam\\nto escape.\\nQ. Explain the principle on which some form\\nof trap works\\nA. The trap consists of a closed vessel having\\nan outlet that is controlled by a valve; this valve\\nis operated by a float, and when sufficient water\\nhas condensed in the vessel to raise the float the", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0084.jp2"}, "85": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 69\\nvalve is opened and a part of the water is drained\\norf and the valve then closes. In another type\\nthe valve is operated by a bent tube of elliptical\\ncross-section similar to that which is used in the\\nBourdon steam gauge; opening and closing of the\\nvalves are produced by changes in the temperature\\nof the elliptical tube; these changes of temperature,\\nof course, being caused by the condensation of\\nsteam.\\nQ. Is it necessary to shut down a plant in order\\nto clean a separator or trap\\nA. Not if the plant is properly piped, as each\\nof these pieces of apparatus should be provided\\nwith auxiliary pipes and valves, so that steam or\\nwater may be made to pass temporarily around\\nthem.\\nQ. What are these auxiliary pipes and valves\\nusually called\\nA. By-passes.\\nQ. Give a brief description, illustrating it by a\\ndiagram, of one way in which a by-pass is usually\\narranged.\\nA. For answer, see Koper s Catechism, page\\n172.\\nQ. Why is it always desirable to open, slowly,\\nthe valves that start an engine\\nA. It diminishes the strain that would be\\nthrown on the boiler, as the sudden vent which", "height": "2856", "width": "1768", "jp2-path": "ropersquestions00rope_0085.jp2"}, "86": {"fulltext": "70 QUESTIONS AND ANSWERS FOR\\nwould be given to the steam is liable to produce\\nstrains on the boiler or to cause fluctuations of\\nthe water level. The strains that would otherwise\\nbe thrown on the engine are also avoided.\\nQ. In shutting down an engine, is slowness in\\nclosing the valve also desirable\\nA. Yes; a sudden closing of the valve throws a\\npressure on the valve itself and on the pipe, and\\nalso on the boiler by suddenly checking the flow\\nof steam.\\nQ. Is the use of braces in a boiler necessary\\nA. It would be possible to construct boilers\\nstrong enough without the use of braces such\\nboilers, however, would necessarily have exceed-\\ningly thick plates and the riveting would be extra\\nheavy, so that the first cost of the boiler would be\\nexcessive; moreover, such a boiler would not be\\nsatisfactory, as owing to the thickness of the plates\\nthey would be liable to burn out quickly. The\\neconomy of the boiler would also be poor.\\nQ. For what purposes are angle braces usually\\nemployed\\nA. For bracing the tube sheets of boilers in the\\nsteam space.\\nQ. How are toggle braces usually fastened\\nA. They are usually riveted in at both ends or\\nattached to the shell by lugs; they may be ad-\\njusted by means of a swivel or turnbuckle.", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0086.jp2"}, "87": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 71\\nQ. How would you calculate the quantity of\\nwater which a boiler will hold\\nA. If the boiler is cylindrical, I would multiply\\nthe area of the head in square inches by the\\nlength of the shell in inches and divide by 1728\\nthis will give the number of cubic feet of the\\nwater. If there are any tubes or flues, I would\\nfind their volume similarly and subtract the sum\\nof the volumes of the tubes and flues from the\\ntotal contents of the shell. The remainder when\\nmultiplied b}^ 7J will give the contents of the\\nboiler in U. S. gallons.\\nQ. What is the difference between a hard and\\nsoft patch\\nA. A hard patch is made by taking a piece of\\nplate and attaching it at the desired place by\\nmeans of rivets and calking it in the usual man-\\nner. In a soft patch, a coating of lead or litharge\\nis applied between the two surfaces and the patch\\nis attached with bolts and nuts.\\nQ. Which is the better method of patching,\\nand why\\nA. The hard patch, because in soft patching the\\nbolt holes being larger than the bolts the patch\\nmay be moved moreover, the packing is not\\npositively secure, and though the joint may be\\nsteam- and water-tight for a time, it is a point of\\ndanger.", "height": "2856", "width": "1768", "jp2-path": "ropersquestions00rope_0087.jp2"}, "88": {"fulltext": "72 QUESTIONS AND ANSWERS FOR\\nQ. Suppose the glass water gauge should break,\\ndischarging hot water and steam into the room,\\nwhat would you do\\nA. I would cover one hand with a hat, cap, or\\nother flexible covering and with the other hand\\nwould hold a coat or any piece of cloth in front\\nof my face, and would then shut the water valve\\nand afterward the steam valve. I would run the\\nrest of the day by the gauge cocks, putting in a\\nnew glass water gauge as soon as possible.\\nQ. Suppose that a gauge cock became broken\\noff near the boiler, what would you do\\nA. I would plug up the hole with a piece of\\nwood and use the other gauge cocks, putting in a\\nnew one as soon as possible.\\nQ. When a boiler is foaming, can you tell with\\ncertainty from the gauge glass or from the gauge\\ncocks how much water it contains\\nA. No.\\nQ. What would be the best way to find this\\nA. I would shut down the engine, throw some\\nfresh coal on the fire, shut the damper off, and\\nopen the door the foaming will then quiet down,\\nand the gauge glass and cocks will give nearly\\ncorrect indications.\\nQ. What is the power of a steam engine\\nA. The amount of work it will do in a certain\\nspace of time.", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0088.jp2"}, "89": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. (6\\nQ. What unit of power is used for steam\\nengines\\nA. The horse-power.\\nQ. What is an engine of one horse-power\\nA. An engine that will do 33,000 foot-pounds\\nper minute; that is, it will raise a weight of\\n33,000 pounds one foot per minute, or 550 pounds\\none foot per second.\\nQ. If a certain engine raised a weight of 66,000\\npounds in half a minute, what would be its horse-\\npower\\nA. Four,\\nQ. What factors determine the horse-power of\\na steam engine?\\nA. Length of stroke, diameter of the cylinder,\\nspeed, and the mean effective pressure on the\\npiston.\\nQ. Give the rule for calculating the horse-\\npower of an engine.\\nA. Multiply the area of the piston in square\\ninches by the mean effective pressure (in pounds\\nper square inch); multiply the length of stroke\\nin feet by the number of strokes (twice the num-\\nber of revolutions) per minute; multipty the first\\nproduct by the second and divide by 33,000.\\nQ. What would be the horse-power of an 18 x\\n18 engine at 100 revolutions per minute, with a\\nmean effective pressure of 45 pounds", "height": "2856", "width": "1768", "jp2-path": "ropersquestions00rope_0089.jp2"}, "90": {"fulltext": "74 QUESTIONS AND ANSWERS FOR\\nA. 104 horse-power.\\nQ. What is a convenient formula to remember\\nfor calculating the horse-power\\nA. Horse-power equals QQ nAA in which\\nP mean effective pressure in pounds\\nper square inch,\\nL length of stroke in feet,\\nA area* of piston in square inches,\\nJV number of strokes per minute.\\nQ. Having given the diameter of the cylinder,\\nhow would you calculate the area\\nA. I would square the diameter and multiply\\nby .7854, or if I had access to proper tables I\\ncould find the area from these.\\nQ. Explain what you mean by mean effective\\npressure.\\nA. Mean effective pressure is the average for-\\nward pressure on the piston less the back pressure.\\nQ. Upon what does the average forward 1 pressure\\ndej)end\\ni/ A. It depends upon the initial pressure in the\\ncylinder and the point of cut-off.\\nQ. How could you find the average forward\\npressure in any engine\\nA. By taking an indicator card of the engine,\\ndrawing several vertical lines at equal distances\\nfrom each other on the card, measuring the pres-", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0090.jp2"}, "91": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. t\\nsure on each of these lines and taking the average\\nof these pressures.\\nQ. Suppose that you had no indicator and\\ndesired to know approximately the average for-\\nward pressure\\nA. If I knew the point of cut-off and had\\naccess to tables such as are found in Roper s\\nEngineers Handy-Book, I could find in these\\ntables multipliers corresponding to the point of\\ncut-off which, if multiplied by the boiler pressure\\n(absolute), would give the average forward pres-\\nsure.\\nQ. What do you mean in your answer by ab-\\nsolute pressure\\nA. The pressure above a vacuum.\\nQ. Is this the same as the pressure indicated by\\nthe gauge\\nA. No; it is about 15 pounds more than the\\npressure indicated by the gauge.\\nQ. How would you find the mean effective\\npressure on the piston\\nA. I would find out, as above, the absolute\\naverage forward pressure and deduct from this the\\nabsolute back pressure.\\nQ. What is the back pressure\\nA. It is the pressure opposing the motion of\\nthe piston; in the case of engines that exhaust into\\nthe air it is about 15 pounds per square inch.", "height": "2856", "width": "1768", "jp2-path": "ropersquestions00rope_0091.jp2"}, "92": {"fulltext": "76 QUESTIONS AND ANSWERS FOR\\nQ. What is the effect of back pressure on an\\nengine\\nA. It diminishes its power.\\nQ. What are used with engines to diminish the\\nback pressure\\nA. Condensers.\\nQ. Given the following conditions, could you\\ncalculate the horse-power of an engine\\nStroke, 12 inches;\\nDiameter, 12 inches;\\nBoiler pressure gauge, 80 pounds;\\nSpeed counter, 300 revolutions per minute;\\nBack pressure gauge, 5 pounds;\\nCut-off, J.\\nA. I should also need to have an indicator\\ncard or the multiplier that corresponds to a cut-off\\nof J.\\nQ. If this multiplier is .5965, explain how you\\nwould work out the horse-power.\\nA. The absolute initial pressure is 80 plus 14.7,\\nor 94.7 pounds; multiplying this by .5965 I have\\n56.45 as the average forward pressure. The back\\npressure is 5 plus 14. 7, or 19. 7. The mean effective\\npressure, therefore, is 56.45 minus 19.7, or 36.75\\npounds per square inch. The area of piston is\\n12 X 12 X .7854, or 113.1 square inches. Thefor-\\nP LAN\\ninula being H. P. co I should have sub-\\noo,UUU", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0092.jp2"}, "93": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 77\\nstituting figures, H. P. 36.75 X 1 X 113.1\\nX 600 -v- by 33,000, or 75 horse-power.\\nQ. What would have been the gain in mean\\neffective pressure, supposing that the above engine\\nhad been used with a condenser in which there\\nwas a vacuum of 22 inches\\nA. Since each inch of vacuum corresponds to\\nabout J pound, the back pressure would have been\\nabout 11 pounds less than the atmospheric pressure,\\nand therefore the mean effective pressure would\\nhave been about 11 pounds greater.\\nQ. Is the initial pressure in the cylinder neces-\\nsarily the same as the pressure in the boiler\\nA. No; it is generally less for several reasons\\nThere is a loss of pressure in the steam pipes and\\nports due to friction; and, further, a loss by radi-\\nation and condensation. A throttling governor or\\na leaky piston will also lower the pressure in the\\ncylinder as compared to the boiler pressure.\\nQ. What is the common value of the steam\\npressure used in the cylinder of a high-pressure\\nengine\\nA. From 80 to 90 pounds.\\nQ. Is a pressure of 90 pounds to the square\\ninch more economical than a pressure of, say,\\none-half that amount\\nA. Yes; for with the lower pressure the loss by\\natmospheric pressure is about 15 pounds, or about", "height": "2856", "width": "1768", "jp2-path": "ropersquestions00rope_0093.jp2"}, "94": {"fulltext": "78 QUESTIONS AND ANSWERS FOR\\none-third of the pressure on the piston, whereas\\nwith high pressure the loss due to atmospheric\\npressure is only about one-sixth.\\nQ. Is an engine larger than necessary for the\\nwork to be done economical in the use of\\ncoal\\nA. No; an engine running below the load for\\nwhich it was designed wastes steam. If it has a\\nthrottling governor, the steam is throttled at light\\nloads, which reduces the pressure without doing\\nany useful work, and this means a loss in econ-\\nomy; if the engine has an automatic cut-off, the\\nexpansion is increased at light loads, and this also\\ndiminishes the economy of the engine, because\\nthere is one point of cut-off that is more econom-\\nical than any other and the engine is rated at this\\npoint of cut-off.\\nQ. Is there any power derived from the gover-\\nnor or fly-wheel on an engine\\nA. None whatever; the governor acts merely to\\nkeep the speed of the engine constant, having\\nmuch the same function as does a bridle on a\\nhorse. The fly-wheel gives out only as much\\npower as it receives from the engine, serving\\nmerely to make the revolution more steady and to\\ncarry the engine past the dead centers.\\nQ. Explain the difference between a condensing\\nand a non-condensing engine.", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0094.jp2"}, "95": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. /t\\nA. In a non-condensing engine steam after hav-\\ning expanded in the cylinder and done its work\\nescapes either into the atmosphere or into a heat-\\ning system; in a condensing engine the steam ex-\\nhausts into a condenser where it comes in contact\\nwith some cooling substance, in consequence of\\nwhich it is condensed and a partial vacuum is\\nproduced behind the piston.\\nQ. What is the object of condensing\\nA. To do away with the back pressure on the\\npiston, and consequently to increase the mean\\neffective pressure and the power.\\nQ. In what ratio does the addition of a con-\\ndenser increase the power of an engine?\\nA. In the same ratio which the vacuum in a\\ncondenser bears to the mean effective pressure.\\nQ. Suppose the mean effective pressure without\\nthe condenser was 40 pounds and the condenser\\nhad an effective vacuum of 26 inches, what would\\nbe the percentage increase in power owing to the\\nuse of the condenser\\nA. Twenty-six inches correspond to 13 pounds.\\nThe increase in power is therefore or 32.5 per\\ncent.\\nQ. Does it require power to operate a con-\\ndenser\\nA. Yes; but usually less than is gained by its\\nuse.", "height": "2856", "width": "1768", "jp2-path": "ropersquestions00rope_0095.jp2"}, "96": {"fulltext": "80 QUESTIONS AND ANSWERS FOR\\nQ. Is there gain in economy of fuel as well as\\nin power by the use of a condenser\\nA. Yes; from 20 to 35 per cent, depending\\nupon the size and type of engine.\\nQ. Why are not all engines used with con-\\ndensers\\nA. Because in small engines the saving is not\\nenough to pay for the additional first cost and the\\nincreased labor and attention necessary; also the\\nexhaust steam in many cases can be used to ad-\\nvantage in heating; the cost of the water for con-\\ndensing might also, in some places, be greater\\nthan the saving in fuel.\\nQ. Roughly, how much water is required for\\ncondensing\\nA. About 25 times as much as passes through\\nthe engine.\\nQ. What is the difference between a simple\\nengine and a multiple expansion engine\\nA. A simple engine is one in which the steam\\nis used expansively in only one cylinder the\\nmultiple expansion engine is one in which the\\nsteam is partially expanded in the first cylinder,\\nand then passes into one or more other cylinders\\nwhere it receives a further expansion.\\nQ. What are compound, triple expansion, and\\nquadruple expansion engines\\nA. A compound engine is one in which the", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0096.jp2"}, "97": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 81\\nsteam expands twice; a triple expansion engine is\\none in which it expands three times; and a quad-\\nruple expansion engine is one in which it expands\\nfour times.\\nQ. What do you understand by the term com-\\npounding\\nA. Using steam expansively in two or more\\ncylinders.\\nQ. What is the object of compounding en-\\ngines\\nA. To obtain economy in the use of steam.\\nQ. What names are given to the different cyl-\\ninders of multiple expansion engines?\\nA. The one that takes steam direct from the\\nboiler is called the high-pressure cylinder; that\\none in which it expands last before passing to the\\natmosphere or condenser is called the low-pressure\\ncylinder; if there are any others they are called\\nintermediate cylinders.\\nQ. What is a receiver Why is it necessary\\nA. A chamber in which steam is stored after it\\nleaves one cylinder until it is admitted into the\\nnext. It is necessary for engines the cranks of\\nwhich are set at different angles. For instance, in\\nthe two-cylinder engine they would be placed at\\n90 degrees apart, and therefore one cylinder would\\nnot be taking stea.ni during the time that the pre-\\nceding cylinder was exhausting. Therefore a\\n6", "height": "2856", "width": "1768", "jp2-path": "ropersquestions00rope_0097.jp2"}, "98": {"fulltext": "82 QUESTIONS AND ANSWERS FOR\\nchamber is necessary to store the steam until it is\\nwanted.\\nQ. What is the object of setting the cranks at\\ndifferent angles\\nA. To secure a more uniform turning force on\\nthe crank shaft.\\nQ. Why does not the fly-wheel accomplish this\\nresult\\nA. It does, but if it can be achieved without a\\nfly-wheel it is better. Moreover, in marine en-\\ngines a fly-wheel cannot be conveniently used.\\nQ. Are compound engines commonly operated\\nwith condensers?\\nA. Yes; it is desirable to so operate them. The\\nlow-pressure cylinders of multiple expansion en-\\ngines often have a mean forward pressure of only\\na few pounds, or on light loads may even have a\\nnegative forward j)ressure which, instead of aiding\\nthe other cylinders, tends to diminish the power\\nof the engine; therefore the use of the condenser\\nis in such cases particularly desirable.\\nQ. What would you understand by the term\\nhigh-speed engine\\nA. One in which the rotative speed or number\\nof revolutions per minute was high.\\nQ. What advantages do high-speed engines pos-\\nsess in comparison with low speed\\nA. They are less expensive; are more economic", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0098.jp2"}, "99": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 83\\ncal to operate; run more smooth! y; and they are\\nespecially adapted for driving electric machinery,\\nwhich requires a high speed of rotation and a\\nuniform angular velocity.\\nQ. Why should a high-speed engine cost less\\nA. Because the power of an engine depends\\nupon the area of piston, stroke, mean pressure,\\nand speed, increasing directly in proportion to the\\nincrease in any one of these factors; therefore, by\\nincreasing the speed, any one of the other three\\nfactors may be proportionately cut down. Hence,\\nby doubling the speed of an engine it may be\\nbuilt very much smaller and consequently more\\ncheaply for a given horse-power.\\nQ. Why are high-speed engines more economi-\\ncal in the use of steam\\nA. Assuming that the valve motions are equally\\nefficient, and other things are equal in the two\\nclasses of engines, the high piston speed engine\\nwill be more economical; for one of the principal\\nlosses is due to initial condensation and evapora-\\ntion in the cylinder, and this is proportionately\\nless when more steam passes through a given\\ncylinder in a given time. Hence the loss from\\nthis source is less in the high-speed engine than in\\nthe low-speed engine.\\nQ. What is an automatic cut-off engine, and\\nhow does it differ from a throttling engine", "height": "2856", "width": "1768", "jp2-path": "ropersquestions00rope_0099.jp2"}, "100": {"fulltext": "84 QUESTIONS AND ANSWERS FOR\\nA. An automatic cut-off engine is one the speed\\nof which is kept constant under varying loads by\\na governor that changes the cut-off so that steam\\nis admitted longer for heavy loads than for light\\nloads. In a throttling engine the time of admis-\\nsion remains the same for all loads, and the initial\\npressure is regulated by a governor which opens\\nand closes the throttle valve.\\nQ. Which is the less economical, and why\\nA. The throttling engine; for when the pressure\\nis reduced by a throttle valve the steam expands\\nwithout doing useful work, and the energy rep-\\nresented by this expansion is wasted.\\nQ. Under what conditions would it be advisable\\nto use throttling; engines\\nA. When the load is uniform, or nearly so,\\nsince throttling engines that use a plain slide valve\\nare considerably simpler and cheaper to build than\\nare automatic cut-off engines.\\nQ. What is the difference between single- and\\ndouble-acting engines\\nA. In single-acting engines steam is admitted\\non one side of the piston only; in double-acting\\nengines steam is admitted first on one side of the\\npiston and then on the other.\\nQ. What are the advantages of each of these\\ntypes\\nA. The double-acting engine, for the same", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0100.jp2"}, "101": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 85\\ndiameter of cylinder, length of stroke, pressure,\\nand speed, develops double the power of the single-\\nacting engine. The single-acting engines, however,\\nmay be made much simpler, needing no piston-\\nrod, cross-head, or guides. They may be run\\nfaster than the same size of double-acting engine,\\nas the strain always acts in the same direction and\\nas they may be readily arranged, so that the\\ncrank and the moving parts dip in oil at every\\nrevolution.\\nQ. What does the term valve gear of an\\nengine comprise?\\nA. All the mechanism employed in distributing\\nsteam.\\nQ. Of what parts does the simplest form of\\nvalve gear consist?\\nA. Of a plain slide valve and eccentric and the\\nnecessary rods or links for transmitting the mo-\\ntion of the eccentric to the valve.\\nQ. Describe a plain slide valve and illustrate it\\nby means of a diagram.\\nA. The diagram shows the valve in its central\\nposition where steam is neither being admitted to\\nnor exhausted from the cylinder. Vis the valve;\\nS S are the steam passages through which the\\nsteam passes to the cylinder C from the steam\\nchest X. The steam chest is always filled with\\nlive steam when the throttle valve is open. E is", "height": "2856", "width": "1768", "jp2-path": "ropersquestions00rope_0101.jp2"}, "102": {"fulltext": "86 QUESTIONS AND ANSWERS FOR", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0102.jp2"}, "103": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 87\\nthe exhaust passage in communication with the\\nexhaust pipe which allows the steam to pass into\\nthe atmosphere or condenser after it has done its\\nwork in the cylinder. R is the valve rod which\\nderives its motion from the eccentric and imparts\\nit to the valve.\\nQ. Explain the action of the valve.\\nA. In the position of the valve shown in the\\ndiagram, the piston is moving to the left and is\\nnearly at the end of its stroke while the valve is\\nmoving to the right. A little farther on in its\\nmotion the valve will uncover the steam passage\\non the left and will admit steam behind the piston.\\nThe admission of steam will continue until on the\\nreturn stroke the valve again covers the steam\\npassage. During this period the passage on the\\nright will have been uncovered and in communi-\\ncation with the exhaust chamber E, thus allowing\\nsteam to exhaust until this passage is again covered\\nby the valve. After this takes place the process\\nis reversed, steam is admitted to the right hand\\nend of the cylinder and exhausted from the left.\\nQ. What are the four important evejats in the\\ndistribution of steam which occur in every revolu-\\ntion of the engine\\nA. Admission, cut-off, release, and compression.\\nAdmission starts when the passage is first un-\\ncovered and continues up to the point of cut-off,", "height": "2856", "width": "1768", "jp2-path": "ropersquestions00rope_0103.jp2"}, "104": {"fulltext": "55 QUESTIONS AND ANSWERS FOR\\nwhich is the moment at which the passage is again\\ncovered release occurs when the passage is open\\nto the exhaust chamber and continues until the\\npassage is again closed compression takes place\\nfrom the time of closing the exhaust passage and\\nlasts until steam is again admitted.\\nQ, During what part of the process does expan-\\nsion take place\\nA. Expansion continues from the time of cut-\\noff up to release.\\nQ. Explain the meaning of the terms lap, lead,\\neccentricity, travel, over-travel, and angular ad-\\nvance.\\nA. There are two laps, the outside or steam lap\\nand the inside or exhaust lap when the valve is\\nin its central position, outside lap is the distance\\nwhich the outer edge of the valve extends over the\\nouter edge of the steam passage inside lap is the\\ndistance which the inner edge of the valve laps\\nover the inner edge of the steam passage. Lead\\nis the amount of opening in the steam port at the\\nmoment at which the piston begins its stroke. If\\nthe piston begins its stroke before the steam pas-\\nsage is open the lead is called negative. Eccen-\\ntricity or throw of the eccentric is the distance\\nfrom the center of the engine shaft to the center\\nof the eccentric. The travel of the valve is the\\ntotal distance which it moves, and is equal to twice", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0104.jp2"}, "105": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 89\\nthe throw of the eccentric. Over-travel is the\\ndistance which the valve travels beyond what is\\nnecessary to fully uncover the steam passage.\\nAngular advance is the angle by which the eccen-\\ntric is in advance of the position which would\\nbring the valve in its central position with the\\ncrank on a dead center.\\nQ. How would you set the slide valve of an\\nengine\\nA. I would place the crank on a dead center\\nand give the valve the necessary amount of lead,\\nthen I would turn the engine to the other dead\\ncenter and see if the valve has the same amount\\nof lead; if so, it is properly set, if not, the valve\\nmust be adjusted by means of the valve rod and\\nnuts so as to make the leads equal.\\nQ. How can you find the exact dead center\\nA. I would place a spirit level on the top or\\nbottom of the stub end or connecting rod boxes,\\nand I would move the crank up and down a little\\nuntil level was shown.\\nQ. What is a link motion and what is its\\npurpose\\nA. A link motion consists of two eccentrics\\nand rods, and a slotted link. It is used for revers-\\ning an engine and for varying its points of cut-off.\\nQ, Explain how the Stevenson link accom-\\nplishes this.", "height": "2856", "width": "1768", "jp2-path": "ropersquestions00rope_0105.jp2"}, "106": {"fulltext": "90 QUESTIONS AND ANSWERS FOR\\nA. The two eccentrics are placed on the shaft in\\nsuch a way that if the valve were operated by one\\nthe engine would move forward, and if by the\\nother it would move backward. The link being\\nattached to the end of the two eccentric rods\\nreceives a rocking motion. A movable block to\\nwhich the valve rod is attached is carried in the\\nslot of the link. When the block is at the end of\\nthe link nearest the forward eccentric, the engine\\nwill move forward; when the block is at the other\\nend the engine will be reversed as the block is\\nmoved nearer the intermediate position the travel\\nof the valve becomes less and consequently the\\ncut-off becomes earlier. When the block is in the\\ncentral position the travel of the valve is not\\nenough to uncover the ports, consequently the\\nengine remains at rest.\\nQ. In the original form of D slide valve, what\\nis the cause of the friction between the valve and\\nits seat, and how can this be avoided to a great\\nextent\\nA. The friction is caused by the steam pres-\\nsure which is on the back of the valve forcing it\\ntightly against its seat. This can be avoided to\\na considerable extent by the use of pressure plates\\nwhich relieve the back of the valve from this\\npressure.\\nQ. Is there any form of valve which is natu-", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0106.jp2"}, "107": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 91\\nrally balanced, and if so, is there any objection to\\nthis form?\\nA. Yes; the piston valve. The objection to\\nthis valve is that the seat wears uneven, and they\\nare therefore somewhat difficult to keep tight.\\nBy proper construction the bushings which form\\nthe seat can be arranged so that they can be easily\\ntaken out and replaced.\\nQ. Next to the slide valve gear, what is the most\\ncommon valve gear used on stationary engines, and\\nwhat are the important differences between it and\\nthe plain slide valve gear\\nA. The Corliss. The Corliss gear instead of the\\nsingle valve which admits and exhausts steam has\\nfour independent valves which are operated by a\\nsingle eccentric and wrist plate: these four valves\\nhave a partial rotation about an axis; two of\\nthem are for admission and cut-off and the other\\ntwo being for release and compression. The two\\nsteam valves are connected to the wrist plate in\\nsuch a way that they can be detached at any\\nmoment, This is accomplished by a tripping\\nmechanism which is controlled by the ball gov-\\nernor. The cut-off is therefore under the direct\\ncontrol of the governor, although release and com-\\npression are constant.\\nQ. How does a four-valve engine differ from the\\nslide valve and Corliss gears", "height": "2856", "width": "1768", "jp2-path": "ropersquestions00rope_0107.jp2"}, "108": {"fulltext": "92 QUESTIONS AND ANSWERS FOR\\nA. Like the Corliss it has four independent\\nvalves, but like the plain slide valve their motion\\nis positive and they have no releasing mechanism;\\nthe cut-off is varied by the travel of the valve.\\nQ. What relative advantages have the Corliss\\nand the four- valve types\\nA. The Corliss valve gear gives a sharp and\\nquick cut-off and wastes very little power in fric-\\ntion; as the valves, however, are controlled by a\\nspring or dashpot they cannot be run at a high\\nspeed. The main advantage of the four- valve gear\\nis that it can be run at nearly as high speed as a\\nsingle valve machine, while it preserves most of\\nthe economy of the Corliss gear.\\nQ. What advantage have both of these gears\\nover the single valve gears\\nA. A separate passage is provided for admitting\\nsteam to the cylinder and for exhausting it,\\ntherefore, the entering steam does not, as in the\\nsingle valve gear, come in contact with compara-\\ntively cold walls; consequently there is much less\\nloss by condensation, and these two gears are much\\nmore economical in the use of steam.\\nQ. Suppose the slide valve becomes leaky from\\nwear, what would you do\\nA. I would take it out, have its face planed, and\\nthe seat filed and scraped.\\nQ. What is a rotary valve", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0108.jp2"}, "109": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 93\\nA. A valve which has a revolving motion.\\nQ. What is a semi-rotary valve\\nA. A valve which has a motion of revolution,\\nbut which does not make a complete revolution;\\nas, for example, the Corliss valve.\\nQ. What is a gridiron valve\\nA. A valve with several small narrow openings\\nin it, and having very much the appearance of the\\nkitchen utensil of that name.\\nQ. Is the cut-off produced by the link motion\\ncapable of producing as satisfactory results as the\\nautomatic cut-off?\\nA. No; because in the case of the link varying\\nthe cut-off also varies the lead.\\nQ. What is an eccentric\\nA. It is a device used to take the place of a\\ncrank, and consists of a circular disc and sur-\\nrounded by a strap which turns freely on it; the\\ncenter of the disc is somewhat off the center of\\nthe shaft on which the eccentric is mounted.\\nQ. What are the chief methods used for gov-\\nerning the speed of stationary engines\\nA. Varying the initial pressure in the cylinder\\nto suit the load by means of the centrifugal gov-\\nernor actuating or throttling valve, and varying the\\npoint of cut-off by means of a governor actuating\\nthe valve gear.\\nQ. Which is the better method, and why", "height": "2856", "width": "1768", "jp2-path": "ropersquestions00rope_0109.jp2"}, "110": {"fulltext": "94 QUESTIONS AND ANSWERS FOR\\nA. Varying the point of cut-off, because it gives\\ncloser regulation and greater economy in the use\\nof steam. It is also much less liable to cause\\nknocking under very light loads.\\nQ. In setting the valves of an engine, is there\\nany difference in the leads given at the two ends\\nA. Yes; a little more lead is given at the crank\\nend of the cylinder in order to make up for the\\ndifference in the area of the two sides of the piston\\ndue to the piston rod, and also to allow for the short-\\nening of the valve motion on that side as wear is\\ntaken up.\\nQ. Suppose that the nuts which hold the valve\\non the stem should work loose, what would you do\\nA. I would set the engine on the dead center,\\nhead end, and after taking the steam chest cover\\noff would adjust the nuts so that the valve showed\\na little lead at the head end; then I would turn the\\nengine to the other center, and if the proper amount\\nof lead showed there the valve would be all right;\\nif not, I would, by adjusting nuts, give the proper\\namount of lead and then put on the steam chest\\ncover.\\nQ. Explain in detail how you would set the\\nvalves on a Corliss engine of the so-called crab-\\nclaw type.\\nA. See that the governor is on the safety-pin\\nand take off the hook rod from the wrist plate.", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0110.jp2"}, "111": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 95\\nAdjust the dashpot rods and reach rods so that\\nthe wrist plate may be turned through its entire\\ntravel, taking up the steam valves but without\\nreleasing them next, take out the safety-pin, let-\\nting the governor down and again move the wrist\\nplate in this case the safeties on the releasing\\ncams should keep the crabs down so that they will\\nnot touch the blocks on the bell cranks and will,\\ntherefore, not open the steam valves. Xext, turn\\nthe wrist plate into its central position and adjust\\nthe connections between the plate and the exhaust\\nvalves so that the edges of the ports and the valves\\ncorrespond; adjust the connections between the\\nwrist plate and steam valves so as to give the\\nproper amount of lead (about one-quarter inch),\\nturn the eccentric until the rocker arm is vertical\\nand adjust it so that the wrist plate will be central.\\nXext, adjust the eccentric rod by turning the\\neccentric shaft to a dead center and adjust the\\nlength of the rod so that the travel mark in this\\ndirection just corresponds with the center mark\\nthen turn the eccentric to the other dead center\\nand see if the other travel mark corresponds with\\nthe center mark. If so, the rod is properly\\nadjusted. Next, put the engine on its head end\\ncenter and turn the eccentric so as to give the\\nproper lead and make it fast; then turn the engine\\nto the other center, and if you have the same lead", "height": "2856", "width": "1768", "jp2-path": "ropersquestions00rope_0111.jp2"}, "112": {"fulltext": "96 QUESTIONS AND ANSWERS FOR\\nthe adjustment is correct. Now put the governor\\nin its running position, turn the engine over and\\nadjust the rods so as to give equal cut-off.\\nQ. At what cut-off is the Corliss engine usually\\nrun?\\nA. About one-quarter stroke.\\nQ. How late can the cut-off be made\\nA. Not more than half stroke.\\nQ. In case the lead of the valves at the two ends\\nwere different, what might cause this\\nA. The eccentric rod might be either too long or\\ntoo short. If it were too long it would show too\\nmuch lead on the crank end, and if too short it\\nwould show too much lead on the head end.\\nQ. How can the point of cut-off be lengthened\\non the Corliss valve gear\\nA. By lengthening the head end reach rod or\\nshortening the crank end rod.\\nQ. Does a Corliss require as much compression\\nas a high-speed engine of the same size, and why\\nA. No, because it does not run as fast; therefore,\\nthe moving parts have not the same amount of\\nenergy stored in them, and hence do not need so\\nmuch of an air cushion in the cylinder at the end\\nof the stroke.\\nQ. If you wish to make a Corliss engine do\\nmore work without increasing the boiler pressure\\nor altering the speed, how could you do this", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0112.jp2"}, "113": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 97\\nA. Decrease the lap of the steam valve and turn\\nthe eccentric back proportionately.\\nQ. In what ways may a governor be made to\\nvary the cut-off?\\nA. By a releasing mechanism as with the Corliss\\nvalve gear, by the action of the ball governor on\\nthe block of a link, and by a shaft governor.\\nQ. Describe a shaft governor and its method of\\naction.\\nA. In the shaft governor one or more weights\\nare placed in the fly-wheel, and the centrifugal force\\nof these weights is balanced against one or more\\nsprings. The weights are attached to pivoted arms,\\nand these arms are connected to the eccentric\\nactuating the valve gear. The action of the gov-\\nernor is as follows: When the speed increases, the\\ncentrifugal force on the weights tends to move\\nthem away from the shaft, and their motion is\\ntransmitted through pivoted arms so as to alter the\\nposition of the eccentric, varying either its angular\\nadvance or both, and in this way shortening the\\ncut-off.\\nQ. What difference does it make on the distribu-\\ntion of steam, whether the cut-off be varied by\\naltering the angular advance or by changing the\\nthrow of the eccentric?\\nA. Changing the angular advance increases the\\nlead at the same time as it decreases the cut-off.\\n7", "height": "2856", "width": "1768", "jp2-path": "ropersquestions00rope_0113.jp2"}, "114": {"fulltext": "yo QUESTIONS AND ANSWERS FOR\\nWhen the throw of the eccentric is changed the\\nreverse action takes place.\\nQ. What method then should you consider the\\nbest for varying the cut-off\\nA. A method in which both the throw of the\\neccentric and angular advances are changed by the\\ngovernor.\\nQ. Having given the number of revolutions of\\nthe ball governor and the diameter of the engine\\npulley, how would you find the diameter of the\\ngovernor shaft pulley\\nA. I would multiply the diameter of the engine\\npulley by the number of revolutions and would\\ndivide the product by the number of revolutions\\nof the governor.\\nQ. Having given the number of revolutions\\nwhich the governor is to make and the diameter\\nof the governor shaft pulley, how would you\\ncalculate the proper diameter of the pulley to be\\nplaced on the engine shaft to operate the gov-\\nernor\\nA. I would multiply the number of revolutions\\nof the governor by the diameter of its pulley and\\ndivide the product by the number of revolutions\\nof the engine.\\nQ. What do you consider the best material for\\nthe foundation of machines\\nA. Hard-burned brick laid in Portland cement.", "height": "2882", "width": "1827", "jp2-path": "ropersquestions00rope_0114.jp2"}, "115": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 99\\nQ. Cannot satisfactory foundations be made of\\nconcrete\\nA. Yes; if the work is carefully done the\\nfoundation will be quite as good, but I believe\\nthat there is a greater risk of careless work in the\\nconcrete foundations than in the brick.\\nQ. What determines the proper depth for foun-\\ndations\\nA. The size of the engine and character of the\\nground. They should always be carried deep\\nenough so as to rest on solid ground. If the\\nground at the surface is sufficiently solid, no greater\\ndepth need be used than would give sufficient\\nweight for the foundation to hold the engine down\\nand to take up the vibrations of the engine.\\nQ. How would you proceed to start an engine\\nA. I would first see that all the drips were open;\\nI would then slightly open the throttle valve and\\nwarm the cylinder up gradually; then I would\\nopen the valve still further and start the engine\\nslowly, gradually bringing the engine up to speed;\\nand after it becomes thoroughly warmed up I\\nwould close the drips.\\nQ. Suppose you had a Corliss engine and the\\nmain valve on the engine was broken, how could\\nyou stop the engine\\nA. I would throw the eccentric hook out of\\ngear and stop by means of the starting bar.\\ntofC.", "height": "2856", "width": "1768", "jp2-path": "ropersquestions00rope_0115.jp2"}, "116": {"fulltext": "100 QUESTIONS AND ANSWERS FOR\\nQ. Suppose you discovered that the cylinder\\nwas worn hollow in the middle, what would you\\ndo?\\nA. I would have it rebored.\\nQ. In case the crank or wrist pin should be cut\\nor worn oval, how would you proceed\\nA. I would caliper them and file them round.\\nQ. If the shoes in the cross-head guides become\\nworn, what would r ou do\\nA. I would put liners between the back of the\\nshoe and the cross-head, or would replace them\\nwith a new set of shoes.\\nQ. In case the eccentric slipped or turned on\\nthe shaft so as to stop the engine, what would you\\ndo?\\nA. I would put the engine on the center, take\\noff the bonnet of the steam chest and move the\\neccentric round in the direction in which it used\\nto run until the valve had the proper lead; I would\\nthen fasten the eccentric securely in place with the\\nseat screw or a key.\\nQ. Suppose the eccentric should become worn\\nflat at two points, in the direction of push and\\npull, what course would you adopt to remedy\\nthe difficulty\\nA. I would file it down to the smallest diameter\\nof the worn part.\\nQ. For the lubrication of the engine or any", "height": "2927", "width": "1815", "jp2-path": "ropersquestions00rope_0116.jp2"}, "117": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 101\\nother piece of machinery, how much oil is it\\nadvisable to use\\nA. No more than is absolutely necessary to\\nkeep the bearings reasonably cool. The use of\\nan excessive amount of oil is not only costly but\\nincreases an accumulation of gum and dirt in the\\nbearings.\\nQ. Suppose that any bearings of the engine\\nshould heat, what would you do\\nA. I would first examine the oil cups to see if\\nthe bearings were getting the proper amount of oil.\\nIf they were and the bearings were new, I would\\ncool them temporarily by surrounding them with\\nice, or if possible, of course I would stop the\\nengine and try to find out what was the cause. If\\nthe appearance of the bearings were smooth and\\nuniform, I would try to loosen them a very little at\\na time if this did not remedy the trouble, I\\nshould consider that the bearings were out of line\\nand would reline them. If the bearings are dirty\\nfrom an accumulation of gum, I would clean them\\nwith strong lye and oil while the engine is in\\nmotion. A mixture of flour of sulphur and oil is\\noften effective in stopping the heating of bearings.\\nQ. When an engine is stopped, how should the\\ncylinder drips be left\\nA. They should be left open so as to allow the\\ncondensed steam to escape.", "height": "2856", "width": "1768", "jp2-path": "ropersquestions00rope_0117.jp2"}, "118": {"fulltext": "102 QUESTIONS AND ANSWERS FOR\\nQ. Explain how you would pack a stuffing\\nbox.\\nA. I would first remove all the old packing and\\nclean out the box, then cut the new packing to the\\nproper length and put it in place, having the joints\\nat opposite sides of the box; I would then screw\\nup the stuffing box just far enough to stop the\\nleakage. If it is screwed up too tight, the power\\nof the engine will be diminished and the packing\\nwill be quickly worn away. The packing should,\\nof course, be perfectly free from dust or grit.\\nQ. Suppose that a packing in the piston becomes\\nloose, what would be the effect\\nA. Steam would leak past the piston, materially\\ncutting down the power of the engine and wasting\\ncoal.\\nQ. How often should a piston be examined\\nA. Two or three times a year at least, and, of\\ncourse, at any time when it is suspected that the\\npacking or rings need looking after.\\nQ. What should be done supposing that the\\njoints between the rings and the head are corroded\\nA. They should be ground with emery and oil,\\nor if badly corroded, should of course be faced up\\nin a lathe.\\nQ. What would be the effect of screwing down\\nthe packing of the spindle of a ball governor too\\ntightly?", "height": "2927", "width": "1815", "jp2-path": "ropersquestions00rope_0118.jp2"}, "119": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 103\\nA. It would interfere with the free movement of\\nthe governor and cause the engine to regulate badly.\\nQ. Suppose that you heard a creaking noise in\\nthe cylinder, to what would you suspect this were\\ndue and what would you do to remedy it\\nA. I should suspect the presence of moisture in\\nthe cylinder, and I would open the cylinder drip-\\ncocks.\\nQ. What are some of the causes of knocking\\nin engines, and how would you proceed to remedy\\nthe various cases\\nA. Knocking may be due to a great variety of\\ncauses. One is lost motion in the boxes either of\\nthe cross-head, crank pin or pillow blocks, or to a\\nlooseness of the key holding the piston rod in the\\ncross-head. To stop it, of course, the lost motion\\nshould be taken up either by means of the key or\\nby riling the edges of the boxes. Knocking may\\nbe due to the wrist of the cross-head or crank pin\\nbeing worn out of round. In this case the crank\\nor wrist pin should be turned up. If the knock-\\ning is caused by the engines being out of line, the\\nremedy would be, of course, to line up the engine\\nexactly. Often it is caused by the packing around\\nthe piston rod being too tight. To remedy the\\ntrouble, take out the old packing and put in new,\\nscrewing it up no tighter than is necessary to just\\nprevent the escape of steam. Sometimes knock-", "height": "2856", "width": "1768", "jp2-path": "ropersquestions00rope_0119.jp2"}, "120": {"fulltext": "104 QUESTIONS AND ANSWERS FOR\\ning is caused by lost motion in the adjustment\\nbetween the valve and the valve rod; in this case\\nremove the cover of the steam chest and adjust the\\njam-nuts on the valve rod. If, as is sometimes\\nthe case, knocking is caused by the crank being\\nahead of the steam, the trouble will be removed by\\nmoving the eccentric forward so as to give more\\nlead to the valve. The knocking may, however,\\nbe caused by too much lead, in which case the\\neccentric should be moved back. Knocking may\\nbe caused bj^ the too early closing of the exhaust;\\nin this case the exhaust chamber in the valve\\nshould be enlarged. Sometimes there is too little\\nclearance between the piston and the cylinder\\nhead, in which case the cylinder head should be\\nturned off a little on the inside. It has happened\\nthat too little counter-bore in the cylinder produced\\nknocking, because the piston rings wore a shoulder\\nat the ends of the cylinder and when the keys or\\npacking rings were set out the edges struck these\\nshoulders and caused the knock. In this case the\\nremedy is to counter-bore the cylinder again. A\\nsomewhat similar trouble occurs on the ends of\\nthe guides shoulders are worn in them and\\nproduce knocking the remedy in this case, of\\ncourse, is to replane the guides. Knocking is also\\ncaused by a loose follower plate. In this case the\\ntrouble is obviated by bringing the bolts up tight.", "height": "2927", "width": "1815", "jp2-path": "ropersquestions00rope_0120.jp2"}, "121": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 105\\nQ. hat does a steam-engine indicator do\\nA. It records the pressure in the steam cylinder\\nat every part of the stroke.\\nQ. Describe briefly its construction.\\n.4. The indicator consists of a small cylinder,\\nwhich contains a piston, the rod of which is\\nenclosed in a spiral spring which opposes the\\nmotion of the piston. The piston rod after pass-\\ning through the top cylinder cover is attached\\nby means of a parallel motion to a pencil on the\\nend of a long, light lever. This pencil moves in\\na vertical straight line whenever the piston moves.\\nAnother cylinder with an axis parallel to the first\\ncarries a paper drum, and this drum is attached\\nby means of a cord and a reducing motion to the\\ncross-head of the engine, so that the movement of\\nthe drum is j: roportional to the movement of the\\ncross-head. When the little cylinder of the indi-\\ncator is shut off from connection with the main\\nsteam cylinder by a cock, the pencil when held\\nagainst the drum makes a horizontal line. If\\nnow the cock be opened, thus admitting to the little\\ncylinder of the indicator the same pressure that\\nexists in the main cylinder, the pencil will trace a\\nfigure, every point of which is at a height from the\\nhorizontal proportional to the number of pounds\\npressure in the main cylinder at that point of the\\nstroke.", "height": "2856", "width": "1768", "jp2-path": "ropersquestions00rope_0121.jp2"}, "122": {"fulltext": "106 QUESTIONS AND ANSWERS FOR\\nQ. What is the atmospheric line in the indicator\\ndiagram\\nA. It is the horizontal line drawn by the pencil\\nwhen the little cylinder of the indicator is open\\nto the atmosphere.\\nQ. What things about an engine can you ascer-\\ntain by taking an indicator diagram\\nA. First, the forward pressure of the piston and\\nthe back pressure at every point in the stroke,\\nfrom which can be calculated the average forward\\nand average back pressure and the mean effective\\npressure on the piston. Second, the power of the\\nengine under all conditions, if in addition to tak-\\ning the indicator diagram we know also the speed.\\nThird, the diagram shows when steam is admitted,\\ncut off, exhausted, and compressed, and therefore\\nshows whether the valves are properly set.\\nQ. Explain how you would calculate the mean\\neffective pressure from an indicator card, and state\\nwhat you would need to know.\\nA. I would need to know the scale of the spring.\\nI would draw a vertical line at each end of the\\ndiagram, then I would draw 20 vertical lines\\nparallel to this, dividing the card into equal spaces,\\nexcept the first and last spaces which would be\\none-half size. Then on these verticals I would\\nmeasure the length between the back pressure line\\nand the forward pressure line, and mark each", "height": "2927", "width": "1815", "jp2-path": "ropersquestions00rope_0122.jp2"}, "123": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 107\\nlength on a long strip of paper. The sum of all\\nthese lengths I would divide by 20, which would\\ngive the average length of ordinates, and these\\nmultiplied by the scale of the spring will give\\nthe mean effective pressure.\\nQ. Is the power furnished by the crank end of\\nthe engine the same as that furnished by the head\\nend, assuming that the indicator cards are exactly\\nalike\\nA. No while the mean effective pressure would\\nbe the same the area of the crank end of the\\npiston is not all effective since steam does not press\\non that portion of the piston to which the piston\\nrod is attached therefore, in calculating the power\\nof the crank end the area of the piston rod should\\nbe subtracted from the area of the piston, and the\\ndifference between the two areas should be used\\nin the formula for horse-power.\\nQ. For what is a condenser used\\nA. A condenser is used to condense steam ex-\\nhausted from an engine so as to reduce the back\\npressure against which the engine is working.\\nQ. What effect has the condenser on the power\\nof a given engine\\nA. It increases the power of the engine from 20\\nto 30 per cent.\\nQ. What are the principal types of condensers\\nused", "height": "2856", "width": "1768", "jp2-path": "ropersquestions00rope_0123.jp2"}, "124": {"fulltext": "108 QUESTIONS AND ANSWERS FOR\\nA. There are two types jet condensers and\\nsurface condensers.\\nQ. What is the difference between the two\\ntypes?\\nA. In jet condensers the steam to be condensed\\ncomes in contact in the condenser pump with the\\ncondensing water; in surface condensers the steam\\nand condensing water do not mix, one of them\\nbeing in a series of tubes and the other being in a\\nvessel surrounding the tubes.\\nQ. What are the advantages of the two types\\nA. Surface condensers have the advantage for\\nuse on shipboard, since the condensed steam not\\ncoming in contact with the salt condensing water\\nit may be used again in the boilers. Steam of\\nany pressure may be condensed and the vacuum\\nis usually higher than in jet condensers they are\\nmuch more expensive, however, and are more\\nliable to have their vacuum impaired by the leak-\\ning of tubes.\\nQ. Can a surface condenser be converted into a\\njet condenser and vice versa f\\nA. The surface condenser can be used as a jet\\ncondenser by admitting the steam and injection\\nwater into the same chamber; but a jet condenser\\ncannot be used, of course, as a surface condenser.\\nQ. At what temperature does a jet condenser\\nwork best?", "height": "2927", "width": "1815", "jp2-path": "ropersquestions00rope_0124.jp2"}, "125": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 109\\nA. At about 100\u00c2\u00b0 Fahr.\\nQ. What vacuum can be obtained in a good\\ncondenser\\nA. Up to about 26 inches.\\nLESS PRACTICAL QUESTIONS.\\nQ. What is power What is the unit of power\\nA. Power is the rate of doing work; that is to\\nsay, the number of foot-pounds of work done per\\nminute. The ordinary unit of power is the horse-\\npower, which is a rate of doing work equal to\\n33,000 foot-pounds per minute.\\nQ. Suppose that a pump raises 66,000 pounds\\nof water four feet and the time required for doing\\nit is two minutes, what is the horse-power\\na 66,000 X 4 ,_\\nA. Thehorse-power 33?000 2 4 H. P.\\nQ. What is the rule for obtaining the horse-\\npower in any given case\\nA. Multiply the number of the pounds raised\\nby the number of feet which it is raised, and\\ndivide by the number of minutes which it takes\\nto do the work. Divide further by 33,000 and the\\nresult is the number of horse-power.\\nQ. How could you measure the power required\\nby a certain machine if it were driven either\\ndirect from an engine or from a shaft which\\nreceives power from an engine", "height": "2856", "width": "1768", "jp2-path": "ropersquestions00rope_0125.jp2"}, "126": {"fulltext": "110 QUESTIONS AND ANSWERS FOR\\nA. I would indicate the engine with the machine\\nrunning, and calculate the power from the indicator\\ncard; I would then stop the machine and indicate\\nthe engine again and calculate the power from the\\ncard. The difference between the two powers will\\nbe practically the power required for operating the\\nmachine.\\nQ. Suppose that the machine, instead of being\\ndriven by an engine, were operated by an electric\\nmotor, could you measure the power, and if so,\\nwhat instruments would you require and how\\nwould you proceed\\nA. Yes; if I had the proper instrument. I\\nshould need an ammeter and voltmeter of suit-\\nable range. I would measure the current with the\\nammeter by connecting it so that the main cur-\\nrent passed through the instrument, and I would\\nmeasure the voltage of the motor by connecting\\nthe voltmeter across the brushes. If the motor\\nis a direct current motor the products of the volts\\nand the current divided by 746 will give the horse-\\npower.\\nQ. How would you calculate the weight which\\ncan be lifted with a lever by the application of a\\ncertain force at one end of the lever?\\nA. Multiply the applied force by the distance\\nfrom its point of application to the fulcrum, and\\ndivide this product by the distance from the ful-", "height": "2927", "width": "1815", "jp2-path": "ropersquestions00rope_0126.jp2"}, "127": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. Ill\\ncrum to the weight to be lifted. The quotient\\nwill be the weight which can be lifted.\\nQ. What is heat, and how does it differ from\\ntemperature\\nA. Heat is a form of energy, while temperature\\nis a measure not of the heat in a body, but of the\\ntendency of that body to give up its heat to other\\nbodies.\\nQ. So far as the engineer is concerned, how is\\nheat generally produced?\\nA. By the combustion of fuel in the furnace of\\nthe boiler; the combustion being due to a combi-\\nnation of the oxygen in the air with the constit-\\nuents of the fuel.\\nQ. Describe the instrument with which tem-\\nperature is measured.\\nA. Temperature is measured by means of a ther-\\nmometer, which consists in its ordinary form of a\\nsmall hollow glass tube with a bulb at its bottom.\\nAfter the air has been exhausted from the tube it\\nis partially filled with mercury and the upper end\\nis sealed. Then, either the tube itself is graduated\\nor it is placed in a case which has graduations by\\nwhich the height of mercury in the tube can be\\nread. Whenever the instrument is heated the\\nmercury column rises owing to the expansion of\\nmercury in the bulb, but when it is cooled the\\nopposite action takes place.", "height": "2856", "width": "1768", "jp2-path": "ropersquestions00rope_0127.jp2"}, "128": {"fulltext": "112 QUESTIONS AND ANSWERS FOR\\nQ. How are the graduations made in the ordi-\\nnary Fahrenheit thermometers\\nA. The instrument is placed in melting ice and\\nthe position of the mercury column marked 32\u00c2\u00b0; it\\nis then placed in boiling water at atmospheric\\npressure and the new position of the mercury\\nmarked 212. The distance between the two marks\\nis divided into 180 equal parts called degrees.\\nQ. What other thermometers are used besides\\nthe Fahrenheit\\nA. The Centigrade and Reaumur.\\nQ. What is the difference between the Centi-\\ngrade and the Fahrenheit scale\\nA. In the Centigrade the point at which mercury\\nstands when the thermometer is placed in melting\\nice is marked zero; and the point for boiling water\\nis marked 100. The distance between the two\\nparts is divided into 100 equal parts.\\nQ. What is the unit of heat?\\nA. The unit of heat is the amount of heat\\nwhich will be able to raise the temperature of 1\\npound of water 1 degree.\\nQ. What is the specific heat of any sub-\\nstance\\nA. It is the number of heat-units necessary to\\nraise the temperature of 1 pound of it 1 degree.\\nQ. Is there any relation between units of heat\\nand units of work", "height": "2927", "width": "1815", "jp2-path": "ropersquestions00rope_0128.jp2"}, "129": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 113\\nA. One heat-unit equals 778 units of work (foot-\\npound).\\nQ. What is latent heat\\nA. Latent heat is heat absorbed by a body when\\nit changes its physical state. For instance, when\\nit changes from a solid to a fluid state, as from ice\\nto water, the heat absorbed is called the latent\\nheat of liquefaction. The heat absorbed in chang-\\ning from water to steam is called the latent heat of\\nvaporization.\\nQ. In what ways is heat transferred from one\\nbody to another\\nA. It is transferred by radiation, conduction, and\\nconvection.\\nQ. In a boiler, how is it transferred from the fire\\nto the steam\\nA. By conduction in the iron, and from the iron\\nto the particles of water touching the iron; it is\\nthen transferred from these particles to the others\\nby conduction and convection.\\nQ. What substances are in general the best con-\\nductors of heat?\\nA. The metals.\\nQ. What kind of substances radiate heat best\\nA. Substances of dark color with roughened\\nsurfaces.\\nQ. Why are the coverings of steam pipes\\npainted white", "height": "2856", "width": "1768", "jp2-path": "ropersquestions00rope_0129.jp2"}, "130": {"fulltext": "114 QUESTIONS AND ANSWERS FOR\\nA. Because we desire to have as little heat as\\npossible radiated from the pipes, and white radiates\\nless than dark colors.\\nQ. Why should a bare copper pipe carrying\\nsteam be kept brightly polished\\nA. Because if allowed to become dull more heat\\nwould be radiated.\\nQ. What are some of the best non-conductors\\nof heat?\\nA. Magnesia, mineral wool, hair felt, and cork.\\nQ. What would be the objection to leaving\\nsteam pipes bare\\nA. There would be a waste of fuel caused by\\nloss of heat, which is radiated from the pipes;\\nthere would be a loss of pressure in the steam and\\na condensation of steam into water, which, if\\ncarried over into the engine, would be liable to give\\ntrouble.\\nQ. How many pounds of air will be required\\nto burn a pound of coal\\nA. About 12 pounds.\\nQ. What is the cause of smoke\\nA. Smoke is caused by imperfect combustion\\nof the fuel the black appearance being due to the\\npresence of small unburned particles hanging\\nsuspended in the air.\\nQ. What are some of the principal fuels used\\nin making steam", "height": "2927", "width": "1815", "jp2-path": "ropersquestions00rope_0130.jp2"}, "131": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 115\\nA. Coal, coke, wood, petroleum, and gas.\\nQ. What are the chief constituents of coal\\nA. Carbon is the chief constituent. Coal also\\ncontains hydrogen and nitrogen and sulphur,\\ntogether with the constituents forming the ash.\\nQ. How many heat-units are produced by the\\ncomplete combustion of one pound of good coal\\nA. About 13,000.\\nQ. What is the difference between anthracite\\nand bituminous coal\\nA. Anthracite is nearly all carbon, while bitumi-\\nnous coal has a large percentage of other materials.\\nQ. How many pounds of wood (roughly) are\\nneeded to produce as much heat as a pound of coal\\nA. About 2\\\\ pounds.\\nQ. How great an evaporation per pound of coal\\ncan be obtained practically\\nA. About 11 pounds.\\nQ. What proportion does the ash bear to the\\namount of fuel\\nA. The ash will vary anywhere from 1 to 30\\nper cent, of the amount of fuel.\\nQ. Of what is the atmosphere composed\\nA. Of a mixture of about one part (by volume)\\nof oxygen to four parts nitrogen.\\nQ. Does air have weight\\nA. Yes; a weight per cubic foot varying with\\nthe pressure.", "height": "2856", "width": "1768", "jp2-path": "ropersquestions00rope_0131.jp2"}, "132": {"fulltext": "116 QUESTIONS AND ANSWERS FOR\\nQ. To what is the atmospheric pressure, so-\\ncalled, due?\\nA. It is due to the pressure which the air exerts\\non all bodies by virtue of its weight. As the\\natmosphere extends to a distance of some forty-\\nfive miles from the earth s surface, every square\\ninch is subjected to a pressure equal to the weight\\nof a column of air one square inch cross-section\\nand some forty-five miles long.\\nQ. How does the weight per cubic foot compare\\nwith that of steam at atmospheric pressure\\nA. The weight of air is about double the weight\\nof steam.\\nQ. What is the effect of the application of heat\\nto air?\\nA. It expands the air s volume for\\neach degree rise in temperature.\\nQ. How much is the pressure of the atmosphere\\nat sea level\\nA. About 14.7 pounds per square inch.\\nQ. What instrument is used to measure atmos-\\npheric pressure\\nA. The barometer.\\nQ. Will the barometer read higher on a moun-\\ntain or at the sea level\\nA. It will read higher at the sea level, because\\nthe mercury column is forced up by the weight of\\na longer column of air.", "height": "2927", "width": "1815", "jp2-path": "ropersquestions00rope_0132.jp2"}, "133": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 117\\nQ. Will water boil at the same temperature on\\na mountain as at sea level\\nA. Xo; it boils at a lower temperature on a\\nmountain, because the pressure of the atmosphere\\nwhich tends to prevent the steam from rising from\\nthe surface of the water is less on a mountain than\\nat sea level.\\nQ. What is the composition of water\\nA. Water is composed of about eight parts, by\\nweight, of oxygen to eleven parts of hydrogen.\\nQ. What is the weight per cubic foot of water\\nA. The weight per cubic foot of moderately\\npure water is about 62.5 pounds. Impurities in\\nthe water will increase its weight so that sea water\\nis much heavier than fresh water.\\nQ. In what three physical states or forms does\\nwater exist?\\nA. In the form of ice, water, and steam.\\nQ. What is necessary to change from one form\\nto the other\\nA. We can change the physical state of water\\nby either applying or withdrawing heat from it.\\nQ. At what temperature does water boil\\nA. This depends upon its purity and the pres-\\nsure acting upon it. Pure water at sea level boils\\nat 212\u00c2\u00b0 Fahr.\\nQ. Is the boiling-point of salt water the same\\nas that of fresh?", "height": "2856", "width": "1768", "jp2-path": "ropersquestions00rope_0133.jp2"}, "134": {"fulltext": "118 QUESTIONS AND ANSWERS FOR\\nA. No; it is higher.\\nQ. What is the weight of a cubic foot of ice\\nA. About 57 pounds.\\nQ. How many units of heat are necessary to\\nchange a pound of ice into water\\nA. About 142.\\nQ. What is the scientific name given to this\\nnumber\\nA. The latent heat of liquefaction.\\nQ. How many heat-units are necessary to con-\\nvert a pound of water into steam\\nA. At atmospheric pressure, about 965.\\nQ. How many cubic inches of water are there\\nin a gallon\\nA. In the standard U. S. gallon, 231.\\nQ. What would be the pressure per square inch\\nproduced by a column of water 10 feet high\\nExplain how you would calculate this.\\nA. A cubic foot of water weighs 62. 5 pounds,\\ntherefore a cubic inch weighs 62.5 divided by 1728.\\nA column of water 12 inches high and one square\\ninch cross-section would weigh 12 times this\\namount, or .434 pound. Therefore, the pressure\\nproduced by the column 10 feet high would be\\n.434 times 10, or 4.34 pounds per square inch.\\nQ. What is the difference between hard and\\nsoft water?\\nA. Hard water is water that holds mineral", "height": "2927", "width": "1815", "jp2-path": "ropersquestions00rope_0134.jp2"}, "135": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 119\\nsalts in solution. Soft water is water that is\\npractically free from impurities.\\nQ. What do you understand by the term\\nhead applied to water\\nA. I understand a difference in level or the\\npressure due to that difference in level.\\nQ. What is steam\\nA. Steam is the gaseous form of water, and is\\nproduced from water by the action of heat.\\nQ. Can you see steam\\nA. No; steam itself is invisible, being, like air,\\nwithout color. If, however, a jet of steam be\\nallowed to flow into the air it will form a cloud;\\nthis cloud is not the steam itself, but is produced\\nby water particles condensed from the steam.\\nQ. What is the relative volume of space occu-\\npied by steam and by the water from which it\\nis produced?\\nA. At atmospheric pressure a cubic inch of\\nwater when changed into steam will occupy a\\nspace of about one cubic foot. Of course, if the\\nsteam is subjected to a greater pressure its volume\\nwill become proportionately less.\\nQ. What is superheated steam?\\nA. It is ordinary dry steam, which, after being\\nremoved from contact with the water from which\\nit is produced, is raised by the application of heat\\nto a higher temperature.", "height": "2856", "width": "1768", "jp2-path": "ropersquestions00rope_0135.jp2"}, "136": {"fulltext": "120 QUESTIONS AND ANSWERS FOR\\nQ. Is there any relation between the pressure of\\nsteam and its temperature\\nA. Yes; a certain temperature always corre-\\nsponds to a certain pressure. The actual values of\\npressure and temperature are given in steam tables.\\nQ. What is the temperature of steam at 60\\npounds gauge pressure; 100 pounds; and 135\\npounds\\nA. 307\u00c2\u00b0, 337\u00c2\u00b0, and 358\u00c2\u00b0, respectively.\\nQ. In the steam tables, what is the meaning of\\nlatent heat of vaporization\\nA. The number given in the tables in the\\ncolumn under latent heat means the number of\\nunits of heat which must be applied to a pound of\\nwater at the corresponding pressure in order to\\nchange it into steam at that pressure.\\nQ. When a pound of steam at a temperature of\\n100 pounds gauge pressure condenses, how much\\nheat is given off\\nA. In condensing it gives up a number of heat-\\nunits equal to the latent heat of steam at that\\npressure. During this process the temperature of\\nthe steam does not change.\\nQ. After all the steam is condensed into water,\\nsuppose that the water cools to a lower tempera-\\nture, how much heat is given off\\nA. The number of heat-units given off will be\\nequal to the heat of the liquid (or sensible heat)", "height": "2927", "width": "1815", "jp2-path": "ropersquestions00rope_0136.jp2"}, "137": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 121\\nat the higher temperature less that at the lower\\ntemperature.\\nQ. What is the weight of a cubic foot of steam\\nA. This depends entirely upon its pressure.\\nAt atmospheric pressure the steam from a cubic\\ninch of water occupies about one cubic space, so\\nthat its weight per cubic foot would be about 3-7V5-\\nof the weight of water. The weight of the cubic\\nfoot of water being 62.5 pounds, the weight of a\\ncubic foot of steam at atmospheric pressure will\\nbe found by dividing 62.5 by 1700.\\nQ. If you put a thermometer first in the steam\\nspace of a boiler and next in the water space, will\\nits readings be any different in the two places\\nA. Xo; the temperature of water and of steam\\nin contact with it is always the same.\\nQ. What is the specific gravity of a substance\\nA. The ratio of its weight to an equal bulk of\\nwater.\\nQ. What is the difference between cast and\\nwrought iron\\nA. Cast iron is less pure, and contains carbon\\nand other impurities. It has a crystalline struc-\\nture and cannot be hammered or drawn out like\\nwrought iron.\\nQ. What is steel\\nA. Steel is a modification of iron produced by\\nmixing with it a small percentage of carbon;", "height": "2856", "width": "1768", "jp2-path": "ropersquestions00rope_0137.jp2"}, "138": {"fulltext": "122 QUESTIONS AND ANSWERS FOR\\nthe amount of carbon being determined by the\\nspecial properties which it is desired to produce\\nin the steel.\\nQ. What is the effect of heat on iron or steel\\nA. It expands it, and up to a certain point\\n(about 600\u00c2\u00b0 Fahr. increases its strength some-\\nwhat.\\nQ. What is brass\\nA. Brass is an alloy of copper and zinc in\\nvarious proportions.\\nQ. What is bronze\\nA. Bronze is an alloy of copper and tin.\\nQ. What do you understand by the term\\ntensile strength of a material\\nA. I understand the number of pounds of pull\\nthat must be exerted on a piece with one square\\ninch cross-section in order to rupture the piece.\\nQ. What do you understand by the term com-\\npressive strength, and what other expression is\\noften used?\\nA. The expression crushing strength is often\\nused. The crushing strength is the number of\\npounds per square inch that must be applied in\\norder to crush the material under test.\\nQ. What is the tensile strength of cast iron,\\napproximately, and what is its crushing strength\\nA. Tensile strength, about 16,000 pounds per\\nsquare inch; crushing strength, about 100,000.", "height": "2927", "width": "1815", "jp2-path": "ropersquestions00rope_0138.jp2"}, "139": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 123\\nQ. What are the tensile and compressive\\nstrengths of wrought iron\\nA. They are nearly equal to each other, being\\nabout 50,000 pounds per square inch.\\nQ. What is the strength of steel\\nA. The strength of steel varies very greatly\\naccording to its composition. Mild steels low in\\ncarbon have a strength of about 50,000 pounds.\\nSteels high in carbon may have a strength as high\\nas 200,000 pounds per square inch.\\nSTEAM HEATIXG.\\nQ. What are the two principal systems of steam\\nheating in use at the present day\\nA. The gravity and the reducing systems.\\nQ. What are the distinguishing features of the\\ngravity system\\nA. The boiler is placed below the level of any\\nradiator. Steam is generated at a pressure rarely\\nexceeding ten pounds and is carried to the radia-\\ntors through a supply main and branches. From\\nthe other end of the radiator a branch connects to\\na return main, which carries the water of con-\\ndensation back to a low point in the water space\\nof the boiler.\\nIn this system the circulation or return flow of\\nwater to the boiler is produced by gravity alone.\\nQ. What are the advantages of this system", "height": "2856", "width": "1768", "jp2-path": "ropersquestions00rope_0139.jp2"}, "140": {"fulltext": "124 QUESTIONS AND ANSWERS FOR\\nA. Its chief advantages are its simplicity, ease\\nof operation, and cheapness in first cost. It is as\\neconomical, in fact more so, considered simply\\nfrom the heating standpoint, although when the\\nheating system is auxiliary to a power plant the\\nreducing system may be cheaper in operation.\\nQ. What are the necessary valves in the gravity\\nsystem\\nA. A stop valve in the riser near the boiler, and\\na stop and check valve in the return pipe, where\\nit enters the boilers with the stop valve nearest the\\nboiler, and a blow-off valve.\\nQ. What other fittings should a boiler have\\nA. Safety valve, pressure gauge, gauge cocks,\\nand water gauge glass.\\nQ. In this system, how do we get the extra\\nsupply of feed- water that will be required on ac-\\ncount of leakage or waste\\nA. The boiler is connected to the city mains\\nthrough a valve.\\nQ. Is a pump, inspirator, or injector necessary\\nA. No because the pressure used is so low\\nthat the city pressure is always sufficient to force\\nwater into the boiler.\\nQ. When put in charge of a boiler, what would\\nyou do in order to find out whether or not it were\\nin good working condition\\nA. Examine the fittings of the boiler and see", "height": "2927", "width": "1815", "jp2-path": "ropersquestions00rope_0140.jp2"}, "141": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 125\\nthat the stop valves are closed. Turn on city\\npressure (if this pressure is higher than the safe\\nworking pressure of the boiler, the feed valve\\nmust be kept sufficiently closed to prevent the\\npressure on the boiler from rising to a dangerous\\npoint) and notice if the reading of the gauge cor-\\nresponds with the pressure at which the safety\\nvalve blows. Open the gauge cocks and let the\\nboiler gradually fill. When the water gets high\\nenough try the water-gauge cock. Fill the boiler\\ncompletely, closing the cocks and safety valve,\\nand turn the city connection until the gauge shows\\na pressure a little less than the blow-off pressure.\\nThen examine carefully all accessible parts of the\\nboiler to see if there is any leakage.\\nQ. Explain what is the proper method of start-\\ning up when the boiler has been out of use and\\ncontains no water.\\nA. Fill the boiler with water to second gauge\\ncock and open the steam stop valve. Start a fire\\nslowly so that the water and boiler may be heated\\ngradually and evenly in order to avoid strains\\nfrom unequal expansion. As soon as the pressure\\ngauge shows one or two pounds examine all pipe\\nand the radiators for leaks. These being tight\\nthe steam may be raised to the desired pressure.\\nQ. Explain what should be done when a boiler\\nis to be shut down for the summer.", "height": "2856", "width": "1768", "jp2-path": "ropersquestions00rope_0141.jp2"}, "142": {"fulltext": "126 QUESTIONS AND ANSWERS FOR\\nA. Let the fire go out and allow the boiler to\\ncool for several hours, then open the blow-off\\nvalve and let all water drain from the boiler; at the\\nsame time allow air to enter the boiler through\\ncocks or safety valve. Open all jet- and drip-\\ncocks in order to drain any water that may have\\ncollected in the fittings or connections. Finally,\\nclean the boiler of all dirt and ashes.\\nQ. What would you do if at any time a serious\\nleak should occur in the mains or radiators\\nA. If the leak were in a radiator I would shut\\nit off by closing its two valves. If, however, the\\nleak were in the mains or branch connections, I\\nwould shut off both stop valves and draw the fire.\\nQ. What are the important features of the re-\\nducing system of steam heating\\nA. Steam is generated at a high pressure for\\npower purposes. This steam is afterward re-\\nduced to a low pressure by passing it through a\\nreducing valve.\\nThe steam condensed in the radiators passes\\nthrough the return pipe into a trap, and from the\\ntrap to a receiver tank or hot well, from which\\nit is forced into the boiler by a pump or injector.\\nQ. What is the purpose of the trap\\nA. To take the water of condensation from the\\npipe without letting any of the steam escape.\\nQ. In a system where steam is carried to the", "height": "2927", "width": "1815", "jp2-path": "ropersquestions00rope_0142.jp2"}, "143": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 127\\ntop of the building and then distributed to the\\nradiators through vertical risers, where is it desir-\\nable to place an auxiliary trap, and why?\\nA. There should be a trap to take the drip\\nfrom the bottom of all the supply risers in order\\nto keep these risers free from water of condensa-\\ntion, which would impair the circulation of steam.\\nQ. What is a reducing valve\\nA. It is a valve for lowering the pressure of\\nsteam.\\nQ. Describe any forms of reducing valve with\\nwhich you are familiar.\\nA. In one variety the valve is of the piston\\ntype and is pressed upward by the low pressure\\nsteam and downward by a lever and weight. High\\npressure steam is in an annular chamber surround-\\ning the hollow piston. When the pressure in the\\nheating system falls below that for which the\\nweight is set the piston is forced downward. This\\nmovement opens a series of small ports by which\\nthe live steam passes through the hollow piston and\\nout through its open bottom into the heating sys-\\ntem. As soon as the pressure on the under side\\nis as great as that for which the weight is set the\\npiston rises and live steam is shut off.\\nAnother variety consists of a balanced valve\\nhaving two discs of the same size on the same\\nstem. The live steam presses up against one disc", "height": "2856", "width": "1768", "jp2-path": "ropersquestions00rope_0143.jp2"}, "144": {"fulltext": "128 QUESTIONS AND ANSWERS FOR\\nand down against the other. As these discs are\\nof the same size the live steam has no tendency\\nto move the valve. Motion is produced by a\\nweight and lever which tend to open the valve,\\nand by the action of the low pressure steam on a\\ndiaphragm, which tends to close it. An adjustable\\nspring is sometimes used in place of a weight and\\nlever.\\nQ. With a reducing valve, how can the pressure\\nin the heating system be raised or lowered\\nA. By moving the weight on the lever or ad-\\njusting the tension on the spring.\\nQ. What fittings should be placed on the main\\nsupply pipe of a reducing system\\nA. A stop or throttle valve, a reducing valve\\nand a low reading pressure gauge.\\nQ. What openings has the receiver tank\\nA. One for the entrance of condensed steam\\nfrom the heating system one for the entrance of\\ncity water one for emptying the tank one for a\\nvent to the atmosphere finally, one connecting\\nwith the suction of the boiler feed pump.\\nQ. What fittings are often placed on a receiver\\ntank?\\nA. A water gauge glass, to show the level\\nat which the water stands in the tank, and a\\ndevice consisting of a float and lever which opens\\nthe valve admitting steam to the pump when-", "height": "2927", "width": "1815", "jp2-path": "ropersquestions00rope_0144.jp2"}, "145": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 129\\never the level of the water in the tank rises above\\na certain height.\\nQ. To which system does the ordinary method\\nof heating with exhaust steam belong?\\nA. To the reducing system. The steam engine\\ntakes the place of the reducing valve.\\nQ. Why is it necessary to employ an oil sepa-\\nrator when exhaust steam is used for heating\\nA. In order to extract the oil which has been\\ntaken up by the steam in its passage through the\\ncylinder.\\nQ. What harm would result in leaving the oil\\nin the exhaust steam\\nA. This oil would accumulate in the pipes and\\nboiler. It would leak out of joints in the piping\\nand at the seams and tube ends of the boiler. It\\nwould also produce foaming.\\nQ. W T hat is the Webster vacuum system\\nA. It is a reducing system in which the circula-\\ntion is produced by a vacuum pump attached to\\nthe return pipes.\\nQ. W r hat are the advantages of the Webster\\nvacuum system?\\nA. It diminishes the back pressure on the en-\\ngine, and allows the use of a smaller size of pipes;\\ndifferent radiators on the same system may be kept\\nat different temperatures, and radiators may be\\noperated at a level below that of the receiving tank.", "height": "2856", "width": "1768", "jp2-path": "ropersquestions00rope_0145.jp2"}, "146": {"fulltext": "130 QUESTIONS AND ANSWERS FOR\\nQ. Describe that method of piping known as\\nthe single pipe system.\\nA. Each radiator has but one outlet and one\\nvalve. The condensed steam flows back through\\nthe same branch pipes and risers as carry the\\nsteam supply, and is collected in a trap, from\\nwhich it is taken to the boiler in the same way as\\nin the double pipe system.\\nQ. What are the advantages and disadvantages\\nof the single pipe system\\nA. Its chief advantage is its lower first cost. It\\nhas the disadvantage of a poorer circulation.", "height": "2927", "width": "1815", "jp2-path": "ropersquestions00rope_0146.jp2"}, "147": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 131\\nQUESTIONS FOR MARINE ENGINEERS.\\nEngineers desiring to enter the Merchant Marine\\nare required to pass an examination before the\\nSupervising Steam Inspector of their district.\\nThe name and address of the Inspector can be\\nobtained from the Secretary of the Treasury.\\nThe requirements for engineers are not very\\ndefinitely established by law, as will be seen by\\nreading the extract from the rules of the Board of\\nSupervising Inspectors. (Seep. 132.)\\nIn a bill introduced by Senator AVm. P. Frye,\\nwhich embodies the recommendations of the United\\nStates Delegates to the International Marine Con-\\nference, the requirements of the various grades\\nare presented in much greater detail. Although\\nthis bill was not passed, the recommendations\\ntherein contained have had an undoubted influ-\\nence, and act as a guide to the supervising steam\\ninspectors in determining upon the fitness of\\napplicants.\\nIn the following extracts from the Rules and\\nBill will be found only those sections that apply\\nparticularly to the qualifications of marine engi-\\nneers and to the range of subjects in which they\\nmust be proficient.\\nAs the requirements for chief engineer extend", "height": "2856", "width": "1768", "jp2-path": "ropersquestions00rope_0147.jp2"}, "148": {"fulltext": "132 QUESTIONS AND ANSWERS FOR\\nbeyond the scope of the Roper s Handy-Books,\\nno questions for that grade have been included in\\nthis book.\\nEXTRACT FROM THE RULES AND REGULATIONS\\nOF THE BOARD OF SUPERVISING INSPECTORS\\nOF STEAM VESSELS.\\n1. Before an original license is issued to any\\nperson to act as a master, mate, pilot, or engineer,\\nhe must personally appear before some local board\\nor a supervising inspector for examination but\\nupon the renewal of such license, when the dis-\\ntance from any local board or supervising in-\\nspector is such as to put the person holding the\\nsame to great inconvenience and expense to appear\\nin person, he may, upon taking the oath of office\\nbefore any person authorized to administer oaths,\\nand forwarding the same together with the license\\nto be renewed, to the local board or supervising\\ninspector of the district in which he resides or is\\nemployed, have the same renewed by the said in-\\nspectors if no valid reason to the contrary be\\nknown to them and they shall attach such oath\\nto the stub end of the license, which is to be re-\\ntained on file in their office; Provided, however,\\nThat the applicant for renewal is at the time per-\\nsonally within the jurisdiction of the United States\\nInspection Laws, as defined in sections 4400 and\\n4447 of the Revised Statutes.* And inspectors\\nare directed when licenses are completed, to draw\\nProviso substantially repealed by Act of Congress ap-\\nproved May 28, 1896.", "height": "2927", "width": "1815", "jp2-path": "ropersquestions00rope_0148.jp2"}, "149": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 133\\na broad pen and red-ink mark through all unused\\nspaces in the body thereof, so as to prevent as far\\nas possible illegal interpolation after issue.\\nMates, assistant engineers, or second-class pilots\\nserving under five-years license, entitled by license\\nto raise of grade, shall have issued to them new\\nlicenses for the grade for which they are qualified,\\nthe local inspectors to forward to the supervising\\nInspector-General the old license when surren-\\ndered, with the report of the circumstances of the\\ncase. New licenses may also be issued in the case\\nof license lost by wreck, fire, or any other cause,\\nupon a satisfactory showing of such loss to the in-\\nspectors, duly sworn to.\\nAnd inspectors will, before granting an original\\nlicense to any person to act as an officer of steam\\nvessels, require the applicant to make his written\\napplication upon the blank form authorized by the\\nBoard of Supervising Inspectors, which application\\nshall be filed in the records of the inspector s office.\\nInspectors shall also, when practicable, require\\napplicants for pilot s license to have written in-\\ndorsement of the master and engineer of one vessel\\nupon which he has served, and of the licensed\\npilot as to his qualifications. In the case of\\napplicants for original engineer s license, they\\nshall also, when practicable, have the indorsement\\nof the master and engineer of a vessel on which\\nthey have served, together with one other licensed\\nengineer.\\nNo original master s, mate s, pilot s, or engin-\\neer s license shall be issued hereafter or grade in-\\ncreased except upon written examination, which", "height": "2856", "width": "1768", "jp2-path": "ropersquestions00rope_0149.jp2"}, "150": {"fulltext": "134 QUESTIONS AND ANSWERS FOR\\nwritten examination shall be placed on file as\\nrecords of office of the inspectors issuing said\\nlicense.\\nAny applicant for examination for license who\\nhas been refused for want of knowledge or other\\nqualifications, may come before any local board\\nfor re-examination after one year has expired, on\\npresentation of a letter from the board that had\\nrefused him.\\nAny person who has served as master, com-\\nmander, pilot, or engineer of any steam vessel of\\nthe United States, in any service in which a license\\nas master, commander, pilot, or engineer was not\\nrequired at the time of such service, shall be\\nentitled to license as master, commander, pilot, or\\nengineer, if the inspectors, upon written examina-\\ntion as required for applicants for original license,\\nmay find him qualified Provided, That the ex-\\nperience of any such applicant within three years of\\nmaking application has been such as to qualify him\\nto serve in the capacity for which he makes applica-\\ntion to be licensed; but no such license shall be\\ngranted except under such restrictions. as may be\\nprescribed by the supervising inspector of the dis-\\ntrict in which the applicant files his application.\\n(Officers of the naval militia who are) applicants\\nfor license as master or pilot of steam vessels of the\\nnaval militia, after passing an examination for\\ncolor blindness, may be examined by the inspec-\\ntors as to their knowledge of the pilot rules and\\nhandling of vessels, and if the applicant be found\\nqualified in the judgment of the inspectors, he\\nmay be granted a special license as master or pilot", "height": "2927", "width": "1815", "jp2-path": "ropersquestions00rope_0150.jp2"}, "151": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 135\\non such vessels on the waters of the district in\\nwhich such license is granted, and for no other\\npurpose.\\nAll licenses issued to officers of the naval\\nmilitia provided for in the preceding paragraph of\\nthis section, or in section 3 of this rule, shall be\\nsurrendered upon the party holding it becoming\\ndisconnected from the naval militia by resigna-\\ntion or dismissal from such service and no license\\nshall be issued as above except upon the official\\nrecommendation of the chief officer in command\\nof the naval station of the State in which the\\napplicant is serving.\\n2. The classification of engineers shall be as\\nfollows\\nCHIEF.\\nChief engineer of ocean steamers.\\nChief engineer of condensing lake, bay, and\\nsound steamers.\\nChief engineer of non-condensing lake, bay,\\nand sound steamers.\\nChief engineer of condensing river steamers.\\nChief engineer of non-condensing river steamers.\\nAny person holding chief engineer s license\\nshall be permitted to act as first assistant on any\\nsteamers of double the tonnage of same class\\nnamed in said chief s license.\\nEngineers of all classifications may be allow r ed\\nto pursue their profession upon all waters of the\\nUnited States, in the class for which they are\\nlicensed, if found upon examination qualified\\ntherefor.", "height": "2856", "width": "1768", "jp2-path": "ropersquestions00rope_0151.jp2"}, "152": {"fulltext": "136 QUESTIONS AND ANSWERS FOR\\nFIRST ASSISTANT.\\nFirst assistant engineer of ocean steamers.\\nFirst assistant engineer of condensing lake,\\nbay, and sound steamers.\\nFirst assistant engineer of non-condensing lake,\\nbay, and sound steamers.\\nFirst assistant engineer of condensing river\\nsteamers.\\nFirst assistant engineer of non-condensing river\\nsteamers.\\nEngineers of lake, bay, and sound steamers\\nwho have actually performed the duties of engi-\\nneers for a period of three years shall be entitled\\nto examination for engineer of ocean steamers,\\napplicant to be examined in the use of salt-water\\nmethod employed in regulating the density of the\\nwater in boilers, the application of the hydrom-\\neter in determining the density of sea water,\\nand the principle of constructing the instrument,\\nand shall be granted such grade as the insjjectors\\nmay find him comjDetent to fill.\\nAny assistant engineer of ocean steamers of\\n1500 gross tons burden and over, having had\\nactual service in that position for one year, may,\\nif the local inspectors in their judgment deem it\\nadvisable, have his license indorsed to act as\\nchief engineer on lake, bay, sound, or river steam-\\ners of 750 gross tons or under.\\nSECOND ASSISTANT.\\nSecond assistant engineer of ocean steamers.\\nSecond assistant engineer of condensing lake,\\nbay, and sound steamers.", "height": "2927", "width": "1815", "jp2-path": "ropersquestions00rope_0152.jp2"}, "153": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 137\\nSecond assistant engineer of non-condensing\\nlake, bay, and sound steamers.\\nSecond assistant engineer of condensing river\\nsteamers.\\nTHIRD ASSISTANT.\\nThird assistant engineer of ocean steamers.\\nThird assistant engineer of condensing lake\\nand sound steamers.\\nFirst, second, and third assistant engineers\\nmay act as such on any steamer of the grade of\\nwhich they hold license or as such assistant\\nengineer on any steamer of a lower grade than\\nthose to which they hold a license.\\nInspectors must designate upon the certificate of\\nany chief or assistant engineer the tonnage of the\\nvessel on which he may act\\nProvided, however, That any engineer whose li-\\ncense is designated by tonnage may act in similar\\ncapacity on any steamer of larger tonnage, pro-\\nvided the engine in said steamer is not larger\\nthan the one to which his tonnage license re-\\nstricted him. That Form 2 130 J, special license\\nto engineers, be issued only to engineers in\\ncharge of vessels of 10 tons and under, and that\\nall other licenses to engineers be issued on Forms\\n2129 and 2130, according to grades specified in\\nthis section.\\n3. Assistant engineers may act as chief en-\\ngineers on high-pressure steamers of 100 tons\\nburden and under of the class and tonnage or\\nparticular steamer for which the inspectors, after\\na thorough examination, may find them qualified.", "height": "2881", "width": "1819", "jp2-path": "ropersquestions00rope_0153.jp2"}, "154": {"fulltext": "138 QUESTIONS AND ANSWERS FOR\\nIn all cases where an assistant engineer is per-\\nmitted to act as first (chief) engineer, the inspec-\\ntors shall state on the face of his certificate of\\nlicense the class and tonnage of steamers or the\\nparticular steamer on which he may so act.\\nAny (officer of the naval militia who is an)\\napplicant for license as chief engineer or assistant\\nengineer of steam vessels of the naval militia\\nmay be examined by inspectors and granted a\\nspecial license as such, and for no other purpose,\\nif, in the judgment of the inspectors, he is quali-\\nfied. (See last paragraph of Section 1 of this rule.\\n4. It shall be the duty of an engineer, when he\\nassumes charge of the boilers and machinery of a\\nsteamer to forthwith thoroughly examine the\\nsame, and if he finds any part thereof in bad con-\\ndition, caused by neglect or inattention on the\\npart of his predecessor, he shall immediately re-\\nport the facts to the local inspectors of the dis-\\ntrict, who shall thereupon investigate the matter\\nand if the former engineer has been culpably\\nderelict of duty, they shall suspend or revoke his\\nlicense.\\n5. No person shall receive an original license as\\nengineer or assistant engineer, except for special\\nlicense on small pleasure steamers of 10 tons\\nand under, and ferryboats, saw-mill boats, pile-\\ndrivers, and other nondescript similar small ves-\\nsels, navigated outside of ports of entry and de-\\nlivery, who has not served at least three years in\\nthe engineer s department of a steam vessel, a\\nportion of which experience must have been ob-\\ntained within three years preceding the applica-\\ntion", "height": "2927", "width": "1815", "jp2-path": "ropersquestions00rope_0154.jp2"}, "155": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 139\\nProvided, That any person who has served a\\nregular apprenticeship to the machinist trade in a\\nmarine-engine works for a period of not less than\\nthree years, and any person who has served for a\\nperiod of not less than three years as a locomo-\\ntive engineer, stationary engineer, or as an\\napprentice to the machinist trade in a locomotive\\nor stationary- engine works, and any person who\\nhas graduated as a mechanical engineer from a\\nduly recognized school of technology, may be li-\\ncensed to serve as an engineer on steam vessels,\\nafter having had not less than one year s experi-\\nence in the engine department of steam vessels,\\nwhich experience must have been obtained either\\nwithin one year before or one year subsequent to\\nthe acquisition of the skilled knowledge above\\nmentioned (which fact must be verified by the\\ncertificate in writing of the licensed engineer or\\nmaster under whom the applicant has served,\\nsaid certificate to be filed with the application of\\nthe candidate) and no person shall receive li-\\ncense as above, except for special license, who is\\nnot able to determine the weight necessary to be\\nplaced on the lever of a safety valve (the diam-\\neter of valve, length of lever, distance from\\ncenter of valve to fulcrum, weight of lever, and\\nweight of valve and stem being known) to with-\\nstand any given pressure of steam in a boiler, or\\nwho is not able to figure and determine the strain\\nbrought on the braces of a boiler with a given\\npressure of steam, the position and distance apart\\nof braces being known, such knowledge to be\\ndetermined by an examination in writing and the", "height": "2881", "width": "1819", "jp2-path": "ropersquestions00rope_0155.jp2"}, "156": {"fulltext": "140 QUESTIONS AND ANSWERS FOR\\nreport of examination filed with the application\\nin the office of the local inspectors and no\\nengineer or assistant engineer now holding a li-\\ncense shall have the grade of the same raised\\nwithout possessing the above qualifications. And\\nno original license shall be granted any engineer\\nor assistant engineer who cannot read and write\\nand does not understand the plain rules of arith-\\nmetic.\\nEXTRACTS FROM THE FRYE BILL.\\nSection 128. That no steam vessel can obtain\\na clearance or legally proceed to sea from any port\\nin the United States or navigate any waters of\\nthe United States which are common highways\\nof commerce or open to competitive navigation,\\nexcepting public vessels of the United States and\\nvessels of other countries, unless the engineers\\nthereof have obtained and possess valid certifi-\\ncates of competency or certificates of service ap-\\npropriate to their several stations.\\nSec 129. That the minimum complement of\\nengineers for vessels licensed for carrying pas-\\nsengers shall be as follows Seagoing steamers\\nTwin-screw steamers with machinery of over ten\\nthousand indicated horse-power, one chief engineer\\nof the highest grade and nine assistant engineers,\\nof whom at least three shall hold certificates as\\nfirst assistants and three as second assistants.\\nSec. 130. Twin-screw steamers with machinery\\nfrom five thousand to ten thousand indicated\\nhorse-power, one chief engineer of the grade from\\nfive thousand to ten thousand indicated horse-\\npower and nine assistants, of whom at least three", "height": "2927", "width": "1815", "jp2-path": "ropersquestions00rope_0156.jp2"}, "157": {"fulltext": "STEAM ENGINEERS AXD ELECTRICIANS. 141\\nshall hold certificates as first assistants and three\\nas second assistants.\\nSec 131. Single-screw steamers with machinery\\nof over ten thousand indicated horse-power, one\\nchief engineer of the highest grade and six assist-\\nants, of whom at least three shall hold certificates\\nas first assistants and two as second assistants.\\nSec 132. Single-screw steamers with machinery\\nof from five thousand to ten thousand indicated\\nhorse- power, one chief engineer of the grade from\\nfive thousand to ten thousand indicated horse-\\npower and five assistants, of whom at least three\\nshall hold certificates as first assistant and one as\\nsecond assistant.\\nSec 133. Single-screw steamers with machinery\\nof from two thousand to five thousand indicated\\nhorse-power, one chief engineer of the grade and\\nfive assistants, if there are many auxiliaries inde-\\npendent of the main engines; if there are very few\\nauxiliaries, three assistants. In the first case, at\\nleast three of the assistants shall hold certificates\\nas first assistant and one as second assistant in\\nthe second case, two shall be first assistants and\\none second assistant.\\nSec 134. Single screw steamers with machinery\\nof less than two thousand indicated horse-power,\\none chief engineer of the grade, except as provided\\nfor the cases where first and second assistants may\\nbe in charge, and two assistants, of whom one\\nshall be a first assistant.\\nSec 135. Paddle-wheel steamers, one chief en-\\ngineer of grade according to horse-power and two\\nto five assistants, depending on number of aux-", "height": "2881", "width": "1819", "jp2-path": "ropersquestions00rope_0157.jp2"}, "158": {"fulltext": "142 QUESTIONS AND ANSWERS FOR\\niliaries. If there are five assistants three shall\\nhold certificates as first assistant and one as second\\nassistant; if there are less than five assistants, at\\nleast one shall hold a certificate as first and one as\\nsecond assistant.\\nSec. 136. Steamers navigating lakes, bays,\\nsounds, and rivers: There shall in every case be\\na chief engineer of the grade corresponding to the\\nhorse-power, except, as elsewhere provided, when\\nfirst and second assistants are allowed in charge,\\nand a number of assistants depending on the size\\nand complexity of the machinery and the duration\\nof the trip between terminals; but in no case shall\\nany steamer on routes of longer than fourteen\\nhours duration be allowed to run with less than\\ntwo engineers, including the chief engineer, and\\nwhen there is only one assistant he shall hold a\\ncertificate at least as high as second assistant, pro-\\nvided that in the case of small pleasure steamers\\nof ten tons and under a third assistant engineer\\nmay have charge of the machinery.\\nSec. 137. That on every steamer engineers hold-\\ning a certificate of higher grade than that required\\nmay perform the duties of the lower grade.\\nSec 138. That before a steamer is licensed for\\ncarrying passengers the supervising inspector of\\nthe district must be notified of the service she is\\nintended to perform, and he shall make personal\\ninspection of the machinery and decide upon the\\nminimum complement of engineers in those cases\\nwhere it is not specifically provided for. In his\\ndecision he will be governed by the arrangement\\nand complexity of the machinery, the subdivision", "height": "2927", "width": "1815", "jp2-path": "ropersquestions00rope_0158.jp2"}, "159": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 143\\nof water-tight bulkheads, and all other matters\\nwhich increase the difficulty of properly caring for\\nthe machinery.\\nSec. 139. That in all cases, including those\\nspecifically provided for, he is authorized to in-\\ncrease the complement if, in his judgment, the\\ncomplexity and arrangement of the machinery, the\\nnumber of auxiliaries, and the arrangement of\\nbulkheads make it necessary to the adequate care\\nand supervision of the machinery while in op-\\neration. Should the owner of the steamer deem\\nthe number assigned too great he may appeal to\\nthe Supervising Inspector-General, transmitting\\nplans of the vessel and machinery in sufficient\\ndetail to enable an intelligent decision to be ren-\\ndered.\\nSec. 140. That, in the case of steamers used\\nentirely as freight-carriers and not carrying pas-\\nsengers, the number of engineers shall be decided\\nby the supervising inspector after a personal in-\\nspection and knowledge of the intended service.\\nSec 141. That in all cases there shall be a\\nchief engineer of the appropriate grade, except as\\nelsewhere provided, when first and second assist-\\nants are allowed in charge.\\nSec 142. That, if the vessel is a seagoing one\\nand the duration of the voyage is more than forty-\\neight hours, there shall always be at least three\\nengineers, including the chief, and one of the as-\\nsistants must hold a certificate as first assistant.\\nIf the voyage lasts less than forty-eight hours\\nthere may be two engineers only.\\nSec 143. That if the vessel does not go to sea,", "height": "2881", "width": "1819", "jp2-path": "ropersquestions00rope_0159.jp2"}, "160": {"fulltext": "144 QUESTIONS AND ANSWERS FOR\\nbut navigates only bays, sounds, lakes, and rivers,\\nthere must be two engineers if the average num-\\nber of hours under way per day exceeds ten or if\\nthe number of hours for any single regular run\\nexceeds twelve. Where the duration of the trip is\\nless than herein specified one engineer only will\\nbe required.\\nSec. 144. That in the case of pile-drivers, saw-\\nmill boats, and other small craft, not carrying\\npassengers, a third assistant engineer may have\\ncharge of the machinery if it does not exceed one\\nhundred indicated horse-power. That a special\\ncertificate may be granted authorizing the holder\\nto act as engineer on steamers of ten tons and un-\\nder, not carrying passengers or freight for pay, if\\nthe local inspectors are satisfied that the candidate\\nis competent.\\nSec 145. That the classification of engineers\\nin the merchant service of the United States shall\\nbe as follows Chief engineer of machinery ex-\\nceeding ten thousand indicated horse-power, chief\\nengineer of machinery between five thousand and\\nten thousand indicated horse-power, chief engineer\\nof machinery between two thousand and five\\nthousand indicated horse-power, chief engineer of\\nmachinery of two thousand indicated horse-power\\nand less, first assistant engineer, second assistant\\nengineer, third assistant engineer.\\nSec 146. That first assistant engineers may act\\nas chief engineers of engines of less than three hun-\\ndred indicated horse-power and second assistant\\nengineers may have charge of engines of less than\\none hundred indicated horse-power, provided the", "height": "2927", "width": "1815", "jp2-path": "ropersquestions00rope_0160.jp2"}, "161": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 145\\nvessel in which such engines are placed is used in\\nriver or harbor service only or does not go to sea\\nbeyond twenty miles.\\nSec 147. That a chief engineer for engines of\\nten thousand indicated horse-power and upward\\nmust be at least thirty years old and must have\\nserved at least five years at sea as a chief engineer\\nor first assistant with engines of over two thousand\\nindicated horse-power. He must be able to super-\\nintend the construction of machinery for two\\nthousand indicated horse-power and upward, and\\nto devise and direct the repair of any accident to\\nthe machinery likely to occur. He must be able\\nto secure a general average of ninety per centum\\non the examination for chief engineer hereinafter\\nprovided for and an average of seventy-five per\\ncentum on such additional questions as may be\\ngiven by the examining board for this grade and\\nthe next lower.\\nSec 148. That the requirements for a chief en-\\ngineer for machinery of from five thousand to ten\\nthousand indicated horse-power shall be the same\\nas for a chief engineer for machinery of over ten\\nthousand indicated horse-power, except that he\\nshall only be required to secure an average of\\neighty per centum on the general examination for\\nchief engineer and seventy per centum on the spe-\\ncial questions for this grade and the next higher.\\nSec 149. That a chief engineer for machinery\\nof from two thousand to five thousand indicated\\nhorse-power must be at least thirty years of age\\nand have served at least five years as chief engineer\\nof a seagoing steamer or as first assistant with", "height": "2881", "width": "1819", "jp2-path": "ropersquestions00rope_0161.jp2"}, "162": {"fulltext": "146 QUESTIONS AND ANSWERS FOR\\nengines from two thousand to five thousand indi-\\ncated horse-power. He must be able himself to do\\nor direct the adjustment of any part of the engines\\nand to run the lines for them and erect them in\\nthe vessel. He must be conversant with work on\\nboilers and piping and able to direct the repair of\\nany accident to them as well as the accidents likely\\nto occur to the engines. He must secure seventy\\nfive per centum on the general examination for\\nchief engineer.\\nSec. 150. That a chief engineer for machinery\\nof two thousand indicated horse-power or less\\nmust be at least thirty years of age and must have\\nserved at least five years as a first assistant or\\nthree years as a first assistant with engines of two\\nthousand indicated horse-power and over in a sea-\\ngoing ship. He must be able to make himself\\nor to direct the making of any ordinary repairs\\nto any part of the machinery. He must secure\\nsixty-five per centum on the general examination\\nfor chief engineer.\\nSec. 151. That a first assistant engineer must\\nbe at least twenty-five years of age and must have\\nserved at least two years as a second assistant.\\nHe must understand the working of every part of\\nthe machinery and be able himself to make the\\nadjustment directed by the chief engineer. He\\nmust understand the use of all the mechanics\\ntools employed in work about marine machinery\\nand be himself skilled at some trade connected\\nwith the making or fitting of such machinery. He\\nmust secure at least sixty-five per centum on the\\nexamination for his grade.", "height": "2927", "width": "1815", "jp2-path": "ropersquestions00rope_0162.jp2"}, "163": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 147\\nSec. 152. That a second assistant engineer must\\nbe at least twenty-three years of age and must\\nhave served at least one year as a third assistant.\\nHe must understand the working of marine ma-\\nchinery and be able to start, stop, and care for it\\nwhile in motion. He must understand the usual\\nremedies for such things as heated journals, low\\nwater, and foaming, and be able to fit and adjust\\nbearings, pack stuffing boxes, and do other ordi-\\nnary work about marine machinery. He must be\\nproficient in some trade connected, with the build-\\ning of marine machinery. He must secure at\\nleast sixty-five per centum on the examination for\\nhis grade.\\nSec. 153. That a third assistant engineer must\\nbe at least twenty-one years of age. He must\\neither be a machinist by trade and have had at\\nleast one year s experience with engines and\\nboilers on a vessel or on shore, or be a journeyman\\nmechanic in a trade connected with the building\\nof marine machinery, and have had one year s\\nexperience in the engine department of a steam\\nvessel or two years experience with engine and\\nboiler on shore, or have had at least three years\\nexperience in the engine department of a steam\\nvessel. He must secure at least sixty-five per\\ncentum at the examination for his grade.\\nSec 154. That the examinations for the two\\nhigher grades of chief engineer shall be held by a\\nboard consisting of the supervising inspector of\\nthe district and two local inspectors of boilers,\\nand shall take place not oftener than twice a year,\\nand only then if there are applicants. The exam-", "height": "2881", "width": "1819", "jp2-path": "ropersquestions00rope_0163.jp2"}, "164": {"fulltext": "148 QUESTIONS AND ANSWERS FOR\\nination for the other two grades of chief engineer\\nshall be held by a board of three local inspectors\\nof boilers. These shall be held at least twice a\\nyear, and once a quarter if there are more than\\nfive applicants.\\nSec. 155. The examination for first, second, and\\nthird assistant engineers shall be conducted by the\\nlocal inspector of boilers at least once each quarter\\nif there are applicants.\\nSec. 156. That when an applicant for any of\\nthe grades of engineers hereinbefore enumerated\\nhas not had the service in the merchant marine of\\nthe United States contemplated, but has had\\nequivalent service with marine machinery else-\\nwhere, of which he can produce satisfactory evi-\\ndence, he shall be admitted to examination, and,\\nif found to be possessed of the requisite degree of\\nproficiency, shall be certificated the same as if his\\nprevious service had been in the merchant marine\\nof the United States.\\nSec 157. That applicants for every grade of\\nengineer must satisfy the examining board that\\nthey are of sober and correct habits and, if\\ncalled upon by the examining board to do so,\\nmust furnish the names of the vessels on which\\nthey have previously served, together with the\\nnames of the masters and chief engineers, to whom\\nthe board may address interrogatories if they deem\\nit necessary to establish the character of the appli-\\ncant. If the service has been on shore the testi-\\nmonials must be signed by an employer.\\nSec. 158. That nothing contained in the fore-\\ngoing rules is to be construed to deprive any engi-", "height": "2927", "width": "1815", "jp2-path": "ropersquestions00rope_0164.jp2"}, "165": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 149\\nneer of the certificate which he now holds or of\\nthe privilege of renewal in accordance with the\\nrules heretofore existing, except as hereinafter\\nprovided.\\nSec 159. That, if an engineer with a certificate\\ndesires to qualify for duty with machinery of\\ngreater horse-power than that of the class with\\nwhich he is serving, he must make application\\nand pass the examination provided for above for\\nsuch higher class of machinery, and this is to\\napply to the various grades of assistants as well as\\nto those of chief that is, an engineer may con-\\ntinue to hold his certificate for the same kind and\\npower of machinery, but if he desires to serve\\nwith larger or different machinery he must pass\\nthe examination for the grade he desires to hold,\\nas herein provided.\\nSec 160. That solutions of problems and an-\\nswers to questions shall be given in ink, and no\\ncandidate will be permitted to leave the examiner s\\nroom until a paper is finished and handed in, and\\nall the examination papers shall be referred to the\\nSupervising Inspector-General of Vessels, with the\\nexaminer s recommendations indorsed thereon\\nand placed on file. Any examiner, officer, or em-\\nployee of the inspection service assisting a can-\\ndidate in any manner in the solution of his ques-\\ntions will be dismissed from the service.\\nSec 161. That, in case it shall be proved by\\noath or affirmation that the certificate of compe-\\ntency or the certificate of service of a master,\\nmate, or engineer has been lost, destroyed, or\\nunintentionally mislaid, the same shall be reissued", "height": "2881", "width": "1819", "jp2-path": "ropersquestions00rope_0165.jp2"}, "166": {"fulltext": "150 QUESTIONS AND ANSWERS FOR\\nfrom the records in the office of the Supervising\\nInspector-General of Vessels, through the inspec-\\ntor to whom the application for renewal is made.\\nSec. 162. That all certificates of competency\\nand of service shall be made in duplicate, one\\ncopy of which, under the seal of the Treasury\\nDepartment and hand of the Supervising Inspec-\\ntor-General of Vessels, shall be issued to the per-\\nson entitled to the same by the inspector before\\nwhom the candidate appeared for examination, by\\nwhich inspector the certificate shall be sealed and\\ncountersigned.\\nSec. 163. That the qualifications required for\\nthe several grades below mentioned shall be as\\nfollows Third assistant engineer First. He\\nmust know the names of the different parts of a\\nsteam engine and boiler and of the fittings and\\nmountings, including condenser and pumps.\\nSecond. He must be able to lay and start fires\\nand raise steam and understand the precautions to\\nbe taken to prevent injury to the boiler must\\nknow how to tend water, fire, and clean fires\\nalso what to do in case of low water.\\nThird. He must be able to start, stop, and re-\\nverse the engine, and know what precautions to\\nobserve in starting to prevent injury to engines\\nand boilers.\\nFourth. He must know what to do to engines\\nand boilers in case of foaming, and the course to\\nbe pursued in the case of hot bearings.\\nFifth. He must be able to read the steam and\\nvacuum gauges and other instruments about the\\nmachinery intelligently.", "height": "2927", "width": "1815", "jp2-path": "ropersquestions00rope_0166.jp2"}, "167": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 151\\nSixth. He must know the first four rules of\\narithmetic and be able to write a legible hand.\\nSec. 164. Second assistant engineer First. He\\nmust be able to give a description of the boilers\\nand engines in common use on board ship and of\\nthe fittings and connections used with them, in-\\ncluding the way in which boilers are braced,\\nand the use and management of the different\\nvalves, cocks, levers, and so forth.\\nSecond. He must be able to tell how ordinary-\\nrepairs to boilers are made, such as hard and soft\\npatching., riveting, expanding tubes, calking\\nseams, plugging leaky tubes, and so forth.\\nThird. He must understand the use of the\\nthermometer, barometer, salinometer, steam and\\nvacuum gauges, gauge cocks, and glass water\\ngauges, and in general all other fittings about the\\nmachinery.\\nFourth, He must be able to tell what foaming\\nand priming are, how discovered, and their effects\\non boilers and engines, and what is done to stop\\nthem.\\nFifth. He must be able to tell the course to be\\npursued in raising steam and getting engines and\\nboilers ready for work, and the process followed\\nwhen the machinery is no longer needed on reach-\\ning port, including both the cases when the fires\\nare to be banked and when the boilers will not be\\nneeded for several days.\\nSixth. He must be able to tell how to ascertain\\nwhether the journals are working properly and\\nwhat to do to prevent heating, and to remedy it if\\nit does occur.", "height": "2881", "width": "1819", "jp2-path": "ropersquestions00rope_0167.jp2"}, "168": {"fulltext": "152 QUESTIONS AND ANSWERS FOR\\nSeventh. He must be able to tell how firing\\nshould be conducted and how a fire should be\\ncleaned.\\nEighth. He must be able to tell what to do in\\ncase of low water.\\nNinth. He must be able to tell how to lay up\\npacking and how to pack stuffing boxes, pump\\npistons, and so forth.\\nTenth. He must know enough arithmetic to be\\nable to work any problem under the fundamental\\nrules and common fractions. He must be able to\\nwrite a legible hand and write an ordinary letter\\nso as to show a fair knowledge of spelling and\\ngrammar.\\nSec. 165. First assistant engineer First. Fa-\\nmiliarity with all the ordinary types of engines\\nand boilers explanation of the different parts,\\ntheir object, and method of working.\\nSecond. Duties in raising steam and getting un-\\nder way in maintaining a good performance\\nwhile under way and when ship is anchored\\nor secured.\\nThird. Description of common derangements\\nthat may happen, such as foaming, hot journals,\\nand so forth, with account of procedure to remedy\\nthem also tell what should be done to prevent\\nthem.\\nFourth. Repairs Tell how patches are put on\\na boiler, tubes expanded, and so forth.\\nFifth. Adjustment of journals and valve gear\\nsetting of valves.\\nSixth. Use of steam-engine indicator and ex-\\nplanation of diagrams taken with it, as well as", "height": "2927", "width": "1815", "jp2-path": "ropersquestions00rope_0168.jp2"}, "169": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 153\\ncalculation of indicated horse-power from dia-\\ngram.\\nSeventh. Expansion of steam object of how\\naccomplished in practice.\\nEighth. Familiarity with instruments used about\\nmachinery, steam and vacuum gauges, thermom-\\neter, barometer, and so forth how they should\\nbe fitted to insure accurate readings.\\nNinth. Fittings and mountings of engines, boil-\\ners, and auxiliaries description of safety valves,\\nsafety-feed arrangements, gauge cocks, and glass\\ngauges on boilers, and so forth.\\nTenth. Description of the steam pumps in com-\\nmon use, and explanation of any derangements to\\nwhich the} are liable.\\nEleventh: Problems in connection with measure-\\nment of coal bunkers, oil tanks, position of weight\\non safety-valve lever, and so forth.\\nTwelfth. Acquaintance with the rules of arith-\\nmetic through percentage and proportion, and of\\nmensuration, to enable the solution of such prob-\\nlems as in paragraph eleven. Legible handwriting\\nand knowledge of spelling and grammar.\\nThirteenth. Ability to make a sketch, with fig-\\nured dimensions, from the machinery, so that in\\ncase of a broken part a new one could be made\\nfrom his sketch.\\nSec 166. Chief Engineer. First Boilers: These\\nshall include all the common makes of boilers\\nlikely to be found in any vessel on which the ap-\\nplicant would serve, and also a knowledge of how\\nthe various parts are put together, the advantages\\nof different kinds of riveting, the methods of brae-", "height": "2881", "width": "1819", "jp2-path": "ropersquestions00rope_0169.jp2"}, "170": {"fulltext": "154 QUESTIONS AND ANSWERS FOR\\ning, the attachments commonly used, including\\nimproved forms, and the use of forced draft, and\\nthe changes in boilers consequent thereon.\\nSecond. Engines: The different kinds in com-\\nmon use, including those used with paddle wheels;\\ndescription of their different parts and methods of\\nfitting them together.\\nThird. Valves: Different kinds in common use\\nand advantages of forms now in use over older\\nones which have been abandoned. How to set\\nvalves. Cut-off, how effected, and how different\\npoints of cut-off change dimensions of valve. De-\\nscriptions of modern valve gears with screw and\\npaddle engines, explanation of working, and how\\nvariable cut-off is secured with them. Derange-\\nments common to valves and valve gears.\\nFourth. Journals: How fitted in different places,\\nprovision for lubrication for preventing heating,\\nand for taking up wear. This is to include shaft\\nand connecting rod journals and thrust bearings.\\nFifth. Condensers Object of, explanation of\\nforms in common use. Methods of packing tubes,\\npreventing crawling, and for good distribution of\\nthe steam.\\nSixth. Pumps Air, circulating, feed, and aux-\\niliary pumps Description of the varieties in\\ncommon use. Description of their connections,\\nas of air and circulating pumps to the condenser.\\nVacuum, how produced value of and how af-\\nfected by derangement of pumps or peculiarities\\nof working of engine.\\nSeventh. Propelling instruments, including screw\\nand paddle wheel Description of the forms in", "height": "2927", "width": "1815", "jp2-path": "ropersquestions00rope_0170.jp2"}, "171": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 155\\ncommon use and explanation of the advantages of\\nforms now in use over older ones. Description of\\nmethods of securing propelling instruments to\\nshafts and of bearings for same.\\nEighth. Electric machinery: Practical descrip-\\ntion of dynamo-electric machines as fitted on board\\nship and of the parts requiring adjustment. Acci-\\ndents likely to occur to dynamos, and what to do\\nto remedy them. Practical points on the wiring\\nof ships, and points to be looked after to insure\\ngood working. Electric lamps and connection to\\nmains.\\nXinth. Refrigerating and hydraulic machinery:\\nDescription of the forms commonly fitted on board\\nship. Description of process of working and state-\\nment of points to be looked after to insure good\\nworking.\\nTenth. Care of machinery: This will include\\nquestions in regard to precautions to be observed\\nin raising steam so as to prevent injury to engines\\nand boilers; precautions to be observed to prevent\\nderangements while in operation procedure on\\nreaching port and laying up for a few days; and\\nprocedure when engines and boilers are to be laid\\nup for a long period, say of several months or more.\\nEleventh. Accidents liable to occur, even with\\ncare, and how to remedy them.\\nTwelfth. Accidents liable to occur due to care-\\nlessness or neglect, and what should be done if\\nthey do occur.\\nThirteenth. Accidents that have occurred in ap-\\nplicant s own experience, or of which he knows,\\nand what was done to remedy them.", "height": "2881", "width": "1819", "jp2-path": "ropersquestions00rope_0171.jp2"}, "172": {"fulltext": "156 QUESTIONS AND ANSWERS FOR\\nFourteenth. List of machine and hand tools\\nusually carried on board ship, and general idea of\\nwork that can be done on board in any case of\\nnecessity.\\nFifteenth. Economy in the use of stores. Tell\\nhow engines should be run, firing of furnaces con-\\nducted, and lubrication looked after and regulated\\nso as to secure the best economy. Effect of change\\nof pitch of propeller on econonw. Also of varia-\\ntion in ratio of heating to grate surface.\\nSixteenth. He must be acquainted with the\\nprinciples of expansion and the modern theory of\\nheat, and be able to solve, with the assistance of\\nhis own books or without books, according as the\\nexamination papers may be set, questions in econ-\\nomy and duty in connection with engines and\\nboilers.\\nSeventeenth. He must understand how to apply\\nthe indicator and to draw the proper conclusion\\nfrom diagrams, and to construct the approximate\\ndiagrams for any given data.\\nEighteenth. He must be able to produce, with-\\nout a copy, a fair working drawing of any of the\\nmachinery, with figured dimensions fit to work\\nfrom.\\nNineteenth. Strength of materials: Calculations\\nfor thickness of boiler shells, size of bolts to stand\\na given strain, and so forth.\\nTwentieth. Inspection of coal, oil, and so forth.\\nPoints to be desired and those to be avoided.\\nTwenty-first. He must be able to explain the\\nformation of scale and the precipitation of salt.\\nand the precautionary means adopted in respect", "height": "2927", "width": "1815", "jp2-path": "ropersquestions00rope_0172.jp2"}, "173": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 157\\nthereto, with jet condenser and with surface con-\\ndenser.\\nTwenty-second. He must understand the general\\nprinciples involved in the construction of the\\nvacuum and steam gauges, of the barometer, ther-\\nmometer, and salinometer.\\nTwenty -third. He must be familiar with the\\ngeneral results obtained from past experience in\\nrelation to corrosion, pitting, and galvanic action\\nin boilers, and the use of zinc and of soda in\\nboilers.\\nTwenty-fourth. He must possess an intelligent\\nknowledge of the properties of the lubricants,\\nboiler cements, and india rubber in general use in\\nsteamers.\\nTwenty-fifth. He must understand the cause of\\nspontaneous combustion and the formation of ex-\\nplosive gases in coal holes and the precautionary\\nmeasures proper to prevent accidents from these\\ncauses.\\nSec 167. Special examination for the two high-\\nest grades of chief engineer: First Theory of the\\nsteam engine. Explanation of the advantages of\\nmultiple expansion engines, steam jacketing, high\\nspeeds, and so forth.\\nSecond. Theory of boiler design and construc-\\ntion. Effect of changes in ratios of heating and\\ngrate surface area through tubes and chimney.\\nProduction of draft, natural and forced. Influence\\nof proportions on economy of steam production.\\nFeatures of design requiring special care to insure\\ngood circulation, prevent foaming, and so forth.\\nThird. Theory of boiler incrustation and corro-", "height": "2881", "width": "1819", "jp2-path": "ropersquestions00rope_0173.jp2"}, "174": {"fulltext": "158 QUESTIONS AND ANSWERS FOR\\nsion and explanation of means taken to prevent\\nand remedy effects of same.\\nFourth. Theory of condensers and connected\\npumps. Elements necessary to economy and effi-\\nciency.\\nFifth. Design of machinery and boilers of a\\ngiven power.\\nSixth. Strength of materials. Ability to calcu-\\nlate necessary size of any part of the machinery\\nand boilers.\\nSeventh. Theory of friction as presented in ma-\\nrine machinery: Anti-friction metals. Lubrica-\\ntion and lubricants, including inspection and tests\\nof latter.\\nEighth. Valves and valve gears. Thorough\\nknowledge of the various kinds, the theory of their\\naction, advantages and disadvantages, and what\\nconsiderations govern the choice of a particular\\nvalve gear for special use.\\nNinth. Theory of electric light installations on\\nboard ship, including details of dynamos, wiring,\\nsafety fuses, and so forth; care of dynamos; pre-\\ncautions to be followed in wiring and so forth.\\nTenth. Theory of refrigerating machinery and\\nprecautions to be looked after in its installation.\\nEleventh. Theory of hydraulic machinery, in-\\ncluding pumps, hoists, steering gear, and so forth;\\ndetails of installation and so forth.\\nTwelfth. Building machinery and erection of\\nsame on board ship. The applicant must be able\\nto tell the whole process of building any part of\\nthe machinery and boilers, and give the details of\\nits alignment and erection on board ship.", "height": "2927", "width": "1815", "jp2-path": "ropersquestions00rope_0174.jp2"}, "175": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 159\\nThirteenth. Questions on supposititious break-\\ndowns will be given, and the applicant asked for\\nhis explanation of the best method of repair, if a\\nrepair is practicable, or what should be done to\\nget the vessel into port if the break cannot be re-\\npaired.\\nFourteenth. Questions will be given to test the\\nability of applicant to estimate the time and cost\\nfor repairs to be made in port, full details of the\\nparts to be repaired being given.\\nQUESTIONS FOR THIRD ASSISTANT ENGINEERS.\\nQ. What is a damper, and where is it placed\\nA. A damper is an apparatus for controlling the\\nsupply of air to boiler furnaces. They are fitted\\nsometimes in the funnel and sometimes at the\\nmouth of the ashpit. They are to be closed\\nwhenever the engines are stopped; when there is\\npriming in the boiler, or in any case where it is\\ndesired to diminish combustion.\\nQ. When there are no dampers, what is done\\ninstead of closing the damper, and what is the\\nobjection to this\\nA. The doors of the smoke boxes and the fur-\\nnaces are opened. This is very objectionable, be-\\ncause the sudden rush of cold air striking the\\nheated surface of the boiler produces contractions\\nwhich are liable to result in cracked tubes or plates\\nand in leaks.", "height": "2881", "width": "1819", "jp2-path": "ropersquestions00rope_0175.jp2"}, "176": {"fulltext": "160 QUESTIONS AND ANSWERS FOR\\nQ. What are the necessary fittings of a marine\\nboiler\\nA. A funnel with its air casings, the up-takes,\\nsmoke-boxes, and doors, fire doors, bars, bridges;\\nmain stop-valves, safety valves, and thier drain\\npipes; feed check valves blow-off and scum\\ncocks; water gauge glasses, water gauge cocks, and\\nsteam whistle.\\nQ. Through what apparatus does the steam\\npass from the time it leaves the boiler until it re-\\nturns again\\nA. The boiler, steam pipes, cylinder, condenser,\\nair-pump, hot well and feed pump.\\nQ. How many blow-off cocks are there and why\\nA. One on the bottom of the boiler and one on\\nthe ship s side. When both are open water will\\nrun from the sea into the boiler if steam is not up;\\nif steam is up its pressure will blow the water out.\\nThe object of having two cocks is to provide\\nagainst one of them being open.\\nQ. Suppose that the upper cock of the water\\ngauge should be closed or choked up, where would\\nthe water stand\\nA. At the top of the glass.\\nQ. And if the upper one were opened with the\\nlower one closed\\nA. The water would remain at the same level\\nthat it had.", "height": "2927", "width": "1815", "jp2-path": "ropersquestions00rope_0176.jp2"}, "177": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 161\\nQ. In testing the height of the water by the\\ngauge cocks, which one would you open first and\\nwhat should come out\\nA. The bottom one. Water.\\nQ. Which one would you open next\\nA. The top one, and I should expect steam to\\ncome out.\\nQ. Suppose that water comes out of the top one\\nalso, what would you do\\nA. I would blow off until water was at the\\nproper level.\\nQ. Suppose that steam had come out the bot-\\ntom one, what would you have done\\nA. I would check the tires instantly, closing the\\ndampers, then I would draw them. I would shut\\ndown the engine, and as soon as the boiler had\\ncooled off would pump in water. I would examine\\nboth ends of the boiler to see if the tubes are leak-\\ning, and if they are, I would attempt to stop them\\nby expanding the ends; if this did not remedy the\\nleaking of all, I would plug up the worst ones.\\nQ. How would you change the water in the\\nboiler when the steam is up\\nA. By increasing the feed and opening the scum\\ncock.\\nQ. Suppose that the scum cock is stuck fast,\\nwhat would you do\\nA. I would open the blow-off cocks.", "height": "2881", "width": "1819", "jp2-path": "ropersquestions00rope_0177.jp2"}, "178": {"fulltext": "162 QUESTIONS AND ANSWERS FOR\\nQ. Suppose that upon attempting to relieve the\\npressure on the boilers through the safety valve\\nyou found that it was stuck, what would you do\\nA. I would check the fires and draw them, and\\nas soon as the boiler was sufficiently cool would\\nrepair the valve.\\nQ. What might be the effect of letting the water\\nin the boiler get too low\\nA. The top of the combustion chamber and the\\ntubes might be burned, or it might even cause an\\nexplosion.\\nQ. What might be the effect of too high water\\nin the boiler?\\nA. Priming, and possibly the breaking of the\\ncylinder head.\\nQ. Explain how you would proceed in starting\\na new fire in the boilers.\\nA. I would first see that the valves in the water\\ngauge were open and would try the gauge cocks.\\nHaving found that the water level was all right I\\nwould cover the grate bars with a thin layer of\\ncoal; then, if I had fire in another boiler, I would\\ntake two or three shovelfuls from this other\\nboiler and put it on the grate and throw on either\\nsoft coal and wood or shavings and then gradually\\nadd fresh coal. I would open the upper gauge\\ncock in the boiler so as to let the air that is con-\\ntained in the water escape.", "height": "2927", "width": "1815", "jp2-path": "ropersquestions00rope_0178.jp2"}, "179": {"fulltext": "STEAM EXGIXEEKS AND ELECTRICIANS. 163\\nQ. How would you clean your fires\\nA. I would let the fire burn down on one side\\nfrom front to back, meanwhile keeping the other\\nside in good condition; then I would pull out the\\nashes and clinkers from the side that had burned\\ndown, cleaning all the walls at the same time, and\\nWould pull over the good part of the fire from the\\nother side and put on fuel as fast as it was needed;\\nthen, after allowing the clinkers and ashes to cool,\\nI would pull them out, and proceed in the same\\nway as on the first side.\\nQ. What regulates the depth of fuel to be\\ncarried on the grates\\nA. The draft.\\nQ. What is priming, and what causes it\\nA. Priming is tlie carrying over of water from\\nthe boiler into the engine in the form of a spray. I*\\nmay be caused by poor design of the boiler giving\\ntoo small a steam space or, in a well-designed\\nboiler, it may be caused by canying the water at\\ntoo high a level and by irregular firing.\\nQ. How can you tell whether there is priming\\nor not\\nA. Priming often causes a clicking sound in the\\ncylinder of the engine. By opening a valve and\\nallowing steam to escape into the air the appear-\\nance of the jet will tell whether the steam is dry\\nor not. If it has a milky or cloudy appear-", "height": "2881", "width": "1819", "jp2-path": "ropersquestions00rope_0179.jp2"}, "180": {"fulltext": "164 QUESTIONS AND ANSWERS FOR\\nance close to the orifice there is evidently prim-\\ning.\\nQ. What would you do in case you found there\\nwas priming\\nA. I would open the cylinder drip cocks and\\nclose the damper of the boiler and lower the water\\nlevel.\\nQ. What sometimes causes the appearance of\\nflame at the top of a funnel, and is this desirable\\nor not\\nA. Whenever flames come out of the top of a\\nfunnel this shows that the gases have not been\\nunited within the combustion chamber as they\\nshould have been. The cause of this would be a\\ntoo small supply of air in the combustion chamber.\\nCombustion taking place outside of a boiler is\\nextremely undesirable, as it means a waste of fuel.\\nQ. How can you prevent salting of the boiler?\\nA. By scumming and blowing off a part of the\\nwater in the boiler.\\nQ. How can you tell the density of the water in\\nthe boiler\\nA. By the reading of the salinometer.\\nQ. What density is proper\\nA. A density such that the salinometer reads\\nabout\\nQ. How is the salinometer made, and how do\\nyou use it", "height": "2927", "width": "1815", "jp2-path": "ropersquestions00rope_0180.jp2"}, "181": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 165\\nA. The salinometer consists of a glass bulb car-\\nrying a weight on its bottom and a graduated\\nstem attached to its top, the graduations being\\nin 32ds or 33ds. To use it, all that is necessary\\nis to put it in a vessel of the fluid whose density\\nit is desired to know, and it will sink to the amount\\ncorresponding to the density. The reading of\\nthe stem, which is just even with the surface of\\nthe liquid, will tell what the density is.\\nQ. What are scum cocks\\nA. They are cocks placed on a boiler for the\\npurpose of getting rid of any dirt which may be\\nfloating on the surface of the water in the boiler;\\nthe} are placed, therefore, a little below the usual\\nwater line. They are connected by a pipe which\\nleads to another coo 1 on the vessel s side.\\nQ. When you receive an order to stop the\\nengines, what would you shut and what would you\\nopen?\\nA. I would shut the throttle valve and the sea\\ninjection valve and would also close the dampers.\\nI would open the safety valve.\\nQ. What would you do before starting an\\nengine\\nA, I would warm it up by opening the drain\\ncocks and blowing steam through it and the con-\\ndenser. I would also examine the various valves,\\nincluding the injection and discharge valves, to see", "height": "2881", "width": "1819", "jp2-path": "ropersquestions00rope_0181.jp2"}, "182": {"fulltext": "166 QUESTIONS AND ANSWERS FOR\\nthat they are open or free to open, as the case\\nmay be.\\nQ. Explain in detail what valves and cocks\\nshould be opened before starting the engine.\\nA. The main stop valve, the check valve, the\\ndrain cocks on cylinders and jackets, the blow-\\nthrough cocks, the sea inlet for circulating water.\\nQ. What would you do in case the engine were\\nracing\\nA. I would attach the governor, if there were\\none, and I would stand at the throttle valve ready to\\nclose it as the steam rises. I should also run with\\na lowered boiler pressure and would ease up on\\nthe injector.\\nQ, Why is soda sometimes put into a boiler, and\\nwhat kind of soda is used\\nA. Common washing soda is put in boilers in\\norder to neutralize any acid that may be in the\\nfeed-water which might cause pitting.\\nQ. How can you prevent the formation of black\\nsmoke\\nA. Black smoke is due to imperfect combustion\\nand can generally be prevented, partially, by ad-\\nmitting air into the combustion chamber so as to\\nunite with the combustion gases. There is usually\\nin marine boilers a small door underneath the rear\\nbridge which can be opened so as to admit the\\nnecessary amount of air.", "height": "2927", "width": "1815", "jp2-path": "ropersquestions00rope_0182.jp2"}, "183": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 167\\nQ. Suppose that one of a set of boilers does not\\nget the proper amount of feed, although the check\\nvalve is sufficiently open; what might cause this\\ntrouble\\nA. There are several possible causes, such as\\nleaky joints or pipes or feed pump glands or a leaky\\nfeed relief valve. It may be that the steam pres-\\nsure in this boiler is higher than in the others, or\\nthe suction may be partially closed up between\\nthe suction cock and hot well. The feed suction\\ndischarge valves may not be tight.\\nQ. About how many tons of coal should you\\nexpect to burn per day in six furnaces, each hav-\\ning a width of 3 feet and about the usual length\\nA. The usual length being about 6 feet, the\\ntotal grate area would be 6 X 3 X 6, or 108 square\\nfeet. Each square foot will burn about 15 pounds\\nper hour; therefore, the total number of pounds\\nburned per hour would be 1620. and per day of 24\\nhours would be 38,880. Since there are 2240\\npounds in a ton, the number of tons would be 17 J,\\nnearly.\\nQ. How many cubic feet are occupied by a ton\\nof coal\\nA. About 35.\\nQ. How would you calculate the amount of\\nstress on a boiler stay\\nA. Multiply the area (in square inches) of the", "height": "2881", "width": "1819", "jp2-path": "ropersquestions00rope_0183.jp2"}, "184": {"fulltext": "168 QUESTIONS AND ANSWERS FOR\\nspace supported by the stay by the pressure car-\\nried on the boiler, and divide the product by the\\narea of the stay.\\nQ. How would you calculate the proper weight\\nfor a lever safety valve so that it will blow off at\\na given pressure\\nA See Roper s Catechism, page 50.\\nQ. Su]3pose you have been using 8 gallons of\\noil a day, costing 85 cents per gallon, and you now\\nby more careful attention to the lubricators cut\\ndown the consumption to 6 gallons per day, but\\nyou use a little better oil, costing 95 cents per gal-\\nlon, what will be the difference in expense for one\\nmonth\\nA. The original cost per day was 85 times 8\\ncents, or $6.80.\\nThe cost with the new oil is 95 times 6\\ncents, or $5.70.\\nThe gain per day is $6.80 less $5.70, or\\n$1.10.\\nThe gain in one month is $1.10 times 30, or\\n$33.00: (Ans.)\\nQ. A vessel has, in order to complete her voyage,\\na distance of 2100 miles to go it actually takes\\n150 hours to make the run, what is the average\\nspeed per hour\\nA. 2100 -f- 150 13J miles per hour. (Ans.)\\nQ. From 7 a.m., on the 20th of June, to the 3d", "height": "2927", "width": "1815", "jp2-path": "ropersquestions00rope_0184.jp2"}, "185": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 169\\nof August, 10 p.m., the coal consumption was 3168\\ntons; the distance passed over in this time was\\n14,784 knots; what is the average consumption of\\ncoal and average speed\\nA. The time is 44 days 15 hours, or 1056 hours.\\nThe coal consumption per hour is 3168 -f-\\n1056, or 3 tons.\\nThe coal consumption per day is 24 X 3,\\nor 72 tons.\\nThe speed is 14,784 -v- 1056, or 14 knots per\\nhour. (Ans.)\\nQ. If the counter stands to-day at noon at\\n95,321 and to-morrow at noon it stands at 98,237,\\nwhat will be the average number of revolutions\\nper minute\\n98237\\n95321\\n60)243(4^ (Ans.)\\n240\\n12)2916(243\\n24\\n3\\n51\\n48\\n36\\n36\\nQ. Suppose at 10 a. m. the counter stands at\\n54,606, and the engine is making 60 revolutions\\nper minute, at what time will the counter stand\\n100,026?", "height": "2881", "width": "1819", "jp2-path": "ropersquestions00rope_0185.jp2"}, "186": {"fulltext": "170\\nQUESTIONS AND ANSWERS FOR\\nA. 100026\\n54606\\n60)757(12 hrs. 37 minutes.\\n60\\n60)45420(757\\n420\\n157\\n120\\nft\\n342\\n300\\n37\\n420\\n420\\n10.37 p.m.\\n(Ans.)\\nQ. Suppose that an engineer receiving\\nweek strikes for an increase of S3 per week;\\nidle for ten weeks, but at the end of that tir\\nceives employment at the higher rate, how loi\\nit take him to make up the wages he lost whiL\\nA. His lost wages are 15 X 10, or $150.\\nIt will take him 150-7-3 weeks, or 50\\nto make up for the lost time. (An\\nQ. Suppose that the rate of burning per\\nfoot of grate surface per hour is 20 pouin\\nsuppose that a ton of the coal used occ\\nspace of 40 cubic feet; how many cubic\\ncoal would be burned in ten hours on a\\nfeet by 3 feet?\\nA. 6 X 3 X 20 X 10, or 3600 nuif\\npounds of coal burned.\\n2240 pounds occupy 40 cubic feet, or 56\\npounds occupy 1 cubic foot.\\n3600 pounds occupy 3600 -r- 56, or 64$fc or\\n64-f- cubic feet. Ans.\\nd a\\ne is\\nre-\\nwill\\ndie?\\neeks\\nmare\\nf and\\nries a\\niet of\\nrate 6\\nof", "height": "2836", "width": "1778", "jp2-path": "ropersquestions00rope_0186.jp2"}, "187": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 171\\nQ. You have 6 furnaces, each 6 feet long by 3\\nfeet wide, the rate of burning is the same as the\\npn jecling question, and every pound of coal e vap-\\nor o+y 3S 9 pounds of water; how many tons of coal\\nwi be used in ten hours, and how many tons of\\nwa r will be evaporated\\nThe area of grates is 6 X 6 X 3, or 108\\nsquare feet.\\nThe number of pounds burned per hour is\\n103 X 20, or 2160.\\nThe number of pounds of water evaporated\\nis 2160 X 9, or 19,440.\\nThe number of tons of coal burned in 10\\nhours is 2160 X 10 -f- 2240, or 9^, or\\n91-i- tons.\\n?he number of tons of water evaporated is 9\\ntimes this amount, or 86-^f or 86-j-^- tons.\\n(Ans.)\\nQ. vessel starts on a voyage of 1200 miles\\nwith tons of coal after having steamed 500\\nmiles is found that 30 tons of coal have been\\nconsumed. If the remainder of the voyage is\\nma. the same rate of steaming, how much coal\\nwill be left at the end of the voyage\\nA. 30 -I- 5 6, the number of tons used per\\nhundred miles. Therefore, 1200 miles will require\\n12 X 6, or 72 tons. Hence, there will be 8 tons\\nleft at the end of the voyage.", "height": "2887", "width": "1781", "jp2-path": "ropersquestions00rope_0187.jp2"}, "188": {"fulltext": "3145 5905\\n2516 4480\\n172 QUESTIONS AND ANSWERS FOR\\nQ. In 24 hours steaming the tally of baskets of\\ncoal for each watch was 100, 105, 110, 107, 104,\\n103. If each basket weighed 45 pounds, what\\nwould be the consumption per day in tons\\nA. 100 629 2240)28305(12 tons 1425 lbs.\\n105 45 2240 (Ans.)\\n110\\n107\\n104\\n103 28305 1425\\n629\\nQ. An engineer who receives $15 per week lays\\naside of his pay; how many weeks will it take\\nhim to save up $250\\nA. 15 6 2J dollars, the amount saved per\\nweek 250 2-J- 100, the number of weeks\\nnecessary.\\nQUESTIONS FOR SECOND ASSISTANT ENGINEERS.\\n[In addition to the following, the candidate should be\\nprepared to answer the questions for third assistant engi-\\nneers.]\\nQ. Trace the passage of steam from the boiler,\\nnaming all the parts and valves which it passes\\nfrom the time it leaves the boiler until it comes\\nback as feed-water.\\nA. Steam passes from the dome or dry pipe\\nthrough the stop valve into the main steam pipe", "height": "2836", "width": "1778", "jp2-path": "ropersquestions00rope_0188.jp2"}, "189": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 173\\nfrom the main steam pipe it passes through another\\nstop valve, through a separator, through the throt-\\ntle valve into the steam chest; from the steam chest\\nit passes through the high-pressure steam valve,\\nthrough the steam port into the high-pressure cyl-\\ninder. It forces the piston to the end of its stroke\\nand then exhausts into the intermediate steam\\nchest or into the receiver. From here it passes\\nthrough the intermediate slide valve and steam\\nport into the intermediate cylinder, expands and\\ndrives the piston to the end of the cylinder and\\nexhausts into the low pressure steam chest where\\nit drives the piston over by its expansion and ex-\\npands into the condenser. It is there condensed\\nand passes the foot valve into the air-pump, and\\nthen through the air-pump bucket valve and head\\nvalve into the hot well. If a surface condenser is\\nused, the condensed steam is pumped by the feed\\npump through the feed pipe and relief valve\\nthrough a feed water heater and through another\\nlength of feed pipe past the check valve into the\\nboiler.\\nQ. What is a gusset stay, and where is it used in\\na boiler\\nA. It is a stay made of iron plate which is\\ncarried from the front or back of the boiler to the\\nboiler shell it is secured at each end by means of.\\nangle irons and rivets.", "height": "2887", "width": "1781", "jp2-path": "ropersquestions00rope_0189.jp2"}, "190": {"fulltext": "174 QUESTIONS AND ANSWERS FOR\\nQ. What is double riveting, and in what parts\\nof the boiler is it used\\nA. Double riveting consists of two rows of rivets\\nplaced either zigzag or opposite each other the\\ncurvilinear seams are double riveted as well as the\\nlongitudinal seams in the furnace chamber and\\nthe horizontal seams of the ends.\\nQ. What is calking, and how is it done?\\nA. Calking means the closing up of the seams\\nof boilers or iron vessels so as to make them\\nsteam- or water-tight. After the edges have been\\nplaced true and the plates riveted together, the\\nedges are calked by a hammer and chisel, the\\niron being struck with the chisel in such a way as\\nto close the joint.\\nQ. Describe as many different methods as you\\nknow of fastening the ends of the mainstays of\\nthe boiler, and state their relative merits.\\nA. First Forked eye-bolts are tapped into the\\nends of the boiler and secured to them by a nut: the\\nstay is secured at each end to them by a wrought\\niron pin and cotter, which prevents the pin from\\ndrawing back this form is very convenient, as by\\ndriving out the end pins the stays can be gotten\\nout of the way in a few moments. Second The\\nend is made larger than the body of the stay and\\nis threaded it is then secured to the boiler by nuts\\nand washers inside and out. This arrangement", "height": "2836", "width": "1778", "jp2-path": "ropersquestions00rope_0190.jp2"}, "191": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 175\\nis mechanically good, but is somewhat difficult to\\nremove. Third: The ends of the stay are made\\nwith a T head and are fastened between a pair\\nof angle irons with rivets and bolts.\\nQ. What is a rivet stay, and where are such\\nstays commonly used\\nA. A rivet stay consists of a long rivet passing\\nthrough a thimble, or distance piece of iron which\\nis placed between the plates to be stayed together.\\nThe ends of the rivets are then headed over in the\\nusual way. The more common plan, however, is\\nto tap both plates and thread the rivet, screwing the\\nrivet through both plates and afterward heading\\nthe ends of the rivet over, which does away with\\nthe necessity of using the thimble.\\nQ. Where do boiler tubes generally leak, what\\nare some of the causes, and how is the trouble\\nrepaired\\nA. Tubes usually leak at the combustion cham-\\nber end. Leaks are caused by allowing the\\nplates and ends of the tubes to become foul,\\nin which case they are liable to be overheated;\\nanother cause is blowing off of boilers under\\nsteam pressure. The trouble may be repaired\\nusually by expanding the tubes. When they are\\nmuch worn they should be driven in slightly from\\nthe smoke box end and re-expanded and rebeaded.\\nQ. Where do the tube sheets usually crack?", "height": "2887", "width": "1781", "jp2-path": "ropersquestions00rope_0191.jp2"}, "192": {"fulltext": "176 QUESTIONS AND ANSWERS FOR\\nWhat are the reasons, and what methods are em-\\nployed for repairing\\nA. The tube sheets generally crack in between\\nthe tubes. The cracks are caused sometimes by\\nallowing scale to collect on the inside of the\\nsheet or by the opening of furnace doors, which\\nallows a current of cold air to strike the heated\\nmetal and produces contractions of the plates.\\nOne method of repairing is to cut a hole in a plate\\nlarge enough to encircle the tube nearest the crack,\\nfastening this small plate on to the boiler sheet\\nso as to cover the crack.\\nQ. What part of a marine tubular boiler is the\\nfirst to be injured by low water?\\nA. The top of the combustion chamber.\\nQ. Why are blow-off cocks fitted to each boiler,\\nand how many are usually supplied\\nA. The blow-off cock is fitted to the bottom of\\nthe boiler shell, so that all deposit can be blown\\nout of the boiler at its lowest point. One blow-off\\ncock is fitted to each boiler, and is connected by\\npipe to a cock or valve in the ship s bottom.\\nQ. At what heights are water gauge cocks\\nplaced, and must the cocks themselves necessarily\\nbe placed at these heights?\\nA. There are usually three cocks, one of which\\nis placed at a height of about 3 inches above the top\\nof the combustion chamber; the next one at the", "height": "2836", "width": "1778", "jp2-path": "ropersquestions00rope_0192.jp2"}, "193": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 177\\nworking water level, and the third in the steam\\nspace. It is not absolutely necessary that the\\ncocks themselves should be placed at this level;\\nthey may be placed at any desired position, pro-\\nvided that a pipe extends from each of them into\\nthe boiler, having its open end at the heights given\\nabove.\\nQ. In a dead weight safety valve, how would\\nyou calculate the weight required\\nA. The weight is equal to the area of the valve\\nemployed by the pressure of pounds per square\\ninch at which the valve is to blow off.\\nQ. Of what should the rubbing surface of safety\\nvalves be\\nA. Of brass, gun metal, or nickel, so that\\nthey will not corrode and stick.\\nQ. Explain in detail the construction of the\\nglass water gauge and how it acts. To what de-\\nrangements is it liable, and how are these repaired\\nA. A water gauge consists of a long glass tube\\nfixed in a brass stuffing box at each end; these\\nstuffing boxes are usually connected together by\\nbrass columns, and the whole arrangement is\\nattached to the boiler shell, the stuffing boxes\\nhaving an opening into the boiler controlled by a\\nvalve whose stem is threaded into the boiler shell.\\nThe lower stuffing box also has a drain cock for\\nblowing out the glass. The purpose of the gauge\\n12", "height": "2887", "width": "1781", "jp2-path": "ropersquestions00rope_0193.jp2"}, "194": {"fulltext": "178 QUESTIONS AND ANSWERS FOR\\nis to show the level of the water in the boiler, and\\nas its bottom is in connection with the water\\nspace and its top with the steam space, the water\\nwill rise in the tube to the same height in the\\nboiler. The principal derangements are the\\nbreaking of the glass and choking up with im-\\npurities. When the glass breaks, the two cocks\\nwhich are connected with the boiler are clos\\nand a new glass is put in. If it becomes choked up\\nwith dirt, it may be cleaned by opening the drain\\ncock and allowing the steam and water to rush\\nthrough the glass.\\nQ. You will sometimes see water gauges with\\npipe connections to the top and bottom instead of\\nwith a direct connection into the boiler what is\\nthis arrangement, and what is its advantage\\nA. One pipe runs to the steam dome and the\\nother to the bottom part of the boiler; the object\\nbeing to prevent, so far as possible, certain dis-\\nturbances in the water level in the glass, which,\\nwith the original arrangement, might be caused\\nby priming or by the boiling of the water.\\nQ. Why do some steam gauges have an inverted\\nsyphon pipe below them\\nA. The syphon contains water whose object is\\nto prevent the heat of the steam from injuring the\\nmachinery of the gauge.\\nQ. W T hen the syphon is used, why is a small", "height": "2836", "width": "1778", "jp2-path": "ropersquestions00rope_0194.jp2"}, "195": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 179\\ncock put on the pipe leading to the steam\\ngauge\\nA. This cock is a drain cock on the boiler side\\nof the syphon, placed at a level equal to the\\nhighest point to which water can rise in the other\\nleg. Without this cock the indicated pressure will\\nbe too high, owing to the weight of the water which\\nwould collect in the boiler leg of the syphon.\\nQ. What is meant by the salting of a boiler,\\nand how is it prevented?\\nA. Salting means allowing the water in the\\nboiler to become very dense. It is prevented by\\noccasionally blowing off a portion of the water in\\nthe boiler and taking in water which is less\\nsaline.\\nQ. What is the difference between the formation\\nof scale and salting of the boiler\\nA. Salting is the gradual increase in the density\\nof the water owing to the salt being left behind\\nwhen the water is turned into steam, whereas\\nscale is the deposit of insoluble substances like\\nlime and magnesia on the heating surface.\\nQ. What is the density of ordinary sea water,\\nand how is it ascertained\\nA. About one part of salt to 33 parts of water,\\nor about 5 ounces per gallon. The density is as-\\ncertained by a salinometer, which consists of a\\nfloat and graduated stem.", "height": "2887", "width": "1781", "jp2-path": "ropersquestions00rope_0195.jp2"}, "196": {"fulltext": "180 QUESTIONS AND ANSWERS FOR\\nQ. At what density should boilers be worked\\nA. In general, at a density not exceeding ^3,\\nor 10 ounces of salt per gallon.\\nQ. What are scum cocks, and how are they ar-\\nranged and used\\nA. Scum cocks are cocks placed on the shells of\\nthe boiler and connected to a pipe leading to the\\nship s side on which a cock is placed. From the\\ncock on the boiler shell pipes lead into the boiler\\nand are fitted on the end with a dish or trough\\nslightly below the ordinary water line. The. scum\\ncocks are used to remove dirt floating on the water\\nsurface and also a portion of the salt which is\\ncarried up b} the steam bubbles to the surface.\\nQ. What is boiler scale, and what bad effects\\ndoes it produce\\nA. Scale is produced by deposition of the im-\\npurities contained in feed- water, and usually con-\\nsists of a mixture of magnesia and lime salts and\\nsome common salt. It naturally collects at the\\nhottest part of the boiler and causes the plates to\\nburn, tubes to leak, and also diminishes the effi-\\nciency of the boiler.\\nQ. Explain how the formation of scale can be\\nbest prevented and how it is removed from the\\nboiler.\\nA. It is prevented best by never wasting any\\nsteam or water in vessels which have a surface", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0196.jp2"}, "197": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 181\\ncondenser. With a jet condenser frequent blow-\\ning off is employed to prevent it. When scale is\\naccumulated it is removed by chipping it off with\\nhammers or a long chisel.\\nQ. Explain how you would proceed to stop a\\nleak from a split tube.\\nA. I would close the ashpit doors and drive\\ninto the tube a plug of soft wood at each end of\\nthe tube the plugs will swell up owing to the\\nmoisture, and the tube will fill up with solid sub-\\nstances which will stop the leak.\\nQ. Describe the piston of a steam cylinder.\\nA. The piston usually consists of a cast-iron\\ndisc stiffened with strong ribs. The disc is turned\\nto an accurate circle on its outer edge, having\\ngrooves in it to receive the piston rings. The pis-\\nton rings are made with a slight opening and\\nspring so that they press out against the cylinder\\nsurface and make a steam ij pe joint.\\nQ. For what are cylinder drain cocks used, and\\nwhy is a valve sometimes placed on them\\nA. Drain cocks are used for blowing out any\\nwater that may collect in the cylinders through con-\\ndensation or on account of priming. In the case of\\ncondensing engines a valve is fitted to them which\\nopens outward only, the object being to allow the\\nw r ater to be blown without permitting any air to\\nrush in which would impair the vacuum.", "height": "2887", "width": "1781", "jp2-path": "ropersquestions00rope_0197.jp2"}, "198": {"fulltext": "182 QUESTIONS AND ANSWERS FOR\\nQ. Explain how a cylinder escape valve is made,\\nand for what it is used.\\nA. A cylinder escape valve consists of the valve\\nseat and valve, the latter being loaded with the\\nspiral spring. The amount of load is regulated\\nby means of a screw which passes through the\\nvalve cover and presses on the disc which fits on\\nthe top of the spring. The object of the valve is\\nto form a self-acting relief which will allow any\\nsudden accumulation of water from priming or\\nother cause to pass out of the cylinder without\\ndamage. These valves are covered with guards or\\ndomes with an escape pipe, so that the hot water,\\nwhich is ejected from them, may not be thrown\\nover the attendant.\\nQ. What is the object of using multiple expan-\\nsion engines?\\nA. In order to obtain a greater economy in\\ncoal consumption. Other things being equal, the\\neconomy depends upon the difference between the\\ntemperature at which steam is taken into the\\ncylinder and that at which it is exhausted. Since\\nthe lowest possible temperature is that corre-\\nsponding to the absolute vacuum, it is obvious\\nthat in order to make the difference of tempera-\\nture great, we must admit the steam at a high\\npressure; but if the steam underwent its entire\\nexpansion in a single cylinder there would be a", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0198.jp2"}, "199": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 183\\ngreat deal of condensation in the cylinder, since\\nthe incoming high pressure steam would come\\nin contact with comparatively cold walls the\\nexpansion is therefore divided between two or\\nmore cylinders. A further advantage of having\\nseveral cylinders is that the cranks are placed at\\nan angle to each other, and more uniform turning\\nmoment is secured.\\nQ. When engines are to be stopped with steam\\nup, what would you close and what open\\nA. I would close the throttle valve and the sea\\ninjection valve, and unless I were sure that the\\ncheck valves on the boilers were tight, I would\\nshut the feed so that no water would be lost from\\nthe boilers by blowing through the check valves.\\nI would also close the damper doors; it might be\\nadvisable also to open the safety valve.\\nQ. What would you do before starting\\nA. I would open the drain cocks and blow\\nsteam through the cylinders and condenser so as\\nto gradually warm them up. I would examine\\nthe valves to see that the proper ones were opened,\\nas, for example, the feed check valves, the injec-\\ntion and discharg3 valves, and would then gradu-\\nally turn the engine around.\\nQ. What is the racing of an engine, and what\\ndanger is attached to it What can be done to\\nprevent it", "height": "2887", "width": "1781", "jp2-path": "ropersquestions00rope_0199.jp2"}, "200": {"fulltext": "184 QUESTIONS AND ANSWERS FOR\\nA. The racing of an engine is the revolution of\\nthe engine at a very rapid rate, and is caused by the\\npropellor coming out of water owing to the pitch-\\ning of the ship. The racing causes sudden and\\nheavy strains on the machinery, such as may cause\\na breakdown, unless the most careful attention\\nis given by the engineer. A governor is often\\nfitted to the engines. In any case I would pro-\\nceed under easy steam and should cut down the\\nsupply of injection water.\\nQ. What kind of a governor is employed\\nA. A centrifugal governor.\\nQ. With a surface condenser, what valves should\\nbe open some time before starting an engine\\nA. The main stop valve and the main check\\nvalves to the boiler, the sea inlet for the circu-\\nlating water, and all drain cocks on the cylinders\\nand jackets. The discharge valves should be ex-\\namined to see if they are free to lift.\\nQ. What is a steam jacket, and wh}^ is it\\nused? With what engines are they generally\\nfound\\nA. The steam jacket is a casing around a cylin-\\nder, leaving a hollow space between it and the\\ncylinder, which is kept supplied with steam from\\nthe boiler. The object of a steam jacket is to\\nprevent, as far as possible, condensation in the\\ncylinder. Jackets are generally found with multi-", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0200.jp2"}, "201": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 185\\npie expansion engines. They are covered with felt\\nor some other non-conductor to prevent the radia-\\ntion of heat.\\nQ. What cocks are found on steam jackets, and\\nwhy\\nA. The steam jacket is supplied with a steam\\ncock for turning on and shutting off steam from\\nthe boiler, and also with drain cocks, so that any\\naccumulation of water in the jacket may be blown\\noff into the hot well.\\nQ. Name the principal j^ipes used with the en-\\ngines and boilers of a steamer, and tell to what\\nthe ends of the pipes are connected.\\nA. The main steam pipe connecting the stop\\nvalve on the boiler to the steam chest on the\\nengine. Donkey steam pipe connecting the donkey\\nstop valve of the boiler to the donkey steam\\nchest. Cylinder jacket pipe running from the\\nboiler to the jacket of the cylinder. Steam whistle\\npipe, pipes for any engines, or winches on deck a\\nfeed pipe connecting boiler with the feed pumps.\\nCirculating water pipe connecting the inlet on the\\nvessel s side with the circulating pump; feed suc-\\ntion pipes connecting suction of the pumps and\\nthe hot well. A pipe connecting the air pump\\ndischarges with a valve on the ship s side and the\\nhot well. Cylinder drain pipes connected to the\\ndrain cocks and the hot well blow-off and scum", "height": "2887", "width": "1781", "jp2-path": "ropersquestions00rope_0201.jp2"}, "202": {"fulltext": "186 QUESTIONS AND ANSWERS FOR\\npipes connecting the cocks on the boiler to cocks\\non the ship s side.\\nQ. Trace the passage of the circulating water for\\nthe surface condenser through the valves and pipes\\nthat it passes.\\nA. The water is taken from the sea through a\\nvalve on the ship s side, passes through or around\\nthe condenser tubes to the foot valve of the circu-\\nlating pump, then through the pump, cylinder,\\nand head valve, and back through the discharge\\nvalve on the ship s side.\\nQ. What is the path of steam from the boiler\\nuntil it gets back to the hot well\\nA. It passes through the main valve on the\\nboiler, the main steam pipe and separator, if any,\\nthe throttle valve, valve chest, through the cylinder\\nor cylinders, through the exhaust pipe into the sur-\\nface condenser, and then falls to the bottom of the\\ncondenser in the form of water from there it is\\ntaken from the air pump and discharged into the\\nhot well.\\nQ. What is atmospheric pressure, how is it\\nmeasured, and what is its average value\\nA. Atmospheric pressure is the pressure due to\\nthe weight of the air. It varies with the height\\nabove sea level, having a value of about 14.7\\npounds\u00c2\u00abat sea level and growing less as the height in-\\ncreases. It is measured by means of the barometer.", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0202.jp2"}, "203": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 187\\nQ. What is absolute pressure, and is absolute\\npressure shown by the steam gauge\\nA. Absolute pressure is the pressure above a\\nperfect vacuum. The steam gauge which under\\nthe pressure of the atmosphere only reads zero\\ndoes not measure the absolute pressure in the\\nboiler. To obtain the absolute pressure it is nec-\\nessary to add the atmospheric pressure (about\\n14.7 pounds) to the reading of the steam gauge.\\nQ. What is a barometer, and for what is it used\\nA. A barometer is an instrument consisting of\\na glass tube, sealed at its upper end, properly\\ngraduated and partially filled with mercury. It is\\ninverted with its lower end immersed in a vessel of\\nmercury. It is employed to measure the pressure\\nof the atmosphere the greater the pressure of the\\natmosphere the higher does the column of mercury\\nstand in the tube.\\nQ. Can a barometer be used instead of a vacuum\\ngauge\\nA. Yes the top of the tube being connected\\nto the condenser instead of being sealed up.\\nThe height of the column then indicates vacuum\\nin the condenser instead of atmospheric pressure.\\nQ. Are the indications of both steam and vacuum\\nvaried by changes in the barometer, and if so, why\\nA. Yes if, for example, the reading of the\\nbarometer changes from 29 to 31 inches this would", "height": "2887", "width": "1781", "jp2-path": "ropersquestions00rope_0203.jp2"}, "204": {"fulltext": "188 QUESTIONS AND ANSWERS FOR\\ncorrespond to a change in atmospheric pressure of\\none pound, so that the steam gauge will read one\\npound too little and the vacuum gauge one pound\\ntoo much, since the position of the needle de-\\npends upon the difference between the pressure to\\nbe measured and the atmospheric pressure.\\nQ. When the reading of the vacuum gauge is\\n20 inches, what will be the vacuum in the con-\\ndenser? Explain how you arrive at this result.\\nA. 20 inches corresponds to a pressure of 10\\npounds, and this is the difference in pressure be-\\ntween the atmosphere and the pressure in the\\ncondenser since the pressure of the atmosphere\\nis 14.7, the pressure in the condenser will be 14.7\\nminus 10, or 4.7 pounds,\\nQ. Explain the construction of the thermometer,\\nand state for what it is used.\\nA. A thermometer usually consists of a small\\nglass bulb communicating with a fine glass tube\\nair is exhausted from the tube which is partially\\nfilled with mercury. When it is exposed to heat the\\nmercury expands and rises in the tube, which is\\ngraduated. In the English or Fahr. scale the\\nposition at which the mercury stands when sur-\\nrounded by melting ice is marked 32; when im-\\nmersed in boiling water it is marked 212. The\\nintervening space between these two marks is\\ndivided into 182 equal parts, called degrees.", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0204.jp2"}, "205": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS 189\\nQ. A water ballast donkey pump has a diam-\\neter of 7 stroke of 15 and is double acting,\\nmaking 120 revolutions per minute. The cylin-\\nder is one-third empty each stroke. How long\\nwill it take to pump out 125 tons\\nA. The quantity of water pumped per stroke is\\n7 X 3i X V 5 cubic inches, or 110 cubic\\ninches. -7 1 x,7rs-4x jo m 3 4,s cuins.\\nThe quantity per minute is 110 X 240, or\\n26,400 cubic inches.\\n125 tons 125 X 2000 pounds.\\n125 X 2000 62| or 4000 number of\\ncubic feet in 125 tons.\\n4000 X 1728 -4- 26,400 number of min-\\nutes required 26 If f (Ans.\\nQ. A coal bunker 6 9 wide at the top and\\n5 3 at the bottom has a length of 20 3 and is\\n8 high how many tons of coal will it contain\\nA. The mean width is one-half 6 9 -f 5 3\\nor 6 feet.\\nThe cubic contents are 6 X 8 X 20J, or 972\\ncubic feet.\\nAt 40 cubic feet per ton the number of tons\\nwill be 972 40 24JJ, or 24^- tons.\\nQ. What will be the cost in dollars of a sheet\\nof lead 12 9 long by 8 4 broad by J thick,\\nat 9 cents per pound, the weight of a cubic foot of\\nlead being 691^ pounds", "height": "2887", "width": "1781", "jp2-path": "ropersquestions00rope_0205.jp2"}, "206": {"fulltext": "190 QUESTIONS AND ANSWERS FOR\\nA. 12 9 153 8 4 100 The num-\\nber of cubic inches is 153 X 100 X J, or\\n3825 cubic inches.\\nThe weight of a cubic inch of lead is\\n691 T 2 o- 1728, or T pound.\\nThe total weight of the lead is 3825 X tc\\nor 1520 pounds.\\nThe cost is 1520 X 9 cents, or 13,680 cents\\n136^ dollars. (Ans.)\\nQ. A spring-loaded safety valve has a waste\\npipe 20 feet high. If it became filled with water,\\nwhat extra pressure would be on the valve\\nA. y 4 oVo pound is the pressure due to 1 foot,\\n20 feet will cause X 20, or 8 ^V\\npounds pressure. (Ans.\\nQ. A tank 2 3 high, 2 6 wide, and 3 9\\nlong has 90 gallons of oil in it how far from the\\ntop is the oil\\nA. 2 3 27 2 6 30 3 9 45\\n90 X 231 20,790 number of cubic\\ninches in 90 gallons.\\n45 X 30 1350 number of square\\ninches in bottom of tank.\\n20,790 -r- 1350 15^, the number of\\ninches the oil will rise in the tank.\\n30 153% 4 5- 14^-? tne number of inches\\nthe oil is from the top.", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0206.jp2"}, "207": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 191\\nQ. Subtract 1 2| from 2 2f and multiply\\nremainder by 8.\\nA. 2 2f 2 2f 11\u00c2\u00a3\\n1 W 8\\nllf 95 (Ans.)\\nQ. If there are two bunkers each 5 6 wide by\\n14 3 high, what length must they have so as to\\ncontain 80 tons of coal? State how many cubic\\nfeet you allow per ton.\\nA. 5^ X 14J- 78f number of square feet\\nin each.\\n2 X 78f 156f number of square feet\\nin both,\\nAt 40 cubic feet per ton, 80 tons will occupy\\n3200 cubic feet.\\n3200 156f 20 3 T y nearly. (Ans.\\nQ. Add together the following 18 3J 3\\n9J 14 3 7^\\nA.\\nft\\n9 5 n. 7 Q 9\\nIS\\n3 1 18 33V\\n3\\n14\\n9i 3 9if\\n14\\n3\\nI\\n7 7 Q 71 4\\n16 32\\n9 5// 90\\n^3T ^3T\\n3A V 3 T V\\n47 Iff 47 1 f\\nQ. How many tons will be contained in a bun-\\nker 25 long, 18 6 high, having a width at the\\nbottom of 19 and at the top of 21", "height": "2887", "width": "1781", "jp2-path": "ropersquestions00rope_0207.jp2"}, "208": {"fulltext": "192 QUESTIONS AND ANSWERS FOR\\nA. The mean width is 20 feet. The cubic con-\\ntents will be 20 X 25 X 18J, or 9250\\ncubic feet.\\nAt 40 cubic feet per ton the number of tons\\nwill be 9250 -f- 40, or 231 tons. (Ans.)\\nQ. The broadest part of the coupling bolt has\\na diameter of 3fV, the diameter of the narrow-\\nest part is 2-J the length is 7J what is the\\ntaper per foot\\nA Q3 07 5 f\\nJi.. Oyg- L% yg-\\nT 5 g -J- 1\\\\ the taper per inch.\\nX 12 -T- 7J the taper per foot.\\nT V X 12 or 1\\n7 V -s- fi M of on e inch, or a\\nlittle over J (Ans.\\nQ. What is f of\\nT 2 2V\\nQUESTIONS FOR FIRST ASSISTANT ENGINEERS.\\n[In addition to these the candidate should be prepared\\nto answer the questions for third and second assistant engi-\\nneers.]\\nQ. Suppose you were put in charge of the\\nengines of a boat you were never on before and that\\nyou had a day s time before starting, what would\\nyou do on going into the engine room\\nA. I would trace all pipes and connections\\nto find out whence they come and where they", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0208.jp2"}, "209": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 193\\nlead, and would examine all the cocks and valves\\nin these connections I would then examine the\\nboiler, carefully taking off all the doors and going\\ninside to examine the stays and their fastenings\\nand the tubes and flues, taking a hammer with\\nme to sound the boiler plates I would then take\\nthe furnace bars out and the bridge down and go\\ninto the combustion chamber so as to examine\\ncarefully the ends of the tubes I would then\\ninspect all the valves and cocks on the boiler next\\nI would examine the engines, looking at the\\npiston and valve gear and at all parts where there\\nis any friction I would then examine the con-\\ndenser and the valves of all pumps finally, I\\nwould examine the shaft and its bearings and the\\nstuffing box.\\nQ. Explain in detail what occurs to coal when\\nit is burned in a boiler, tracing its passage from\\nthe furnace door to the stack.\\nA. Coal is thrown through furnace doors on the\\nfire the heat of the fire liberates the hydrogen\\nand hydrocarbon gases from the coal, and this as\\nwell as the pure carbon mixes with the oxygen\\nthat is contained in the air coming up through the\\ngrate bars these mixed gases burst into flame in\\nthe furnace and the products of combustion pass\\nthrough the tubes and flues, giving up a large\\namount of their heat to the water in the boiler\\n13", "height": "2887", "width": "1781", "jp2-path": "ropersquestions00rope_0209.jp2"}, "210": {"fulltext": "194 QUESTIONS AND ANSWERS FOR\\nthe products of combustion then pass into the\\nup-take and funnel and escape to the outside air.\\nQ. Where would you expect to find thin plates\\nin a boiler, and how would you detect the thin-\\nness\\nA. Plates usually become thin by wear in the\\nashpits, at the back of the combustion chamber,\\nin the shell at the water line, and a. little above\\nthe line of the fire bars in the furnace. A thin\\nplate can be detected generally by sounding with\\na hammer small holes can also be drilled at any\\npart that is suspected and of course afterward\\nplugged up.\\nQ. How are boiler tubes l fixed\\nA. They are driven from the smoke box end\\nthrough both tube plates until they project a little\\nover J of an inch into the combustion chamber\\nand remain about J inch outside of the tube plate\\nat the smoke box end the tubes are then\\nexpanded either by tapered drift or by a tube\\nexpander. The ends of the tubes in the combus-\\ntion chamber are then beaded over, while those\\nat the other end are sometimes left without bead-\\ning, so that in case of leakage the tubes may be\\ndriven in and beaded again.\\nQ. What is a superheater, and how is it con-\\nstructed\\nA. A superheater is an apparatus placed in the", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0210.jp2"}, "211": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 195\\nup-take or at the base of the funnel, so arranged\\nthat the products of combustion pass around and\\nthrough it before they escape up the chim-\\nney. Its purpose is to impart an additional\\namount of heat to the steam from the boiler\\nbefore it passes to the engine. A simple form of\\nsuperheater consists of a wrought-iron drum built\\nwith tubes the products of combustion pass\\nthrough the tubes and around the shell, the steam\\nbeing inside the drum.\\nQ. What fittings should a superheater have\\nA. It should have a valve for cutting off steam\\nconnection from the boiler and also from the\\nengine. It should also have a by-pass, so that the\\nsuperheater may be thrown out of action. It also\\nrequires a safety valve and a gauge glass, the lat-\\nter being for the purpose of showing whether the\\nsuperheater is clear of water, as excessive priming\\nmay sometimes fill it.\\nQ. What causes a draught in a funnel\\nA. The difference in weight between the hot\\ngases in the funnel and the weight of a column of\\nexternal air of the same volume.\\nQ. The draught is sometimes checked, what is\\nthe cause of it? What symptoms would you\\nnotice, and how would you remedy the trouble?\\nA. The draught is sometimes checked by a down-\\nward current of air meeting the upward rush of hot", "height": "2887", "width": "1781", "jp2-path": "ropersquestions00rope_0211.jp2"}, "212": {"fulltext": "196 QUESTIONS AND ANSWERS FOR\\nair as it ascends the chimney, the action being ac-\\ncompanied by a buzzing noise. This down draught\\nis the result of the admission through the furnace of\\ntoo small a quantity of air to supply the exhaust,\\ndue to the ascending column of hot air in the fun-\\nnel the down draught can therefore be stopped\\nby partially closing the damper and opening the\\nfire doors.\\nQ. What parts of a steam plant should be cov-\\nered with non-conducting covering, and why\\nA. The boiler, the up-takes, base of the funnel,\\nall steam pipes, the cylinders, the heaters, separa-\\ntors, and, in general, all apparatus that has steam\\ninside of it. The object of a covering is to pre-\\nvent, so far as possible, the radiation of heat.\\nSuch radiation would not only make the boiler\\nand engine room excessively hot, but would also\\nresult in the waste of fuel.\\nQ. What substances are used for making non-\\nconducting coverings\\nA. Asbestos, hair felt, mineral wool, and mag-\\nnesia are the most common.\\nQ. Do steam gauges indicate the total pressure\\nof the steam\\nA. Steam gauges indicate the pressure of\\nsteam above the atmosphere only, and their indi-\\ncations are therefore about 14.7 pounds below the\\nvalue of the total pressure.", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0212.jp2"}, "213": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 197\\nQ. For what purpose is a salinometer used, and\\nhow is it constructed\\nA. A salinometer is an instrument used to\\nfind out the density of water. It consists of a\\nweighted bulb attached to a graduated stem.\\nQ. Explain the action of the salinometer and\\nhow it is graduated to read.\\nA. The salinometer indicates the amount of\\nsalt or other matter held in solution in the water\\nby the depth to which it sinks. The fresher the\\nwater, the lower it will sink. It is graduated in\\n32ds, each 32d representing about 5 ounces of\\nsalt per gallon of water.\\nQ. What is necessary in order that the sali-\\nnometer give correct indications\\nA. It must be used at the temperature at which\\nit is marked.\\nQ. Suppose that the check valve of one of a\\nset of boilers should have a piece broken off the\\nvalve, what trouble would this cause, and what\\nwould you do to remedy it\\nA. The boiler whose check valve is broken\\nwould get more than the proper amount of the\\nfeed water, while the other boilers would have a\\ngreat difficulty in getting sufficient amount. To\\nremedy this, I would close the broken valve par-\\ntially and, if possible, would open up the other\\nvalves more than before.", "height": "2887", "width": "1781", "jp2-path": "ropersquestions00rope_0213.jp2"}, "214": {"fulltext": "198 QUESTIONS AND ANSWERS FOR\\nQ. In modern marine engines, when a link\\nmotion is not used, what takes its place\\nA. Some patent valve gear, such as Joy s.\\nQ. What causes the friction on a slide valve,\\nand how can the amount of this friction be re-\\nduced\\nA. The friction is caused by the action of the\\nsteam on the unbalanced area of the slide valve,\\npressing it against the valve seat with a force that\\nis equal to this area multiplied by the steam pres-\\nsure. This friction can be diminished by reliev-\\ning the back of the valve from the steam pressure;\\nthis is accomplished by forming a vacuum or ex-\\nhaust steam pressure space at their backs by\\nmeans of a brass packing held up to the valve\\nwith springs or india-rubber. This space is put\\ninto communication with the condenser or exhaust,\\nand therefore a pressure equal to the vacuum\\ntends to lift the valve from its seat.\\nQ. Explain how you could measure the travel\\nof the eccentric rod.\\nA. The travel of the eccentric rod is the dis-\\ntance moved by the rod on the up or down-stroke.\\nIf the sheave be off, the travel can be measured\\nby measuring the distance between the shaft\\nopening and the center of the eccentric disc\\nthis multiplied by 2 will give the travel of the\\nrod. If the sheave cannot be conveniently taken", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0214.jp2"}, "215": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 199\\noff the shaft the travel can be measured in this\\nway: Subtract the width, of the thickest part of\\nthe sheave from the broadest part, and the re-\\nmainder will be the full travel.\\nQ. Explain the construction of the surface\\ncondenser.\\nA. A surface condenser consists of an iron box\\ncontaining a large number of tubes these tubes\\nmay be either horizontal or vertical, and are\\nmade of brass. At each end of the tubes are\\ntube plates through which the tubes pass, there\\nis often a supporting plate in the middle. At\\neach end of the condensers are doors or openings,\\nso that the ends of the tubes may be examined or\\nrepaired when necessary. In some cases steam is\\nadmitted to the tubes, and the injection water\\npasses around the outside of the tubes; in other\\ncases steam is led into the space around the tubes,\\nand water passes through them, the latter practice\\nbeing the more general.\\nQ. Suppose that a tube splits, what would you\\ndo?\\nA. I would drive in a wooden plug at each end,\\nand keep it there until I had an opportunity of\\ntaking out the tube and replacing it with a new\\none.\\nQ. Where do surface condensers become foul,\\nand how are they cleaned?", "height": "2887", "width": "1781", "jp2-path": "ropersquestions00rope_0215.jp2"}, "216": {"fulltext": "200 QUESTIONS AND ANSWERS FOR\\nA. Surface condensers become foul both on the\\ninside and outside of tubes. The outside of the\\ntube has a deposit owing to. the salt water the\\nsteam side of the tube fouls owing to the action\\nof the grease and oil that are in the steam coming\\nfrom the cylinders. The condensers are cleaned 1 1 y\\nscalding them with hot water taken from the boiler\\nwith a hose. Caustic soda is also generally used.\\nQ. What is a vacuum, and with what appar-\\natus is it produced\\nA. A vacuum is a space devoid of pressure. It\\nis impossible to produce a perfect vacuum, but a\\npartial vacuum is produced by means of a con-\\ndenser and air pump.\\nQ. Explain how you would proceed to produce\\na vacuum with a jet condenser.\\nA. I would first open the blow-through valve,\\nallowing the steam to blow out all air and water\\nin the condenser and at the same time to warm\\nthe condenser up; as soon as steam issues from\\nthe snifting valve I would shut the blow-through\\nvalve and open the injection cocks the cold\\nwater will then mix with the steam, condense it\\nand form a vacuum. As soon as the gauge shows\\na sufficient vacuum I would shut off the injection\\ncocks, so as to prevent the condenser s filling.\\nQ. Explain the method of operation if the\\ncondenser were of the surface type.", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0216.jp2"}, "217": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 201\\nA. Some time before starting I would open the\\ninjection valve, so that the circulating water\\nmight enter the injection tubes and cool them\\nthen as soon as the engines are started the steam\\ncoming in contact with these cold tubes will be\\ncondensed, and after the first two or three turns\\nof the engine the condenser will be clear.\\nQ. How is the vacuum maintained\\nA. By the constant condensation of the used\\nsteam by means of cold water or cold tubes and\\nby constant clearing of the condenser by the air\\npump.\\nQ. Why does the condensation of steam make\\na vacuum\\nA. Because a cubic foot of steam when con-\\ndensed into the form of water occupies only about\\none cubic inch of space.\\nQ. What is the advantage of a surface con-\\ndenser over the jet condenser?\\nA. The injection water is not mixed with the\\nwater of condensation; the boilers are therefore at\\nall times supplied with fresh water, thus prevent-\\ning the formation of scale, increasing the dura-\\nbility of the boiler, and making a saving in the\\nconsumption of fuel.\\nQ. Explain the meaning of the terms injec-\\ntion water and water of condensation,\\nA. Injection water is the water introduced", "height": "2887", "width": "1781", "jp2-path": "ropersquestions00rope_0217.jp2"}, "218": {"fulltext": "202 QUESTIONS AND ANSWERS FOR\\ninto the condenser for the purpose of condensing\\nthe steam; water of condensation is the water\\nresulting from the condensation of the steam itself.\\nQ. About how much injection water is neces-\\nsary to condense steam\\nA. About twenty-five times the amount of the\\nwater of condensation.\\nQ. Has the air pump as much duty to perform\\nin the case of surface condensers as with jet con-\\ndensers\\nA. No with surface condensers the air pump\\nhas only to extract the air and the water of con-\\ndensation in the case of the jet condensers it has\\nnot only to extract this, but also the injection\\nwater.\\nQ. How is the amount of vacuum in the con-\\ndenser determined\\nA. By the vacuum gauge.\\nQ. What is the meaning of a reading of 16\\ninches on the vacuum gauge\\nA. Two inches of mercury corresponds closely\\nto 1 pound of vacuum therefore 16 inches of\\nmercury represents 8 pounds vacuum, that is to\\nsay, a pressure 8 pounds less than atmospheric\\npressure, or a pressure of about 6. 7 pounds abso-\\nlute.\\nQ. What is a circulating pump For what pur-\\npose is it used, and how is it driven", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0218.jp2"}, "219": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 203\\nA. A circulating pump is one used to cause\\nwater from the sea inlet to circulate through the\\ncondenser tubes; it is operated sometimes by a\\nlever connected to the main engine, and in other\\ncases by means of an independent engine.\\nQ. Why is an air valve sometimes fitted to a\\ncirculating reciprocating pump\\nA. So that the air will tend to obviate the solid\\nresistance that would otherwise be offered by the\\nwater.\\nQ. Explain the difference between a bucket air\\npump, a piston air pump, and a plunger air pump.\\nA. A bucket air pump has a brass piston\\npacked with a spun-yarn gasket to keep it tight\\nthe body of the bucket has perforations allowing\\nwater to pass through on the down stroke. The\\naction of the pump is as follows On the down\\nstroke the water rushes through the perforations\\nof the bucket, and as soon as the up-stroke be-\\ngins the weight of the water forces down the\\nindia-rubber valve the bucket lifts the water up\\nand discharges through the head valve the water\\nthat was taken in through the bucket on the\\ndown stroke at the same time a vacuum is cre-\\nated on the under side of the bucket, into which\\nthe condensed water and air flow from the con-\\ndenser ready to be taken by the bucket on the\\nnext down stroke.", "height": "2887", "width": "1781", "jp2-path": "ropersquestions00rope_0219.jp2"}, "220": {"fulltext": "204 QUESTIONS AND ANSWERS FOR\\nA piston air pump, usually a double-acting\\npump, has suction and delivery valves at both\\nends. The bucket in this case is solid, and the\\nwater is taken and forced out of the pump on\\nboth the outward and return strokes.\\nA plunger air pump has a solid plunger or ram\\nworking through a bushing.\\nQ. When the condenser is working and the air\\npump bucket is at the top of its stroke, at what\\nheight will the water stand in the condenser, as\\ncompared with the level of water in the air-pump\\nchamber\\nA. The comparative level in the two places de-\\npends upon the intensity of the vacuum existing\\nin the two places, that in the chamber being\\nalways the best. If the vacuum in the pump\\nwere 29 inches and that in the condenser 28\\ninches, the difference in vacuum would be 1 inch\\nor pound, which corresponds to a difference in\\nlevel of water of 1.1 feet, so that the level in the\\ncondenser would be that amount below the level\\nin the pump.\\nQ. With a surface condenser and single-acting\\nair pump, what would be the effect of a leaky foot\\nvalve? What would be the effect of a leaky\\nbucket if there is also a foot valve\\nA. Provided the foot valve is sufficiently im-\\nmersed in water, its leaking will not affect the", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0220.jp2"}, "221": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 205\\nworking of the pump the effect of a leak in the\\nbucket depends upon whether the pump is work-\\ning to its full capacity. In ordinary cases the\\nair pump never works anywhere nearly full of\\nwater. Suppose that the pump ought to lift, say,\\none gallon of water each stroke and by reason of\\nthe leak one-half gallon passed back, then the\\nwater would rise in the condenser high enough\\nso that the bucket would lift one and one-half\\ngallons; but as one-half would be allowed to pass\\nback through the leak, the proper amount of one\\ngallon would be actually left at each stroke. In\\ncase the pump were working at its full limit and\\nthe bucket were leaky, the condenser would grad-\\nually fill up.\\nQ. What is the temperature at which water\\nusually stands in the hot well What would be\\nthe effect of temperature lower or higher than\\nthis amount\\nA. The temperature usually varies from 110 to\\n130 degrees. A higher temperature than this is\\nliable to cause a deterioration of valves, and a\\nlower temperature will produce an increase in the\\nconsumption of fuel.\\nQ. How could you tell whether the inlet valve\\nof the circulating pump were open to the proper\\namount\\nA. By the vacuum gauge and by the condenser.", "height": "2887", "width": "1781", "jp2-path": "ropersquestions00rope_0221.jp2"}, "222": {"fulltext": "206 QUESTIONS AND ANSWERS FOR\\nIf the valve is open too little, the condenser will\\nget hot and a low vacuum will result if the\\nvalve is too far open, the condenser will get too\\nmuch water and will become cold, although the\\ngauge will show a good vacuum.\\nQ. What is the object of placing a pet cock or\\nvalve on the feed pump, and where should it\\nbe placed\\nA. It should be placed above the suction valve\\nof the pump it enables the engineer to see if the\\nengine is working, and also it forms an air cushion\\nwhich prevents heavy knocking in the pump.\\nQ. How are the ends of surface condenser tubes\\nfastened\\nA. One method is to tap the holes in the tube\\nsheet for a part of the thickness after the tube is\\nput in place, a packing is inserted around it, and\\na brass ferrule is screwed in which forces the pack-\\ning up against the tube. Another method is to\\nmake use of a wood ferrule fitting around the tube\\nwhich is driven into the tube plate.\\nQ. What is a snifting valve, and where is it\\nplaced and what is its purpose\\nA. A snifting valve is a small relief valve\\nwhich is placed on the bottom of the condenser.\\nIt is arranged in such a way that the vacuum in\\nthe condenser keeps the valve closed, and in case\\nof an excessive pressure in the condenser the", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0222.jp2"}, "223": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 207\\nvalve will open and relieve it. Such valves are\\nnot always used now, especially with compound\\nengines, as the necessity of starting with a good\\nvacuum is not so great as with simple engines.\\nQ. What is cushioning in a steam cylinder?\\nWhat produces it and what advantage is it?\\nDoes the amount of the exhaust pressure affect it\\nA. Cushioning is caused in the cylinder by the\\nclosing of the exhaust before the piston has com-\\npleted its stroke. The advantage lies in the pro-\\nduction of a sort of cushion owing to the elasticity\\nof the compressed steam, which takes off from\\nthe piston the heavy knock that would otherwise\\ntake place at the end of a stroke. The amount\\nof cushioning depends upon the exhaust lap and\\nthe back pressure, increasing if either of these are\\nincreased.\\nQ. About what vacuum should the vacuum\\ngauge show when the engines are working all right,\\nand to what absolute pressure does this corre-\\nspond\\nA. About 27 inches. This corresponds to a\\npressure of about 13^ pounds below the atmos-\\nphere, or about 1.2 pounds absolute.\\nQ. What is the extreme height to which, theo-\\nretically, water can be drawn by a suction pump,\\nand how does this compare with the result\\nobtained in practice", "height": "2887", "width": "1781", "jp2-path": "ropersquestions00rope_0223.jp2"}, "224": {"fulltext": "208 QUESTIONS AND ANSWERS FOR\\nA. The extreme vertical height is about 34 feet.\\nIn practice it is difficult to exceed 26 feet.\\nQ. What is a vacuum Can it move a piston\\nA. A vacuum is a space devoid of pressure.\\nA vacuum cannot, strictly speaking, move a\\npiston. It is the preponderance of the atmos-\\npheric pressure above that of the vacuum which\\nmoves the piston.\\nQ. When the temperature of the water in the\\ncondenser is 212 degrees, what is the vacuum in\\nthe condenser?\\nA. There is no vacuum in the condenser, be-\\ncause the water will boil at that temperature and\\ngive off steam that will have a pressure equal\\nto the atmospheric pressure.\\nQ. What is the temperature of the following\\n(1) Melting ice (2) the hot well (3) boiling\\nwater (4) steam at 60 pounds gauge pressure\\n(5) steam at 100 pounds (6) steam at 135\\npounds (7) the hot gases in the funnel?\\nA. Melting ice, 32 degrees Fahr. hot well, 120\\ndegrees boiling water in open air, 212 degrees\\nsteam at 60 pounds, 307 degrees steam at 100\\npounds, 338 degrees steam at 135 pounds, 358\\ndegrees hot gases, from 600 to 700 degrees.\\nQ. What are the effective heating surfaces in a\\nmarine boiler Are the vertical surfaces as effi-\\ncient as horizontal", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0224.jp2"}, "225": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 209\\nA. The effective heating surfaces of a marine\\nboiler are those portions situated above the fire\\nbars which are exposed to the heat of the flame\\nand the products of combustion. Vertical sur-\\nfaces are much less efficient than horizontal.\\nQ. In what ways could you ascertain the pres-\\nsure in a steam boiler\\nA. The ordinary method is, of course, by the read-\\ning of the steam gauge. If this were out of order an\\napproximate determination of the pressure could be\\nmade by seeing at what position the safety valve\\nwould blow off. If neither of these were avail-\\nable, a still rougher method would be to take a\\nbottle containing a thermometer and blow off\\nsteam from one of the gauge cocks into the bottle.\\nAfter the thermometer has reached its maximum\\nreading I would find from tables what pressure\\nof the steam corresponded with the temperature\\nshown by the thermometer.\\nQ. How could you test the trueness of the pro-\\npeller shaft without lifting it\\nA. I would slacken the coupling bolts and see\\nif the distance between the edges of the couplings\\nis the same all around I would stretch a line hor-\\nizontally along the shaft and measure from it to\\nthe sides of the couplings if they are of the\\nsame diameter all the distances should be the\\nsame.\\n14", "height": "2887", "width": "1781", "jp2-path": "ropersquestions00rope_0225.jp2"}, "226": {"fulltext": "210 QUESTIONS AND ANSWERS FOR\\nQ. Suppose the air-pump rod should break and\\nyou had no extra rod on board or nothing with\\nwhich you could make one, what would you do\\nA. The condenser ought to be arranged with a\\nby-pass, so that by means of valves it could be\\nshut off and the engine run non-condensing. If\\nthere is no by-pass, I would rig up a temporary\\nexhaust pipe and run non-condensing.\\nQ. Suppose that the cylinder head cracked or\\nbroke, what would you do\\nA. I would endeavor to repair it with iron\\nor, if I had no suitable pieces of iron, I would\\nstrengthen it with plank and ropes or wire if it\\nwas impossible to do this, I would, of course,\\ndraw my fires and let the boat go under sail.\\nQ. Suppose the crank pin should break, what\\nwould you do\\nA. I would remove it and replace it with a new\\none if there was one on board if not, it would be\\nnecessary to detach the propeller shaft and go\\nunder sail.\\nQ. Suppose the cut-off mechanism should be\\nbroken at one end, what would you do\\nA. If I could not readily repair it I would\\nremove the mechanism from the other end also\\nand would work the engines full stroke.\\nQ. Examine the following indicator cards and\\nstate what faults they show in the engines.", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0226.jp2"}, "227": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 211\\nA. See Roper s Engineers Handy Book,\\npages 545-548.\\nDiagram from simple slide valve engine, 16 x 30\\nDiagram from 18 x 36 engine with cut-off valve operated by Kendal\\nGovernor.", "height": "2887", "width": "1781", "jp2-path": "ropersquestions00rope_0227.jp2"}, "228": {"fulltext": "212 QUESTIONS AND ANSWERS FOR\\nDiagram from simple slide valve engine, 9 x 15\\nDiagram from same, 9 x 15 engine, with different valve setting.", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0228.jp2"}, "229": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 213\\nQ. A certain surface is 14 3f long by 7 1\\\\\\nbroad what is the area in square feet and deci-\\nmals of a square foot\\nA. 14 3f 14.3125 7 1J 7.125\\n14.3125 X 7.125 101.9765625 (Ans.)\\n3 J or .25\\nJ .75 or .0625\\n3| .3125\\nli 1.5 or .125\\n14.3125\\n7.125\\n715625\\n2862\u00c2\u00a70\\n143125\\n1001875\\n101.9765625\\nQ. An oil tank 3 long by 2 broad has a height\\nof 3 On Wednesday the height of the oil is\\nnoted in the glass gauge, and on the following\\nTuesday at the same hour the height is again\\nnoted, the difference in height being 8-J- what is\\nthe average consumption per day in gallons and\\ndecimals of a gallon\\nA. 3 X 2 X 144, or 864 area in square\\ninches of floor of tank.\\nThe time from Wednesday to Tuesday is 6", "height": "2887", "width": "1781", "jp2-path": "ropersquestions00rope_0229.jp2"}, "230": {"fulltext": "214 QUESTIONS AND ANSWERS FOR\\nThe number of cubic inches of oil used is\\n864 X 8.5, or 7344.\\nThe number of gallons is 7344 -r- 231 and\\nthe number of gallons per day is one-\\nsixth of this.\\n6 )7344\\n231)1224(5.299 nearly. (Ans.)\\n1155\\n690\\n462\\n2280\\n2079\\n201\\nQ. How long will it take to pump out a tank\\n30 by 20 3 by 6 4 The diameter of the\\npump, which is double acting, is 8 and its stroke\\nis 10 the pump makes 70 revolutions per min-\\nute the pump is full at each stroke.\\nA. The volume of the tank is 30 X 20J X 6J,\\nor 3847.5 cubic feet.\\nThe amount of water per stroke is 7854 X\\n8X8X10X4 or 452. 39 cubic inches.\\nThe amount of water per minute is 452.39\\nX 70 X 2 h- 1728, or 36.65 cubic feet.\\nThe number of minutes required is 3847.5\\n-s- 36.65, or 104.98 minutes. (Ans.)\\nQ. What is the approximate weight of a cast-", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0230.jp2"}, "231": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 215\\niron piston 18 diameter and 2 thick? What\\nweight do you allow per cubic foot for the cast\\niron\\nA. The volume of the piston is .7854 X 18 X\\n18 X 2, or 508.9392 cubic inches.\\n508.9392 -5- 1728 the number of cubic\\nfeet.\\nAllowing 450 pounds per cubic foot, the\\n508.9392 X 450 1QO ro\\nweight will be or 132.53.\\n1728\\n(Ans.)\\nQ. A scale of iron rust which you have taken\\noff weighs 10 ounces the composition of rust is\\n112 parts by weight of iron to 48 parts oxygen\\nhow many ounces of iron was in this scale\\nH2 X 10 1120\\nA. The amount of iron is\\n112 48 160\\n7 ounces. (Ans.\\nQ. Suppose that a bar of iron has a weight of\\none ton suspended on it, and it is found to stretch\\none inch in 12,000 what will be the stretch of a\\nsimilar bar whose length is 20 if a weight of 10\\ntons is suspended upon it\\nA. With 10 tons suspended on it instead of 1\\nton, the bar would stretch 10 inches in 12,000, or\\nx^oo of its length, ^m 20 feet is -^nftj- of 1\\ninch. T 2 ^o \u00c2\u00b0f an ncn 2 inch. (Ans.", "height": "2887", "width": "1781", "jp2-path": "ropersquestions00rope_0231.jp2"}, "232": {"fulltext": "216\\nQUESTIONS AND ANSWERS FOR\\nQ. There are 275 tons of coal in the bunkers,\\nthe average percentage of ash being 15 how much\\nactual fuel is there in the bunkers\\nA. If the ash is 15 per cent., the actual amount\\nof coal is 100 15, or 85 per cent.\\n275\\n.85\\n1375\\n2200\\n233.75 tons. (Ans.)\\nQ. What is the square of 271.6? What is the\\ncube of 54.3?\\nA.\\n271.6\\n271.6\\n16296\\n2716\\n19012\\n5432\\n73766.56 (Ans.)\\n54.3\\n54.3\\n1629\\n2172\\n2715\\n2948.49\\n54.3\\n884547\\n1179396\\n1474245_\\n160103.007 (Ans.)\\nQ. A tank in a steamer 20 6 diameter by 22\\n3 deep is to be used for a coal bunker, but\\nthe bottom to the height of 4 cannot be used\\nfor coal how many tons of coal can be put in", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0232.jp2"}, "233": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 217\\nthe tank, and how long will it last if the average\\nrate of consumption is 40 tons per day\\nA. The area of the tank is. 7 854 X 20.5 X 20.5\\nsquare feet.\\nThe space available for coal has a depth of\\n22 3 4 18 3 or 18.25 feet.\\nThe volume in cubic feet is .7854 X 20.5\\nX 20.5 X 18.25, or 6023.4125.\\n.7854\\n330.05\\n20.5\\n18.25\\n39270\\n165025\\n15708\\n66010\\n16.10070\\n264040\\n20.5\\n33005\\n805\\n6023.4125\\n322\\n40)6023.4125(150.5853 tons.\\n330.05\\n40\\n202\\n200\\n234\\n200\\n341\\n320\\n212\\n200\\n125\\n120\\n5", "height": "2893", "width": "1832", "jp2-path": "ropersquestions00rope_0233.jp2"}, "234": {"fulltext": "218 QUESTIONS AND ANSWERS FOR\\n40)150.5853(3.\\n7646 days.\\n120\\n305\\n280\\n258\\n240\\n185\\n160\\n253\\n240\\n13\\n.7646 days\\n.3524 hours\\n24\\n60\\n30584\\n21.1440 minutes.\\n15294\\n18.3524 hours.\\n.144 minutes\\n60\\n8.640 seconds.\\nAnswer The coal will last (assuming that a\\nton occupies a space of 40 cubic feet) 3 days, 18\\nhours, 21 minutes, and 8.64 seconds.\\nQ. What is the sum of and in deci-\\nmals\\nA. 2T 13636\\n36842\\n.50478 (Ans.)", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0234.jp2"}, "235": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 219\\n22)3. 00000(. 13636 19)7.00000(. 36842\\n22 57\\n80 130\\n66 114\\n140 160\\n132 152\\n80 80\\n66 76\\n140 40\\n132 38\\nQ. An engine after being compounded gener-\\nated 20 per cent, more power from the same\\namount of fuel (10 tons a day) how many tons\\nof coal will be used if the engine be worked com-\\npounded at the original power?\\nA. If we call the old power 100 per cent. the\\nnew power will be 120 per cent. Then 120 100\\n10 number of tons which will be used.\\n10 X 100 120 Si tons. (Ans.)\\nQ. If the coal consumption is 30 tons a day,\\nand if each of the six watches throws away 36\\nbaskets of ashes weighing 50 pounds each, what\\npercentage of the fuel is ash\\nA. 36 X 50 1800 pounds, the ash per day.\\n2240 X 30 67,200, the total number of\\ntons of fuel burned per day.", "height": "2893", "width": "1832", "jp2-path": "ropersquestions00rope_0235.jp2"}, "236": {"fulltext": "220 QUESTIONS AND ANSWERS FOR\\n67200)1800.000(.027 nearly.\\n134400\\n456000\\n.027 2.7 percent, (Ans.)\\nQ. A cylinder has a diameter of 30 The\\npacking ring is too large and a piece of an\\ninch is cut out of it then when it is put in\\nplace there is an opening of in the ring what\\nis the difference between the diameter of the\\ncylinder and diameter of the ring before it was\\ncut?\\nA. The circumference of the inside of the cyl-\\ninder is 3.1416 X 30 94.248\\n-gV .03125\\nA .5625\\n94.248 .03125 -f .5625 is the diameter\\nof the ring before it was cut.\\nTherefore the difference between the diame-\\nter of the cylinder and that of the ring is\\n(94.248 .03125 -f 5625) -94.248, or\\n5625 .03125 inch 53125 (Ans.\\nQ. What is the horse-power of an engine\\nwhose cylinder is 36 in diameter, whose stroke\\nis the same and which makes 40 revolutions per\\nminute if the mean effective pressure is 40\\npounds", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0236.jp2"}, "237": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 221\\n.7854 3\\n36 40\\n47124 120\\n23562 40\\n28.2744 4800\\n36 2\\n1696464 9600\\n848232\\n1017.8784\\n1017.*\\n9600\\n61072800\\n916092\\n33000)9771648.00(296 horse-power. (Ans.)\\n66000\\n317164\\n297000\\n201648\\n198000\\n3648\\nThe area of the piston is .7854 X 36 X 36,\\nor 1017.8784 square inches.\\nThe horse-power is equal to the area X fl\\nX 40 X 2 X 40 -T- 33,000, or 296 horse-\\npower. (Ans.\\nQ. What is the proportion between the area of\\nan 8 steam pipe and of a cylinder of 40 diam-\\neter?", "height": "2893", "width": "1832", "jp2-path": "ropersquestions00rope_0237.jp2"}, "238": {"fulltext": "222 QUESTIONS AND ANSWERS FOR\\nA. The areas are in proportion to the squares\\nof the diameters and are therefore as 8 X 8 40\\nX 40, or as 64 1600, or 1 25.\\nQ. If the feed- water has 4J ounces of salt per\\ngallon, and if you continuously blow off -J of the\\ntotal feed, what will be the degree of saltness in\\nthe boiler\\nA. 62.5 per cent.\\n62.5 100 4.5 Answer.\\n4.5 X 100 n o i /a n\\n7. 2 ounces per gal. Ans.\\nQ. The blow-off cock on the bottom of a boiler\\nis 13 below sea level the water level in the boiler\\nis carried 9 above the blow-off cock how much\\npressure will be needed in the boiler to enable you\\nto blow out water\\nA. The water level in the boiler is below the\\nsea level by an amount equal to 13 9,\\nor 4 feet.\\n4 feet corresponds to a pressure of .434 X\\n4, or 1.736 pounds.\\nTherefore a pressure a little greater than this\\nwill be needed in order to blow out.\\nQ. If the feed-water has 4^- ounces of salt per\\ngallon, and if you do not wish to exceed a salt-\\nness of 9J ounces in the boiler, what percentage\\nof the feed-water must be blown off", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0238.jp2"}, "239": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 223\\nA. 9.5 4.2 100 Answer.\\n100 X 4.2 U2 t (Ans\\n9.5 l\\nREQUIREMENTS FOR ENGINEERS IN THE\\nREVENUE MARINE.\\nThe requirements for engineers in the Revenue\\nMarine are about the same as those for chief\\nengineers in the Merchant Marine, as will be seen\\nby comparing the following extract from the\\ngeneral orders of the treasury department with the\\ncorresponding paragraphs in the Frye Bill. On\\nthis account no questions and answers for candi-\\ndates have been inserted.\\n1. No person will be examined for, or commis-\\nsioned a second assistant engineer in, said service\\nwho is not a citizen of the United States.\\n2. Candidates must not be less than twenty-\\none nor more than twenty-eight years of age, and\\nmust be of vigorous constitution, physically sound\\nand well formed, and not less than five feet three\\ninches in height.\\nThe application for examination must be in the\\nhandwriting of the applicant and addressed to\\nthe Secretary of the Treasury. It must state the\\ndate and place of birth, and the State of which a\\nresident. If the applicant be of foreign birth it\\nmust be shown that he is a citizen of the United\\nStates.\\n3. The application must be accompanied with\\nsatisfactory evidence of the good moral character", "height": "2893", "width": "1832", "jp2-path": "ropersquestions00rope_0239.jp2"}, "240": {"fulltext": "224 QUESTIONS AND ANSWERS FOR\\nand correct habits of the applicant, and certificates\\nshowing his experience either in a machine shop\\nor in charge of a steam engine in a technical insti-\\ntution, or in the engine room of a steamer, as\\nrequired by paragraph 5.\\n4. Candidates will be required to pass a satis-\\nfactory examination as to their physical qualifica-\\ntions before a board of medical officers to be desig-\\nnated by the Secretary of the Treasury. The\\nphysical examination will precede the profes-\\nsional, and should the candidate be found phys-\\nically disqualified he will be examined no further.\\n5. To be eligible for examination a candidate\\nmust have had not less than eighteen months ex-\\nperience in a machine shop, or responsible charge\\nof a steam engine for that length of time or, if a\\ngraduate of a technical institution, he must have\\nhad the full four years course in mechanical\\nengineering and in addition to either of the three\\npreceding requirements, he must also have had\\nnot less than six months experience in charge of,\\nor assisting in, the care and management of the\\nsteam machinery of a sea-going vessel in actual\\nservice.\\n6. Candidates having been found physically\\nqualified will be examined professionally by a\\nboard of engineer officers of the Revenue Cutter\\nService, in the following subjects, the questions\\nand answers all being written\\n(a) Grammar, spelling, punctuation, composi-\\ntion, penmanship.\\n(b) Statement of shop and engineering expe-\\nriences and sea-service.", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0240.jp2"}, "241": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 225\\n(c) Elementary mathematics, including arith-\\nmetic, algebra, geometry, trigonometry, and the\\nuse of logarithms.\\n(d) Elementary mechanics and physics, in-\\ncluding mechanical powers, friction, laws of fall-\\ning bodies, force, work, etc.\\n(e) Practical problems connected with steam-\\nengineering, such as calculation of loss by blowing\\noff, gain by use of heaters, amount of condensing\\nwater required, safety valye problems, etc.\\nIncrustation and corrosion in marine\\nboilers and problems connected with combustion.\\n(g) Marine boilers, description of various\\ntypes, with their advantages and disadvantages,\\nrepairs to same, practical management of boilers,\\nand discussion of accidents and difficulties, such\\nas foaming, back-draft, etc.\\n(h) Heat, steam, theory of expansion, use of\\nsteam.\\nThe steam-engine indicator, interpretation\\nfrom diagrams therefrom, calculation of horse-\\npower and evaporation from diagrams.\\nj) Marine engines description of the various\\ntypes including those used with paddle-wheels,\\nwith advantages and disadvantages, special atten-\\ntion being given to multiple-expansion engines,\\npractical questions relative to care and manipula-\\ntion of engines, overhauling and repairs, align-\\nments, etc.\\nValves and valve-gears as applied to marine\\nengines, including those used on side-wheel\\nsteamers, but with special attention to modern\\ntypes used with propeller engines.\\n15", "height": "2893", "width": "1832", "jp2-path": "ropersquestions00rope_0241.jp2"}, "242": {"fulltext": "226 QUESTIONS AND ANSWERS FOR\\n(7) Condensers, pumps, steam gauges.\\n(m) Strength of materials, including simple\\nproblems in proportions of marine engines and\\nboilers. Inspection of materials.\\n(?i) Screw propellers. Description of common\\ntypes; definitions and simple problems connected\\ntherewith.\\n7. The professional examination will be com-\\npetitive, and all candidates who pass the mini-\\nmum standard will be placed upon an eligible\\nlist in the order of proficiency exhibited by them\\nrespectively, in the examination. From this list\\nselections will be made in regular order as vacan-\\ncies occur, until another examination is held.\\n8. The standard of proficiency has been fixed at\\n75 per cent. and candidates failing to obtain that\\naverage will be rejected. They may, however, if\\notherwise qualified, take another examination\\nwhen the next board shall be convened. Failure\\nin the second examination will result in the final\\nrejection of the candidate.\\n9. No person shall be originally appointed to a\\nhigher grade than that of second assistant engineer.\\n10. Any person producing a false certificate of\\nage, time of service, character, or making a false\\nstatement to the Board of Examiners, shall be\\ndisqualified for appointment.\\n11. An} r person who subsequent to his exami-\\nnation may become disqualified from moral consid-\\nerations, will not be recommended for appointment.\\n12. All correspondence with reference to the\\nprovisions of this order should be addressed to\\nthe Secretary of the Treasury, AYashington, D. C.", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0242.jp2"}, "243": {"fulltext": "L\\nSTEAM ENGINEERS AND ELECTRICIANS. 227\\nELECTRICAL QUESTIONS.\\nQUESTIONS FOR DYNAMO TENDERS.\\n(Based upon low-pressure, direct-current work.)\\ni\\nQ. What are the essential parts of a dynamo\\nA. The armature, the field magnet, and com-\\nmutator and brushes.\\nQ. What are the functions of these parts\\nA. The magnet and armature when moved rela-\\ntively to each other set up an electric pressure\\nbetween the ends of the armature coils. When-\\never the two ends are connected by a conductor\\nan electric current will flow the commutator\\nand brushes serve to collect the current and to\\nmake the current flow always in the same direc-\\ntion in the external circuit.\\nQ. What do you mean by the external circuit\\nA. That portion of the circuit outside of the\\ndynamo.\\nQ. What analogy has a dynamo to a pump\\nA. The dynamo may be considered as a pump\\nwhich raises electricity from a low level or pres-\\nsure to a high level or pressure.\\nQ. Upon what does the pressure produced by the\\ndynamo depend?\\nA. Upon the number of turns of wire in the", "height": "2893", "width": "1832", "jp2-path": "ropersquestions00rope_0243.jp2"}, "244": {"fulltext": "228 QUESTIONS AND ANSWERS FOR\\narmature coils, upon the strength of the field\\nmagnets and upon the speed of revolution.\\nQ. What would be the effect on a given dyna-\\nmo of increasing the speed of the driving engine\\nA. It would increase the pressure furnished by\\nthe dynamo, although not in an exact proportion\\nto the change in speed.\\nQ. How is an armature constructed practically\\nA. The armature consists first of a shaft on\\nwhich are mounted a large number of thin, cir-\\ncular, iron discs. These discs are held together\\nby bolts and are fastened to the armature shaft by\\na sort of spider. These discs together form a cyl-\\ninder the outer surface of which has usually a\\nnumber of grooves cut in it running parallel to\\nthe armature shaft. The coils of the armature,\\nwhich consist of copper wire insulated with cot-\\nton, are wound around the cylindrical core, the\\nwires being laid in the grooves. The grooves are\\ngenerally lined with a thin insulating material\\nsuch as paper fiber or even mica, and the wires\\nare painted over with shellac or special armature\\nvarnish. Finally, on the outside are wound bind-\\ning wires so as to hold the armature coils in place.\\nQ. What is the purpose of the cylindrical iron\\ncore in the armature\\nA. If the iron core were not used a large part\\nof the magnetism produced by the field magnet", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0244.jp2"}, "245": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 229\\nwould be wasted, as the magnetic lines of force\\nwould not pass across the space wherein the arma-\\nture coils rotate. The iron core keeps these lines\\nof force within the proper space.\\nQ. What is the object of making the core of\\nthin discs rather than of solid metal\\nA. If it were made of solid metal it would\\nbecome very hot, and this would not only produce\\na waste of energy, but it would also injure and\\nperhaps entirely destroy the insulation of the\\narmature coils.\\nQ. Is the magnet of the dynamo a permanent\\nmagnet\\nA. In early dynamos it was in modern times\\nit is always an electro-magnet.\\nQ. What is an electro-magnet\\nA. An electro-magnet consists of a piece of iron\\nor soft steel surrounded by a coil of wire carrying\\nan electric current.\\nQ. How many poles has an electro-magnet\\nA. It must have at least two, or it may have\\nany even number of poles, such as 2, 4, 6, 8, etc.\\nIn any case half are of one polarity and the other\\nhalf of the opposite polarity.\\nQ. How are dynamo machines classified accord-\\ning to the winding of their field magnets\\nA. Into three classes: Series, shunt, and com-\\npound machines.", "height": "2893", "width": "1832", "jp2-path": "ropersquestions00rope_0245.jp2"}, "246": {"fulltext": "230 QUESTIONS AND ANSWERS FOR\\nQ. What is a series machine\\nA. A series machine is a dynamo through\\nwhose field-magnet coils flows all the current pro-\\nduced by the machine. This is accomplished by\\ntaking a wire from one brush, carrying it the re-\\nquired number of times around the field magnet\\nand then connecting it to the external circuit the\\nother end of the external circuit is connected to\\nthe other brush.\\nQ. What is a shunt dynamo\\nA. One in which only a portion of the total\\ncurrent of the machine passes through the field-\\nmagnet coils.\\nQ. What is a compound dynamo\\nA. A dynamo having two windings: one series\\nwinding, around which the main current flows\\nand a shunt winding, through which a fraction of\\nthe main current flows.\\nQ. For what class of work is a shunt machine\\nused?\\nA. A shunt machine is used when it is desired\\nto maintain a constant pressure at all loads.\\nQ. Does a shunt machine maintain a constant\\npressure at all loads\\nA. Nearly so; the pressure falls off a little as\\nthe load increases.\\nQ. What system of distribution requires a con-\\nstant pressure at all loads", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0246.jp2"}, "247": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 231\\nA. The ordinary parallel or multiple system\\nused for the lighting of buildings.\\nQ. Are shunt machines used in general for this\\nclass of work\\nA. Xo; they have been superseded very largely\\nby the compound machine, which gives a closer\\nregulation of pressure.\\nQ. What is meant by an overcompounded\\nmachine\\nA. One which automatically raises the pressure\\na little in proportion as the load increases.\\nQ. What are the advantages of such a machine\\nover one that would maintain the pressure abso-\\nlutely constant?\\nA. Such a machine would make up for a slight\\nfall in the speed of an engine, which takes place\\nas the load increases; it also makes up for a loss\\nin pressure on the circuit wires, which loss is pro-\\nportional to the load which they carry.\\nQ. How is overcompounding actually obtained\\nA. By increasing the number of turns in the\\nseries coil of a compound machine above what\\nwould be necessary to give a constant pressure\\nmachine.\\nQ. Can the pressure furnished by a shunt or\\ncompound dynamo be varied and if so, how\\nA. Yes; it could, of course, be varied by alter-\\ning the speed of the engine, but the common", "height": "2893", "width": "1832", "jp2-path": "ropersquestions00rope_0247.jp2"}, "248": {"fulltext": "232 QUESTIONS AND ANSWERS FOR\\nmethod is to insert an adjustable resistance called\\na rheostat in series with the shunt field coils.\\nWhen the arm of the rheostat is turned one way\\nmore resistance is thrown into the shunt circuit,\\nwhich cuts down the current flowing around the\\ncoils. As this diminishes the strength of the\\nfield magnet the pressure furnished by the\\nmachine is lessened. Moving the rheostat arm\\nin the other direction cuts out resistance and\\nraises the pressure.\\nQ. How are machines classified with regard to\\ntheir field magnets\\nA. They are classified according to the number\\nof poles into bi-polar, or two-pole machines, and\\nmulti-polar, when the number of poles is greater\\nthan two.\\nQ. How does the number of brushes compare\\nwith the number of poles\\nA. As a rule, there are as many sets of brushes\\nas there are poles.\\nQ. What are the two principal methods of\\nwinding armatures?\\nA. The ring winding and the drum winding.\\nQ. Explain what must be done in setting the\\nbrushes so as to secure freedom from sparking.\\nA. In a bi-polar machine the positive and neg-\\native brushes must be exactly opposite each\\nother. In the four-pole machine these brushes", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0248.jp2"}, "249": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 233\\nmust .be at a distance of 90 degrees from each\\nother. In any case the brushes must fit the sur-\\nface of the commutator accurately, and the rocker\\narm which carries them must be turned into the\\nposition of least sparking.\\nQ. What care must be given to a dynamo in\\norder to make it run properly\\nA. It must be kept clean and dry. The bear-\\nings, of course, need no more nor no less atten-\\ntion than similar bearings in other machinery.\\nThe parts which require the most care are the\\ncommutator and brushes.\\nQ. Explain in detail what care must be given\\nto the commutator.\\nA. The commutator should be kept clean by\\noccasionally wiping it with a hard-cotton cloth,\\nand a very little vaseline should occasionally be\\nput on it so as to diminish the friction between\\nthe commutator and brushes. Oil should never\\nbe put on it. The commutator will in course of\\ntime become roughened, and therefore it should\\nbe occasionally smoothed by holding a piece\\nof very fine sandpaper against it while the\\nmachine is turning. If the commutator gets out\\nof true it must be turned down.\\nQ. How is the commutator turned down in the\\ncase of a small-sized armature?\\nA. The armature is taken out from its bearings", "height": "2893", "width": "1832", "jp2-path": "ropersquestions00rope_0249.jp2"}, "250": {"fulltext": "234 QUESTIONS AND ANSWERS FOR\\nand mounted in a lathe, and the commutator is\\nturned off just like any other piece of metal.\\nQ. Is there any particular necessity for observ-\\ning care in turning down the commutator\\nA. Yes the tool should take only a very fine\\ncut, and after the job is finished the commutator\\nshould be very carefully examined to see that no\\ntwo commutator segments have been accidentally\\nconnected by a little piece of copper that has\\nbeen partially torn off from one segment by the\\ncutting tool and pushed over so as to touch the\\nnext segment.\\nQ. Suppose that there had been a connection\\nestablished between two commutator segments and\\nthat this had not been discovered the armature\\nis then. put back in place and the machine started\\nup, what would be the effect\\nA. The coil whose ends are connected to these\\ntwo commutators would become very much heated,\\nand unless the machine were stopped the whole\\narmature would become badly damaged. There\\nwould also probably be considerable sparking at\\nthe brushes.\\nQ. After the brushes are once properly fitted so\\nthat the machine runs without sparking, what care\\nmust be given to them\\nA. They must be occasionally cleaned, and if\\nany sparking occurs they should be immediately", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0250.jp2"}, "251": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 235\\nadjusted so as to stop it. If the brushes are of\\ncopper they should be raised from the commutator\\nwhenever the machine is stopped, so that they\\nmay not be injured in case the machine were for\\nany reason turned backward.\\nQ. What would be the effect of allowing the\\ndynamo to become wet\\nA. The insulation of the armature and field\\ncoils would be injured if not entirely destroyed.\\nIt would be, as we say, grounded that is, put in\\nelectrical connection with the frame of the machine.\\nQ. What do you mean by the term badly\\ngrounded\\nA. The armature, for example, would be badly\\ngrounded if the insulation resistance between the\\ncoils and the iron core became very low.\\nQ. How many ohms insulation resistance be-\\ntween the armature or field coils and the frame is\\nit usual to demand in a good dynamo\\nA. An insulation resistance of at least 1,000,000\\nohms.\\nQ. How could you determine whether or not\\nthe machine were grounded\\nA. I should take a magneto bell and connect\\none terminal to the frame of the machine, being\\ncareful to have the connection on a metal surface\\nwhich had been made clean and bright. The\\nother terminal of the magneto I would connect to", "height": "2893", "width": "1832", "jp2-path": "ropersquestions00rope_0251.jp2"}, "252": {"fulltext": "236 QUESTIONS AND ANSWERS FOR\\none of the brushes. It is understood that the\\nmachine is not to be operated while the test is\\nbeing made. I would then turn the handle of\\nthe magneto, and if the bell sounded I should\\nknow that there was a bad ground somewhere in\\nthe machine. To locate it I would raise the\\nbrushes from the commutator and turn the mag-\\nneto again. If it rings this shows that there is a\\nground either in the brush holders or in the field\\ncircuit. I would then disconnect the field circuit\\nfrom the brush holders and test each separately,\\nand after having found, for instance, that the\\nground was in the field coils I would disconnect\\nthem so as to find in which particular coil the\\ntrouble existed. I would afterward test the\\narmature to find if there were any ground\\nin it.\\nQ. In case you found that there was a ground\\nin the armature, what would you do\\nA. I would examine it carefully, especially at\\nthe commutator end, to see if it were caused by a\\ncollection of metal dust and oil or by anything\\nelse which I could remedy. If the cause of the\\ntrouble could not be found it would be necessary\\nto take the armature out and send it to some shop\\nwhere they make a specialty of rewinding arma-\\ntures.\\nQ. Suppose that you were at a distance from", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0252.jp2"}, "253": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 237\\nsuch a shop, would you attempt to repair the\\ntrouble yourself\\nA. If it were a small ring- wound armature I\\nmight do so, but certainly would not attempt it\\nin any other case.\\nQ. Suppose that a ground were found to exist\\nin one of the field coils, what would you do?\\nA. I should not hesitate to attempt to repair\\nthat. I would take out the spool on which the\\ncoil is mounted and would put it in a lathe and\\ncarefully unwind the coil, winding the wire up at\\nthe same time on some sort of drum or reel so as\\nnot to kink or injure it in any way. I would\\noccasionally test with a magneto bell, connecting\\none terminal to the metal of the spool and the\\nother terminal to the wire, and would keep on\\nunwinding until the coil showed free from a\\nground; then I would repair the place where the\\ntrouble was found by putting in some new insula-\\ntion or new wire as might be needed, and would\\ncarefully wind back the wire in exactly the same\\nway that it had been wound by the manufacturer.\\nI would then replace the spool in the machine,\\ntesting again for grounds, and would reconnect the\\nmachine, and after making a final test for grounds\\nwould start it up.\\nQ. What is a direct connected machine\\nA. A direct connected dynamo is one which is", "height": "2893", "width": "1832", "jp2-path": "ropersquestions00rope_0253.jp2"}, "254": {"fulltext": "238 QUESTIONS AND ANSWERS FOR\\ndriven by an engine without the use of the belt\\neither the armature shaft is connected to the en-\\ngine shaft by means of the flexible coupling or\\nmore commonly the engine shaft is made extra\\nlong with an out-board bearing, and the armature\\nis mounted on this shaft, the field magnets being\\nattached to the extended bedplate of the engine.\\nQ. What advantages and disadvantages can you\\nthink of in connection with direct connected\\ndynamos\\nA. Their advantages are economy of space,\\nquietness in operation, and increased efficiency,\\nsince losses in belt transmissions are done away\\nwith. Such generators are, however, more costly,\\nsince they must run at a comparatively low speed,\\nthey being subject in this respect to the limita-\\ntions of the engine. A belted machine may have its\\nframe thoroughly insulated from earth while the\\ndirect connected machine, if the armature is\\nmounted on the engine shaft, cannot enjoy this\\nadvantage.\\nQ. Does a single ground on the circuit or in the\\nmachine do any harm\\nA. No it requires two grounds. Nevertheless,\\nin case a ground exists it should be promptly\\nlocated and the trouble remedied.\\nQ. In case of two grounds existing, what things\\nmay occur?", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0254.jp2"}, "255": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 239\\nA. The fuse or fuses may blow one or more of\\nthe conductors may become overheated or a spark\\nmay pass across the grounded spot, and either of\\nthese last two effects may set fire to any combus-\\ntible matter in the vicinity.\\nQ. Explain the general method by which elec-\\ntrical energy is distributed for ordinary house\\nlighting.\\nA. The distribution is very similar to a water\\nsystem in which water is pumped from a tank at\\na low level to an elevated tank and then led from\\nthis tank through pipes to the various points\\nwhere it is. to be used, and after having been used\\nis led back through another set of pipes to the low\\nlevel tank from which the water is again pumped\\nup to be used again. The dynamo corresponds to\\nthe pump the copper wires correspond to the dis-\\ntribution pipes and the two bus bars on the\\nswitchboard correspond to the two tanks. The\\nswitches correspond to the valves, the ammeters\\ncorrespond to water meters, and the voltmeters\\ncorrespond to pressure gauges.\\nQ. What is the high-pressure system of con-\\nductors called in electrical distribution\\nA. The positive, or plus\\nQ. What is the low-pressure set of conductors\\ncalled?\\nA. The negative, or minus", "height": "2893", "width": "1832", "jp2-path": "ropersquestions00rope_0255.jp2"}, "256": {"fulltext": "240 QUESTIONS AND ANSWERS FOR\\nQ. Explain how, practically, a generator is con-\\nnected to a switchboard, describing the materials\\nused and the manner in which they are in-\\nstalled.\\nA. There are several methods of construction..\\nThe conductors may be carried overhead ascend-\\ning vertically from the machine terminals to the\\nceiling of the dynamo room and then across the\\nceiling and vertically downward to the fuse termi-\\nnals of the machine switches on the switchboard.\\nIn this class of construction the conductors may be\\nbare copper rods or may be wire insulated with\\nfire- and weather-proof or rubber insulation. The\\nconductors in either case are attached to porcelain\\ninsulators. If bare copper rods be used, that por-\\ntion of their length which is near the generator\\nshould be covered with insulating tape.\\nAnother and more common method is to carry\\nthe conductors under the floor of the dynamo\\nroom, placing them in iron pipe or conduit in this\\ncase the conductors should be insulated with rub-\\nber, or a lead-covered cable may be used.\\nA third method is to carry the conductors under\\nthe floor in a brick or concrete duct covered with\\niron plate in such cases the conductors may be\\nmounted on porcelain, but as this necessitates a\\nvery large duct it is better to use for conductors a\\nlead-covered cable.", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0256.jp2"}, "257": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 241\\nQ. Trace the connections from the generator ta\\nthe bus bars, stating through what pieces of appa-\\nratus the current would pass.\\nA. Starting from the positive brush the con-\\nductor runs from the brush to a fuse terminal on\\nthe machine switch the current after passing\\nthrough this fuse passes through the positive blade\\not the machine switch and then through the\\nammeter (or ammeter shunt) and through a con-\\nnecting strip to the positive bus bar. From the\\nnegative bus bar the current passes through a cop-\\nper strip to the machine switch, through the blade\\nof the switch and the corresponding fuse and\\nthen through a conductor which extends from the\\nfuse terminal to the negative brush.\\n_ Q. What is the object of a fuse, and of what is\\nit made\\nA. A fuse generally consists of a piece of com-\\nposition metal,\u00e2\u0080\u0094 usually some alloy of lead which\\nwill melt at a fairly low temperature,\u00e2\u0080\u0094 soldered\\nto copper terminals, these terminals being of such\\nshape that they may be conveniently clamped\\nunder lugs provided to receive them. The fuse is\\nintended to melt whenever a current exceeding a\\ncertain strength passes through it. It therefore\\nserves to protect either the circuit conductors\\nor the machine from overheating due to the pas-\\nsage of too great a current.\\n16", "height": "2893", "width": "1832", "jp2-path": "ropersquestions00rope_0257.jp2"}, "258": {"fulltext": "242 QUESTIONS AND ANSWERS FOR\\nQ. What are used instead of fuses, and what\\nare their advantages\\nA. Circuit breakers. They are more certain in\\ntheir action, especially with large currents. The\\nlarge fuses which must be used for large currents\\nare very unreliable, and fuses, for example which\\nare intended to melt with a current of, say, 500\\namperes may be melted by a current below that\\nvalue or may not blow until the current has risen\\nto perhaps 1000 amperes.\\nQ. What is the general principle on which cir-\\ncuit breakers are constructed\\nA. A circuit breaker is essentially a switch\\nwhich automatically opens when the current ex-\\nceeds a certain amount. It is closed against the\\npressure of the spring, which pressure will throw\\nit open if the switch is not held in by a sort of\\ntrigger or catch. This trigger is controlled by a\\ncoil through which the current passes. If the cur-\\nrent becomes greater than a certain value the coil\\nsucks up an iron rod attached to the trigger and\\nreleases it; the compressed spring then being free\\nto act upon the switch interrupts the circuit.\\nQ. What circuit breakers are usually provided\\nby the switchboard\\nA. One for each generator. In many installations\\neach feeder circuit is provided with a circuit\\nbreaker, no fuses at all being: used on the board.", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0258.jp2"}, "259": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 243\\nQ. What is the difference between a double-pole\\nbreaker and single-pole circuit breaker\\nA. The same difference as exists between a\\ndouble-pole switch and a single-pole switch. The\\ndouble-pole switch when open interrupts both the\\npositive and negative sides of the circuit the\\nsingle-pole interrupts only one side.\\nQ. Which kind of circuit breaker is the better\\nto use, a double or single pole\\nA. The double pole.\\nQ. When single-pole circuit breakers are used\\nwith compound machines, in which of the con-\\nnections between the djmamo and switchboard\\nmust the circuit breaker be placed\\nA. In the side opposite that in which the series\\ncoil is connected.\\nQ. When two or more compound machines are\\nrun together, how many connections run from the\\ndynamo to the switchboard from each machine\\nA. There are three large conductors namely,\\nthe positive, the negative, and the equalizer.\\nQ. What is the purpose of the equalizer connec-\\ntion, and what does it connect\\nA. The equalizing connection runs from the\\ninner end of the series field coil to the correspond-\\ning point on the other machine. It passes from\\nmachine No. 1 to a switch on the switchboard,\\nthen back to machine No. 2. If there are more\\nL", "height": "2893", "width": "1832", "jp2-path": "ropersquestions00rope_0259.jp2"}, "260": {"fulltext": "244 QUESTIONS AND ANSWERS FOR\\nthan two machines the equalizing connection runs\\nfrom the series coil to the switch on the board and\\nfrom the switch to an equalizer bus bar. The\\npurpose of the equalizing connection is to enable\\nthe machines to be operated together satisfactorily.\\nIf it were not used the machines would not tend\\nto divide up the total load properly. By adjust-\\ning the rheostats the machines can be made to take\\ntheir proper share of the load without the equal-\\nizing connection; but if the speed of one engine\\ndiminished slightly the machine corresponding\\nwould take a much less portion of the load, and\\nthis action would be aggravated so that shortly\\none machine would be carrying all the load and\\nperhaps driving the other as a motor. The equal-\\nizing connection prevents this action.\\nQ. What small connections are there between\\nthe generators and the switchboard\\nA. The field connections which may be run in\\neither of two ways. First, the outer end of the\\nfield coil on the generator is connected to one\\nof the rheostats by a wire and a return wire con-\\nnects the other terminal of the rheostat to a brush\\nof the proper polarity; in the second method the\\nreturn wire is omitted, a connection being made\\nbetween the rheostat terminal and the bus bar of\\nthe proper polarity.\\nQ. What are the principal devices to be found", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0260.jp2"}, "261": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 245\\non a switchboard, and what is the purpose of\\neach?\\nA. (1) An ammeter in the circuit of each gener-\\nator for the purpose of measuring the current\\npassing through each machine. (2) One or more\\nvoltmeters. If only one voltmeter be used it is\\nprovided with a many point switch by which it\\nmay at will be connected to the bus bar or to the\\nterminals of any generator. If there be two volt-\\nmeters, one is connected permanently to the bus\\nbars and the other is provided with a switch. (3)\\nA rheostat for each generator, by which the pres-\\nsure furnished by each machine may be varied.\\n(4) Circuit breakers or fuses in the machine cir-\\ncuits and in the feeder circuits, whose function is\\nto interrupt any particular circuit through which\\nan excessive current may for any reason flow. (5)\\nSwitches for disconnecting the generators from the\\nbus bars. (6) Switches for disconnecting the dis-\\ntribution circuits from the bus bars. (7) A ground\\ndetector whose purpose is to -show if any part of\\nthe circuit becomes connected to the earth.\\nQ. Explain the arrangement and action of a\\ntwo-light ground detector when used on a 110-\\nvolt circuit.\\nA. The two-light ground detector consists of\\ntwo 110- volt lamps connected in series across the\\nbus bars. A point on the circuit between the two", "height": "2893", "width": "1832", "jp2-path": "ropersquestions00rope_0261.jp2"}, "262": {"fulltext": "246 QUESTIONS AND ANSWERS FOR\\nlamps is connected to earth by attaching it to a\\nconvenient water pipe. The operation is as fol-\\nlows: So long as the insulation of the system is\\nunimpaired the two lights will burn dimly and\\nequally so, since they have only 55 volts pressure\\nbetween their terminals. If, however, there is a\\nbad ground on one side of the circuit, say, the\\npositive, the lamp connected to the positive side\\nwill become very much more dim, since there is\\nnow an auxiliar}^ circuit across its terminals\\nthrough the earth. The other lamp will burn\\nbrightly, since the pressure between its terminals\\nis very much greater than before.\\nQ. Suppose that one of the ground detector\\nlamps burns brightly, how would you proceed,\\npractically, to find the ground\\nA. I would open the circuit switches one by one\\nand watch the ground detector to see if the open-\\ning of any one of them made the lamps again\\nboth burn equally dim. If this were the case I\\nshould know that the ground were located on that\\npart of the circuit controlled by this switch. I\\nwould then go out to the first distribution board\\non that circuit with a portable ground detector, if\\nI had one, and connect it up at that point. I\\nwould then open the switches or fuses one by one\\nuntil I found which branch contained the ground.\\nI would then leave that branch disconnected and", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0262.jp2"}, "263": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 247\\nwith a magneto bell would test different parts of\\nthat branch circuit, splitting it up into sections at\\nsome convenient outlet or switch. In this man-\\nner the ground would be located within quite\\nclose limits. If I found that the ground were on\\na short piece of the circuit on which a fixture were\\nconnected I would disconnect the fixture, and\\ntest with the bell both the fixture and the wiring.\\nIf the wiring showed the ground I would run in a\\nnew piece of wire to take its place.\\nQ. When three-pole switches are used for\\nmachine switches, what is connected to each\\nblade?\\nA. The positive side of the generator to one of\\nthe outside blades, the equalizer to the middle\\nblade, and the negative side of the machine to the\\nother outside blade.\\nQ. May shunt machines be run together in\\nmultiple?\\nA. Yes.\\nQ. Do shunt machines when run in multiple\\nneed an equalizer?\\nA. No,\\nQ. Explain how you would proceed if you had\\none machine in operation and you desired to start\\nup a second in multiple with it to take care of an\\nincrease in load, both machines being compound.\\nA. I would start up engine No. 2 and adjust", "height": "2855", "width": "1755", "jp2-path": "ropersquestions00rope_0263.jp2"}, "264": {"fulltext": "248 QUESTIONS AND ANSWERS FOR\\nits rheostat until the voltmeter showed its pres-\\nsure to be about volt greater than that of\\nmachine No. 1. If each machine had a three-pole\\nswitch I would close the switch of No. 2, adjust-\\ning the rheostat handles until the ammeters read\\nalike (if the machines are of the same size) and\\nthe bus bars are at the desired voltage. If the\\nmachines have a two-pole switch with a separate\\nswitch for the equalizer, I would close the equal-\\nizer switch first and then close the double-pole\\nmachine switch, afterward adjusting the rheostats.\\nQ. Sometimes you will see a switch in the field\\ncircuit. Should this ever be opened when that\\nmachine is in operation\\nA. Never.\\nQ. What would be the effect of opening the\\nswitch\\nA. It would produce a strong spark at the\\nswitch, and would be liable to seriously injure the\\ninsulation of the field coils of the machine, be-\\ncause the opening of the circuit produces for a\\nmoment a very high electric pressure that is liable\\nto pierce the insulation.\\nQ. Suppose two machines designed for 400\\namperes each are operating in multiple on a load\\nof 600 amperes, and the fuses or circuit breaker\\nof one of the machines opens the circuit, what\\neffect would you notice", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0264.jp2"}, "265": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 249\\nA. There would probably be great sparking or\\nflashing at the commutator of the other machine,\\nbecause it would be very much overloaded.\\nQ. What would you do in this case\\nA. Quickly open the circuit switches one by\\none and if this did not remedy the trouble, open\\nthe machine switch; and if this did not stop it,\\nturn the rheostat handle so as to lower the voltage\\nto the smallest possible amount and shut down\\nthe engine. If the trouble were due to nothing-\\nmore than overloading, it would be remedied by the\\nopening of a sufficient number of circuit switches.\\nQ. What are some of the troubles to which\\nrheostats are liable\\nA. Some of the coils may be burned out or\\ngrounded, or some of the contacts may become\\ndefective.\\nQ. In case a single machine is running and a\\ncoil of its rheostat should burn out, what would\\nbe the effect\\nA. The lamps on the circuit would all go out,\\nsince the opening of the field circuit would de-\\nstroy the magnetism of the machine and it would\\nfurnish no pressure.\\nQ. How would you remedy the difficulty tem-\\nporarily\\nA. By connecting wire across the terminals of\\nthe burned- out coil.", "height": "2855", "width": "1755", "jp2-path": "ropersquestions00rope_0265.jp2"}, "266": {"fulltext": "250 QUESTIONS AND ANSWERS FOR\\nQ. Suppose that two machines were running in\\nmultiple at the time the rheostat coil burned out,\\nwhat would happen\\nA. One of the machines would become over-\\nloaded, producing serious sparking or flashing.\\nQ. Suppose that one coil of the rheostat be-\\ncame grounded, how would you remedy it\\nA. By disconnecting that coil from the others\\nand putting in a temporary connection of wire to\\ntake its place.\\nQ. What are some of the methods of construct-\\ning rheostats for dynamos\\nA. The older method was to make up coils of\\nwire insulated on porcelain or other suitable\\nmaterial and mounted in an iron framework or\\nbox, the terminals of the coils being connected to\\nsuitable brass plates over which the rheostat arm\\nplayed. The more modern method is to imbed\\nthe wire coils in an insulating enamel, the wires\\nbeing wound in a flat coil instead of a spiral, so\\nthat they may lie very close to the iron frame-\\nwork this construction gives much greater com-\\npactness.\\nQ. How is the Weston switchboard voltmeter\\nconstructed\\nA. It consists of a permanent magnet of horse-\\nshoe form between the poles on which is pivoted\\na small coil of very fine wire connected to proper", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0266.jp2"}, "267": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 251\\nterminals. Whenever a current passes through a\\nwire the coil tends to turn in a certain direction\\nagainst the action of springs which tend to hold it\\nin place. The stronger the current the greater the\\ndeflection of the coil. Attached to the coil is a\\nlight needle which plays over a graduated scale.\\nQ. How does the ammeter differ from this\\nA. The ammeter is constructed in the same\\nway, but only a very small fraction of the current\\nto be measured passes through the coil. The\\ngreater part of the current passes through the\\nshunt of the instrument, this shunt being placed\\nin one of the leads coming from the machine.\\nThe terminals on the shunt are connected to the\\nterminals on the ammeter through a pair of flexi-\\nble leads about ten feet long.\\nQ. Would it do any harm to cut off a part of\\nthese leads\\nA. Yes it would totally destroy the accuracy\\nof the instrument. Each instrument requires a\\nspecial pair of leads of the proper resistance.\\nQ. How could you roughly test the accuracy of\\nyour ammeters\\nA. By operating first one machine on a certain\\nnumber of lamps at 110 volts exactly then throw\\noff that machine and operate the same number of\\nlamps with the other machine at the same pres-\\nsure. If the readings of the ammeter ^vere prac-", "height": "2855", "width": "1755", "jp2-path": "ropersquestions00rope_0267.jp2"}, "268": {"fulltext": "252 QUESTIONS AND ANSWERS FOR\\ntically the same in the two cases it is fair to\\nassume that they are reasonably correct. The\\nammeters can also be tested against the circuit\\nbreakers. If the circuit breaker always goes off at\\nthe same reading of the ammeter it may be as-\\nsumed that the ammeter has not lost its accuracy.\\nQ. How can the voltmeter be tested by com-\\nparison with some other voltmeter supposed to be\\ncorrect\\nA. The two voltmeters are connected up in\\nmultiple across the bus bars.\\nQ. Would you attempt to repair an ammeter or\\nvoltmeter that was out of order\\nA. On no account.\\nQ. How does a direct current motor differ from\\na dynamo as regards construction\\nA. Only in details of design. Practically, any\\ndirect current dynamo will operate satisfactorily\\nas a motor if current be supplied to it.\\nQ. What would you do in case you desired to\\nreverse the direction in which a motor runs\\nA. I would change the connections so as to re-\\nverse the direction of current through either the\\nfield or the armature, and if necessary to prevent\\nsparking would shift the rocker arm that carries\\nthe brushes.\\nQ. For what class of work are series motors\\nused?", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0268.jp2"}, "269": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 253\\nA. Series motors are used in those cases where\\nit is necessary to start with full load and where\\nautomatic regulation for constant speed is not\\nnecessary, as in hoists, cranes, street railway,\\netc. J\\nQ^ When are shunt motors used\\nA. 9 In those cases where automatic regulation\\ntor constant speed is desired.\\nQ. Are compound motors ever used\\nA. Yes in cases where closer speed regulation\\nthan that given by shunt motors is desired.\\nQ. How is the change of speed accomplished in\\nthe case of the series motor supplied from a con-\\nstant pressure circuit\\nA. There are two methods commonly used\\nOne is to change the pressure supplied to the\\nmotor by putting in series with it a rheostat in\\nwhich more or less pressure is used up according\\nto the position of the rheostat handle. Lowering\\nthe pressure supplied to the motor lowers its\\nspeed, and vice versa; the other is to change the\\nstrength of the field of the motor. The field\\ncoils are wound in sections, and the ends of the\\nsections are brought out to a species of commu-\\ntator called the controller. In one position of the\\ncontroller handle the sections are connected in\\nseries, which cuts down the current strength and\\nmakes the field magnet comparatively weak In", "height": "2855", "width": "1755", "jp2-path": "ropersquestions00rope_0269.jp2"}, "270": {"fulltext": "254 QUESTIONS AND ANSWERS FOR\\nthe next position three of the sections, for ex-\\nample, will be in series, and three others in series,\\nand the two sets of three will be connected in\\nmultiple. This arrangement diminishes the re-\\nsistance of the circuit and lets more current\\nthrough; another position puts more sections in\\nmultiple and fewer in series, and so on until the\\nfinal step puts all the sections in multiple, giving\\nthe lowest possible resistance and the strongest\\npossible field. Frequently, the combination of\\nthe two methods is used, the resistance being em-\\nployed on the first positions of the rheostat\\nhandle in order to cut down the excessive flow of\\ncurrent on starting.\\nQ. In what way are shunt motors regulated for\\nchanges in speed when supplied from constant\\npressure circuits\\nA. By putting resistance coils in series with the\\narmature and cutting out more or less of them\\naccording as a higher or lower speed is desired, or\\nb} putting a rheostat in series with the field cir-\\ncuit and varying the current around the field coils\\nby adjusting the rheostat handle.\\nQ. How are compound motors regulated for\\nchanges in speed\\nA. Generally like shunt motors, although in\\nsome cases the series coils are wound in sections\\nthrown in series and multiple by the controller.", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0270.jp2"}, "271": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 255\\nQ, In starting up a shunt or compound motor,\\nwhat precaution is necessary and why\\nA. Considerable resistance must be put in series\\nwith the armature. If this were not done the\\nvery low resistance of the armature would permit\\nthe flow of an enormous current which would\\nblow fuses or overheat the armature coils and\\ncause excessive sparking at the brushes. As the\\nmachine speeds up this resistance is cut out.\\nThe whole arrangement is automatically arranged\\nfor by the starting box that is supplied with each\\nmotor.\\nQ. What other protective devices are required\\nwith shunt motors\\nA. Motors must be protected from the danger\\nof overload which by slowing down the motor\\ndiminishes its back electro-motive force. This\\nwould allow an excessive current to flow, which if\\nlong continued would burn out the armature\\ncoils. Formerly this protection was provided by\\nfuses. At the present time a circuit breaker\\nmounted on the starting box is almost universally\\nemployed. Another thing that must be guarded\\nagainst is the accidental temporary interruption of\\nthe supply circuit (which would of course stop\\nthe motor) and its being subsequently closed\\nagain. If this happened it would throw full\\nvoltage on the motor armature, and this would", "height": "2855", "width": "1755", "jp2-path": "ropersquestions00rope_0271.jp2"}, "272": {"fulltext": "256 QUESTIONS AND ANSWERS FOR\\nresult in an excessive flow of current. To guard\\nagainst this difficulty the starting box is arranged\\nso that whenever the pressure of the circuit is\\ndiminished below a certain amount or is zero in\\ncase of actual interruption of the circuit, the rheo-\\nstat arm is pulled back into the position which\\nthrows a resistance in series with the armature.\\nQ. What is a motor generator\\nA. A combination of motor and generator on\\nthe same shaft.\\nQ. How are dynamos and motors rated\\nA. Dynamos are rated, as regards their capacity,\\nin kilo watts, and motors are rated in horse-power.\\nQ. What is the relation between the kilo watt\\nand the horse-power\\nA. One horse-power is practically equivalent to\\nkilo watt.\\nQ. What is the arrangement of the Edison\\nthree-wire system\\nA. See Roper s Catechism, page 311.\\nQ. Can a system of house wiring installed on\\nthe Edison three-wire system be operated from\\none machine, and if so, how\\nA. Yes; the two outside feeders must be con-\\nnected together so as to be of the same polarity\\nand joined to one of the brushes or bus bars.\\nThe neutral feeder must be connected to the other\\nbrush or bus bar.", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0272.jp2"}, "273": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 257\\nQ. Is this arrangement ever employed in prac-\\ntice\\nA. Often; it is arranged so that the change of\\nconnections is made by a double-throw switch. In\\none position of the switch the house circuit is\\nthrown on to the Edison mains; in the other posi-\\ntion of the switch the circuit is thrown on to the\\nhouse generator.\\nQ. What is the commercial efficiency of a\\ndynamo\\nA. It is the ratio between the amount of elec-\\ntric power furnished by the dynamo and the\\namount of mechanical power delivered to the\\ndynamo.\\nQ. How can the efficiency of a dynamo be\\nmeasured\\nA. By indicating the engine when the dynamo\\nis full loaded and noting the reading of the am-\\nmeter and voltmeter, then indicating the engine\\nwhen the dynamo is running idle with no current\\nflowing through the fields. The difference between\\nthe horse-power of the two indicator diagrams is\\nvery closely the amount of mechanical power sup-\\nplied to the dynamo. The product of the volts\\nand amperes divided by 746 gives the power de-\\nveloped by the dynamo the quotient of the lat-\\nter by the former is the commercial efficiency of\\nthe dynamo.\\n17", "height": "2855", "width": "1755", "jp2-path": "ropersquestions00rope_0273.jp2"}, "274": {"fulltext": "258 QUESTIONS AND ANSWERS FOR\\nQUESTIONS FOR ELECTRICIANS OR WIREMEN.\\nQ. What are the principal systems of distribu-\\ntion for electric lighting?\\nA. The series system and the parallel system.\\nQ. What is the difference between the two s}*s-\\ntems\\nA. In the series system the lamps are connected\\nin tandem, the entire current flowing successively\\nthrough each lamp. In the multiple system the\\ncurrent from the dynamo is divided, a part flow-\\ning through each lamp. After passing through\\nthe lamps the separate currents unite and flow\\nback to the dynamo.\\nQ. On which of these systems are motors gener-\\nally operated\\nA. On the parallel system.\\nQ. To what class of work is the series system\\npractically confined?\\nA. To outside arc lighting.\\nQ. What is the vital necessity on a series sys-\\ntem to make the lighting successful\\nA. The series system must be a constant cur-\\nrent system that is to say, cutting out or in more\\nor less of the lamps must not alter the value of\\nthe current.\\nQ. What is necessary on the multiple or paral-\\nlel system", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0274.jp2"}, "275": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 259\\nA. This system is necessarily a constant poten-\\ntial or constant pressure system that is, turning\\non or of! lamps must not materially alter the pres-\\nsure on any other lamps.\\nQ. What is the Edison three- wire system\\nA. The Edison three- wire system is a peculiar\\ncombination of series and multiple systems. Two\\nlamps are placed in series with each other and the\\nsets of two are in multiple with each other. A\\nconductor, called the neutral, connects the point\\nof junction of the lamps which are placed in\\nseries with each other and runs to the point of\\njunction of the two generators (in series with each\\nother) which supply the system.\\nQ. What is the advantage of the Edison system\\nA. The Edison system secures economy in the\\nsize of wire, from the fact that it permits the dis-\\ntribution at a higher pressure without saiy serious\\ndisadvantages for example, the distribution on\\nthe feeders and mains is essentially at 220 volts\\nwhile the pressure on the branch circuits and the\\nlamps is only 110 volts.\\nQ. Could not the same economy be obtained by\\nusing a simple multiple system with 220-volt\\nlamps\\nA. Yes; but it is difficult to make good 220-\\nvolt lamps and 110- volt lamps are superior to\\nthem. Moreover, the lower pressure lamp is more", "height": "2855", "width": "1755", "jp2-path": "ropersquestions00rope_0275.jp2"}, "276": {"fulltext": "260 QUESTIONS AND ANSWERS FOR\\ndesirable from the standpoint of safety, since\\nthere will be less liability to leakage from the cir-\\ncuit when the lower pressure is used. A shock\\nfrom the 110 volts is scarcety noticeable or at any\\nrate not disagreeable, while the shock from 220\\nvolts is quite severe.\\nQ. What determines the necessary size of wire\\nin any particular case\\nA. There are two requirements which must be\\nmet First, the wire must be large enough so that\\nthe current that will flow through it will not heat\\nit beyond a certain amount; this requirement has\\nbeen definitely laid down by the Fire Under-\\nwriters, who provide tables stating the allowable\\ncurrent for various sizes of wire. Second, the\\nsize of wire is determined by the aimount of\\nenergy which we are willing to lose on it. This\\nloss of energy depends on the current that will\\nflow and the resistance of the conductor.\\nQ. What loss of pressure is allowable on con-\\nductors\\nA. There is no definite rule for this. In build-\\nings, the total loss of pressure from the gener-\\nator to the most distant lamps seldom ex-\\nceeds 5 per cent, and with the ordinary system\\nof multiple wiring is rarely more than 3 per cent,\\nof the voltage of the lamps. A part of the loss is\\non the feeders, another part on the mains, and the", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0276.jp2"}, "277": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 261\\nrest on the branches and in the switches, fuses,\\netc.\\nQ. Explain how you would calculate the size\\nof wire to be used in the following case Ten 16\\nc. p. lamps whose voltage is 110 are to be sup-\\nplied by current from a dynamo 200 feet away.\\nThe loss permissible is 1 per cent.\\nA. Since the allowable loss is 1 per cent, the\\nvolts lost will be 1.1. The current for ten lamps\\nwill be practically 5 amperes. The total length\\nof wire will be 2 X 200, or 400 feet. By Ohm s\\nlaw C or R-=. _ Therefore R or\\n22, hence the wire must be of such size that 400\\nfeet, of it has a resistance of not over 22 ohm. 1000\\nfeet of this size would have a resistance equal to\\n.22 X 1000 divided by 400, or .275. Looking in\\nthe wire tables under the column headed ohms per\\n1000 feet, it will be found that a No. 4 wire fulfils\\nthe requirement. Finally, looking in the table of\\nsafe carrying capacities given by the National\\nBoard of Fire Underwriters it is found that a No.\\n4 wire will more than carry the current with\\nsafety.\\nQ. What varieties of electric wiring are there\\nA. Open work, such as porcelain work and\\nmoulding work and concealed, where the wires\\nare carried on porcelains or in conduits.", "height": "2855", "width": "1755", "jp2-path": "ropersquestions00rope_0277.jp2"}, "278": {"fulltext": "262 QUESTIONS AND ANSWERS FOR\\nQ. What kind of conduits are used at the pres-\\nent day\\nA. For the great bulk of the work iron or steel\\nconduits, of which there are two varieties: one in\\nwhich the tube, which is practically a gas-pipe, is\\nlined with some insulating compound; the other,\\nwhere the tube is covered inside and out by a\\nhard enamel.\\nQ. What is circular loom conduit, and in what\\ncases can it be used and where must it not be used\\nA. Circular loom tube is a semi-flexible con-\\nduit made of paper and covered with cotton,\\nwhich is used in buildings of wooden construc-\\ntion, particularly in cases where it is desired to\\ninstall electric work in an old building. The cir-\\ncular loom is used to cover the wires run down\\npartitions, since it may be fished in without injur-\\ning the finished work in the house. It is abso-\\nlutely useless in those cases where it is liable to be\\nsubjected to moisture or is in contact with cement;\\nit must therefore be regarded as a makeshift, to\\nbe used only in those cases where iron conduit\\ncannot on account of its stiffness be installed or\\nwhere the work could not be done on porcelain\\nwithout destroying costly finished surfaces.\\nQ. Is there any difference as to the number of\\nwires carried in a C. L. tube or in an iron\\nconduit", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0278.jp2"}, "279": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 263\\nA. Yes; only one wire is carried in C. L. tube;\\nin iron conduit two wires are carried in the two-\\nwire system and three in the three-wire system,\\nexcept occasionally in case the feeders are so large\\nthat it is not possible to draw more than one wire\\nin the tube.\\nQ. What is the best way to cut off iron con-\\nduit, and why\\nA. By means of a hack-saw. This method gives\\na smoother cut and leaves less ragged edges, and\\ndoes not injure the lining or the enamel as much\\nas the use of ordinary pipe cutters.\\nQ. After cutting off a piece of pipe, what should\\nbe done to the ends\\nA. They should be smoothed with a reamer or\\nfile.\\nQ. In making joints in conduits, how should\\nthe joints be treated\\nA. The pipes should be screwed into the coup-\\nlings so that they butt against each other, the\\nthreads being previously treated with white lead\\nso as to make a water-tight joint.\\nQ. What are the principal troubles to be\\navoided in doing conduit work\\nA. Too many bends, joints that are not butted\\ntogether properly and are not water-tight, and\\nrough edges at the joints and at the outlets that\\nwill injure the insulation of the wires.", "height": "2855", "width": "1755", "jp2-path": "ropersquestions00rope_0279.jp2"}, "280": {"fulltext": "264 QUESTIONS AND ANSWERS FOR\\nQ. How are conduit tubes fastened into outlet\\nor switchboxes\\nA. There are several methods One is to tap\\nthe outlet box with a thread and screw the conduit\\ninto this; another is to put a lock-nut on the pipe\\noutside of the box and another lock-nut inside: a\\nthird is to put a coupling outside and a special in-\\nsulated nut inside the box, which nut screws into\\nthe coupling.\\nQ. What are the disadvantages of the first\\nmethod\\nA. It is very difficult to get the switch or out-\\nlet box to stand plumb; especially when, as in\\nthe case of gang switches, several pipes enter and\\nleave the box.\\nQ. What is the general arrangement at a sub-\\nswitchboard for bringing in the tubes and wires\\nconveniently\\nA. The switchboard proper is surrounded by an\\nouter wooden or iron box the walls of which are\\nabout 3 inches or 4 inches distant from the inner\\nwall. The latter is generally made of thin slate\\nor marble. The conduit tubes are brought\\nthrough the outer box and stop there. The wires\\ncontinue through holes in the inner slate walls\\nand are attached to the proper terminals. The\\nspace between the inner and outer walls is covered\\nby the trim of the door. By this arrangement", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0280.jp2"}, "281": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 265\\nthe rough box can be put in before the conduit\\nwork is done and the switchboard proper inserted\\nat a later date when the building is nearing com-\\npletion and the door and trim finally put on just\\nin time to be finished by the painters.\\nQ. Why are ends of conduit tubes plugged up\\nas soon as they are installed\\nA. For two reasons: one to prevent any small\\nobjects from getting into the tubes and stopping\\nthem up, the other to prevent the condensation of\\nmoisture in the tubes, which would injure the\\ninsulation of the system.\\nQ. What are the commercial sizes of conduit at\\nthe present time\\nA. Conduits are sized according to their nominal\\ninternal diameter, the sizes being -f^- J -fa y\\nft 1\u00c2\u00a3 W, 1* W, and 2|\\nQ. How many bends would you allow in a run\\nof conduit?\\nA. That would depend somewhat on the length\\nof run; in any case I w^ould not allow more than\\nfour.\\nQ. Explain how wires are put into a conduit\\nsystem.\\nA. A springy steel wire about y\\\\ of an inch wide\\nand y 1 of an inch thick, having a length usually of\\n100 feet, is pushed into a length of conduit from\\none of the outlets. A man at the outlet on the", "height": "2855", "width": "1755", "jp2-path": "ropersquestions00rope_0281.jp2"}, "282": {"fulltext": "266 QUESTIONS AND ANSWERS FOR\\nother end pulls this wire through and with it a\\npulling cord or wire. The two wires to be drawn\\nare then attached to the cord or wire and are gradu-\\nally worked in by the pulling on one end assisted\\nby a pushing and twisting motion on the other end.\\nThe friction of the wire against the walls of the\\nconduit is diminished by blowing in powdered\\nsoapstone before the wires are drawn in.\\nQ. What kinds of insulation are used on wires,\\nand for what class of work are these used\\nA. The kind of insulation used depends upon\\nthe pressure to be used on the system. For\\nelectric bell and other signal work, where only a\\nfew cells are used, the pressure not exceeding 10\\nvolts, a comparatively low insulation is sufficient.\\nIn such cases a wire is covered with two or more\\nlayers of cotton impregnated in paraffin. For out-\\nside wiring the conductors are covered with two\\nor three layers of braided cotton, imj^regnated\\nwith some bituminous insulating compound.\\nThese wires are called weather-proof wires. For\\ninside wiring on porcelain an insulation called\\nfire- and water-proof has been largely used; the\\nwire is covered with a cotton braid impregnated\\nwith w r hite lead, and afterward another covering\\nof cotton braid is put on and slicked over with the\\nweather-proof insulation. The practice now is\\nalmost universally to use an insulation made up", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0282.jp2"}, "283": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 267\\nof a mixture of rubber and other insulating mate-\\nrials, usually of a bituminous nature. The higher\\nthe pressure to be used, the greater the percentage\\nof rubber that should be employed.\\nQ. With a run of 100 feet of conduit hav-\\ning three bends, how large size of wire could you\\ndraw in, there being two wires to the tube\\nA. About a No. 8, B. S.\\nQ. How can you tell whether or not the con-\\nductors in a conduit tube are all right\\nA. Roughly by means of the magneto bell. I\\nwould connect one terminal of the bell to the tube,\\nfiling a bright spot for making the connection,\\nand with the other terminal of the magneto would\\ntouch first one of the conductors and then the\\nother if the insulation is very bad the bell will\\nring. If not, the bell will make no noise. After\\nmaking this test I would connect one terminal to\\nthe other wire and test for short circuit. If the\\nbell were silent on both of these tests I should\\npssume that the wires were in good condition.\\nQ. Magneto bells are sold as 10,000 ohms,\\n15,000 ohms, 25,000 ohms, etc., up to 50,000\\nohms. What do these terms mean, and which\\none would you consider best for testing\\nA. A 50,000 ohm bell is one which is sup-\\nposed to ring through a resistance connected\\nacross its terminals as great as 50,000 ohms. A", "height": "2861", "width": "1787", "jp2-path": "ropersquestions00rope_0283.jp2"}, "284": {"fulltext": "268 QUESTIONS AND ANSWERS FOR\\n10,000 ohm bell is supposed to ring through a re-\\nsistance of 10,000 ohms. I would, of course,\\nprefer the 50,000 ohm bell for testing.\\nQ. What other method of testing the insulating\\nresistance is more accurate\\nA. The test with a voltmeter.\\nQ. Why are two wires carried in the iron tubes\\nA. Because it is safer and because if alternating\\ncurrents are used on the circuit there would be\\notherwise an excessive loss of pressure.\\nQ. What is a distribution board, and by what\\nother names is it called\\nA. A distribution board is a small switchboard\\nwhere the current from a main feeder is dis-\\ntributed to supply smaller feeders or branch cir-\\ncuits. It contains fuse blocks and often switches.\\nOther names are sub-switchboard, panel board,\\ntablet board, cut-out box, and center of distribu-\\ntion.\\nQ. What is a fuse, and why and where is it used\\nA. A fuse consists of a piece of metal, usually\\nsome alloy of lead which will melt at a fairly low\\ntemperature, soldered to copper terminals. It is\\nintended to melt whenever the current passing\\nthrough it exceeds the safe carrying capacity of\\nthe wire which the fuse is designed to protect.\\nFuses are placed at all points of a circuit where\\nthere is a change made in the size of the wires.", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0284.jp2"}, "285": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 269\\nQ. What is a closed arc lamp, and what are its\\nadvantages over the open arc\\nA. The closed arc lamp is one in which the\\nsmall inner globe surrounds the arc, preventing,\\nto a great extent, air from coming into contact\\nwith the arc. The principal advantages of the\\nclosed arc lamp are that the consumption of the\\ncarbons is very much diminished and the light is\\nsteadier.\\nQ. At what rate do carbons burn in the two\\ntypes of lamp?\\nA. Carbons last about seven hours in the open\\narc lamp and about one hundred hours in the\\nclosed arc lamp.\\nQ. When a single lamp is used on a constant\\npressure circuit, what is the general arrangement\\nof the mechanism\\nA. The current which comes from the line to\\nthe positive lamp terminal passes through a coarse\\nwire coil and then through a chain or brush con-\\ntact to the upper carbon. After passing through\\nthe upper carbon across the arc and through the\\nlower carbon it flows through a wire resistance to\\nthe other terminal of the lamp and thence to the\\nline. This wire resistance is arranged so that it\\ncan be readily varied.\\nQ. Explain the operation of the lamp.\\nA. When the current passes through the coil", "height": "2861", "width": "1787", "jp2-path": "ropersquestions00rope_0285.jp2"}, "286": {"fulltext": "270 QUESTIONS AND ANSWERS FOR\\nit raises an iron armature or core to a certain\\nheight depending upon the strength of the cur-\\nrent. Attached to this armature is a clutch de-\\nvice which raises the upper carbon and l strikes\\nthe arc. The lamp burns gradually, consuming\\nthe carbons and lengthening the arc. As the arc\\nlengthens its resistance increases and the current\\nbecomes less which allows the armature to drop\\ndown slightly. The clutch trips against a stop\\nwhich lets the upper carbon rod slide through a\\nlittle, thus shortening the arc until the current\\nhas increased enough to lift the clutch off from\\nthe tripping stop. The feeding of the lamp then\\nceases and the lamp continues to burn until the\\narc again becomes too long, when the operation is\\nrepeated.\\nQ. What would you understand by a 2000 c. p.\\nlamp?\\nA. The meaning of this expression is indefi-\\nnite. With open arc lamps I should understand\\na lamp which along the direction in which it\\ngives the greatest amount of light (about 45 de-\\ngrees from the horizontal) produces an intensity\\nof illumination equal to that of 2000 candles.\\nQ. How much current passes through such a\\nlamp, and what is the approximate pressure be-\\ntween its terminals and the amount of power used\\nin the lamp", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0286.jp2"}, "287": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 271\\nA. The current is about 10 amperes; the pres-\\nsure, about 45 volts (not including that which is\\nlost in the wire resistance) and the power there-\\nfore is about 450 watts.\\nQ. What would you understand by a 2000 c. p.\\nclosed arc lamp\\nA. One that uses about 450 watts power.\\nQ. What current is used in a nominal 2000\\nc. p. closed arc lamp\\nA. When burning steadily, about 5 amperes.\\nWhen the lamp first starts up it may be as high\\nas 9 amperes.\\nQ. What voltage exists across the arc of the\\nclosed arc lamp\\nA. About 80 or 90 volts.\\nQ. Why is a wire resistance placed in series\\nwith the arc for lamps used on constant pressure\\ncircuits\\nA. For two reasons: First, a certain amount of\\nresistance is necessary to steady the arc; second,\\nthe remainder of the resistance is used to cut\\ndown the pressure from 110 volts to about 50\\nvolts.\\nQ. Could not two of these lamps be connected\\nup in series across 110 volts circuit and so obviate\\nwasting a large amount of energy in the wire\\nresistance\\nA. The construction of the lamps would have", "height": "2861", "width": "1787", "jp2-path": "ropersquestions00rope_0287.jp2"}, "288": {"fulltext": "272 QUESTIONS AND ANSWERS FOR\\nto be modified; an auxiliary fine wire coil con-\\nnected across the arc is introduced and placed so\\nthat it controls the armature operating the clutch\\ndevice. As the arc lengthens the pressure between\\nthe two carbons increases, and this sends more\\ncurrent around the fine wire coil which lowers the\\narmature and causes the clutch to feed.\\nQ. Are the closed arc lamps ever connected two\\nin series\\nA. Yes; across a voltage of 220 or more.\\nQ. In connecting up arc lamps, does it make\\nany difference which terminal of the lamp is con-\\nnected to the positive side of the circuit\\nA. Yes; the upper carbon must be connected\\nto the positive side of the circuit, else the greater\\npart of the light will be thrown uj^ward to the\\nceiling instead of downward, as it should be.\\nQ. How can you tell whether the connection\\nhas been properly made\\nA. While the lamp is burning look at the arc\\nthrough a smoked glass; in the case of open arc\\nlamps, the upper carbon should have a little crater\\nat its lower end, while the lower carbon should burn\\nslightly pointed. With closed arc lamps the differ-\\nence in appearance in the two carbons is very\\nmuch less, though in either case the upper carbon\\nwill be the brighter. If a Weston voltmeter is at\\nhand the polarity can be tested by means of it.", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0288.jp2"}, "289": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 273\\nQ. What is the difference between a single-stroke\\nbell and a vibrating bell\\nA. A single-stroke bell is one which makes only-\\none stroke for each time that circuit is closed; a\\nvibrating bell is one whose hammer continues to\\nvibrate as long as the circuit is closed. A vibrat-\\ning bell may be changed into a single-stroke bell\\nby short-circuiting the make and break mounted\\non the armature.\\nQ. Suppose that you had several bells that you\\ndesired to have vibrate simultaneously from one\\npush-button, how could you arrange them\\nA. There are two ways: First, the bells could\\nbe connected in multiple; second, all but one of\\nthe bells could be changed to single stroke, that\\none being left vibrating then the whole number\\ncould be connected in series with each other and\\nwith the battery and push-button.\\nQ. Show by diagram how you could connect\\nthree bells to ring by a single push-button.\\nA.\\nQ. Draw the connections for two bells to be\\nrung by either of two push-buttons.\\n18", "height": "2861", "width": "1787", "jp2-path": "ropersquestions00rope_0289.jp2"}, "290": {"fulltext": "274 QUESTIONS AND ANSWERS FOR\\nA.\\n-tt-\\n5~5 odioci\\nQ. Draw the connections for a return call be-\\ntween two points.\\nA.\\nQ. Draw the connections for an annunciator\\nsystem.\\nA.\\nAMtomttfte\\nSignal Bell.\\nQ. What is an automatic set-back, and how is\\nit arranged\\nA. An automatic set-back is a device by which", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0290.jp2"}, "291": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 275\\nan annunciator shows only the last call which has\\nbeen made. This is accomplished by an auxil-\\niary electro-magnet placed in the annunciator so\\nconnected that current flows through it whenever\\nany push-button is pressed. Attached to its arma-\\nture is the rod which resets the needles.\\nQ. Draw the connections for a return call an-\\nnunciator system.\\nA. See Roper s Handy-Book, page 762.\\nQ. Should there be an automatic set-back on an\\nelevator annunciator\\nA. No.\\nQ. How does a burglar-alarm system differ\\nfrom an ordinary annunciator system\\nA. The push-buttons that are placed in doors\\nor window casings are of a different pattern, and\\nmoreover several are connected in multiple on\\none circuit. The annunciator has an additional\\nbell in the auxiliary circuit, which circuit is\\nclosed if any one of the drops operate. This\\nbell will therefore continue to ring until some one\\nrestores the drops to their normal position. The\\nannunciator has several attachments not found on\\nthe ordinary annunciator, such as a switch to\\nthrow the instrument off in the daytime, a switch\\nby which the condition of the batteries may be\\ntested, and another which is thrown when it is\\ndesired to test the condition of any circuit with-", "height": "2861", "width": "1787", "jp2-path": "ropersquestions00rope_0291.jp2"}, "292": {"fulltext": "276 QUESTIONS AND ANSWERS FOR\\nout the noise of the bell. Sometimes a clock is\\nadded which automatically throws off the instru-\\nment at any desired hour.\\nQ. What kind of battery cells are used with\\nannunciator systems\\nA. Cells of the so-called open-circuit type and\\nusually some form of the zinc-carbon-sal-ammo-\\nniac cells.\\nQ. How many cells are necessary\\nA. This depends entirely on the number of\\npoints on the instrument and upon the distance\\nand size of wire. In houses, as a rule, four cells\\nwill be sufficient. If the distances are very long\\nit will be necessary to increase the number of\\ncells in series and if the number of points on the\\ninstrument is large, as, for example, in hotels,\\nthen it will be desirable to connect several of the\\ncells in multiple with each other.\\nQ. What principal systems of watchmen s clock\\nare there\\nA. The battery system and the magneto system.\\nQ. Explain how a battery system is arranged\\nand operated.\\nA. The wiring of the system is similar to that\\nof the simple annunciator system. The push-\\nbuttons are of such a shape that a circuit can be\\nclosed in them only by the insertion of a certain\\nkey that the watchman carries. The annunciator", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0292.jp2"}, "293": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 277\\nof the ordinary system when slightly modified\\nbecomes the watchman s clock, the signal bell\\nand automatic set-back being omitted. The ar-\\nmature of each drop operates a needle which\\npunctures a hole in the paper recording dial\\nwhich is divided into spaces corresponding to the\\nhours and fractions of an hour. This dial makes\\none complete turn in twelve hours, and therefore\\nthe position of the holes tells at what time the\\ncircuit was closed by the watchman. The dial\\nalso has a number of circles marked on it corres-\\nponding to the number of stations, and each\\nneedle pricks its holes in one of the circular\\nspaces formed by these rings, so that a hole in a\\ncertain ring shows that the key has been put in\\nthe corresponding station push-button.\\nQ. How does a magneto system differ from a\\nbattery system\\nA. The wiring and clock are practically the\\nsame, but instead of a special push-button to be\\noperated by a key a small magneto is placed at\\neach station. The watchman carries a handle by\\nwhich he turns the shaft of the magneto arma-\\nture. This sends a current through the corres-\\nponding coil at the clock and causes its needle to\\nmake a record.\\nQ. What are the advantages of a magneto\\nsystem over the battery system", "height": "2861", "width": "1787", "jp2-path": "ropersquestions00rope_0293.jp2"}, "294": {"fulltext": "278 QUESTIONS AND ANSWERS FOR\\nA. There are no batteries to renew and to take\\ni3are of and the watchman cannot make a proper\\nrecord on the dial without actually going to the\\nstation; whereas with the battery system, if the\\nwatchman can get at the two wires leading to any\\nstation to connect them together, he can make the\\ndock register just as well as by going to the station.\\nQ. What is a Lechanche cell\\nA. A Lechanche cell has for one pole a zinc\\nrod, for the other a carbon plate, and the two are\\nimmersed in a solution of sal-ammoniac. In addi-\\ntion to this there is a block of compressed man-\\nganese binoxide.\\nQ. What is the object of this manganese\\nA. It prevents what is known as polarization of\\nthe cell.\\nQ. What are the effects of polarization\\nA. The voltage is diminished and the resistance\\nincreased by the accumulation on the carbon plate\\nof particles of hydrogen gases.\\nQ. What voltage does a single Lechanche cell\\nproduce\\nA. About 1J- volts.\\nQ. How could you obtain a voltage of 15 volts\\nwith Lechanche cells\\nA. By connecting ten of them in series.\\nQ. What are dry cells, and what are their ad-\\nvantages and disadvantages", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0294.jp2"}, "295": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 279\\nA. They are cells in which the solution has\\nbeen reduced to a pasty condition. Their only\\nadvantage is their greater portability their dis-\\nadvantages are a high resistance and greater polar-\\nization.\\nQ. Why and how is a zinc battery plate amal-\\ngamated\\nA. Zincs are amalgamated so as to prevent the\\nconsumption of the metal when the circuit of the\\nbattery is open. The process of amalgamation\\nconsists of dipping the zinc into weak sulphuric\\nacid until it is clean, and then rubbing mercury\\non its surface with a cloth until it looks bright all\\nover.\\nQ. What is the best form of zinc pole, and why\\nA. The best form is that which gives a cell of\\nthe least resistance, and this depends upon the\\nform of the other pole. In order to diminish the\\nresistance the plates should expose as much sur-\\nface as is possible, and the distance between the\\nplates should be as small as possible. Therefore,\\nif the carbon pole is of cylindrical form the best\\nshape for the zinc would be a hollow cylinder\\nsurrounding the carbon.\\nQ. Which is the better for a carbon plate, one\\nwhich is very dense and close in structure or one\\nwhich is porous\\nA. The porous carbon is much better, as the", "height": "2861", "width": "1787", "jp2-path": "ropersquestions00rope_0295.jp2"}, "296": {"fulltext": "280 QUESTIONS AND ANSWERS FOR\\noxygen taken up in the pores assists in removing\\nthe hydrogen particles that collect on the carbon\\nplate and produce polarization.\\nQ. When cells of the zinc-carbon-sal-ammoniac\\ntype fail to operate properly, what would you\\ndo?\\nA. I would examine first the zinc plate and see\\nif it were eaten up, and if so, I would replace it\\nwith a new one. If the zinc is all right I would\\nexamine the solution, and if this is of a yellowish\\ncolor a new solution is needed. If the cell has\\nbeen in use some time it will be desirable to boil\\nthe carbon plate for some time in water.\\nQ. Is the zinc-carbon-sal-ammoniac cell suitable\\nfor use in operating small motors or lamps\\nA. No; the cell polarizes too readily; for such\\nwork the bichromate cell or the Edison-Lalande are\\nadapted.\\nQ. Describe the bichromate cell.\\nA. The bichromate cell consists of a zinc and a\\ncarbon plate in a solution of chromic acid. As\\nthe zinc is attacked by chromic acid even when\\nthe circuit is open, the cell is arranged so that\\nwhen not in use the zinc can be raised and held\\nout of contact with the acid.\\nQ. What is the pressure furnished by a bichro-\\nmate cell?\\nA. About 2 volts.", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0296.jp2"}, "297": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 281\\nQ. Describe the Edison- Lalande cell.\\nA. The Edison-Lalande cell consists of a zinc\\nand a copper oxide plate suspended in a solution\\nof caustic potash.\\nQ. What is the pressure furnished by the Edi-\\nson-Lalande cell\\nA. About -j% volt.\\nQ. Will a larger size cell give a higher voltage\\nthan a small cell\\nA. No; the voltage is the same, but the resist-\\nance of the larger cell is less.\\nQ. In mixing up a sal-ammoniac solution, is it\\nbetter to use warm or cold water\\nA. Warm water, because the sal-ammoniac when\\ndissolving produces a considerable degree of cold,\\nand this is liable to crack the glass jars.\\nQ. Describe the Daniell cell, gravity pattern.\\nA. The Daniell cell consists of a copper termi-\\nnal made up of thin sheet copper, which is placed\\nin the bottom of the glass jar; crystals of copper\\nsulphate are strewn over the plate and water is\\nadded until the jar is nearly full. A zinc plate is\\nsuspended at the top of the jar and a little sul-\\nphuric acid added to start the cell.\\nQ. What is the voltage of the Daniell cell, and\\nfor what kind of work is it adapted\\nA. The voltage is about one volt. The cell is\\nadapted to work in which the circuit is closed", "height": "2836", "width": "1825", "jp2-path": "ropersquestions00rope_0297.jp2"}, "298": {"fulltext": "282 QUESTIONS AND ANSWERS FOR\\npractically all the time, as in telegraph work and\\nin certain signal s} T stems.\\nQ. What kind of cells are used for operating\\nburglar-alarm and watchmen s clock systems, and\\nhow many?\\nA. Some form of the zinc-carbon-sal-ammoniac\\ncell. The number needed depends upon the dis-\\ntances and the clock used, but generally about six\\nwill be sufficient.\\nQ. When the wires of bell, burglar- alarm, or\\nwatchmen s clock system are installed in conduit,\\nis there any limit to the number of wires that\\nmay be put in one tube\\nA. As many wires may be put in one tube as\\ncan be readily drawn in and out.\\nQ. What kinds of wire are used for this class\\nof work?\\nA. Generally a wire insulated with two layers\\nof cotton dipped in paraffin, called annunciator\\nwire, is used on account of its cheapness. Office\\nwire, which is a heavier insulation of the same\\nkind, is used generally for the battery or common\\nwire. In better classes of work a rubber-covered\\nwire is used for the common wire and a weather-\\nproof or fire- and weather-proof insulation for the\\nother wires.\\nQ. What are the two principal telephone sys-\\ntems", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0298.jp2"}, "299": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 283\\nA. The exchange system and the intercommu-\\nnicating system.\\nQ. What is the difference between the arrange-\\nments of the two systems\\nA. In the exchange system two wires run from\\na central point to each telephone subscriber.\\nThese wires are each connected to the drop or\\nindicating device of the exchange switchboard.\\nThe exchange operator, by means of convenient\\nplugs and cords, connects the circuit of any one\\nsubscriber to the circuit of the party with whom\\nhe desires to speak. In the intercommunicating\\nsystem there are as many wires as there are\\ninstruments plus two or three common wires, and\\nall of these wires run to each instrument termi-\\nnating in a switch. By throwing this switch to\\nthe point corresponding to any desired party a\\nsubscriber puts himself in communication with\\nthat party.\\nQ. How does a subscriber call up Central on the\\nexchange system\\nA. There are two methods of calling one\\nwhere a battery and vibrating bell is used, the\\nother where a magneto bell is placed at each\\ninstrument. The battery call is suitable for short\\ndistances only, while the magneto is equally good\\nfor short and long distances. At the exchange\\nthere is a sort of an annunciator device in each", "height": "2836", "width": "1825", "jp2-path": "ropersquestions00rope_0299.jp2"}, "300": {"fulltext": "284 QUESTIONS AND ANSWERS FOR\\ncircuit, so that when the subscriber presses his\\nbutton or turns the crank of his instrument, as\\nthe case may be, a corresponding shutter falls on\\nthe exchange switchboard.\\nQ. How are calls made by the exchange oper-\\nator?\\nA. On the battery call system, the wiring and\\ngeneral arrangement being the same as for the\\nreturn call annunciator system, the operator\\npresses the button corresponding to the instru-\\nment of the subscriber desired. In the magneto-\\ncall system the operator has a magneto connected\\nwith a cord and plug. The plug is put into the drop\\ncorresponding to the subscriber desired, and the\\noperator then turns her magneto handle which\\nrings a magneto bell on the instrument.\\nQ. What method of calling is generally used\\non intercommunicating systems\\nA. The battery call.\\nQ. For what kinds of work are the two systems\\nadapted\\nA. The intercommunicating system is adapted\\nto installations of a few instruments where the\\ndistances are not great. Where the number of\\ninstruments is large the trouble from cross-talk\\nbecomes excessive, as does also the cost of wiring.\\nIn such cases it is advisable to use the exchange\\nsystem.", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0300.jp2"}, "301": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 285\\nQ. What is the general principle of the trans-\\nmitter as now used\\nA. The transmitter consists usually of a cup-\\nshaped piece of carbon containing carbon gran-\\nules or particles against which lies a thin carbon\\ndiaphragm; the whole is contained in a hard-\\nrubber case to which is attached the mouthpiece.\\nCurrent from a battery is led into the diaphragm\\nand passes through the contacts between the\\ndiaphragm and the carbon particles, through the\\ncontacts between the particles themselves and to\\nthe contact between the particles or containing\\ncarbon cup, and afterward returns to the other\\npole of the battery. When the mouthpiece is\\nspoken into, the diaphragm is set into vibration,\\nproducing a varying pressure of the carbon con-\\ntacts, which varying pressure produces a varying\\nresistance, and therefore a varying current which\\nis transmitted along the line to the receiver of the\\nother instrument.\\nQ. What is the general construction of the\\nmagneto receiver as now used\\nA. The magneto receiver consists of the mag-\\nnet, either bar shaped or preferably of the horse-\\nshoe pattern, on the pole or poles of which is\\nmounted a coil of fine wire which is connected to\\nthe line. Close to this pole, but not quite touch-\\ning, is a thin, circular, soft, iron diaphragm; the", "height": "2836", "width": "1825", "jp2-path": "ropersquestions00rope_0301.jp2"}, "302": {"fulltext": "286 QUESTIONS AND ANSWERS FOR\\nwhole arrangement is enclosed in a hard-rubber\\ncase.\\nQ. What is the action of the receiver\\nA. The varying currents produced by the\\ntransmitter flow along the line around the roils\\nand produce a varying pull on the diaphragm,\\nwhich sets the air into vibration affecting the\\near.\\nQ. What kind of wire is used for telephone\\ninstallations\\nA. For inside work on exchange systems a\\nweather-proof or rubber insulated wire, twisted\\nevery two inches or so, is employed the size is\\nabout No. 18 or 20 B. S. For single pairs of\\ninstruments or for intercommunicating work an-\\nnunciator wire is used in the cheapest installa-\\ntions, and for a better class of work office wire or\\nfire- and weather-proof is used.\\nQ. What kind of battery cells are used in tele-\\nphone work\\nA. Generally some form of the zinc-carbon-sal\\nammoniac cell.\\nQ. Is the battery on a closed circuit when talk-\\ning is not going on\\nA. No; the battery is thrown off the circuit by\\nan automatic hook which operates when the re-\\nceiver is lifted off the hook.\\nQ. Mention some of the troubles which you", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0302.jp2"}, "303": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 287\\nhave met in the various parts of the telephone\\nsystem.\\nA. In transmitters a packing of the carbon\\nparticles, breaking of the carbon diaphragm, bad\\nconnections from the battery to the transmitter,\\nand running down of the battery from various\\ncauses. In the receiver a broken wire in the coil,\\nbroken wire between the coil of the receiver and\\nthe receiver terminals, and touching of the dia-\\nphragm on the magneto pole. In the magneto\\na grounding of the armature wire on the core or\\na broken wire on the armature, a bad connection\\nbetween the armature and the terminals of the\\nmagneto. On the line a ground, short circuit,\\nor broken wire.\\nQUESTIONS ON ELECTEICAL UNITS, PROPERTIES,\\nAND MEASUREMENT.\\nQ. What are the three most important elec-\\ntrical properties\\nA. Current, electro- motive force, and resistance.\\nQ. What is another term for electro-motive\\nforce?\\nA. Electrical pressure.\\nQ. How may electrical pressure be produced\\nA. The two most important methods are by\\nmeans of chemical action and by the movement\\nof a conductor near a magnet.", "height": "2836", "width": "1825", "jp2-path": "ropersquestions00rope_0303.jp2"}, "304": {"fulltext": "288 QUESTIONS AND ANSWERS FOR\\nQ. What is the unit of electrical pressure\\nA. The volt,\\nQ. What is the instrument called that is used\\nto measure electrical pressure\\nA. The voltmeter.\\nQ. Whenever there is a difference of electrical\\npressure between any two points, what will hap-\\npen if these two points are joined by a conductor\\nA. An electrical current will flow from the high\\npressure point to the low so long as there con-\\ntinues to be a difference of pressure between the\\ntwo points.\\nQ. Is there a mechanical pressure as well as\\nan electrical pressure existing between the two\\npoints\\nA. Yes; the substance which separates the two\\npoints is under an actual mechanical strain, the\\namount of strain increasing with the increase of\\nelectrical pressure.\\nQ. How could you ascertain whether there was\\na difference of pressure between two points\\nA. By connecting a voltmeter between the two\\npoints. If the needle of the voltmeter were de-\\nflected, I should know that there was a difference\\nof pressure between them.\\nQ, What is used as a convenient standard of\\npressure\\nA. A certain kind of cell called the Clark cell.", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0304.jp2"}, "305": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 289\\nQ. What are some of the effects of an electric\\ncurrent\\nA. It heats conductors carrying it, it exerts a\\nmagnetic force on all magnetic substances near the\\nconductors, and it is able to decompose the solu-\\ntions of many chemical substances.\\nQ. What is the unit of current\\nA. The ampere.\\nQ. What is the practical definition of an\\nampere\\nA. An ampere is the current which will deposit\\nfrom a solution of silver nitrate .017 grain of\\nsilver in one second.\\nQ. In the case of flowing water, what would be\\nanalogous to the ampere\\nA. Since the ampere is the unit of rate of flow\\nthe corresponding unit for water would be a flow\\nof one gallon per second.\\nQ. Is the heating effect of an electric current\\nproportional to the strength of current?\\nA. It increases as the current increases, but\\nvery much faster for example, doubling the cur-\\nrent makes the heating effect four times as great\\nin fact, the heating effect is proportional to the\\nsquare of the current.\\nQ. What practical use is made of the heating\\neffect?\\nA. It is used in electric heaters and cooking\\n19", "height": "2855", "width": "1735", "jp2-path": "ropersquestions00rope_0305.jp2"}, "306": {"fulltext": "290 QUESTIONS AND ANSWERS FOR\\ndevices, and in heating the filaments of incandes-\\ncent lamps.\\nQ. Is there any danger in the heating effect\\nA. There would be if the wires used for carry-\\ning currents were too small. In such a case the\\nwires would become so heated as to be liable to\\nset fire to woodwork in their vicinity.\\nQ. What relation exists between the magnetic\\neffect of the current and the number of amperes\\nA. The magnetic effect is strictly proj)ortional\\nto the number of amperes.\\nQ. Is the ability of the current to decompose\\nsubstances also proportional to the number of\\namperes\\nA. Yes; strictly so.\\nQ. What is the resistance of a conductor?\\nA. The resistance of a conductor is the opposi-\\ntion which that conductor offers to the passage of\\nan electrical current.\\nQ. What is the unit of resistance\\nA. The ohm.\\nQ. What is an ohm\\nA. An ohm is the resistance of a column of\\nmercury having a certain definite length (41.85\\ninches) and a certain weight (223 grains) at 32\u00c2\u00b0\\nFahr.\\nQ. Are the standard ohms used in practice\\nmade of mercury", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0306.jp2"}, "307": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 291\\nA. Xo; they are made of wire coiled up in a\\nconvenient form.\\nQ. What effect has the length of the conductor\\nupon its resistance\\nA. The resistance is proportional to its length.\\nQ. How does increasing the cross-section of a\\nconductor affect its resistance\\nA. It lessens it proportionately.\\nQ. Suppose that a certain size of wire 1000 feet\\nlong has a resistance of two ohms, what will be\\nthe resistance of 500 feet of the same wire\\nA. One ohm.\\nQ. And suppose that the diameter of the 500\\nfeet of wire were made one-half its present value,\\nwhat would the resistance be\\nA. Since the diameter is halved, the new area\\nwill be one-quarter and the resistance will be four\\ntimes as great, or four ohms.\\nQ. What is the difference between resistance\\nand conductivity\\nA. Resistance is the opposite of conductivity.\\nQ. When are two conductors said to be con-\\nnected in series\\nA. When they are placed like two horses driven\\ntandem that is, when one end of one conductor\\nis joined to one end of the other.\\nQ. What is the total resistance of two conduc-\\ntors connected in series", "height": "2855", "width": "1735", "jp2-path": "ropersquestions00rope_0307.jp2"}, "308": {"fulltext": "292 QUESTIONS AND ANSWERS FOR\\nA. The total resistance is equal to the sum of\\nthe separate resistances.\\nQ. When are conductors said to be connected\\nwith multiple or parallel\\nA. When they are placed like two horses driven\\nas a pair, the conductors being connected to each\\nother as follows:\\nIf we may suprjose the conductors to be lying\\nin the north and south direction, the north ends\\nwill be connected and the south ends will be con-\\nnected together.\\nQ. What is the rule for rinding the joint resist-\\nance of two conductors connected in multiple\\nA. Divide the product of the two resistances by\\nthe sum.\\nQ. When the resistances are equal, what will\\nbe the joint resistance\\nA. One-half of the resistance of one of them.\\nQ. What is specific resistance\\nA. It is the resistance of a cubic inch of a sub-\\nstance.\\nQ. What are non-conductors\\nA. Substances that have a high specific sub-\\nstance; or, in other words, that offer a strong op-\\nposition to the passage of the current.\\nQ. What are conductors\\nA. Substances having a comparatively low spe-\\ncific resistance.", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0308.jp2"}, "309": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 293\\nQ. What is an insulator\\nA. It is another name for a non-conductor.\\nQ. What class of substances are good conduc-\\ntors, and what class are insulators\\nA. The metals are good conductors and the\\nnon-metals are insulators.\\nQ. What are some of the best conductors\\nA. Copper and silver.\\nQ. What are some of the best insulators\\nA. The best insulators are glass, porcelain,\\nmica, rubber, and dry air.\\nQ. What is Ohm s law?\\nA. In an electric circuit the total current (in\\namperes) is equal to the total electric pressure (in\\nvolts) divided by the total resistance (in ohms).\\nQ. What formula is used to express this law\\nE\\nA. C= Where C equals the current in\\nR\\namperes, E equals pressure in volts, and R equals\\nresistance in ohms.\\nQ. Is this law applicable to circuits carrying an\\nalternating current\\nA. Not without modifications.\\nQ. A certain electric circuit has a total resist-\\nance of 4 ohms, and there is an electrical pres-\\nsure acting amounting to 8 volts, what will be the\\ncurrent\\nA. Two amperes.", "height": "2855", "width": "1735", "jp2-path": "ropersquestions00rope_0309.jp2"}, "310": {"fulltext": "294 QUESTIONS AND ANSWERS FOR\\nQ. How great an electro-motive force will be\\nneeded to send a current of 10 amperes through a\\ncircuit having a resistance of 1 ohm\\nA. Ten volts.\\nQ. Suppose that we find in a circuit a current\\nof 20 amperes, and with the pressure in the cir-\\ncuit is 50 volts, what is the resistance of the cir-\\ncuit\\nA. f\u00c2\u00a7, or 2 ohms.\\nQ. Suppose that we have connected up in series\\nthree batteries, each giving an electro-motive force\\nof 1.5 volts, what will be the pressure between the\\nunconnected ends of the series\\n1 3x 1.5, or4.5 volts.\\nQ. Now, suppose that connected in series with\\nthem is a wire having a resistance of 3 ohms, can\\nyou calculate what current will flow in the cir-\\ncuit?\\nA. Not unless I know the resistance of the\\nbatteries.\\nQ. If the resistance of the batteries is -J- ohm\\neach, what current will flow in this circuit Ex-\\nplain how you will arrive at the result.\\nA. Since each battery has a resistance of -J- ohm,\\nthe total resistance of the circuit will be -f- -j-\\nJr -f 3, or 4J- ohms. By Ohm s law the current\\n4|\\nor 1 ampere.", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0310.jp2"}, "311": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 295\\nQ. Suppose that one of the three batteries was\\nreversed so that it opposes the other two, what\\nwould be the net electro-motive force in circuit\\nA. 3 H, or l\\\\ volts.\\nQ. When the electric pressure is furnished by\\nthe ordinary 110- volt generator, what will be the\\ncurrent flowing if one 16 c. p. lamp of 220 ohms\\nresistance is turned on\\nA. In this case the resistance of the generator\\nis so small compared with the resistance of the\\ncircuit that it may be neglected in the calculation.\\nThe current will therefore be |^J, or J ampere.\\nQ. What will be the current when two lamps\\nare turned on\\nA. By the rule for divided circuits the joint\\n220 X 220\\nresistance is or 110 ohms. The cur-\\n220 -f 220\\nrent will then be or 1 ampere. This is the\\ntotal current flowing through the machine, one-\\nhalf of it flowing through each lamp.\\nQ. What would be the current when ten lamps\\nare turned on?\\nA. In this case, where the resistances of the\\nseparate branches are equal, the joint resistance is\\nequal to the resistance of any one branch divided\\nby the number of branches. The joint resistance\\nis, therefore, or 22 ohms. The current will\\nbe 1 or 5 amperes.", "height": "2855", "width": "1735", "jp2-path": "ropersquestions00rope_0311.jp2"}, "312": {"fulltext": "296 QUESTIONS AND ANSWERS FOR\\nQ. What is a galvanometer, and how can one\\nbe made?\\nA. A galvanometer is an instrument for detect-\\ning or measuring a current. It may consist of a\\nfixed coil of wire and a movable magnet needle\\nwhich is deflected by any current passing through\\na coil, or the coil may be small and movable and\\nthe magnet large and fixed.\\nQ. What is the construction of the Weston\\ninstruments\\nA. They consist of a fixed permanent magnet\\nof horse-shoe form between the poles of which is\\npivoted a coil of fine wire. The indicating needle\\nof the instrument is attached to the coil; the coil\\nis held in the zero position by a bar of fine springs\\nsimilar to the hair-spring of a watch. When the\\ncurrent passes through the coil, the coil is deflected\\nagainst the action of these springs by an amount\\nproportional to the current strength.\\nQ. How would you connect a voltmeter so as\\nto measure the voltage of a battery\\nA. I would connect one terminal of the volt-\\nmeter to one terminal of the battery, and the\\nother terminal of the voltmeter to the other termi-\\nnal of the battery.\\nQ. In the Weston instrument, does it make any\\ndifference which terminal is connected to the zinc\\npole of the battery", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0312.jp2"}, "313": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 297\\nA. Yes; the terminal marked minus should\\nbe connected to the zinc pole, otherwise the needle\\nwill tend to deflect in the wrong direction.\\nQ. What is the most common range of a Wes-\\nton portable voltmeter?\\nA. One reading from zero to 150 volts.\\nQ. Could you measure accurately with such\\nan instrument the pressure of a single battery\\ncell\\nA. No; the reading would be so small as to be\\ninaccurate; it would be like trying to weigh a\\nsmall boy on a set of hay scales.\\nQ. Is there any way to measure accurately\\nwith such an instrument the pressure of a single\\ncell?\\nA. No; the instruments are, however, often\\nmade with a double scale and a double set of ter-\\nminals, the lower scale reading from zero to 5 or\\nfrom zero to 15 volts.\\nQ. Suppose that with such an instrument you\\nwish to measure a voltage which you knew to be\\nin the vicinity of 220, how would you do it\\nA. I would first connect across the circuit,\\nwhose pressure I desire to measure, two 110-volt\\nlamps in series; then I would connect the volt-\\nmeter first so as to measure the pressure between\\nthe terminals of one of the lamps, and next be-\\ntween the terminals of the other lamp. The sum", "height": "2855", "width": "1773", "jp2-path": "ropersquestions00rope_0313.jp2"}, "314": {"fulltext": "298 QUESTIONS AND ANSWERS FOR\\nof the two pressures would be the pressure of the\\ncircuit desired.\\nQ. How would you connect the voltmeter so as\\nto obtain the pressure between the terminals of\\nthe lamp\\nA. I would connect a wire from one terminal\\nof the lamp socket to one terminal of the volt-\\nmeter and another wire from the other terminal\\nof the lamp socket to the other terminal of the\\nvoltmeter.\\nQ. How does the Weston ammeter differ from\\nthe voltmeter in construction\\nA. A strip of heavy metal connects across the\\nterminals of the coil so that it takes the bulk of\\nthe current to be measured, only a very small\\nfraction passing around the coil.\\nQ. How would you connect an ammeter so as\\nto measure the current passing through a certain\\nnumber of incandescent lamps\\nA. I would insert the ammeter in the branch\\ncircuit which supplies those lamps, opening the\\ncircuit at some convenient point and connecting\\none terminal of the opening to the proper termi-\\nnal of the ammeter and the other side of the\\nopening to the other terminal of the ammeter.\\nQ. Suppose that when you had connected up\\nthe ammeter you found that the needle was de-\\nflecting in the wrong direction", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0314.jp2"}, "315": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 299\\nA. I should know that the connections needed\\nto be reversed the plus terminal must be con-\\nnected to the plus side of the circuit.\\nQ. Suppose that you had a coil of copper wire\\nand wished to know its resistance, how could you\\nfind it out\\nA. If I had access to wire tables I would meas-\\nure first the gauge of the wire and would then\\neither measure its length or weigh it, whichever\\nwere the easier. The ordinary wire tables give\\nthe resistance per 1000 feet of various gauges of\\nwire and also the pounds per 1000 feet.\\nQ. How could you measure the resistance\\nA. If I had an ammeter and voltmeter of\\nproper range I would put the ammeter in series\\nwith the wire and pass a current through it. I\\nwould then connect the voltmeter to the terminals\\nof the wire. The reading of the voltmeter would\\ngive the number of volts and the reading of the\\nammeter would give the number of amperes pass-\\ning through the wire, and the quotient of the volts\\ndivided by the amperes is by Ohm s law the re-\\nsistance in ohms.\\nQ. How great a current would you send through\\nthe wire\\nA. That would depend upon the size of wire\\nand the range of the ammeter. I would send a\\ncurrent large enough to give the maximum read-", "height": "2855", "width": "1773", "jp2-path": "ropersquestions00rope_0315.jp2"}, "316": {"fulltext": "300 QUESTIONS AND ANSWERS FOR\\ning of the ammeter unless this heated the wire;\\nin this case I would cut the current down until it\\nproduced no appreciable rise of temperature in the\\nwire.\\nQ. Why would you not use a current great\\nenough to heat the wire\\nA. This would change the very thing which we\\nwant to measure namely, the resistance.\\nQ. Is there any way of measuring resistance\\nwithout the use of both voltmeter and am-\\nmeter?\\nA. Yes the resistance may be measured by\\nmeans of the voltmeter alone, provided we know\\nits resistance.\\nQ. Explain how you would proceed to measure\\na resistance by the voltmeter alone.\\nA. See Roper s Catechism, page 289.\\nQ. For what practical cases is this method\\nlargely used\\nA. For measuring high resistances such as the\\ninsulation resistance of different parts of a dynamo\\nfrom the frame and the insulation resistance of\\nwiring circuits to earth.\\nQ. Show by a diagram how you would connect\\nto measure the insulation of the armature coils of\\na dynamo from the frame.\\nA. See Roper s Catechism, page 290.\\nQ. How would you measure the power used in", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0316.jp2"}, "317": {"fulltext": "STEAM ENGINEERS AND ELECTRICIANS. 301\\nany part of a direct current circuit, for instance,\\nin a group of lamps\\nA. I would connect an ammeter, so that the\\nentire current which flows through the lamps also\\nflows through the ammeter. I would connect a\\nvoltmeter across the branch circuit which supplies\\nthe lamps as near as possible to the lamps. I\\nwould read both instruments and multiply the\\nreadings together, thus obtaining the power in\\nwatts.\\nQ. How can you obtain the horse-power\\nA. By dividing the number of watts by 746.", "height": "2855", "width": "1773", "jp2-path": "ropersquestions00rope_0317.jp2"}, "318": {"fulltext": "WHAT TO DO IN CASE OF\\nACCIDENTS.\\nFIRST AID TO THE INJURED.\\nInjuries caused by machinery are usually ac-\\ncompanied by bleeding. This bleeding may come\\nfrom the arteries, which are the channels through\\nwhich the blood passes on its way from the heart\\nto the various parts of the body. In this case it\\nis of a bright scarlet color, and escapes in spurts\\nlike water from a hose attached to a pump. Or\\nthe bleeding may come from the veins, which are\\nthe channels through which the blood flows on\\nits way back to the heart. In this case the blood\\nwill be dark in color and will flow out in a steady\\nstream without spurting. A third form of bleed-\\ning, known as capillary bleeding, consists in a leak-\\ning of blood from the smallest blood-vessels.\\nCapillary bleeding is easily stopped by folding\\nup a piece of cloth or a handkerchief, placing it in\\nthe wound and tying it there.\\nBleeding from the vein can be stopped by rolling\\nup a handkerchief into a ball, placing it over the\\nvein below the wound and then tying a second\\nhandkerchief tightly around so as to make the\\n302", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0318.jp2"}, "319": {"fulltext": "WHAT TO DO IX CASE OF ACCIDENTS. 303\\nfirst handkerchief press hardly enough upon the\\nvein to close the channel.\\nArterial bleeding is by far the most dangerous,\\nand it must be quickly and completely stopped.\\nThis is done by means of a so-called Spanish\\nwindlass (Fig. I), which consists of a piece of\\n-rope or cloth tied around the limb above the wound\\nand then twisted up tightly by means of a stick.\\nThe arteries lie more deeply imbedded in the\\nmuscles than do the veins, and they cannot be\\ncompletely compressed by the windlass unless a\\nfirm compress, made of a piece of wood, a small\\nstone, or a rolled-up handkerchief, is laid over\\nthe artery. While one person is getting the wind-\\nlass ready, the artery should be temporarily com-\\npressed by another person, who should grasp the\\nlimb with the fingers and put on as strong a pres-\\nsure as possible with his thumbs.\\nIn Figure II, A shows the location of the artery\\nbehind the knee-joint. At B it divides into two\\nbranches.\\nIn Figure III, A indicates the location and the\\ndirection which the artery takes in the thigh.\\nIn Figure IV, A is the artery in upper arm C\\nand B the two arteries on the inner and outer side\\nof the forearm.\\nThe beating of the arteries can be recognized by\\nfeeling in their course, as indicated by the dia-", "height": "2855", "width": "1773", "jp2-path": "ropersquestions00rope_0319.jp2"}, "320": {"fulltext": "304 WHAT TO DO IN CASE OF ACCIDENTS.", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0320.jp2"}, "321": {"fulltext": "WHAT TO DO IN CASE OF ACCIDENTS. 305\\ngram, and the compresses should be applied in\\nthese localities (above the cut or wound).\\nIn addition to the above treatment, the applica-\\ntion of ice or cold to the affected part is beneficial.\\nElevation of the injured limb also tends to check\\nthe bleeding.\\nNever make a man sit or stand up, if he has\\nlost much blood, for he is very apt to faint, which\\nmay cause death.\\nIt is always well to keep the head lower than\\nany other part of the body, in order to prevent\\nfainting and to decrease the work of the heart.\\nBURNS.\\nBurns may be divided, according to their ex-\\ntent, into three classes. First, those in which the\\nskin is merely reddened. Second, those in which\\nblisters are formed. Third, those in which the\\nskin is either partially or wholly destroyed by\\ncharring.\\nThe amount of danger depends entirely on the\\nextent of surface affected, a complete destruction\\nof one-third of the skin on the body usually\\nproving fatal, while, if the skin is only reddened,\\ntwo-thirds of the surface may be affected without\\ndeath resulting.\\nTreatment. As the results of scalds are the\\nsame as those of burns, they should receive the\\n20", "height": "2842", "width": "1792", "jp2-path": "ropersquestions00rope_0321.jp2"}, "322": {"fulltext": "306 WHAT TO DO IN CASE OF ACCIDENTS.\\nsame treatment. The modern antiseptic methods\\nrequire materials that are usually not at hand\\nin an emergency case. The following steps may\\nbe taken previous to the arrival of the physician.\\nIf the size of the burn is not very great, it is\\nsufficient to wrap the affected part in cloths soaked\\nwith a strong solution of common baking soda in\\nwater. If this is not available, soak the cloths in\\na mixture of equal parts of sweet oil and lime-\\nwater.\\nIf blisters have formed, prick them with a\\nneedle so as to let out the liquid, but be careful\\nnot to break or tear off the skin which covers the\\nblister. Give a good drink of whiskey or two\\nteaspoonfuls of aromatic spirits of ammonia.\\nIf the burn be large, in addition to the above\\ntreatment the patient should be at once put to\\nbed and covered with blankets. Hot- water bottles\\nshould be applied to his body, so as to keep up\\nthe temperature and to prevent shock, which\\nwould probably result fatally.\\nH.1\\nft 589", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0322.jp2"}, "323": {"fulltext": "", "height": "2848", "width": "1669", "jp2-path": "ropersquestions00rope_0323.jp2"}, "324": {"fulltext": "", "height": "2874", "width": "1803", "jp2-path": "ropersquestions00rope_0324.jp2"}, "325": {"fulltext": "I", "height": "3032", "width": "1662", "jp2-path": "ropersquestions00rope_0325.jp2"}, "326": {"fulltext": "Kb! g t. 3aaKBBB\\nEra\\nLIBRARY OF CONGRESS\\nHlllgl E I mHi\\nIH\\nMM\\nmm\\nBeSk\\nISiSifiRfiHar^\\n*lffiS$fl235\u00c2\u00bb\\npnffiMlflHMHa\\n9 HH\\nWhHrHPH\\nanliSlg\\nj at aaaa\\nTrffrrnnFWnlHPTffl\\nHHBuShhLh\\nmffiHS\\nHe SHU\\nH\\nnWBMaBmB", "height": "3137", "width": "1874", "jp2-path": "ropersquestions00rope_0326.jp2"}}