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JR H t I~~~~~~~~I F9~~~~~~~~~~~~~ CATECHISM OF THE LOCOMOTIVE, Al BY 11V- N~_ F;c FuOKrr MECHANICAL ENGINEER. PUBLISHED BY THE RAILROAD GAZETTE, 73 BROADWAY, NEW YORK. 1875. Entered, accordingll t-i Act of Congreess, ill the year 1874, by THE RAILROAD GAZETTE, In the office of the Librarian of Congress, at Washington. CILARK W. BIRIYAN & ('.. IRINERIs, E,.'I't() OTYPERS AND IULISIIIHERS, SPRINGFI ELD. M A SS. PREFAC E. BooKs, like individuials have their lhistories, and it seems but proper that in introducing them somewllat of their ancestry should be detailed. The present book originated in this wise: the publishers of the RAILrOAD GAZETTE procured a copy of the'Katechismus der Einriclhtung und des Betriebes der Locomotive," by Georg Kosak. As no English translation of this excellent little book was known to be in existence, the editors of the above paper determined to translate it and adapt it to the American practice in the construction and management of locomotive steamn engines, and republish it in their journal. The translation was therefore made and submitted to the writer for revision and adaptation, according to the original intention. Before the latter was entertained, however, lie had commenced writing an elementary treatise on the locomotive. In revising the first part of the- translation of Alr. Kosak's book, it was found that the latter occupied only to a very limited extent the ground whllich the writer had "staked out" in hlis own incomplete plan. He therefore concluded to aban iv Preface. don the original intention of " adapting" Mr. Kosak's work, and determined to rewrite it and make substantially a new book of it. For the " idea," however, and to some extent its plan, and for much valuable material, the author must acknowledge his indebtedness to Mr. Kosak. In some few cases the language of the translator has been employed, in part or in whole, without quotation mnarks, but with an acknowledgment in a foot-note. A similar plan has also been pursued in using some other books. This was done to avoid cutting up paragraphs and sentences into fragmentary parts with numerous quotation marks. The following books have been consulted and used in writing the Catechism of the Locomotive: Heat considered as a Miode of Motion, by Prof. Tyndall; The Conservation of Energy, by Balfour Stewart; Railway Machinery, by D. K. Clark; Treatise on the Locomotive Engine, by Zerah Colburn; Treatise on the Steam Engine, by W. J. M. Rankine; Indicator Experiments on Locomotives, by Professor Bauschinger; Richards' Steam Indicator, by Charles T. Porter; Die Schule des Locomotivfuhrers, by J. Brosius and R. Koch; Mechanics, by A. Morin; The New Chemistry, by J. P. Cooke, Jr.; Combustion of Coal and the Prevention of Smoke, by C. Wye Williams; A Treatise on Steam Boilers, by Robert Wilson; Reports of the American Railway Master Mechanics' Association; Link Valve Motion, by William S. Auchincloss, and Preface. v Emergencies and How to Treat Them, by Dr. Joseph W. Howe. For the title of the book an apology is perhaps needed, as the word Catechism is associated in nearly all persons' minds we will trust with early religious and theological instruction, and therefore a Catechism of the Locomotive is very apt to sound more ludicrous than scientific. The title of Mr. Kosak's book was adopted before it was determined to rewrite it, and it was afterwards not deemed best to change it. To those who are disposed to smile at it, the precedent of Mr. Bourne's excellent Catechism of the Steam Engine is quoted, and if they will refer to Webster's Dictionary for the definition of the word " catechism,'" they will find that it means "an elementary book.containing a summary of principles in any science or art, but appropriately in religion, reduced to, the form of questions and answers, and sometimes with notes, explanations and reference to authorities," which is exactly what the present book is intended to be. To persons accustomed to books and study, the catechetical form is very apt to seem cumbrous. and awkward, but it has some very decided advantages in writing for those who have not acquired studious habits of thought. To such the question asked presents first a distinct image of the subject to be considered, so that the explanation or instruction which follows is much A* Xvi Prejufce. more apt to be understood than it would be if no such question had been asked. The author is indebted to Mr. D. B. Grant for the use of drawings from which most of the engravings of details of locomotives with which this'book is illustrated have been made, and to other locomotive builders, whose engines are illustrated in the full-page plates, for the drawings thereof. He has also received very valuable aid from Mr. Richard H. Buel, Mechanical Engineer; Mr. William Buchanan, Master Mechanic of the'Hudson River Railroad; Mir. Frank D. Child, Superintendent of the Hinkley Locomotive Works; and Mr. E. T. Jeffrey, Assistant Superintendent of Machinery of the Illinois Central Railroad. The object in writing the book was to furnish a clear and easily understood description of the principles, construction and operation of the locomotive engine of the present day, a subject which is not concisely or adequately treated in any one similar book. If the author has succeeded in making what he has written plain to plain people, his aim will be fully accomplished. No. 73 Broadway, NEW YORK. CONTENTS. PAGE Preface................. iii Introduction............... ix Part I. The Steam Engine. 1..... 1 II. The forces of Air and Steam....... 8 III. On Work, Energy and the Mechanical Equivalent of Heat........22 IV. The Slide-Valve.... 30 V. The, Expansion of Steam........ 47 VI. General 1)escription of a Locomotive Engine. 62 VII. The Locomotive Boiler... 71 VIII. The Boiler Attachments.. 115 IX. The Throttle-Valve and Steam-Pipes.... 155 X. The Cylinders, Pistons, Guide-Rods and Connecting-Rods........ 164 XI. The Valve-Gear...... 181 XII. The, Running-Gear.......... 268 XIII. Adhesion and Traction........ 319 XIV. Internal Disturbing Forces in the Locomotive 328 XV. Miscellaneous......... 335 XVI. Screw Threads, Bolts and Nuts.... 341 XVII. Tenders.............. 349 XVIII. Friction and Lubrication...3.... 358 XIX. Combustion............. 365 XX. The Resistance of Trains...... 406 viii Contents. PAGE. XXI. Proportions of Locomotives..... 412 XXII. Different Kinds of Locomotives...... 427 XXIII. Continuous Train Brakes.442 XXIV. Performance and Cost of Operating Locomotives 448 XXV. Water-Tanks and Turn-Tables...... 451 XXVI. Inspection of Locomotives........ 461 XXVII. Running Locomotives........ 478 XXVIII. Accidents to Locomotives..... 509 XXIX. Accidents and Injuries to Persons..... 533 XXX. Responsibility and Qualification of Locomotive Runners...... 544 List of Books for Mechanics, Locomotive Runners, Firemen, etc,................ 550 Plates 551 A PPENDI X. I. Table of the Properties of Steam..... 585 II. Table of Hyperbolic Logarithims...... 590 III. Table of the Properties of Different Kinds of Fuel. 594 IV. Table of the Resistance of Trains..... 596 Index............. 598 INTRODUCTION. THE Catechism of the Locomotive is intended for a large class of readers, among whom are all kinds of railroad officers and employes, consisting of locomotive runners, firemen, and the many different kinds of mechanics employed in railroad shops and in the construction of locomotive and other kinds of railroad machinery and material. Besides these there are many amateur engineers, students, and persons interested directly or indirectly in railroads, and a not inconsiderable class who are always seeking information on all subjects whatsoever. It is evident, therefore, that the only way to adapt the book to all the classes for whom it is intended, was to make it so plain that the "wayfaring man" will hlave no difficulty in comprehending it. It has therefore been written in as clear language as the writer could command, and the subjects presented are treated as simply and as plainly as his ability enabled him to do, and with the least possible employment of either scientific or practical technicalities. The only deviation from this plan will x Introduction. be found in the use of algebraic symbols to designate arithmetical calculations. This was done to save space, and because it was thought that they could be explained so that even those without any knowledge whatsoever of algebra could easily comprehend them. To such as have no such knowledge the following explanation is given: Suppose it is necessary to add two numbers, say 1,872 and 468. The calculation, if made arithmetically, would be thus: 1,872 468 2,340 This it will be seen occupies the space of several lines of print. If- we want to express this calculation algebraically, it can be done by-simply writing the two numbers and placing the sign +, called plus, between the two, which indicates that they are to be added together, thus: 1,872 +468 To indicate what the sum will be, or what the two added together will amount to, the sign -,called equal to, or the sign of equality, is placed after the two numbers and between them and the sum, thus: 1,872 +468 =2,340, which can be read as follows: 1,872 added to 468 is equal to 2,340. Now the-oily use of the algebraic signs + and = is Introduction. xi that they save time in writing and room in printing, and when persons become accustomed to their use they make plain a number of operations at a single glance, as will be shown hereafter. In the same way that the sign + means added to, the sign - means less or subtracted from, thus: 1,872 - 468=1,404, which is the same as though it was printed as follows: 1,872 less 468 is equal to 1,404. The sign X means multiplied by, or is the sign of multiplication. Thus: 1,872 X 468=876,096; that is, 1,872 multiplied by 468 is equal to 876,096. The sign. means divided by, thus: 1,872 468=4. which means: 1,872 divided by 468 is equal to 4. The samne thing is expressed by putting a line under the dividend and writing the divisor under the line, thus: 1,872 - =4. 468 These signs are combined in various ways. Thus, supposing we wanted to add 1,872 to 468 and then divide the sum by 117, it would be necessary, in order xii Introduction. to represent the arithmetical calculation, to do it as follows: 1872 468 117)2340(20 234 0 Algebraically it would be stated thus: 1872+468 ___ —- - 20. 117 If you wanted to add 124 to the quotient 20 above, the calculation would be as follows: 1872 468 117)2340( 20 234 124 0 144 This operation could be expressed by writing it as follows: 1872+468 -- ~- + 124=144. 117 If we wanted to multiply the quotient 20 by 124 we would simply put the sign x instead of + before 124, thus: 1872+468 x124=2480. 117 Introduction. xiii The sign of subtraction or division can be used in the same way. With these explanations it is believed that any one, with nothing more than an ordinary knowledge of the four elementary rules of arithmetic, can understand all the mnathematics contained in the following pages. A little explanation may also be needed of the method of representing machinery and other structures by mechanical drawings. If we want to represent the outside of any object, say an apple, we make a drawling of it as shown at A. a, B C D Now if we want to show the inside of tie apple, say, the seeds and core, we can cut it in half and rep)resent B xiv Introduction. it as shown at C, which is then called a section or sectional view of the apple. If we represent it as it will appear if we are above it and looking down on it as shown at B, it is called a top view or plan. It is evident, too, that it might be desirable to show the arrangement of the seeds in the apple as they would appear if it was cut through in the other direction, say on the line a b, fig. A, and as is shown at D. There are therefore two kinds of sections; one C, in which the object is supposed to be cut through vertically, and therefore called a vertical section, the other when the object is supposed to be cut.through horizontally, and therefore called a lorizontal sections as shown at D. It is also evident that in looking at a locomotive or any other object, the appearance of the engine depends upon our position in relation to it. Thus, if we stand on the side of it, we see that part of the engine, and a drawing which represents the side, is therefore called a side view or side elevation. A drawing which represents a locomotive or other object as it would appear to us if we stood in front of it, is called a front tiew or front elevation, and a representation of the back part of any object as. it would appear to us if we stood behind it is called a back view or back elevation. Plate I is a side view, Plate II a section, Plate III a top view or plan;* T''l boiler of the locomotive is supposed to be removed in Plate III. Introduction. xv the vignette in the title page is a front view and fig. 71 a back view of a locomotive. If the drawillg is made as the object would appear if it was turned upside down, and we were looking at it from above, then it is called an inverted plan. It is obvious, too, that it is possible to make a great many different sectional views of nearly any object, especially of a machine. Thus, we could suppose a locomotive cut through vertically and lengthwise, as is shown in Plate II. Such a representation is called a longitudinal section. A locomotive could also be cut through crosswise, as shown in fig. 40, which is called a transverse section. It is of course possible to represent a transverse section of a m1aclline like, a locomllotive at a great many different points; for example, it could be shovwn as though it was cut through the smoke-stack as in fig. 40, or through the boiler farther back, as the latter is shown in fig. 42. Usually when a section is shown through a cylindrical object like a smoke-stack or boiler, it is shown througlh its centre. If, however, this is not apparent from the drawing or engraving, it should be stated at what point it is supposed to be taken, thus the section D of the apple is on the line a b of fig. A, and the section C is on the line c d. In drawing sections, the parts whicl are supposed ~to be cut in two are usually shaded with parallel diagonal lines drawn at equal distances apart, as shown in xvi Introduction. the sections of the apple at A and B. Sections are also sometimes represented with'solid black surfaces, as in Plates II and III, and in the engraving of a pump in fig. 66. Objects which are behind others which are in front of them are often shown with dotted lines, so as to inidicate their position. The seeds of the apple are thus indicated at A. It is also customary, in drawings of machinery, to take great liberties with the objects represented and to show them with parts removed or broken away, if their construction can thus be made plainer. It should be remembered that the purpose of drawings of *this kind is not to give a pictorial representation of the object as it appeais to the eye, but to make its construction and mode of operation apparent to the mind. In such drawings therefore all perspective is disregarded. It would lead us too far were we to explain the reasons for this, 2nd therefore readers must accept the assertion without the proof. CATECHISM OF THE LOCOMOTIVE. PART I. THE STEAM ENGINE. QUESTION 1. What is the motive power employed in ordinary steam engines? Answer. The expansive force of steam. QUESTION 2. How is this expansive force of steam applied? Answer. It is applied by admitting it into a cylinder IF. 1. Scale 1 in.=1 foot. A. Cylinder. R. Piston-Rod. B. Piston. D. Front Cylinder-Head. C. Back Cylinder-Head. (A, fig. 1) in which a piston, B, is fitted so as to move air-tight from one end of the cylinder to the other. The steam, if admitted at c, will force the piston B to 1 2 Catechism of the Locomotive. the opposite end* of the cylinder. When it has reached that end, if the steam is allowed to escape and a fresh supply is admitted to the cylinder through the opening d, it will move the piston back again. InI this way, by alternately admitting steam at one end and exhausting it from the other, the piston receives a reciprocating motion, which is communicated to the outside of the cylinder by a rod, R, which is called the piston-rod, which works air-tight through an opening in one of the cylinder-covers, or cylinder-heads, as they are usually called. * In all ordinary locomotives. the cylinders are so placed that the head C through which the liiston-rod works is behind, and the other lead D in front. The two ends-of the cylinder are therefore designated the front and back ends, respectively. Scale a f oot. A. Cylinder. xuB. Piston- ~. Valve-Stem. R. Piston. r.r. Rocker. R. Fiston-Rod. ~,r. F. Fly-Wheel. c. and d. Steam-ways. s. Rocker-Shaft. g. Exhaust-lort. G. Eccentric. V. Slide-Valve. K. Eccentric-Strap. I. Exhaust-Cavity. L. Eccentric-Rod. c. and d. Steam-Ports. f:f. Valve-Seat.. Connecting-Rod. g Exhaust-Port. I.I. Steam-Chest. P. Crankecti rN. Crank-Pin, 01_ X. Eccentric.J G. Ecccntric. K. K. Eccentric-Strap. -ac L. Eccentric-Rod. m1 -0_ The Steam Engine. 5 QUESTION 3. How is this reciprocating motion of the piston converted into rotary motion? Answer. By connecting the end of the piston-rod R (fig. 2) by another rod, E, called a connecting-rod, with a crank, P, which is attached to a revolving shaft, S. It is apparent that if the piston B is moved in the direction shown by the dart R, a rotary motion will be given to the crank in the direction of the dart N. When, however, the crank reaches the position shown by the dotted lines in fig. 5, it is plain that a force applied to move the piston in either direction will no longer produce a rotary movement of the crank and shaft. The same thing will occur when the crank is in the opposite position, shown by the full lines. These two positions are called the dead-points of the crank. QUESTION 4. HOW is the crank of an ordinary steam engine carried past the dead-points? Answer. Stationary engines are usually provided with a large and heavy wheel, called a fiy-wheel (FEF, fig. 2) which is attached to the shaft S. This wheel receives a sufficient amount of momentum from the crank, while the latter is moving from one dead-point to the other, to carry it past those points. QUESTION 5. How is the steam admitted to and exhausted from the cylinder? Answer. It is admitted through two channels, c, d, fig. 2, called steam-ways, cast in the cylinder. These ways terminate in a smooth flat surface, ff, called the valve-seat. Their openings in the valve-seat are called steam-ports. Between them is another port or cavity, g, called the exhaust-port, which communicates with the open air. The form of these ports is long and narrow, as shown in fig. 4, which repre 6 Catechism of the Locomotive. sents a plan of them. Over these ports a valve, V, called a slide-valve, usually made of cast iron, with a cavity, II, on its under side, is fitted so that by moving it backwards or forwards it will alternately cover and uncover the two steam-ports. The valve and valve-seat are inclosed in a sort of box, i]; fig. 2, made of cast iron, called a steam-chest, into which steam is admitted from the boiler by a pipe, J. When the valve is in the position represented in fig. 2, the front steam-port is uncovered and the steam is admitted to the front end of the cylinder, and thus forces the piston towards the back end. If, when the piston reaclles the back end, the valve be moved into the position shown in fig. 3, the back steam-port will be uncovered and steam will be admitted to that end of the cylinder. At the same time it will be observed that the aperture of the front steam-port c and that of the exhaust-port are both covered by the cavity in the slide-valve, so that the steam which was admitted to the front end of the cylinder can escape through the steam-port c into the exhaust-port, and thus into the open air. In this way, by moving the valve alternately back and forth, steam is simultaneously admitted first to one end and exhausted from the other, and vice versa. QUESTION 6. Hoew is the slide-valve moved so as to admit and exhaust the steam at the righ]t time. Answer. This is done by what is called an eccentric, which is a circular disc, C (fig. 6), the axis of which is not in the centre. The outside of the eccentric is embraced by a metal ring, AEi, made in two halves, called an eccentric-strap. The eccentric is attached to the shaft by screws or keys, and revolves with it and The Steam _Engine. 7 inside of the eccentric-strap. To the latter is also attached a rod, L, called an eccentric-rod. It is obvious from fig. 6 that if the eccentric revolves inside of the strap it will impart a reciprocating motion to the rod L. The eccentric, G, strap, Ki, and rod, L, are represented in fig. 2. Before describing their operation, or rather their connection with the valve V, it is necessary to understand that usually the valve-seat is placed on top of the cylinder, in which position it is difficult to connect the eccentric-rod with the valve. For convenience, therefore, what is called a rocker, r r, is placed between the cylinder and the main shaft of the engine. This rocker has two arms attached to a shaft, s, and the two arms have a vibratory motion about it, as indicated by the dotted lines. The eccentric-rod L is attached by a pin to the lower arm of the rocker, and the valve is connected to the upper arm by the rod M, called the valve-stem, or valve-rod. It is obvious that as the shaft S and eccentric G revolve, a reciprocating or vibratory motion will be given to the rocker, which will be communicated to the valve by the valve-stem; and it is only necessary to fix the eccentric in the proper position on the shaft, in relation to the crank and piston, to give the valve the required motion for admitting and exhausting the steam to and from the cylinder at the right time. PART II. THE FORCES OF AIR AND STEAM. QUESTION 7. What is meant by the pressure of the air? Answer. It is the pressure exerted by the weight of the air on every point with which it is in contact. The globe of the earth is surrounded by a layer of air about 50 miles thick, and, like every other substance, the air possesses weight, and hence presses upon every object with which it is in contact. QUESTION 8. How can it be shown that the air possesses weight? Answer. By weighing a flask when it is filled with air, and again when the air is exhausted from it. In the latter condition the weight of the flask will be found to be sensibly less than it was when full of air, showing that the air which the flask contained when it was first weighed increased its weight. QUESTION 9. Why do we not feel this pressure on our bodies? Answer. Because the air surrounds us on all sides, and presses just as much in one direction as it does in another, so that the pressures in different directions just balance each other, or are in equilibrium; but if you disturb this balance, for example, by sucking the air from a tube closed at one end, it will cling to your tongue; or if you take a thick piece of leather under The -Forces of Air and Steam. 9 ordinary conditions it will not adhere to anything, but if it be thoroughly wet and pressed hard against the surface of a smooth stone, so as to force out the air from under it, the stone, as nearly all school-boys know, can be lifted up if a string is attached to the leather; or if the air be sucked out of a tube, one end of which is inserted in a liquid, the latter will be forced up the tube. These phenomena are due to the pressure of the atmosphere in the first case on one side of the person's tongue, pressing it against the mouth of the tube; in the second, to the same pressure on the top of the leather, causing it to adhere to the stone; and in the last, to the weight of the air pressing on the surface of the liquid, forcing it into the vacuum in the tube. QUESTION 10. Wh]at is the amount of.the pressure of the atmosphere, and how is it measured? Answer. It is usually nleasured by the pressure on one square inch of surface, which at the earth's surface is 15 pounds.- If, for example, we have a cylinder, A, fig. 7, with an air-tight piston, B, fitted to it whose area is just one square inch, if we exhaust the air through the tube C from the cylinder above the piston, the air will press against the under side of the piston so that, if no power is required to overcome its friction in the cylinder, the pressure of the air will raise a weight of 15 pounds. The pressure of the air varies, however, as you ascend or descend from the surface of the earth, because as you go up on a mountain or in a balloon the layer of air above you becomes thinner, and, therefore, its weight and consequent ITII common practice it is generally taken at 15 lbs. per square inch, but the average atmospheric pressure is more accurately 14.7 pounds. 10 Catechism of the Locomotive. liig 7 Ad Scale pressure are diminished; and as you descend, as in a deep mine, the layer is tlhicker, and its pressure consequently greater. QUESTION 11. What is steam? Answer. Steam is water changed by means of heat into a gas. At every temperature there is formed from water, on its surface, vapor of which the clouds are formed at all seasons of the year. This change of water into vapor, or evaporation of water, takes place at low temperatures only on its surface, however. But if we heat water in a vessel to a temperature of 212 degrees Fahrenheit, then the inner particles of the mass of water (1ying on the heating surface of the vessel) are changed into steam, and rise to the surface in bubbles, whllich is the phenomenon we call boiling. It must not be imagined, however, that the visible cloud which escapes from a kettle or the exhaust-pipe of a steam engine is true steam. It is rather small The Forces of Air and Steam. 11 particles of water, into which the steam has-condensed through contact with the cold air. True steam is invisible, as we may observe near the mouth of a kettle or the exhaust-pipe of an engine from which we know it is escaping. QUESTION 12. If water is heated in an open vessel what occiurs? Answer. It continues for some time to increase in temperature, and the evaporation becomes more and more rapid. At length bubbles of vapor break out and reach the surface, and the process of boiling or ebullition has begun. When this takes place the temperature of the water ceases to rise, and it remains stationary until all the water has boiled away, the only difference being that if the supply of heat be very great the process is very rapid, and if the supply of heat be small the process is very slow. The point at which ebullition commences is called the boiling-point. QUESTION 13. On what does the boiling-point depend? Answer. Chiefly on the pressure on the surface of the water, but to some extent upon the purity of the water. Thus, boiling, which takes place at 212 degrees under the ordinary atmospheric pressure, in lighter air, as on high mountains, takes place at a much lower temperature than on lowlands, and so water boils in a glass tube from which the air has been exhausted by the warmth of the hand, that is, at 92 degrees. QUESTION 14. What is the pressure of steam which escapesfrom boiling water in an open vessel? Ansuwer. It is exactly equal to the pressure of. the 12 Catechism of the Locomotive. atmosphere in which it is boiled. Ordinarily this is 15 lbs., and the boiling-point 212 degrees; but if we go up on a mountain where the atmospheric pressure is only 10 lbs. per square inch, the water will then boil at a temperature of 193.3 degrees, and the steam which escapes will have the same pressure as the atmosphere, or 10 lbs. per square inch. On the other hand, if we could go down into a mine where the atmospheric pressure was 20 lbs. per square inch, the water would not boil until it was heated to 228 degrees, and the pressure of the escaping steam would then be 20 lbs. per square inch. QUESTION 15. If water is boiled in anc enclosed vessel like a covered tea-kettle or a steam boiler, what occurs? Answer. The steam rises and fills the space above the water, and, if it cannot escape, increases in pressure. The temperature of both the water and the steam rises with the pressure, and will continue to do so as long as the heat is increased, or until the steam can escape or the vessel is exploded. The boiling point also rises as the steam pressure increases. QUESTION 16. Is there any pressure which corresponds to the temperature of steam and water? Answer. Yes. There is a fixed pressure for every temperature, when steam is in contact with water, and its pressure cannot: be increased or diminished without at the same time heating or cooling the water, and the higher the temperature of the water the greater will be the corresponding steam pressure. Thus water at 212 degrees produces steam with a pressure equal to that of the atmosphere; at 240 degrees the steam will have a pressure of 25 lbs., or 10 lbs. more than the atmospheric pressure; at 281 de The Forces of Air and Steam. 13 grees a pressure of 50 lbs.; and at 328 degrees, 100 lbs. As this relation of pressure to temperature is fixed, if we know the one we can tell the other. This is true, however, only where the steam is in contact with water, when it is called saturated steam. If it is separated from water it may be heated to a higher temperature, and is then called superheated steam. QUESTION 17. How is the pressure of steam measured? Answer. In the same way as that of the atmosphere,-that is, by the force exerted on one square inch of surface. Thus if steam is admitted into the cylinder A, fig. 8, under the piston B, whose area is equal to one square inch of surface, supposing, as we did before, that no power is required to overcome its friction in the cylinder, if the steam thus admitted would just balance the atmosphere, its pressure would be equal to 15 lbs. If, besides overcoming the pressure of the atmosphere, it would raise a weight of 15 lbs., then its pressure per square inch would be equal to 30 lbs. When the atmospheric pressure is included with that of the steam, we call it the absolute steam pressure. In ordinary engines, however, the steam must always overcome the pressure of the atmosphere, and therefore the only part of the pressure which is effective is that above, or by which it exceeds, the atmospheric pressure. For example, although the steam admitted under the piston in fig. 8 has an absolute pressure of 30 lbs. per square inch, yet it will only raise a weight of 15 lbs., because it must first overcome the pressure of the air on the other side of the piston. The pressure of the steam used in most stationary and in locomotive engines is, therefore, 2 14 Catechism of the Locomotive. measured by its pressure above the atmosphere. That is, if steam introduced under the piston in fig. 8 will raise a weight of only 15 lbs., we say it has a pressure of 15 lbs. per square inch; if it will raise 50 lbs., its pressure is said to be 50 lbs. per square inch, and so on. The pressure of the atmosphere is disregarded, and all steam-gauges used on locomotives are graduated in that way. In speaking of steam pressure in future, therefore, unless otherwise specified, we shall mean effective and not absolute pressure. QUEsTION 18. What is meant by the expansion oJ steam? Answer. In all gases a repulsion is exerted between the various particles, so that any gas, however small in quantity, will always fill the vessel in which it is held. Steam possesses this same property, and if placed in any vessel the particles in endeavoring to separate from each other will exert a force on all its sides. This force we call the steam pressure. To illustrate this we will suppose that the cylinder A in fig. 8 is half filled with steam of 30 lbs. pressure. If now the supply of steam is shut off, the steam in the cylinder will expand so as to push the piston upward, but with a somewhat diminishing force, the nature of which we will explain hereafter. QUESTION 19. What is meant by the volume of steam Answer. It means the space which the steam occupie s. QUESTION 20. Wlhat is the proportion which exists between the volume and the pressure of steam? Answer. If the temperatures remain the same they are INVERSELY PROPORTIONAL TO EACI-I OTHER; that is, the one increases in the same proportion as the other diminishes. If we admit steam of 30 lbs. The Forces of Air and Steam. 15 Fig 8 j Scale pressure per square inch into the cylinder A, fig. 8, and then cut off the supply by closing the cock C and allow the steam in the cylinder to expand to double its volume by pushing the piston to the end of the cylinder, the steam pressure will then be only 15 lbs.; if it should expand to three times its volume its pressure would be only one-third, or 10 lbs. per square inch. This method for calculating the pressure of steam after it has expanded is correct only for the absolute and not for the effective pressures of steam. In order to ascertain the effective pressures of steam after expansion, it is only necessary to make the calculation with the absolute pressure and deduct the atmosplheric pressure from the result. If, after being thus expanded, - the piston be pushed down again so as to compress the steam into its original space, its pressure will again be 30 lbs., providing no heat has been lost in any way. 16 Catechism of the Locomotive. QUESTION 21. With a cylinder of any given stroke* how can we determine approximately the pressure of the steam after expansion for any given point of cut-off? t Answer. BY MULTIPLYING THE ABSOLUTE PRESSURE PER SQUARE INCH OF THE STEAM IN THE CYLINDER BEFORE IT IS CUT OFF, BY THE DISTANCE FROM THE BEGINNING OF THE STROKE AT WHICH IT IS CUT OFF, AND DIVIDING THE PRODUCT BY THE WHOLE LENGTH OF THE STROKE. Thus, if we have a cylinder whose piston has a stroke of 24 inches, if we cut off the steam at 8 inches, and have an ABSOLUTE pressure of 90 lbs. in the cylinder, the calculation is as follows: 90 x8 24 30 lbs. final pressure. If we cut off at 10, 12 and 15 inches, the final pressure would be 37T, 50 and 56 lbs., respectively. To get the effective pressure deduct the atmospheric pressure from this result. QUESTION 22. What is the proportion between the volume of steam and that of the water from which it is formed? Answer. At the pressure of the atmosphere (15 lbs.) each cubic inch of water will make 1,610 cubic inches of steam. At double that pressure, or 30 lbs. absolute pressure, it will make a little more than half as much, or 838 cubic inches; at four times, or 60 lbs. absolute pressure, 437 cubic inches, or a little more than a fourth as much as at the pressure of the atmosphere. * The stroke of a piston is the distance it moves in the cylinder. and in orl(inary engines is always twice the length of the crank measured from center to center of the shaft and crank-pin. t Th'Ie steam is said to be cut off when the steam-port by which steam is admitted to the cylinder is closed by the valve. The Forces of Air and Steam. 17 QUESTION 23. WihY is it that the quantity of steam at high pressures is somewhat greater than in inverse proportion to the pressure? Answer. Because the boiling-point of water, as has already been explained, is higher as the pressure increases, and therefore the temperature of the steam produced at such pressure is also higher than at lower pressures; and as all gases are expanded by heat, therefore the volume of steam at the higher pressures is somewhat greater than in inverse proportion to its pressure, on account of being somewhat expanded by its high temperature. To make this plain, if we take a cubic inch of water and convert it into steam of atmospheric pressure, its volume will be 1,610 times that of the water, and its temperature 212 degrees.* If we convert this quantity of water into steam with a pressure double that of the atmosphere, the volume of the steam will be 838 times that of the water and its temperature will be 250.4 degrees. If the volume of the steam were exactly inversely proportional to the pressure, the cubic inch of water at double the atmospheric pressure would make only 805 cubic inches of steam; but as the boiling-point at that pressure is 38.4 degrees higher, the steam is expanded 33 cubic inches by the increase of its heat due to the higher boiling-point. A table in the appendix gives the pressure, temperature and volume of saturated steam up to 300 lbs. absolute pressure. QUESTION 24. What is meant by the condensation of steam? * Mlore accurately, 213.1 degrees, if we call the atmospheric pressure 15 lbs., as we have. 2* 18 Catechism of the Locomotive. Answer. It is the reconversion of steam into water by cooling it, or depriving it of part of its heat. It has been shown that the temperature of water must be raised to a certain point to generate steam of a given pressure. If the process is reversed, and we deprive the steam of a part of its heat, some of the steam is then at once reconverted into water, or condensed, and the pressure of that which remains will be reduced just in proportion as the lieat is lost. When the temperature gets below 212 degrees under atmospheric pressure, all the steam will be condensed. As the useful work which steam can do in an engine is due to its pressure, which in turn depends on its temperature, any loss of heat will diminish its effective power. For this reason, all waste of heat from a steam engine should, as far as possible, be prevented. QUESTION 25. Row is tfhe heat of the steam wasted or lost in an ordinary steam engine? Answer. It is wasted in three ways: first, by conduction; second, by convection; and third, by radiation. QUESTION 26. What is meant by these three terms? Answer. 1. By conduction is meant that phenomenon which is manifested when we put one end of a metal bar two or three feet long into the fire and heat it. The heat is then gradually conveyed from one particle of the metal to that next to it until finally the end of the bar farthest from the fire becomes so hot that it cannot be touched. The heat is then said to be conducted through the bar. In the same way the metal of the boiler, pipes, cylinders and other parts of the engine becomes heated on one side, and the heat is thus conveyed to the outside of these parts. The Forces of Air and Steam. 19 2. The air with which they are surrounded then becomes heated, and being then lighter than the cold air, it rises and is again replaced with air which is not heated. In this way the heat is conveyed away by the air, and this phenomena is therefore called convection. 3. If an iron plate be placed in front of an ordinary grate fire three or four feet from it and exposed to the rays of heat from the fire, it will soon become so hot that you cannot bear your hand on it. If you place your hand between the iron plate and the fire you will find that only the side of your hand which is exposed to the fire will become hot, showing that the air between the plate and the fire is not nearly so hot as the plate soon becomes, and therefore that the heat is not conveyed to the plate by the air between it and the fire, but by the rays from the fire. This phenomenon is called radiation. The same thing occurs from any hot body, as for example a coil of steam pipe for heating a room, a steam boiler or cylinder of an engine. QUESTION 27. is there any difference in the conducting and radiating power of different substances? Answer. Yes, very great. The difference in the conducting power of wood and iron is shown if we place one end of a bar of each in the fire. The wood will be consumed without warming the bar more than a few inches from the fire, whereas the iron will soon become hot two or three feet from the fire. Owing to the difference in the conducting power of cotton and wool, we wear cotton clothing in summer and woolen in winter, because cotton allows the heat of the body to be conducted away from it, whereas woolen cloth 20 Catechism of the Locomotive. prevents to a great degree this loss of heat. For the same reason, the venders of roasted chestnuts on our streets wrap them in a piece of blanket to keep them hot, that is, to keep the heat in; and in summer we wrap ice in the same way to keep it cold, that is, keep the warmth of the air out. The wool, being a very bad conductor of heat, simply prevents the heat from being transferred from the inside to the outside, and vice versa. It is for this reason that steam boilers, pipes and cylinders are nearly always covered with wood, and sometimes with felt. The difference in the radiating power of various substances can be shown if we take a large thermometer and heat it up to the temperature of boiling water. If this thermometer is hung up in a room having the temperature of melting ice, it will lose heat in two ways,-first by heating the air whllich surrounds it, that is by convection, and also by radiation. In order to confine ourselves to the latter process, we will suppose that the chamber is a vacuum. If we first cover the bulb of the thermometer with a thin coating of polished silver, and then ascertain how much heat it radiates in a minute, and then coat it with lampblack, and repeat the same experiment,-that is to say, allow the thermometer at the boiling-point to cool for one minute in a vacuum chamber at the freezing-point,-it will be found that the thermometer loses much more in a minute when coated with lamp-black than it did when coated with silver, showing that much more heat is radiated from a surface covered with lamp-black than from polished silver. Generally it may be stated that polished metals radiate much less heat than surfaces which The Forces of Air and Steam. 21 are not polished.* For this reason, as well as for ornament, locomotive and other boilers and cylinders are usually covered with Russia iron or polished brass. * The account of the above experiment is copied from Balfour Stewart's very excellent little book, "Lessons in Elemeutary Physics," of which, and the same author's "Elementary Treatise on Heat," the writer has made frequent use. PART III. ON WORK, ENERGY, AND THE MECHANICAL EQUIVALENT OF HEAT. QUESTION 28. For what purpose are all steam engines used? Answer. They are used to produce motion, which is opposed by some resistance. Thus, if an engine is employed to raise grain from a railroad car to the top of a warehouse, it must produce motion, which is resisted by the weight of the grain; if it is used to saw wood, it must give motion to the saw, which is resisted by the fibres of the wood; a locomotive engine must produce motion of a train of cars, which is resisted by the air, the friction of the journals and the rolling of the wheels on the track; if the locomotive is employed on a grade or incline, besides the frictional resistance referred to it must overcome that due to its own weight and that of the train, which is gradually lifted as it ascends the incline. In producing motion opposed by some resistance an engine is said to be doing "work." QUESTION 29. Can this work be accurately measured?.Answer. Yes-; but in order to measure anything we must first establish some accurate standard or unit of measurement. Thus we say a bar of iron is so many inches long, or a road is so many miles long. In like manner we speak of so many seconds, or minutes, or hours, or days, or years, when we speak of time. So On Work, -Energy and Heat. 23 it is necessary, in order to estimate or measure " work" in a strictly scientific manner, for us to fix upon some accurate standard or unit. In this country and in Great Britain the unit agreed upon for this purpose is the amount of power required to raise ONE POUND ONE FOOT, and is called afoot-pound. If we raise one pound two feet we do two foot-pounds of work; if three feet, three foot-pounds, and so on. Again, if we raise a weight of two pounds one foot high, we likewise do two foot-pounds of work; or if we raise it two feet high, we do four foot-pounds, and so on. In order to determine the amount of work done, we must MULTIPLY THE MOTION PRODUCED (in feet) BY THE RESISTANCE (in pounds), AND THE RESULT WILL BE THE WORK DONE IN FOOT-POUNDS. QUESTION 30. How many' foot-pounds of work are performed in a pile-driving machine in raising a weight of 1,200 lbs. 24 feet? Answer. 1,200x24 —28,800 foot-pounds. QUESTION 31. When this weight is raised, is the force which was exerted in raising it annihilated or lost? Answer. No; because the weight has the capacity of doing an equal amount of work when it falls, from the momentum* it acquires in falling. This power of doing worle which it acquires in falling is called energy. Now, although the weight has no motion-producing power when it is raised to the top of the machine, yet obviously such action is then possible which when it rested on the earth was not possible. It has no energy as it hangs there dead and motionless; but energy is possible to it, and we might fairly use the * MTmentum is not a, very exact term, but is used here because it ordinarily conveys the idea we wish to express. 24 Catech]ism of the Locomotive. term possible energy to express this power of motion which the weight possesses,* and which is therefore called potential energy. As soon as the weight is allowed to fall it acquires a greater velocity the farther it falls, and its potential energy thus becomes and is called actual energy. QUESTION 32. How do we explain such phenomena as the heating of a car-axle while turning under a car, the heating of brake-blocks when the brakes are applied to car-wheels, the heating of an iron rod by hammering, and of a turning tool when cutting a piece of metal? Answer. All of these phenomena ai'e due to the fact that the actual energy of motion is converted into heat, as has been repeatedly proved by many able and ingenious investigators and experiments. QUESTION 33. When the weight of the pile-driver falls, is its energy also converted into heat? Answer. A part is expended in compressing the material into which the pile is driven and in overcoming tlie friction of the earth against the pile, each of which efforts develops heat, and another portion is converted into heat by the impact or blow of the falling weight on the head of the pile. QUESTION 34. Is all energy convertible into heat and heat into energy? Answer. Yes. Science has demonstrated very clearly that they are mutually convertible. QUESTION 35. Has it been ascertained how much heat is equivalent to one foot-pound of work? Answer. Yes; it has been found, front the most carefully-made experiments that the amount of heat * Tyndall's " Heat Considered as a Mode of Motion.' On Work, Energy and Heat. 25 which is required to raise the temperature of one pound of liquid water by one degree of Fahrenheit* is equivalent to 772 foot-pounds of work. It must be remembered that this is the theoretical equivalent of heat, and that only a very small proportion of this amount of work is ever realized from the heat developed by the combustion of fuel. QUESTION 36. If, then, heat is convertible into work and work into heat, can the transmutation of the heat of the steam in the cylinder of an engine into work, and the reverse process, be explained? _Answer. Yes. Take a cylinder, fig. 9, and, in order to make the conditions of the experiment as simple as possible, imagine it to be placed in a vacuum. Now let saturated steam be admitted under tile piston so as to fill the cylinder half full at an absolute pressure of 100 lbs. If we will allow this steam to expand to double its volume and raise the piston without doing any work, and then repeat the experiment with a load of 50 pounds on the piston, whose area is one square inch, it will be found that the temperature of the steam is sensibly less, after lifting the weight, than in the previous experiment, in which it expanded without doing work, showing that part of the heat was abstracted from the steam by doing work, or, in other Fig. 9. words, was converted into work. If Scale ] in.=1 foot. * Thermometers are divided into different scales. The one called the Fahrenheit scale, after its originator, is the one ordinarily used in this country. 3 26'Catechism qo the LocourLotive. then, after the steam has expanded and lifted thle weight, we- press the piston down so that the steaml under the, piston is compressed to its original volume, we shall find that its temperature is the same as before, as the work done in compressing it is converted into heat. In these experiments it is assumed that there is no friction of the piston, nor loss of heat from radiation or conduction. The same phenomena can be observed in machines used for compressing air, wliich is heated to so high a temperature when it is compressed that it is necessary to cool the cylinders of such machines by circulating a current of cold water around them. QUESTION 37. What practical relation is there between the convertibility of heat into work, and the conducting and radiating properties of different substances explained in answer; to Question 27? Answer. The fact that heat is only another form of energy, or "the power of doing work," indicates that its loss by conduction or radiation lessens that power just as much as or more than the loss or waste of coal would, and therefore every effort should be made to protect the different parts of engines from loss of heat by covering them with substances. which conduct or radiate very little heat. Care should also be taken to exclude cold air from circulating in contact with these parts, and excepting for supporting combustion, the nature of which will be explained. hereafter, it should be excludled from the heating surface of boilers. QUESTION 38. Wh1at is meant by the tearm LATENT HEAT OF EVAPORATION? Answer. By latent heat is meant that heat which apparently disappears when water or other liquids are O)n Work, Eneryy and Heat. 27 vaporized. Thus, it is found that if any quantity of water is converted into steanm at any pressure, it is necessary not only to heat it to a temperature equivalent to that of the steam, or to the boiling-point, but after it has reached that temperature an additional amount of heat must be added in order to keep up the process of boiling. Notwithstanding this addition of heat to thle water, the temperature of tile steam prodlucecl will not be higlher than that of the boilingr water, thus showing tlhat a considerable quantity of heat is absorbed, the only effect of wvlich is to clhange the water into a gas or steam. Thlis apparent di-salppearance of heat can be shown if we take a pound of boiling water whose temperature is 212 degrees Land mix it with a pound of ice-cold water at 32 degrees. The result will be a mixture of two pounds of water of a mean temperature of 122 degrees. If now we convert a pound of water into steam at atmospheric pressure, the steam will heat 6.37 lbs. of ice-cold water up to 122 degrees, showing that a pound of steam at atmospheric pressure contains over six times as much heat as a pound of'water of the same teimperature as indicated by a thermometer. A similar apparent disappearance of heat occurs wNhen other liquids are evaporated, and when ice or any otlher solid is converted into a liquid. QUESTION 39. YWhat is the explanation of thlese phenomena? Answer. The exact reasons wlhich will explain them fully are probably not yet clearly understood, but it is at least extremely probable that wlhen any substance is changed from a solid to a liquid, or from a liquid to a gaseous condition, "a large portion of the heat is 28 Catechisim of the Locomotive. spent in doing work against the force of cohesion."* The particles of solid bodies, as we know, are so united that it requires more or less force, according to the nature of the substance, to tear them apart. Now we can conceive that the heat is changed into a form of energy, and in that condition resists this attraction of the particles to each other, and that being thus transformed it has lost the capacity of expanding the mercury in the thermometer. A similar effect takes place when a liquid is converted into a gas. In the former condition the particles move freely about each other and have little or no attraction for each other, but when it becomes a gas they have a repulsion from each other. The.heat is thus converted into the energy of repulsion, and therefore is in reality no longer in the condition of heat and consequently does not affect the thermometer. We can illustrate this by supposing that by using steam heat is converted into work by raising the weight, or drop as it is called, of a pile-driving machine. When the weight is raised to the top of the guides from which it falls, although, as already explained, the heat is converted into potential energy, yet if we attached a thermometer to the drop we would not find that it was any warmer than before the drop was raised. If it were possible to make an instrument sufficiently sensitive to indicate an instantaneous change of temperature in the weight while falling, we would not find any increase of its temperature at the instant it had acquired its greatest momentum and just before it struck the object under it, although its potential energy would at that instant " Balfour Stewart on the Conservation of Energy. On Work, Energy and Heat. 29 be converted into actual energy of motion. If, however, the weight should strike an unyielding object, its actual energy would at once be reconverted into heat, which our thermometer would indicate. The phenomenon of what is called latent heat of evaporation seems to be very Similar to that described-the heat when the water is changed from a liquid to a gaseous condition is transformed into energy, which. as already stated, has no effect upon the mercury of the thermometer. QUESTION 40. What is meant by the TOTAL HEAT of steam? Answer. The "' total heat of steam" is a phrase used to denote the sum of the heat required to raise the temperature of water from some given point up to the boiling-point due to a given pressure, and of the heat which disappears in evaporating one pound of water under a given pressure (or latent heat of evaporation.) Thus the latent heat of one pound of steam at atmospheric pressure (14.7 lbs.) is 966.1 units; and 212 units of heat are necessary to raise water from zero to the boiling-point; therefore the total heat counted from zero of steam of atmospheric pressure is 1,178.1 units. At 100 pounds absolute pressure the latent heat is 885.5 and the sensible heat 327.9 degrees; therefore the total heat measured from -zero is 1,213.4 units. 3* PART IV. THE SLIDE-VALVE. QUESTION 41. What are the essential conditions which a slide-2valve must fulfill in governing the admission and ecahauh t of steam to and from the cylinder of an ordinary engine? Answer. 1. It must admit steam to one end only of the cylinders at one time. 2. It must allow the steam to escape from one end at least as soon as it i admitted to the other end; and 3, it must cover the steamports so as not to permit the steam to escape from the steam-chest into the exhaust-port. QUESTION 42. What was the first form of slide-valve used? Answer. That represented in fig. 10. The smallest Scale 3-16 in. =1 inch. movement of this valve either way opens one of the The Slide -Valve. 31 steam-ports for the admission of steam and puts the other in communication with the exhaust-port. By cutting a piece of ordinary writing paper to the form of the section of the valve, and moving it on the line ff, the action of the valve will be clearly showlln. QUESTION 43. How was the admission and escape of the steam effected by this valve? Answer. In order to explain this clearly, a series of diagrams will be necessary. Before referring to them, however, it should be explained first that the: motion of an eccentric is exactly the same as that of a small crank. It is in fact a crank with a crank-pin whose diameter is very much enlarged. In the diagrams, figs. 11 to 25, the eccentrics will therefore be represented as small cranks, and most of the other parts by their centre-lines and points only, so as to imake the diagrams as simple as possible. The dimensions selected for these illustrations are for the cylinder 16 in. diameter and 24 in. stroke, and a connecting-rod 7 ft. long. The steam-ports are 1i ill., the exhaust-port 2- in., and the metal or bars between them, w hich are called bridges, are 11 in. wide. The eccentric produces a lateral movement of 3 in., which is called its throzw. In fig. 11 the piston is at the beginninug of the backward stroke. The valve is then in the centre of the valve-face, and the eccentric is consequently at lhalf-throw. The slightest movement of the crank in the direction of the dart N will move the eccentric enough to open the front steam-port to: tihe steam and..thle back one to the exhaust. In fig. 12 the piston is represented as having moved 4 in. of its stroke; the valve has then partly opened the front 32 Catechism of the Locomotive. Fi 1~2 — Fe.11. t,,' Fig. 5., "...... Scai. n. /,, 111.. ~ —~,:,! \ T-' HI t. 17.' -, ",, a r'. ~. o........ Sealo } in. - riot' The,S'lide Valve. 33 F-ice. 19 |r..... w I \ j.','.[ / Scale in. 2 foot.', I5 F5~ip 20 b,A,.... 34 Catechism of the Locomotivle. steam-port, and the other one is open to the exhaust. In fig. 13 the piston has moved 8 in. of its stroke, and the ports are now wide open, the front one to the steam an(l the back one to the exhaust. In fig. 14 the piston has moved 12 in., or is at hlalf-stroke, and the valve has then moved as far as it will in that direction. In fig. 15 the piston has moved 16 in. and tie valve has begun to return. In fig. 16 the piston has moved 20 in., and the valve has nearly closed the front port to the steam and the other to the exhaust. In fig. 17 the forward stroke is completed, and both ports are closed by the valve. Figs. 18, 19, 20, 21, 22 and 23 represent the piston and the valve on the return stroke in the positions corresponding with those described for the backward stroke. QUESTION 44. Is there any other method by which the motion of a valve can be represented by a drawing? Answer. Yes, by what are called motion-curves. It is, however, difficult to explain these clearly, and as they are purely imaginary, it is difficult to understand their nature and purpose. Close attention will therefore be required to the following description: We will suppose, in the first place, that the line ff, fig. 25, represents the valve-face, c and d the steam and g the exhaust-port, drawn to a larger scale than in the preceding figures. We will now draw the valve H in the position represented in fig. 11, where the piston is at the beginning of the stroke. In order to show the valve in the position represented in fig. 12, where the piston has moved 4 in. of the stroke, we will draw a line 4-20, four inches below and parallel to Jf, and extend the lines, representing the edges of the ports c, d and g, downward. On the horizontal The Slide Valve. 83 line 4-20 we will now draw the edges i, r, i', r, of the valve in the same position in relation to the port c that it has in fig. 12. We will then draw another horizontal line, 8-16, eight inches belowff, and paiallel to it, andl on this represent the valve in the position shown in fig. 13. In the same way we will draw lines 12, 16, 20 and 24 in. below ff, and draw the valve on each one respectively in the positions shown in figs. 14, 15, 16 and 17. The distance between the lower line 24-0, and ff, will then represent the stroke of the piston, or 24 in. If now we begin from the edge h of the valve on the line ff, and draw a curve, h i j k I mn n, through the same edge of the valve, represented on each of the parallel lines below, the curve will indicate the position of the valve in relation to the steam-port c at each point of the stroke. To illustrate this, suppose we draw lines 1-23, 2-22, and 3-21, one inch. apart and parallel to ff, and between it and 4-20. They will then represent the position of the piston after it has moved 1, 2 and 3 in. from the beginning of the stroke, and where they intersect the curved line will be the position of the edge of the valve when the piston has moved 1, 2 and 3 in. of the stroke. The curved line will in fact represent the position of the valve at any point of the stroke between these lines. Other horizontal lines, 5-19, 618, etc., can be drawn to represent every inch of the iest of the stroke. The curve line h i j k 1 m n, or motion-curve as it is called, will then show the exact position of the edge of the valve and of the width of the opening of the steam-port during the whole stroke. From it we see that the valve opens the port c for the admission of steam simultaneously with the move tScae -16 in. 1 inch. scale 2~-16 ill. = 1 inch. The Slide Jtalve. 37 ment of the piston, and when the latter has made one inch of its stroke the port c is half open. At 4j inches of the stroke the port is wide open,* and at 19~ inches it begins to be closed, but is not completely closed until the end of the stroke. Similar motion-curves, such as h' i' j' 1' r m' n', (represented in fig. 25) can be drawnL to represent thei position of the other edges of the valve, and also for the return stroke. The latter are shown in dotted lines. If we follow the curve h' i' j' k' l' m' n', which represents the position of the edge of the valve h' which governs the exhaust from the back end of the cylinder, we see that the port d is opened and closed to the exhaust simultaneously with the opening and closing of the port c for the admission of steam to the front end of the cylinder, and that they both remain open until the completion of the stroke. The width that the ports are opened by the valve is thus ascertainable from these diagrams, for any point of the stroke, and in fact can be seen at a glance. By the aid of such motion-curves, the movement of slide-valves can therefore be analyzed more perfectly than is possible without them. QUESTION 45. What were some of the disadvantages of valves, like that shown in fig. 10, and which are shown by the motion-curves in fig. 25. Answer. The free admission of the steam until the completion of the stroke by the piston was hurtful to the machinery, as it co-operated with the momentum.of the piston and its connections in producing undue * By cutting a paper section of the valve and placing it on the diagram in each position named, it wvil probably help the reader to understand the movenment,of the valve more and the nature of the motioncurves. 4 38 Catechism of th/e Locomotive. strains in the working parts. The steam then escaped from the cylinder without expansion, so that much of its useful energy was lost. The steam was not allowed to escape from one end of the cylinder until it was admitted at the opposite end, and as the process of exhausting it occupies some time, there was always more or less back pressure until all, the exhaust steam was expelled from the cylinder. In practice, the imperfections of the valve-gear frequently delayed the opening of the ports, both for admitting and exhausting steam, until after the commencement of the stroke of the piston.* QUESTION 46. How may some of these evils be overcome? Answer. By moving the eccentric forward on the axle so that the motion of the valve is advanced to the same extent, and the admission and exhaust of the steam will occur a little before the completion of the stroke of the piston. In this way the steam is admitted into the cylinder so as to act as a cushion to receive the momentum of the piston, and some time is given to the exhaust steam to escape, before the return stroke. QUESTION 47. What is meant by lead? Answer. By lead is meant the width of the opening of the steam-ports at the beginning of the stroke of the piston. On the steam side of the valve it is called outside lead; on the exhaust side inside lead. In fig. 26 the opening h of the steam-port is the outside lead and h' the inside lead. QuESTION 48. What is meant by the travel of a valve? Answer. By the travel we mean the motion of the * D. K. c(lark's " Railway Machinery." Scale 3-16 i. = 1 inch. 40 C'atechism of the Locomotive. valve back and forth, or in other words its stroke. If the arms of the rocker are of the same length, the travel of the valve is equal to the throw of the eccentric. For the preceding illustrations we have selected an eccentric with three inches throw, which is the travel of the valve. QUESTION 49. How is the steam made to work expansively with a slide-valce? Answer. By giving the valve what is called lap. That is, by allowing the edges of the valve when it is in the center of the valve-seat to overlap the edges of the steam-ports, as shown in fig. 27. Where this overlap, L L. is on the outside of the valve, it is called Scale 3.16 in. = I inch. outside lap; when on the inside, I, inside lap. When a valve has lap, those portions of the face* i,, i, and p, q, which cover the steam-ports, being wider than the ports, therefore occupy some time in moving over them, during which time the steam is enclosed in the end of the cylinder, as there is then no communication either with the steam-chest or the exhaust-port. This X The valve-face is the surface of the valve in contact with the valveseat. The Slide- Valve. 41 action is shown very clearly by the motion-curves in fig. 26. The valve in this case has I inch lead. At 41 inches of the stroke of the piston the valve has moved as far as it will go in that direction, and the steam-port has its maximum width of opening. Fromn that point the valve will begin to close the steamport, and at 14- inches of the stroke the port will be entirely covered, and the steam therefore be cut off The port will remain closed until the piston has moved 213 inches, when it will be observed from the motion-curve r s t u v w x, that the port c is opened to the exhaust and the steam escapes, or, as it is technically called, the release takes place. From the time the steam is cut off to the time it is released, it works expansively in the cylinder. QUESTION 50. What relation is there between the amount of laps and the degree of expansion? Answer. The greater the lap with any given travel, the shorter will be the period of admission of steam, and, consequently, the more time and space for expansion. QUESTION 51. What is the effect of inside lap? Answer. It delays the release of the steam. Thus in fig. 26 the valve has 8 in. inside lap. The motioncurve r s t u v w x shows that the release takes place during the back stroke at 213 in. If now there was no inside lap, the dotted line y, x would represent the exhaust edges of the valve, and the release would then occur somewhat earlier, or at 21 in. For this reason no inside lap is usually given to valves for engines which run at high rates of speed, as it allows too little time for the steam to escape. In fact, in - In.speaking simply of lap, outside lap is always mea'nt. 4*[ 42 Catechism of the Locomotive. some cases, what is called inside clearance is given to the valve; that is, the valve as shown in fig. 29, when it is in the middle of the valve-face, does not entirely cover the steam-ports. The effect of this is just the reverse of that produced by inside lap; that is, it causes the release to occur earlier in the stroke. Scale 3-16 in. = 1 inch. QUESTION 52. With the same outside lap, what is the effect of changing the travel of the valve? Answer. By increasing the travel, the period of admission is increased and that for expansion lessened; and by reducing it, the admission is lessened, and the degree of expansion is increased. This is shown by the motion-curves in fig. 28, in which the same valve and ports are represented as are shown in fig. 26, but the valve has a travel of 5 instead of 3 inches. The valve also has the same lead. By following the motion-curve h i j k 1 m?n, it will be seen that the steam is thus admitted up to 20- inches of the stroke of the piston, and the period of expansion, as compared with that in fig. 26, is correspondingly lessened. It will also be seen by comparing fig. 26 with fig. 28 that with the short travel of the valve the ports are __ _ l _ A _ Scale 3-O6 in. 3 inch; 44 Catechism of the Locomotive. not opened so wide as they are when the travel is increased. This evil is practically obviated, however, by making the ports so long that with a comparatively small opening they will still have area sufficient to admit enough steam to fill the cylinders, and it is known that an opening less than the whole area of the steam-ports is sufficient to facilitate the passage of steam into the cylinder. QUESTION 53. How is the exhaust affected by lap and lead? Answer. The steam is released earlier in the stroke in proportion as the amount of outside lap and lead is increased, but the steam-port is also closed to the exhaust, or compression, as it is called, begins earlier with lap and lead than without. Thus, in fig. 25, it will be seen that at the beginning of the stroke both ports are entirely closed; in fig. 26, however, in which the valve has both lap and lead, the port d is nearly wide open at the beginning of the stroke, and by following the motion-curve r s t u v w x, which represents the position of the exhaust edge of the valve, it will be seen that the steam'was released from the port c before the piston had completed its stroke, or when it had still nearly 3- inches to move. In fig. 25 the port c is not opened to the exhaust until the commencement of the stroke, but it remains open to its completion, whereas in fig. 26 it is closed, or compression begins, at 18 inches of the return stroke, as shown by the dotted motion-curve. QUESTIoN 54. How does the action of the connectingrod influence the motion of the valve in relation to the piston? Answer. By delaying the movement of the crank in The Slide- Valve. 45) the backward stroke of the piston, and accelerating it in the forward stroke. This will be best explained by reference to fig. 14, in which the piston is represented in the center of the cylinder, or the middle of the backward stroke. If now we take a pair of dividers set to a length equal to that of the connecting-rod, and from the center, f, describe an arc of a circle, a b, from the center of the shaft, and through the lower half of the circle which represents the path of the crank-pin, we will find that the point of intersection, a, falls short of the vertical line, c d, and that the crank-pin has not made quite one-quarter of a revolution while the piston was moving througll the first half of the backward stroke.'By referring to fig. 21, in which the piston is again in the middle of its stroke, but is moving forward, and by describing another arc of a circle, b a, from the center of the shaft and intersecting the path of the crank-pin, it will be seen that the latter has moved more than a quarter revolution, while the piston has made the first half of the forward stroke. Owing to this angularity, as it is called, of the connecting-rod, the crank-pin is behind the piston during its backward stroke and ahead of it during the forward stroke. As the valve is moved by the eccentric, and it in turn bv the shaft and crank, any irregularities of the latter are of course communicated to the valve. We therefore find, by referring to fig. 26, that the point of cut-off occurs during the backward stroke at 14- inches, and during the forward stroke at 12 inches. A similar inequality is observable in the points of release for tile front and back strokes. It is not, however, a matter of very great practical importance with stationary engines which run at compara 46 Catechism of the Locomotive. tively slow speeds; but if it is thought desirable, the period of admission and the point of release for both strokes can be equalized, either by giving the valve nore lead or lap at one end than the other, or by making the one steam-port wider than the other. The mechanism employed for moving locomotive slidevalves, however, furnishes us with the means of modifying their motion in relation to that of the piston, and of thus equalizing the periods of admission and release for the front and back strokes. Thlie methods of doing this will be more fully explained hereafter. PART V. THE EXPANSION OF STEAM. QUESTION 50. flow can we determine by experiment the pressure of the steam in the cylinder at all points of the stroke? Answer. By the use of an instrument made for that purpose, called an indicator. Its action can be best explained by supposing that we have a small cylinder and piston, 7' fig. 30, (shown on an enlarged scale in fig. 31).........T. __ Stf. 30 Scaled ill. =Ifoot. attached by a pipe Uto one end of the cylinder A, so that when steam is admitted to the latter it will be conducted to the small cylinder T through the pipe U: Over the small piston and attached to it is a spiral spring, s s, fig. 31, which is compressed when the piston rises and extended when it falls. To the top of the piston-rod, V, a pencil, W, is attached. Behind this pencil we will suppose there is a card, a b c d, and that this card is so arranged that we can slide 48 Catechism of the Locomotive. W h Scale j in. 1 inch. it horizontally and in contact with the pencil point. With only the pressure of the atmosphere above and below the piston I, the spring would be neither compressed nor extended, and the piston would then stand in the position shown in fig. 31. If now we move the the card horizontally, the pencil will draw a line, g, h, called the atmospheric line. We will now suppose that the tension of the spring is such that a pressure of 10 lbs. per square inch above or below the piston will either extend or compress the spring I inch. In other words, every pound of pressure per square inch in the piston will move it 1-40 of an inch. If we, could produce a vacuum under the piston, it would be pressed down by the atmosphere above it 15-40, or of an inch. If, when it is thus depressed, we again slide the card along in contact with the pencil-point, it will draw another line, e. f, called' the vacuum-line. Assuming that we have drawn these two lines, and that the piston and card are in the position shown in figs. 30 and 31, we will then suppose that a recipro Thie Expansion of Steamo 49 eating motion can be given to the card by the lever L, M, N fig. 30, which is pivoted at Al and attached at N to the piston-rod by a short connecting-rod. It is obvious that by connecting the upper end L of the lever with a rod, L c, to the card, the latter will be moved backwards and forwards by the motion of the piston B, and that the motion of the card will be simultaneous with that of the piston B, but of course of shorter stroke. We will assume that the stroke of the card is equal to the length of the atmospheric and vacuum lines g h and ef, fig. 31. If now, the piston being at the beginning of the stroke as shown in fig. 30, we admit steam of 85 lbs. effective pressure per square inch (which' is equal to 100 lbs. absolute pressure) into the cylinder A, it will be conveyed through the pipe U to the cylinder T, and will force up the piston 85-40 or 21 inches above the atmospheric line, or 100-40 or 2- inches above the vacuum line, as shown in fig. 32, and the pencil will draw a vertical line, g i, on the card, (represented by a dotted line in fig. 32.) We will suppose that steam is admitted during 8 inches of the stroke, and is then cut off. When the piston B, fig. 30, has moved that distance, which is one-third of its stroke, the card will also have moved one-third of its stroke, and will stand in relation to the pencil in the position represented in fig. 33, and as the absolute steam pressure in the cylinder was maintained at 100 lbs. while the card was moving that distance, the pencil will have drawn a horizontal line, ij. The steam is now cut off and begins to expand, and its pressure is thereby reduced; When the piston of the engine is at half-stroke, the card will also be at half-stroke, and 5 0 iFi e;C~~~~~~' g= -~~~~ -_ 1 I - t of~m Yhz'L, O!3- Si -.: -...-.., Scale in. = inch. Scale ~; in. =1 inch. TAhe Expansion of Steam. 51 the steam will be expanded from 8 to 12 inches of the stroke. By the rule given in the answer to question 20, its absolute pressure would then be 662 lbs., and the indicator-piston will then be pressed down by the spring, so that the pencil will stand in the position shown in fig. 34, or 663 fortieths of an inch above the atmospheric line. The pencil meanwhile will have drawn the curved line j k. When the piston has moved 16 inches, the steam will be expanded to double its volume and its absolute pressure will therefore be 50 lbs., and consequently the pencil will stand 50 fortieths or 1! inch above the atmnospheric line as shown in fig. 35, and the pencil will have continued the curve j k to 1. At 20 inches the steam will have 40 lbs., and at the completion of the stroke 333 lbs. absolute pressure, and the pencil will have completed the curve j k I m n, as shown in figs. 36 and 37. This curve is called the expansion curve, and its form is that which mathematicians call a hyperbolic curve. If the steam is exhausted, the indicator-piston will descend and carry the pencil down to the atmospheric line, and the vertical line n A, fig. 38, will be drawn. On the return stroke, after the steam is exhausted from the main cylinder A, fig. 30, the pencil would draw the atmospheric line g h, fig. 38, thus showing that there is no steam pressure under the piston. Such a diagram is called an indicator diagram.* In practice there are a great many influences which modify it, such as condensation, performance of work, imperfec* The indicator used in practice, to sliow the action of the steam in the cylinders of steam eneines, differs essentially in its construction from that which we have described. The principles of operation are, however, the same in both. We will explain the construction of the Richard's indicator, the one which is now most generally used, hereafter. '52 Catechism of the Locomotive. tion of valve gear, etc., but for the present these are disregarded. QUESTION 56. How can we ascertain the pressure of the steam for any point of the stroke from such a diagram? Answer. By measuring the vertical distance by the expansion curve (fig. 38) from the vacuum or the atnlospheric line, as for example 8 j, 12 k, 16 1, 20 m. As the indicator spring is extended or compressed onefortieth of an inch* from every pound of pressure per square inch, either above or below the indicator piston, if we construct a scale S, S, fig. 38, with division of one-fortieth of an inch each, one of them will represent one pound of pressure per square inch if measured vertically from the atmospheric or vacuum line. If we sub-divide the vacuum line with the same number of parts as there are inches in the stroke of the piston (see fig. 39) we can draw vertical lines from these points and thus determine the pressure by comparing the length of such lines with the scale S, S. Thus the line 8 j measures 100 fortieths of an inch, thus showing that the absolute steam pressure at 8 inches of the stroke was 100 lbs. per square inch; the line 12 k measures 66* fortieths of an inch, thus showing that at 12 inches of the stroke the steam pressure was 66'2 lbs. At 16, 20 and 24 inches of the stroke the vertical lines measure 50, 40 and 33* fortieths; and therefore there were that number of pounds of steam pressure when the piston was at the point of the stroke named. Similar measurements could be made from other points, such as 2, 6, 10, or any other num* Indicator springs are used of various degrees of tension, in proportion to the steam pressure to be indicated. The Expansion of Steam. 53 ber of inches of the stroke. Of course, if we measure from the vacuum line we will have the absolute steam pressure, or the pressure above a vacuum, as it is sometimes called; if we measure from the atmospheric line we will have the effective pressure, or the pressure above,the atmosphere. QUESTION 57. How can we determine the average pressure during the whole stroke of steam which works expansively? Answer. This can be determined approximately by the following method: In the first place, divide the vacuum line (fig. 39) into any number of equal divisions, say six. From the points of division, 4, 8, 12, i I 2 4 6 8 10 12 1410 18 20 2224. Scale 1 in. =1 inch. 16 and 20, which in this case correspond with the points which represent inches of the stroke, draw perpendicular lines, which will divide the indicator diagram into six divisions. It is obvious that during the time the steam is working full stroke the pressure is uniformly 100 lbs. absolute. While the piston is moving from 8 to 12 inches the pressure falls from 100 to 66] lbs., so that at 10 inches we have very nearly the average pressure during the period named. So from 12 to 16, 16 to 20 and 20 to 24 the average is nearly 57.1, 44.4 and 36.3 lbs., respectively. Now, BY'ADDING TOGETHER THE PRESSURES IN THE MIDDLE OF EACH ONE OF A NUMBER OF EQUAL DIVISIONS OF 54 Catechism of the Locomotive. THE STROKE AND DIVIDING BY THE NUMBER OF DIVISIONS, WE WILL OBTAIN APPROXIMATELY THE AVERAGE ABSOLUTE PRESSURE DURING THE WHOLE STROKE. To GET THE AVERAGE EFFECTIVE PRESSURE, DEDUCT THE -ATMOSPHERIC PRESSURE FROM THE RESULT. The calculation would in the above case be as follows: 100 lbs. 100 " 80 " 57.1 44.4 36.3 6)417.8 69.6-Average absolute pressure. 15 54.6-=Average effective pressure. A more accurate way of calculating the average or mean pressure, as it is called, when steam is used expansively, and the one which is usually employed, is to DIVIDE THE LENGTH OF THE PISTON S STROKE IN INCHES BY THE NUMBER OF INCHES AT WHICH THE, STEAM IS CUT OFF: THE QUOTIENT IS THE RATIO OF EXPANSION. GET THE HYPERBOLIC LOGARITHM OF THE RATIO OF EXPANSION FROM THE TABLE OF LOGARITHMS IN THE APPENDIX, ADD 1 TO IT, AND DIVIDE THE SUM BY THE RATIO OF EXPANSION AND MULTIPLY THE QUOTIENT BY THE MEAN ABSOLUTE STEAM PRESSURE IN THE CYLINDER DURING ITS ADMISSION. THE RESULT WILL BE THE MEAN ABSO;LUTE PRESSURE DURING THE STROKE. TO GET THE The Expansion of Steam. 55 MEAN IEEFFECTIVE PRESSURE, DEDUCT THE ATMOSPHERIC PRESSURE. The calculation for the above example would be as follows: 2 — 3 —=Ratio of expansion. 1.098641 x 100=69.95M — ean absolute pressure. 3 69.95 —15=54.95= Mean effective pressure. The table of hyperbolic logarithms given in the appendix will be needed in calculating the mean pressure of steam used expansively: QUESTION 58. WYtat advantages result from using steam expansively? Answer. There is a very important saving in the amount of steam required to do a given amount of work, and the strains and shocks which are produced by the rapid motion of the piston and other reciprocating and revolving parts of the engine are very much diminished by allowing the steam to expand, and thus become reduced in pressure during the latter part of the stroke. QUESTION 59. How is steam saved by using it expa7nsively? Answer. Less steam is required when it is used (:pansively: 1. Because when steam of a high pressure is introduced into the cylinder, and allowed to expand until its pressure is comparatively low, it escapes at a lower pressure than the average pressure during the whole- stroke. If steam of a pressure equal to the average pressure is worked full stroke, it would exert exactly the same force on the piston as the steam of 56 Catechism of the Locomotive. higher pressure did when working expansively, but the pressure in the latter case, when the piston reaches the end of the stroke, or the final pressure, as it is called, would be considerably lower thaIn in the other. The pressure of steam represents energy, or capacityfor doing work, and therefore if we allow it to escape with a comparatively high pressure without doing work, it is a waste of energy. To illustrate this, we will take the same conditions which were used in the answer to Question 60, in calculating the average pressure. In that case the mean absolute pressure of the steam was 69.95 pounds per square inch, but the pressure at the end of the stroke, when the steam escaped, was only 333 pounds absolute. If, therefore, steam had been used of the average pressure through the whole stroke, it would have escaped with a pressure of 69.95 pounds, or more than twice that of the expanded steam, and the work done in both cases would have been the same. 2. There is also another incidental advantage in this, because low-pressure steam can be exhausted more quickly from a cylinder than steam of a high pressure, and consequently there is less. resistance, or back pressure, as it is called, in the exhausted end of the cylinder to the movement of the piston. 3. The causes which produce the greatest economy when steam is used expansively cannot be fully explained without discussing principles of science more abstruse than it is desirable to introduce here. They can, however, with the aid of the table of the " Properties of Steam,"* in the appendix, be illustrated by a * Tlis table is copied from. Colburn's Treatise on the Locomotive Engine. The Expansion of Steam. 57 few simple calculations, so that the economy of using steam expansively will be apparent. For the basis of the calculations the same data and dimensions will be employed that were used iil the previous illustration; that is, a cylinder of 16 in. diameter and piston with 24 in. stroke and steam of 100 lbs. absolute pressure cut off at 8 in. of the stroke. We will suppose, further, that the steam used is generated from water of a temperature of 60 degrees, and we will then calculate the total number of units of heat in the steam used for each stroke of the piston. The area of a piston 16 in. in diameter is 201 square inches; and as the steam is admitted until the piston moves 8 inches of its stroke, therefore the quantity of steam would be 8 times 201 cubic inches, or 1608 201 x8=1608 cubic in. 8 cubic ft. 1728 }From the table it will be seen that one cubic foot of steam of 100 lbs. pressure weighs.2307 lbs.; therefore the weight of the fraction of a cubic foot given above would be calculated as follows:.2307 x 1608 23072 1 -8.2146 lb.=weight of 1608 cubic in. of [728 steam of 100 lbs. absolute pressure. From the table it will be seen that the total heat above zero of steam of 100 lbs. absolute pressure is 1213.4 degrees. That is, as was explained in answer to Question 40,* in order to boil water under a pressure of 100 lbs. per square inch we must first heat water up to 327.9 degrees, and then, to convert it into * In the illustration used in answer to Question 40, steam of 100 lbs. effective pressure was used, whereas in the above case it is absolute pressure. 58 Catechism of the Locomotive. steam, 885.5 degrees more must be added. It was also explained in the answer to Question 35 that one pound of water heated one degree is the standard of measurement or unit of heat. Now if we have 1 lb. of water with a temperature of zero, evidently it will take 1213.4 units of heat to convert it into steam of 100 lbs. absolute pressure. But as the water from which our steam was generated had a temperature of 60 degrees, we must deduct that much front 1213.4: 1213A4 —60.=1153.4=units of heat in one pound of steam of 100 lbs. absolute pressure generated from water of 60 degrees temperature. If now one pound of steam has 1153.4 units of heat, the following calculation will give the units of heat in.2146 lbs.: 1153.4.2146=247.51-=units of heat in.2146 lbs., or 1608 cubic in. of steam of 100 lbs. absolute pressure. It was shown in answer to Question 56 that the average pressure of steam of 100 lbs. cut off at 8 in. of the stroke was 69.95 lbs. per square inch. Disregarding the small fraction, we will call it 70 lbs. Now if we admit steam of this pressure through the whole stroke of the piston, we will use 4,824 cubic inches. It will be found by a calculation similar.to the above, that to generate this quantity of' steam of 70 lbs. pressure from water of a temperature of 60 degrees would require 527 units of heat, or more than twice as many as were required to do the same work with steam of 100 lbs. pressure cut off at 8 inches when using it expansively during the rest of the stroke. The actual difference in practice is not so great as this, because the loss of heat from radiation and condensation in the cylinder and other causes is greater when steam The 2Expansion of Steam, 59 of a high pressure is expanded than wben lower pressure steam is admitted through the,whole stroke. But after allowance is made for all such sources of loss and waste, there is still an enormous gain from using steam expansively. QUESTION 60. What is meant by wire-drawn steam? Answer. It is the fall which the pressure of the steam undergoes during its passage from the boiler to the cylinder,+ and which is due to the contracted opening of the steam pipes or valves. QUESTION 61. What is the economical effect of re. ducing the. pressure, or of wire-drawing it, by partly closing the valve by which it is admitted to the cylinders. Answer. By reducing the pressure of steam in this or any other way, it is -necessary in doing the same amount of work to admit steam to the cylinder for a longer period, and therefore to reduce the degree of expansion. To illustrate the effect of this, we will estimate the total heat required to exert a. pressure of 70 lbs. on the piston described above. It will be assumed that the steam pressure in the boiler is 100 lbs. absolute, and that this is wire-drawn down to 70 lbs. and admitted to the cylinder through the whole stroke. As was shown in the- preceding answer, 4,824 cubic inches of steam are required tb fill the cylinder. Now 3,376.8 cubic inches of steam of 100 lbs. pressure, if expanded to 70 lbs. pressure, will make 4,824 cubic. inches. The total heat required to generate 3,376.8 cubic inches of steam of 100 lbs. absolute pressure from water of- 60 degrees is 519.9 units, so that to do the same Swork by using steam of high pressure cut off at one-third of the stroke, using steam of low boiler * Rankine. 60 Catechism of the Locomotive. pressure full stroke, and using wire-drawn steam full stroke, would, in the exalllmple we have selected, require 247.5, 527 and 519.9 units of heat respectively. QUESTION 62. To what extent can we work steam expansively, with advantage and economy? Answer. The theoretical economiy of using steam increases with the degree of expansion and the pressure. This is shown very clearly in the following table, in the first colunmn of which the number of inches of the piston- stroke is given during which steam is admitted to a cylinder 16 in. in diameter and 24 in. stroke. In the second column is given the pressure of the steam, or initial pressure, as it is called, which must be admitted into the cylinder in order to produce a mean pressure of 70 lbs. per square inch when it is cut off at the point indicated in the first column. In the third column is given the total heat which is required to generate the steam required in each case, and in the last column the percentage of saving is given which results from the different degrees of expansion and a mean pressure of 70 lbs. per square inch in eachcase. RESULTS OF USING STEAM EXPANSIVELY. Initial press- Total heat of Percentage Period of admission or point of cut-off ureof steam steam used, of saving oofadmisin o fu. in pounds in units. compared per square with full inch. stroke. Full stroke... 7 0..527. 18 in. = Thlree-quarters of the stroke, 2.5 408.7 22 12 in. = One-half " " 82.7 309.5 41 8 in.= One-third " 100. 247.5 53 6 in. = One-quarter " 117.4 21.5.9 58 4 in. - One-sixth 1" 150 5 186.5 64. 3 in. = One-eighth 1 ]81.8 165.8 68L 2 in. One-twelfth " 241.4 144.8 72& From this table it will be seen that theoretically 22~ per cent. of heat is saved by cutting off at 3 of The -Expansion of Steam. 61 the stroke and using steam of 72.5 lbs. pressure instead of steam of 70 lbs. worked full stroke. Cutting off at half stroke and using steam of 82.7 lbs., 411 per cent. of heat is saved, and cutting off at quarter stroke with steam of 117.4 lbs. saves 58 per cent. of heat; and at one-twelfth of the stroke, or expanding steam of 241.4 lbs. pressure to twelve times its volume, saves 72- per cent. of heat. As stated before, the above is the theoretical advantage of using steam expansively.. There are, however, practical difficulties in the way of using some of these high degrees of expansion. ~ It has already been explained that if steam is cut off early in the stroke and the degree of expansion increased, the pressure and consequently the temperature of the steam must also be increased. The danger of explosion is greater with the higher pressures, and stronger and more expensive boilers and machinery are therefore needed. With steam of very high temperature the metal of the cylinders, pistons and valves becomes so much heated -that they soften, and then the friction of the one on the other causes them to cut or scratch each other. The high temperature at.the same time destroys the oil or other lubricant used in contact with the steam. It is also impossible to admit and cut off steam very early in the stroke with the ordinary mechanical appliances used for moving slide-valves of locomotives. This latter difficulty will be more fully explained hereafter. 6 PART VI. GENERAL DESCRIPTION OF A LOCOMOTIVE ENGINE. QUESTION 63. What are the princopal parts of an or. dienary locomotive engine? Answer. A boiler for generating steam and a pair of high-pressure steam engines, which are all mounted on a suitable frame and wheels adapted for running on a track consisting of two iron or steel rails. QUESTION- 64. How is the power of high-pressure engines applied to locomotives? Answer. By connecting the engines with the wheels so as to give the latter a rotary motion. QUESTION 65. When they revolve what will occur? Answer. Either they will slip on the track, or the locomotive will move either backward or forward, according to the direction the wheels are turning. QUESTION 66. What will determine whether the wheels will slip or thie locomotive move? Answer. The friction or adhesion, as it is called, between the wheels and the track. If this adhesion is greater than the resistance opposed to the movement of the locomotive, the latter will overcome the resistance; but if the latter is greater than the friction, the wheels will slip. QUESTION 67. Upon what does the amount of friction or adhesion of the wheels depend? General Description. 63 Answer. Chiefly on the weight which they bear, but to some extent upon the condition of the rails. Under ordinary circumstances, the, adhesion of the ewheels of a locomotive is in direct proportion to the weight they carry. QuESTION 68. Why are two cylinders employed on hI(comotives? Answer. Because if only one was used, it would be impossible or very difficult to start the engine, if it should stop on one of the dead points. QUESTION 69. HOW is this dificulty overcome by the use of two cylinde-s? Answer. By attaching the two cranks to the same shaft or axle, and placing them at right angles to each other, so that when the one is at a dead point the other is in the position where the steam can exert the maximum power on the crank. QUESTION 70. How are the cranks oJ an ordinary locomotive made? Answer. They are cast in one piece with the wheels that drive the locomotive, which are therefore called driving-wheels. In this country the centre portion of such wheels, or wheel-centres as they are called, is always made of cast iron, with tires of wrought iron or steel around the outside, and is fastened to the axles of the locomotive. The shaft of a locomotive engine is called the main driving-axle, and the wheels attached to it the main driving-wheels. QUESTION 71. IHow are the cylinders and drivingwheels of a locomotive ustuall/ placed? Answer. The cylinders A, plates I, II and III, are placed at the front end of the locomotive, and the main driving-axle, B3, far enough behind them to per 64 Catechism of the Locomotive. mit the connecting rods, C, to be attached to pins, D, in the cranks, called crank-pins. In this country these cranks are now universally placed on the outside of the wheels, and -therefore the cylinders must be placed far enough apart (as shown in fig. 40 and Plate III) to permit the connecting-rods to be attached to the //~v Fig. 40. Scale I in.=1 foot. crank-pins. The cylinders are therefore placed outside the framesE, 1H', Plate III, (the latter are inside General Description. 65 of the wheels,) and are now nearly always horizontal, although in old engines they are often inclined. Plate I is a side view of an ordinary eight-wheeled American locomotive, Plate II a longitudinal section, Plate III a plan, and fig. 40, a transverse section, through the cylinder and smoke-box. QUESTION 72. What are the smaller wheels, E E, called, and what are they for? A'nswer. They are called truck-wheels and carry the weight of the cylinders and other parts of the front end of the locomotive, and serve to guide and steady the machine in a manner which will be more fully explained hereafter. QUESTION 73. Wy are more than one pair of driving wheels necessary for locomotives? Answer. Because if all the weight which is needed to create the requisite adhesion of the wheels of locomotives to pull heavy loads was placed on one pair of wheels, it would be so excessive as to partly crush and injure the rails. It is therefore distributed, usually on two pairs, but sometimes on three or four or even more pairs. QUEsTION'74. Where is the second pair of drivingwheels usually placed? Answer. These wllheels, F-called tlle back or trailing dri'bing-wlheels-are, in the ordlinary type of locomotives used in this counti'y, situated behind the main driving-wheels, far' enough back to give the room necessary for the boiler, G, between the two axles, as shown in plates I, II and III. QUESTION 75. How are the axles, cylinders, etc., held in the right position in relation to each other? Answer.!B-y longitudinal frames,.IH J1H 1 H which 66 Catechism of the Locomotive. hold the axles in the proper position, and are bolted to the cylinders, and also fastened to the boiler at 1, 1, Plate I. QUESTION 76. flow is a locomotive engine made to run either backward orforward? Answer. By having two eccentrics, J, J, Plate III (also shown in Plate II,) for each cylinder. One of these is fixed or set on the shaft in such a position as to move the valve so that the engine will run in one direction; the other eccentric is set so that the engine will run the reverse way. The ends of the two eccentric rods are attached to what is called a link, L, (Plates II and III,) the object of which is to furnish the means of quickly engaging and disengaging either eccentric rod to or from the rocker, K. The link is operated by a system of levers, consisting of the lifting shaft, M,- and arms, V, N, and the reverse lever, 0, 0, (Plate II). The principles and working of these will be more fully explained hereafter. QUESTION 77. What are the principal parts or "organs " of a locomotive boiler? Answer. 1. A fire-place, or, as it is called a fire-box, G, (Plate II,) which is surrounded with water. 2. A cylindrical part, P P, (Plates I and II,) attached to the fire-box at one end and to a chamber, Q, called the smoke-box, at the other 3. The tubes or flues a a', (Plate II and fig. 40,) which connect the fire-box with the smoke-box and pass through the cylindrical part of the boiler and are surrounded with water. 4. The smoke-stack or chimney P R. QUESTION 78. What is each of these parts or organs for, and of what do they consist? General Description. 67 Anuswer. The fire-box G furnishes the room for burning the fuel, and consists of an inner and outer shell made of boiler plate, with the space between the two filled with water; a grate, b b, (Plate II,) formed of cast-iron bars, with spaces between-them for admitting air for the combustion of the fuel, which is placed on the top of them; a door, C, called the furnace-door, for supplying the grate with fuel; a receptacle, d d, below the grate, to collect ashes, and therefore called the ash-pan, which is supplied with suitable dampers, n n', n for admitting or excluding the air from the fire. The cylindrical part P P, or waist of the boiler as it is sometimes called, contains the greater part of the water to be heated. The flues or tubes, as they are generally called, of which a locomotive has from one to two hundred, are usually two inches in diameter, and about eleven feet long. They conduct the smoke and products of combustion from the fire-box to the smoke-box. These tubes are made of small diameter so as to sub-divide the smoke into many small streams and thus expose it to a large radiating surface through which the heat is conducted to the water. The smoke-stack serves partly for removing into the open air the smoke which passes through the flues, and partly for producing a strong draft of air, which is indispensably necessary for the rapid combustion of the fuel, and also for collecting and extinguishing the sparks from the fire. QUESTION 79. How is the draft produced in locomotive boilers? Ansvwer. By conducting the exhaust steam through 68 Catechism of the Locomotive. pipes (e, e, fig. 40) from the cylinders to the smokebox and allowing it to escape up the smoke-stack from apertures, f,, (Plate II, fig. 40.) called exhaust nozzles. The strong current of steam thus produced in the smoke-stack produces a vacuum, by which the smoke is sucked into the smoke-box with great power and forced out of the smoke-stack into the open air. QUESTION 80. How are the water and juel carried whicd, must be supplied to a locomotive while it is running Answer. The water is carried in a tank, which is constructed in the form of the letter U, so as to give room for the stowage of fuel between its two branches or sides. This tank is carried on a set of wheels, and forms a separate vehicle, independent of the locomotive, called a tender, the construction of which will be explained in a future chapter. QUESTION 81. What are the dimensions of the principal parts of a locomotive? Answer. There is a great variety in the plan, size and capacity of locomotives, but the type which is more generally used in this country than any other, and which- has been selected for the preceding illustrations, and will be described in the succeeding chapters of the Catechism, has four driving and four truck wheels, and weighs in working condition about 60,000 lbs. The following are the dimensions of its principal parts: The driving-wheels are about 5 feet and the truck-wheels from 26 to 30 inclies in diameter. The longitudinal distance between the centres of the driving-wheels is usually about 7 feet, and between the centres of the truck-wheels 5 ft. 9 in., and the total distance from the centre of the back driving General Description. 69 wheels to the centre of the front truck-wheels, which is called the wheelbase, is 21 ft. 8 in. The weight on each driving-wheel is usually about 10,000 lbs., and on each truck-wheel about 5,000 lbs. The cylinders are 16 in. in diameter and the piston has 24 in. stroke, and the connecting-rod is 7 ft. long measured between the centres of the pins to which it is attached. The centres of the cylinders are about 6 feet apart, measured across the track. The fire-box inside is 5 feet long and 2 ft. 11 in. wide, and the cylindrical part of the boiler is 4 feet in diameter measured on the outside of the smallest portion. The water spaces around the fire-box are about 3 inches wide. There are 140 tubes, which are 2 in. in diameter measured on their outside, and 11 ft. long. The inside of the smokestack is 16 in. in diameter, and it is 14 ft. 3 in. high measured from the top of the rails. The tender carries about 1,800 gallons of water and about 8,000 lbs. of coal. When loaded it weighs about 40,000 lbs., making the total weight of the engine and tender 100,000 lbs. The following is a list of parts designated by tile letters of reference on plates I, II, III and fig. 40. A, A, Cylinders. S. Pilot or cow-catcher. B, Main driving-axles. T, Head-light. C, Main connecting-rods. U, Bell. D, Main crank-pins. V. Sand-box. E, E, Truck-whleels. W, Whistle. F, Axle of trailing-wheels. X, I)ome. G, Fire-box. Y Y, Cab or house. H, H. H, Frames. Z, Back or trailing-wheel crankI, I, Frame-clamps. pin. J, J, Eccentrics. Al Pump air-chamber. K, Rockers. Bl, BR. Main driving-wheels. L, link. C(7' C', Supply pipe. Ml. Lifting-shaft. DI Front platform. N, N, Lifting arms, El Bumper timber. O 0, Reverse-lever. F' Fi, Back dlriving-wheels. P P, Cylinder part of boiler. G' Coupling-pilln. Q, Smoke-box. H' Friction-plate. 11 R, Smoke stack. I' Check valve. 70 Catechism of the Locomotive. Kf KV, Foot-board. y, Truck centre-pin. LI Lazy cock. z, Throttle-lever. MI Mud drum, a/ a, Tubes..n Nl, Springs. bV bI, Truck frame. 1t" Pump. c/ cl, Bed-plate. R/ Drop-door of grate. dl, Boiler brace.,S Steam gauge. et el, Sand pipe. VT T1 Feed pipes. fJf', Equalizing lever for drivinga a/ Tubes. wheels. b b, Grates. gt gf, Guide-bars or rods. c, Fire-box tdoor. V/ hV. Receptacle for sparks. d (, Ash p;n. i/ i', Bell rope. ff, Exhaust-nozzles or blast-pipes. -j.], ~Guide yoke. q/, Satety-valvc lever. /9. Valve-stem. h h, Gross-heads. I/ I/, Truck equalizing lever. i i, iulning-board. mn/ nm/t W, Halni rail. j, Throttle-stem. hi, Blow-off cock in mud-druili. i. Throttle-pipe. o/, Spring balance. m nm, Dry pipe. 1pf, Pump plunger. n,'-pipe. qt q/, Foot steps. o o, Steam-pipes. rt. Brace to smoke-box andl framle. p Petticoat pipe. sI sf, Steam-cliest. q, Smuoke-box door. t' ti if, Crown-bars. r, Pistonl. ut, Head-light lamp. s, Spark-deflector or cone. v1, Maiu valve. t, Wire-netting in stack. wo, Blow-off cock handle. u ut u, Boiler-lagging. xf, Bell-cranki for throttle-valve. v, Safety-valve. yf, Piston-rod. w wo, Sector or quadranlt. za, Draw-bar. x, Blow-off cocik. PART VII. THE LOCOMOTIVE BOILER. QUESTION 82. How does the quantity of steam generated in locomotive boilers in a given time compare with that generated in the boilers of stationary and marine engines? Answer. Locomotive engine boilers must produce much more steam in a given time, in proportion to their size, than is required of the boilers of any other class of engines, (excepting perhaps those of steam fire-engines,) because the space which locomotive boilers can occupy and also their weight is limited. QUESTION 83. HOW is their steam-generating capacity increased above that of marine and stationary boilers? Answer. By creating a very strong draft of air through thle fire and then passing the smoke and heated air through a great many small tubes, which are surrounded by water. By this means the smoke and hot air are divided into many small streams or currents which are exposed to the inside surface of the tubes to which and to the surrounding water their heat is imparted. QUESTION 84. How is the action of the exhaust steam in producing a draft in the chimney explained? Answer. The exhaust steam escapes from the cylinders through one or two contracted openings or exhaust-nozzles (f, Plate II, also shown in fig. 40*), * The term blast-orifice is also often used to designate these parts of locomotives. 72 CUatechism of the Locomotive. which point directly up the centre of the chimney or smoke-stack. The exhaust steam escapes from this orifice with great velocity, and expands as it rises, so that it fills the pipe p and the smoke-stack R R. It thus acts somewhat like a plunger or piston forced violently up the chimney, and pushes up the air above it, and, owing to the friction of the particles of air, carries that which surrounds it along up the stack, from which it all escapes finally into the open air, thus leaving a partial vacuum behind in the smokebox. The external pressure of the atmosphere then forces in air through any and every opening in the smoke-box, to take the place of that already drawn out or exhausted from it. As the only inlet is through the tubes, to which the gases of combustion have free access from the fire-box, and as the external air can only pass through the fire-grate, and through the burning fuel, to reach: the fire-box, there-is a constant draft of air through the grate as long as the waste steam escapes from the blast-pipe and up the chimney. It is thus that, within certain limits, the more the steam that is required, the more the steam that is produced; for all the steam used in the engine draws in the air in its final escape, to excite the fire to generate more steam.* Sometimes one blast-orifice is used for each cylinder, as shown in plates II and III and fig. 40; in other cases the exhaust steam from each cylinder escapes through the same orifice. QUESTION 85. HOUw much water is it necessary to evaporate in order to furnish the steam required to run tln ordinary train at its usual speed? *('olburn's Locomotive EngigneeriNg. The Locomotive Boiler. 73 Answer. For an ordinary "American" locomotive,' weighing 60,000 lbs. and with cylinders of 16 inches diameter and 24 inches stroke, from.6,000to 12,()00 lbs. of water must be evaporated per hour. QUESTION 86. How much water will a pound of coal eraporate in ordinary practice?. Answer. The quantity of water which is converted into steam by a pound of coal varies very materially: with the quality of the coal, and the construction and condition of the boiler; but from 6 to 8 lbs. of water per pound of coal is about the average performance of ordinary locomotives. It is, therefore, necessary to burn from 500 to 2,000 lbs. of coal per hour in order to generate the quantity of steam required by ordinary engines. QUESTION 87. How large a grate is needed to burn this quantity of coal? Answer. The maximum rate of combustion may be taken at about 125 lbs. of coal on each square foot of grate surface per hour, so that to burn 2,000 lbs. we need a grate with about 16 square feet of surface. QUESTION 88. How much heating surface is needed.for a given size of grate? Answer. In common practice about 50 square feet of heating surface are given for each square foot of grate. There are, however, no reasons for the proportions of either grate or heating surface which are given, excepting that it has been found that they work well in practice. It is, however, quite certain that the larger a boiler is, and the greater its heating surface in proportion to the steam it must generate, other * In speaking of "American" locomotives, we mean locomotives like that shown in Plate I, with four driving-wheels and a four-wheeled truck, and shall so use the term hereafter. 7 74 Catechism of the Locomotive. things being equal, the more economical will it be in its consumption of fuel, or,:in other words, the more water will it evaporate per pound of coal. QUESTION 89. Why is it necessary to use small tubes or flues in order to have the r quired amount of heating surface? Answer. Because there is a great deal more surface in a simall tube of a given length, in proportion to the space it occupies, than in a large one. Thus a tube two inches in diameter and eleven feet long has 829 square inches of surface, and one four inches in diameter has 1,658 square inches, or just double the quantity. But the four-inch tube occupies four times as much space as the other, as it-is twice as high and twice as wide. Therefore, in proportion to the space it occupies, the tube which is two inchesin diameter has twice as much surface as the larger one. If we compare a two-inch with an eight-inch tube, we will find that the former has four times as much surface, in proportion to its size, as'the eight-inch tube. As the size and weight of locomotive boilers are limited, it is therefore necessary; in order to get the requisite heating surface in the space to which we are confined, to use tubes of small diameter. Small tubes also have the advantage that they may be made of thinner material, and yet have the'same strength to resist a bursting pressure from within, or a collapsing pressure from without,'as larger tubes made of thicker' metal. The advantage of thin tubes is, that the heat inside of them is conducted to the water outside more rapidly than it would be through thicker metal, which is important' when combustion is as rapid as it is in locomotive boilers. The Locomotive Boiler. 75 The reason tubes of smaller diameter than two inches are not ordinarily used is because they are then liable to become stopped up with cinders and pieces of unconsumed fuel. QUESTION 90. How is the fire-box of a locomotive constructed? Answer. It usually consists of a rectangular box (G, figs. 41 and 42) about three feet wider and, for the size of engine we have selected as an example, about five or five and a half feet long inside. This box is composed of metal plates, either iron, steel or copper, which, excepting on the front side, are from 2 to -3 of an inch thick. This box is called the inside shell of the fire-box, and is surrounded by another shell, A B O D E F, fig. 42, of either iron or steel plates, of about the same thickness as those composing the inside. This is called the outside shell of the fire-box and, as alreadcy explained, is so much larger than the inside that there is a space, called the water-space, from 2- to 41 inches wide, on all the sides of the fire-box between the inner and outer plates. The top g, g, of the inside shell, which is called the crown-sheet or crown-plate, is flat, whereas the outside shell is arched, as shown in fig. 42. To the front plate,f the inside shell the tubes a a', a a' are attached. For this reason its thickness is usually made greater than that of the other plates, and is usually from 8 to 3 of an inch. The edges of one of the plates at each corner of the fire-box, where they are united together, as shown in figs. 41 and 42, are bent at right angles, and The width is dleendTent lUpol thie (listance between the rails. or gauge of the road, as it is calle(l. The above size is for a 4 feet 8A in. gauge. 76 Catechism of the Locomotive. the other is fastened to it with rivets from - to 3 of an inch in diameter. The inside and the outside shells of the fire-box are united to each other by a wrought-iron bar or ring (A F, figs. 41 and 42) which completely surrounds the inner shell and closes the water-space between the two shells. This bar is bent and welded to the proper form to extend around the bottom of the inside fire-box, and it is riveted to both shells. The water in the water-space is in free communication with the rest of the water in the boiler; and thus the flat sides of the respective shells of the fire-box are exposed to the full pressure of the steam, which tends to burst the outside shell and collapse the inside one. These flat sides, by themselves, would be unable to resist the strain upon them, but as the strain -upon the respective fire-boxes is in opposite directions, and necessarily equal for equal areas of surface, tie-bolts, n, n, n, n, (figs. 41 and 42,) or, as they are called stay-bolts, which are from a to 1 inch in diameter, are screwed through the plates at frequent intervals, usually from 31i to 41 in. apart, so as to connect the two fire-boxes securely together, the ends of the. stay-bolts being also riveted or spread out by hammering so as still further to increase' their holding power. These bolts, owing to the expansion'and contraction of the boiler and other strains to which they are subjected, very frequently break, and if they are made of solid bars of metal there is no way of discovering with certainty whether they are in good condition or not without taking the boiler to pieces. They should therefore be made of the best quality of wrought iron, brass or copper and should also be made tubular, that is they Fig 4 1. I Scale in. I foot.'A 7 8 (Jatechism of the Locomotive. E ~ a00a a fJ a~ 0a a 04J Fig. 42. Scale 1 in.= 1 foot. should have a hole through the centre, so that when they break the water will escape at the fracture into the hole and the leak will thus indicate the defect and danger. The latter is much greater from this cause than is usually supposed, and it is not unusual to find on taking a boiler to pieces that a large number of the stay-bolts are broken. QUESTION 91. How can the strain on the flat surface of a boiler between the stay-bolts be calculated? Answer. By MULTIPLYING THE AREA IN INCHES The Locomotive Boiler. 79 BETWEEN ADJACENT STAY-BOLT'S BY THE PRESSURE. Tlhe reason for this is, that each stay-bolt must sustain the pressure on a part of the, plate to which it is attached. Thus in fig. 43 it is plain that the bolt S O',, O I —, ( must sustain the pressure on one-half of that part of the plate between it and the bolts v, t, w, u, around it, or the pressure on the square a b d c, whose sides are equal to the distance (4 inches) between the centres.of the bolts. With a pressure of 100 pounds per square inch, the calculation would therefore be: 4 X 4 xlOO= 1,600 lbs. on each bolt. Stay-bolts should never be subjected to a strain of more than one-eighth or one-tenth of their breaking strength. QUESTION 92. flow do stay-bolts often fail without breaking? Answer. By tearing or stripping the thread of the bolt, or that in the plate, but oftener perhaps by the stretching of the plates between the holes. With a heavy pressure, the tendency of the plates between the holes, especially if they are heated very hot, is to 80 Catechism of the Locomotive. ".bulge" outward and thus stretch the hole in every direction until it is so large that the bolt is drawn out without much injury to tile screw-thread. QUESTION 93. How is the flat-top or crown-sheet strengthened? Answer. It is sometimes strengthened with staybolts similar to those used for the'sides, which pass through the inner and outer shells;* but usually the crown-sheet is strengthened by a series of iron bars, (f, f, fig. 41 and 42) called crown-bars, placed on edge, and of considerable depth, which are firmly fastened to it by T-head rivets or bolts. The croln-sheet can therefore only be crushed downwards by bending these bars, which are of great strength. They usually extend crosswise of the length of the fire-box, but are sometimes placed lengthwise. These bars bear on the fire-box only at each end, as shown in fig. 42, and are usually made with a projection, k, k, which *rests on the edge of the side plates. Iron rings or washers from and also by the material used as a lubricant. Some metals, such as brass and other alloys, are much less liable to abrasion and seem to retain lubricants on their surfaces better than other metals, and are therefore much. used for journal and other bearings. Some substances, especially oils, are good lubricants, while other materials of apparently similar nature are not. The reason why these materials possess these properties while others are without them is not known, and the value of any material as a lubricant, or the degree to which another will resist friction without abrasion, can only be tested by experiment. * Rankine. PARIT XIX. COMBUSTION. QrUESTION 3706. What is meant by combustion? Answer. By combustion is meant the phenomenon ordinarily called burning, as when a piece of wood or coal or a candle is burnt. In reality combustion is a union of one of the " chemical elements," oxygen, of which the atmosphere is composed, with the elements which constitute the fuel. QUESTION 371. What is meant by the term "chemical element?" Answer. The science of chemistry has demonstrated that nearly all substances by which we are surrounded are composed of certain other substances, which latter, as far as is now known, are not compounds, and are therefore called elementarq subzstances, or chemical elements. Thus the air by which we are surrounded is composed of two gases, called nitrogen and oxygen; water is composed of hydrogen and oxygen, and coal chiefly of carbon and hydrogen. There are now over sixty of these elementary substances known. From- no one of thenm have chemists been able to extract any material excepting the substance itself. These elementary substances will combine with others so as to form what is apparently a new material, but on weighing it it will be found that the weight of the new material is greater than the original elementary -31* 366 Catechism of the Locomotive. substance, showing that something was added to it w1'ich effected the change.* QUESTION 372. To what fact is this combination or combustion of elementary substances due? Answer. It is owing to the fact-the exact reason for which is perhaps not yet understood fully-that the atoms of the elementary substances of which fuel is composed, that is hydrogen and carbon, and the atoms of oxygen, which forms part of the atmosphere by which we are surrounded, attract each other with great energy when they are excited into activity by the application of heat. QUESTION 373. What phenomenon always attends chemical combination of substances. Answer. Such combination always gives out heat, whereas their separation absorbs heat. It has further been proved by actual experiment that the amount of heat liberated by the chemical union of the same quantity or number of atoms of two or more substances is always the same, and that when, by any cause, the atoms thus joined are separated, exactly the same amount of heat is absorbed.* QUESTION 374. In what proportions do the elementary substances combine with each other? Answer. It is a law of chemistry that each of the elementary substances combines with the others in certain definite proportions only. These proportions vary for the different elements, and have been determined with great accuracy by chemists. Thus, eight parts by weight of oxygen will combine with nitrogen and form atmospheric air, or the same proportion of oxygen will combine with hydrogen and form water, * "The New Chemistry," by J. P. Cooke, Jr. Combustion. 367 or with carbon and form carbonic acid, which is the deadly gas which accumulates at the bottom of wells. Now oxygen always combines with other substances in the proportion of eight parts by weight, or by some simple multiple of eight, that is 8 X 2 —16 parts, or 8x3=24 parts, etc. Each of the other elementary substances also has a certain fixed proportion in Mwhich it combines with others, and this proportion, which is usually given by weight, is represented by a number called its chemical equivalent. Thus 8 is the chemical equivalent of oxygen. Carbon combines with other elements in proportions of 6 and nitrogen in proportions of 14, so that 6 and 14 are the chemical equivalents of carbon and nitrogen. Now 8 parts by weight of oxygen can be made to combine withl 14 parts of nitrogen, or 8X2-16 parts of oxygen will combine with 14 of nitrogen, but it is impossible to make, say 12 parts of oxygen combine with 14 parts of nitrogen. We can combine 14x2=28 parts of nitrogen with 8 parts of oxygen, but no chemical process can make say 10 or 20 parts of nitrogen combine with 8 parts of oxygen. If 20 parts of nitrogen are mixed with 8 parts of oxygen, then the latter will combine with 14 parts of the former, but 6 parts of nitrogen will be left, and chemical combination will then cease. The following table will give the chemical equivalents of the principal elements which enter into the process of combustion of the fuel used in locomotives: Chemical equivalent by weight. Oxygen..................... 8 Nitrogen......................................................14 Hydrogen.............................. Carbon...................................................... 6 Sulphur.............................................. 16 QUESTION 375. What effect do theproportions in which 368 Catechism of the Locomotive. elements are combined have upon the substances which are produced by the combination? Answer. A change in the proportions in which the elements are combined usually alters the entire nature of the substance, so far at least as it affects our senses. For instance, oxygen unites chemically with nitrogen in different proportions, forming five distinct substances, each essentially different from the others, thus: 14 parts ot Nitrogen with 8 of Oxygen forms Nitrous Oxide. 14."'16' " Nitric Oxide. 11' ".' A. 24' " I Hyponitrlous Acid. 14 " " " " 32" " " Nitrous Acid. 14'. " 40" " " INitric Acid. We here find the elements of the air we breathe, by a mere change in the proportions in which they are united, forming distinct substances, whllich differ from each other as much as lautghiny gas (nitrous oxide) does from that most destructive agent nitric acid, commonly called aqua fortis.? QUESTION 376. What occurs when a fresh supply of bituminous coal is thrown on, a bright fire in the fire-box of a locomotive? Answer. The fresh coal is first heated by the fire, and if a sufficient quantity is thrown in to prevent the iminediate formation of flame,t a volume of gas or vapor, usually of a dark yellow or brown color, is given (1ff. The quantity evolved will be greatest when the coal is very small. This gas or vapor is commonly called smoke, but it does not deposit soot and in reality is not true smolke. If a sheet of white paper be held over the vapor as it escapes from the coal and there is Coomlustion of Coal andl the Prevention of Smoke, by C. Wye Williams. t Usually if more than two or three shovels full are thrown in there will be no immediate formation of flame. Crombustion. 369 no flame, the sheet will become slowly coated with a sticky matter of brown color difficult to remove, and hlaving a strong tarry or sulphurous smell; whereas if a sheet of paper is held over smoke it will quickly be covered with black soot. The color and smell left on the paper ill the first case are due to the tarlry matter, sulphur, and other ingredients in the gas. Deprived of the coloring matters, the vapor is a chemical mixture of 2 parts of hydrogen and 6 parts of carbon,. and is called carburetted hydrogen, and is nearly the same as the colorless gas by which our houses are lighted.* A similar gas is generated at the wick of a burning candle or lamp and is consumed in the flame. Before the gas is expelled from the fresh coal the latter mnust be heated to a temperature of about 1,200 degrees, so that if 100 pounds at a temperature of 50 degrees is put on the fire 23,000 units of heat will be absorbed to heat the coal.t Nor is this all, as has been explained in answer to Question 38, when any substance is vaporized a certain amount of heat apparently disappears, which has been called the h]eat of evaporation or of gasification. Average bituminous coal contains about 80 per cent. of carbon, 5 per cent. of hydrogen and 15 per cent. of other substances usually regarded:as impurities. When the coal is heated up to about 1,200 degrees, the 5 per cent. of hydrogen unites with three times its weight of carbon, and thus 20 per cent. of the coal is converted into the gas described. In this process a large amount of heat is absorbed or becomes latent, as it does when water or * A Treatise on Steam Boilers, by Robert Wilson. t The quantitv of heat required to lleait coal is only about olle-fifth that needed to heat the same weight of water to, tile same temlperature. 370 Catechismn of' the Locomotive. any other substance is converted into vapor. It will therefore be seen that the first effect of putting fresh coal on the fire is to cool the fire. This fact has an important bearing on the question of combustion and will be referred tdohereafter. QUESTION 377. How can the process of the combustion of the gas generated from the coal be best explained? Answer. As this gas is substantially the same as ordinary illuminating gas, the manner in which it burns can perhaps be made clearer by examining the combustion of an ordinary gas-light. As stated before, combustion is a chemical union of the' oxygen which forms one of the elements of the air with the hydrogen and carbon of the fuel, which, in this case, form gas. It should be clearly kept in mind that combustion is the result of this union, and that the oxygen is as essential to combustion as coal or gas, and in fact is the fuel of combustion just as much as coal or gas is. If we were to conduct a pipe from the external air into a vessel filled with coal gas we could light the air and it would burn in the gas as the gas burns in. the air. It will be noticed, however, that before either the gas or the air will burn, they must be lighted. Air and gas,. even if mixed together in the same vessel, will not burn unless they are lighted. This can be done by the flame of any burning material, or with a piece of metal heated to a very high temperature, or by an electric spark. In other words it may be said that the atoms of the two gases must be excited into activity by the application of heat, that is, what is called an igniting temperature must be communicated to them before chemical combination will begin. The Co(mbustion. 371 chief feature which distinguishes combustion from other chemical union is the circumstance that the heat generated during the combination is sufficient to maintain an igniting temperature, and the necessity of doing so in order to continue the process is of very great importance in the combustion of coal in locomotive boilers, as will be shown hereafter. QUESTION 3 8. How does an ordinary gas-light burn after it is lighAted? Answer. Under ordinary conditions the hydrogen, which is the most combustible of the two elements of which coal gas is formed, is the first to burn. This part of the combustion forms the lower bluish part of the flame. The combustion of the hydrogen thus separates it from the carbon, which is then set free; and as carbon is never found in a gaseous condition when uncombined with other substances, it at, once assumes the form of fine soot when the hydrogen is burned away from it. This fine soot, or pulverized carbon, is, however, intensely heated by the combustion of the hydrogen. Now carbon when heated to an igniting temperature will, if brought into contact with a sufficient quantity of oxygen, combine with it or be burned. Each particle of carbon thus becomes a glowing centre of radiation, throwing out its luminous rays in every direction. The sparks last, however, but an instant, for the next moment they are consumed by the oxygen which is aroused to full activity by the heat, and only a transparent gas rises from the flame. But the same process continues; other particles succeed, which become heated and ignited in their turn, and it is to this combustion of the solid particles B372 Catechism of the Locomotive. of carbon that the light Which is given out b1y a ga:sburner or candle is due.* QUESTION 379. WTihy does a gas-burner, candle or other Jlame sometimzes smoke? Answer. Because the supply of oxygen is then illsufficient to consume the particles of solid carbon which are set free and which then assu me the form of soot. This can be illustrated if we cut a hole in a card, d d, fig. 210, so as to fit over an ordinary gasburner, b. If we then light the gas and place a glass chimney, a a, over the burner and let it rest on the card, it will be found that the flame will at once begin *" The New Chemistry," by J. P. Cooke, Jr. C'onbu-tion. 373 to smoke, because very little air can then come in contact with the flame, and therefore when the fine particles of carbon are set free by the combustion of the hydrogen, instead of being burned as they would be if the air with its supply of oxygen were not excluded from the flame by the chimney, they escape unconsumed in the form of fine black powder or soot. If we raise the chimney up- from the card, as shown in fig. 211, so as to leave enough space between them.at the bottom of the chimney to permit air to enter so as to supply the flame with oxygen, the smoke will instantly cease, as the particles of carbon are then consumed. The same principle is illustrated in an ordinary kerosene lamp. It is well known that without a chimney the flames of nearly all such lamps smoke intolerably, whereas with a glass chimney and the peculiarly formed deflector which surrounds the wick the light burns without smoke unless the wick is turned up high. The effect of the chimney is to produce a draft, which is thrown against the flame by the deflector, and thus a sufficient supply of oxygen is furnished to consume all the particles of carbon, whereas without the draft produced by the chimney the supply of oxygen is insufficient to ignite all the carbon, which then escapes in the form of smoke or. soot. It must not, however, be hastily assumed that if the flame does not give out a briglt light, therefore the combustion is not complete. As has already been stated, the light of the gas flame is due to the presence of burning particles of solid carbon, which is set free by the'combustion of the. hydrogen with -which it is combined. After it is separated from the hydrogen it immediately assumes a solid form. If the coal gas 32 374 Catechism of the Locomotive. is mixed with a sufficient quantity of air before it is burned, the oxygen in the latter will be in such intimate contact with the former that the difference of affinity of oxygen for the carbon and hydrogen does not come into play, and as there is enough oxygen for all, the carbonl is burnt before it is set free, and as there are then no solid particles in the flame, there is no ligh.-'llis is illustrated by a " Bunsen burner," fig. 212, which is much used in chemical laboratories. It consists of a small tube or burner, a, which is placed inside of another larger tube b. Thie latter has holes, c, c, a little below the top of the small tube. The current of gas escaping from the small tube produces what is called an induced current of air in the large tube. This air enters through the holes c, c, and is Co'mbustion. 375 mixed'with the gas in the tube b, and the mixture is burned at d. The flamee from such a burner gives hardly any light, but tthe heat is intense, as is shown if a metal wire is held in it for a few seconds, as it will very soon glow with heat. QUESTION 380. What important dfferencce is there in the structure of the fjZme of a Bunsen bura er and that of an ordinary gas-burner or candle Ansuwsr. The ga's Wllich escapes from the mouth dof the pie pipe b, fig. 212, is mixed with air, and therefore contai ns within itself the elements which only need to combine to produce combustion; whereas with an ordinary gas-burner or candle the air comes in contact with the flamne only from the outside, or on its surface. This is shown better perhaps in the flame of an ordinary candle. The heat of such a flame distils a gas from the melted tallow, which is similar in nature to that which escapes from coal at a high temperature. Now by observing the candle very closely it will be seen that at the bottom close to the wick there is very little combustion, as the gas there first escapes from the wick and is not heated to a sufficiently. high temperature to burn freely. A little above the lowermost part the flame is of a pale bluish color, Which is due to the combustion of the hydrogen. Above that, \where the carbon is set free, its particles glow with heat imparted by the burning hydrogen and are then consumed by uniting with the oxygen of the air. The combustion occurs only at the surface of the flame, the inside being a mass of combustible gas which cannot burn until it in turn comes in contact with the oxygen of the air. This can be proved by inserting one end of a small tube, fig. 213 (a pipe stem will do), 376 Catechism of the Locomotive. which is open at both ends, into the flame. The combustible gas will then escape at the other end and can easily be lighted with a match. It will be found that the flame from the Bunsen burner is much more intense than that of an ordinary candle or gas-burner. The reason of this is that combustion, as already stated, takes place..through thll whole mass of its flame, whereas an. ordinary flamle burns only at its surface. Common' gas-jets are therefore arranged so that the flames will be flat, thus exposing as much surface to the air as possible, and, as explained in answer to Question 329, in describing the lamps for head-lights, their burners are usually made with a circular wick, through the centre of which a current of air, circulates. This arrangement exposes: a larger surface of the flame to the air, and also with the aid of a chimney furnishes an abundant supply for combustion. In stationary boilers with long flues of a large sectional area the flame will often extend for thirty feet, showing that while combustion is going on only at the surface of the flame,. it takes a long time to complete the process. The same thing is shown if a gas-burner is made with a single round hole. The flame will then be very long and liable to smoke at the top. QUESTION 381. Fromi the preceding considerations what may we injer to be necessary in order to consume coal gas perfectly?.Answer. In the first place, that there must exist a certain degree of what chemists call " molecular activity," which is produced by beat, or what we have called the igniting temperature. The necessity of this is sufficiently obvious with ordinary gas-burners, as they C(ombustion. 377 must always be lighted before they will burn. Now imagine that it was required to burn gas which was issuing from a hundred jets, of every variety of size, in a violent wind storm, or gusts of wind. Obviously it would be necessary to keep a lighted torch all the time to relight those which would be blown out. The gas in a locomotive fire-box is in reality burnt ill a storm of wind more violent than any natural one. It is therefore necessary to be constantly ready to relight the streams of gas lwhich the faintest breath would extinguish, or those of larger volume which have absorbed a great deal of heat and thus reduced the temperature at the time and place of their birth, when they assumed the gaseous form, as was explained in answer to Question 376. To relight them with certainty it is necessary to keep a constant temperature in the firebox high enough to ignite the gas which escapes or is distilled from the coal. Second. That the chemical change in combustion consists simply in the union of the elements burned with the oxygen of the air; and therefore, to burn the gas perfectly, without smoke or waste, enough air must be furnishetl to supply all the oxygen which will combine with the fuel. Third. That the air must be mixed with the gas, otherwise combustion will occurs only at the surface of the flame, and will therefore be so slow that much of the gas will escape unconsumed. It must be clearly kept in mind that no one or two of these requirements alone, without the third, will burn coal perfectly. What is needed is all three in combination. A very common error is to suppose that passing smoke over a hot fire, or in other words, main32* 378 Catechism of the Locomotive. taining an igniting temperature, will alone effect perfect combustion; or that if a sufficient supply of air is admitted, without an igniting temperature in the firebox, the fuel will be burnt completely. Neither of them will accomplish the object alone, and the gas and air must at the same time be thoroughly mixed with the burning gas in the fire-box. QUESTION 382. What substances are produced by the combustion of coal gas? Answer. The hydrogen of coal gas unites during combustion with oxygen in the proportion, as indicated by their chemical equivalents, of 1 part by weight of hydrogen with 8 parts of oxygen, the product of which is water. Of course at the high temperature at which the gases combine or burn the water is produlced in the form of steam. That water or steam is one of. the products of combustion is shown every cold evening, when the insides of shop show-windows are covered with moisture, which is due to the steam that is given off by the burning gas-lights or lamps inside, and is then condensed against the cold glass. Carbon combines with oxygen in two proportions: first, 6 parts of the former will unite with 8 of the latter, forming what is called carbonic oxide; or 6 parts of carbon will combine with 16 parts of oxygen, forming carbonic acid gas or carbonic dioxide, as it is called in some of the new books on chemistry. It is probable that the former compound, that is carbonic oxide, is never or very rarely formed in the flame of coal gas; but, as will be seen hereafter, is a very common and wasteful product of the combustion of the solid portion of the coal which is left after the gas is expelled from it. When there is not enough oxygen for the perfect Combustion. 379 combustion of the carbon in the flame, it smokes, and the carbon escapes in the form of soot. This, as will be shown, may in a locomotive fire-box help to form carbonic oxide after it leaves the flame. QUESTION 383. What remains in the coal after all the gas is expelled by heat? Answer. What remains is ordinarily called coke, which, with the exception of some incombustible substances, such as sand, ashes and cinders, which the coal contains, is nearly pure carbon. QUESTION 384. What is the chemical process of the combustion of' coke? Answer. The solid carbon of the coke when raised to an igniting temperature; or, in other words, on being lighted, unites with the oxygen in one-of the two proportions already given; that is, if the supply of oxygen is sufficient, 6 parts of the carbon of the coke unite with 16 parts of oxygen, forming carbonic acid gas, or carbonic dioxide. If, however, the layer of fuel on the grates is thick, or the supply of air is comparatively small, there will not be enough oxygen to supply 16 parts of the latter to each 6 parts of the carbon, so that when that occurs, instead of combining in that proportion, and thus forming carbonic dioxide, 8 parts of oxygen will unite with 6 parts of carbon and form carbonic oxide.. Now it should be carefully kept in mind that the heat of combustion is due to the union, or, as it is sometimes expressed, it is the clashing together of the molecules of the two elements which unite. If, therefore, only half the quantity of oxygen unites witll 6 parts of carbon, evidently there will be less heat evolved than there would be if twice that amount of oxygen combined with the 380 Catechism of the Locomotive. carbon. From carefully made experiments it was found that the total heat of the combustion of one pound of carbon when converted into carbonic oxide was 4,400 units, whereas when it was converted into carbonic dioxide 14,500 units were. given out. It will thus be seen that it is extremely wasteful to burn coal without a sufficient supply of air to produce carbonic dioxide. The danger of waste from this cause is also increased by the fact that carbonic oxide is colorless and odorless, and therefore its production is not apparent, especially as most persons have the impression that when there is no smoke from a fire combustion is then complete. It burns with a blue or yellowish flame when air is admitted into the fire-box, and its presence can often be detected by these phenomena when the furnace door is opened. QUESTION 385. Hlow can the requisite quantity of air be supplied to the fire in a locomotive fire-box? Answer. It is done in two ways: one is to keep but little coal on the grates, or in the phraseology of firemen, to "carry a light fire." The other method is to admit fresh air above the fire. If the latter plan is adopted when the supply of air through the grates is insufficient for perfect combustion, the carbonic oxide will unite with the oxygen of the air above the fire, nlid thus a second combustion will take place, the product-of which will be carbonic dioxide. It must be kept in mind, however, that not only must there be enough air supplied to the fire to consume the coke, but the gases which are distilled from the coal must also be supplied with oxygen in order to effect their perfect combustion. Even if enough air is admitted to consume the coke perfectly, if the carbonic dioxide Combustion. 381 thus formed is mixed with large quantities of smoke above the fire, the solid carbon or soot of the smoke may then combine with the dioxide and thus form carbonic oxide, if there is not enough fresh air present to furnish the requisite oxygen for the carbon in the smoke. A very common error is to suppose that smoke can be burned by passing it over or through a very hot fire. The smoke mLay thus be made invisible, it is true, but it does not therefore follow that it is perfectly consumed. QUESTION 386. Is it possible to admit too much air into thefire-box of a locomotive? Answer. Yes; probably all the air that is admitted which is not necessary for combustion, or, in other words, the oxygen of which does not combine with the fuel, instead of increasing diminishes the amount of water converted into steam. It does this in two ways; first, by reducing the temperature of the gases in contact with the heating surfaces, and second, by increasing the volume or quantity of the gases which must pass through the tubes. Heat is transmitted through the heating surface of a boiler in proportion to the diff;rence of the tempIerature of the products of combustion on one side and the water on the other.* Thus, if the temperature of the water on one side' is 250 degrees, and the hot gases on the other is -500, there will be only half as much heat. transmitted to the water in a given time as there would be if the gases had a temperature of 750 degrees. If the volume of gases is doubled by the admission of too much air, then obviously in order to pass through the tubes *hllis law is prlhnaps not absolutely correct, but is near enough for our present. illustrationl. 882 Catechism of the Locomotive. they must move at double the velocity, so that not only is their temperature diminished, but the time they are in contact with the heating surface is diminished in like proportion. This is shown by the effect of opening the furnace door, or of allowing the fire to burn away so that portions of the grate are left uncovered. The volume of cold air which will in either of these cases enter the fire-box will be so great that the pressure of the steam in the boiler will begin to fall at once. QUESTION 387. What determines the omount of air which must'be admitted to the fire-box of a locomotive to effect perfect combustion? Answer. This depends chiefly upon the rate of combustion, that is, the number of pounds of coal consumed per hour on each square foot of grate surface. Of course if 100 pounds is burnt it will require twice the supply of air that would be needed if only 50 pounds were burnt. QUESTION 388. How should the air be admitted so as to burn the coal perfectly? Ansuwer. In burning bituminous coal it has been shown that there are two distinct bodies to be dealt with, the one coke, a solid, the other coal gas, which is of course a gaseous body. The combustion of each of these is necessarily a distinct process. If the requisite quantity of air is supplied to the burning coke, or solid portion of the coal, it will, as has been shown, be converted into carbonic dioxide, and thus be perfectly consumed. If the supply of air is insufficient, the product of the combustion will be carbonic oxide, which is very wasteful. If, for example, there is a thick layer of coke on the grate, the air will enter and Combustion. 383 unite with the lower layer of coal and form carbonic dioxide, -but as it rises there will not be enough air to supply oxygen to the carbon, and another equivalent of the latter will therefore combine with the carbonic dioxide and form carbonic oxide. It is evident, though, that the thinner the fire, the easier it is for air to pass through it, and consequently the greater wvill be the quantity which- will enter the fire-box. Nothing would seem easier then than to regulate the thickness of the fire on the grates so that just the needed amount of air would pass through it. If coke alone was to be burned, undoubtedly very perfect combustion would be (and has been) effected in this way, but if a charge of fresh coal, say 100 pounds, is thrown on the fire, the coal gas is very soon generated and escapes into the fire-box. This gas needs an additional amount of air for its combustion. It would seem that this could be supplied by reducing the thickness of the fire still further, so that more air would pass through it than was needed for the combustion of the coke alone. If this was done then too much air would pass through the coke after the gases had all escaped from the fresh coal and were burned. Besides, the passage of the air would be the most restricted after the fresh charge had been put on the fire, just at the time when the most is needed. This difficulty might be overcome if a constant supply of fresh coal just equal to that consumed were kept on the fire all the time, and the thickness of fuel on the grates was then regulated so as to admit just air enough for the combustion of the coke and also that of the gases, the production of which would then be uniform. An ap-'wxoximation to this method of feeding the fire is, in 384 Catechism of the Locomotive. fact, what-is aimed at on most locomotives; and probably the best practical results are produced by that method. Two difficulties are, however, encountered in this method. In the first place it is impossible to feed a fire contihuously with a shovel. Thlere will be intervals between the charges which are thrown in, so that the supply is not uniform, even if the charges do not consist of more than a portion of a shovel-full at a time; and if the fire was fed in this way as uniformly as possible. it would then be necessary to open the furnace door every time fresh coal was put on the fire, and so much cold air would thus be admitted that more would be lost by lowering the temperature of the boiler than would be gained by the improved combustion. Another difficulty also is encountered in this method. of burning coal in locomotives. In order to admit enough. air through the fire it is necessary to keep the latter so thin on the grates that the violent draft produced by the blast lifts the coal from the grate-bars and carries the lighter particles through the fines unconsumed. It is thus extremely difficult to keep the grate uniformly covered with coal, and if it is not, the air will enter in irregular and rapid streams or masses through the uncovered parts, and at the very time when it should be there most restricted. Such a state of things at once bids defiance to all regulation or control, so that it is found almost uniformly that firemen of locomotives keep enough coal on the grates to avoid the danger of "losing their fire," as they express it; that is, having all the burning coal drawn through the tubes by the blast. Now, on the control of lte supply Combustion. 385 of air depends all that human skill can do in effecting perfect combustion and economy; and unless the supply of fuel and the quantity on the bars can be regulated, it will be impossible to control the admission of the air.* Another method of feeding locomotive boilers is to pile up the coal in the back part in a thick layer and slope it downward towards the front, so that there is a comparatively thin fire in front. The mass piled up at the door becomes converted into coke, and the production of gas from the coal is more gradual and uniform than it is when only a small quantity is thrown in at a time, and therefore a more uniform supply of air is needed for its combustion. But it is apparent that very little air can pass through the thick heap of coal at the back part of the fire-box, and that therefore all, or nearly all the air which enters it must come in through a comparatively small portion of the grate. It will of course be difficult to admit the requisite quantity, for the reasons already stated. It is consequently apparent that it is practically impossible to admit enough air through the grates to effect a constantly perfect combustion of bituminous coal. It is, therefore, necessary to admit a portion of the air above the fire. In doing this, however, in order to effect perfect combustion the air thus admitted must be thoroughly mixed with the gases, and in order to be able to enter into chemical combination, or in other words, to burn, the gases must comlbine' with the air at an igniting temperature. If too much air is admitted. it will reduce the temperature in the firebox so much that the gases will not ignite; or, if it is * The Combustionof Coal, by C. Wye Williams. 33 386 Catechisnm of the Locomotive. admitted in strong currents, the air and the gases will flow side by side like the currents of two streams of water, the one muddy and the other clear, which, as is well known, mingle very slowly. Besides, if a hot stream of gas encounters a strong stream of cold air and comes in contact with it only at its surface, the latter will be cooled down below the igniting temperature; whereas if the two had been intimately mixed in the right proportion, the whole mixture would have been hot enough to burn. It is therefore of the utmost importance, tbat the air which is admitted- above the fire slhould-:enter the fire-box in many small jets. None of- the openings for its admission should exceed 2 inch in diameter. With the violent draft in a locomotive fire-box there is an extremely brief period of time for chemical combination to take place after the gases are expelled from the coal and before they are hurried into the tubes. As the chemical action between the gases and the oxygen can only take place when the two are in intimate contact, too much pains cannot be taken to distribute the currents of admitted air and thus mix them with the combustible gases. In many cases means are adopted to delay the air and the gases in the fire-box so as to give them time for chemical combination or combustion before entering -tlhe tubes. QUESTION 389. Does any combustion take place after the gases enter the tubes? Answer. Very little; as the flames are xtinguislcd soon after they enter. QUESTION 390. Why ate the flames extinguished in the tubs? AnSter; They are then in contact with large quan Combustion. 387 tities of incombustible gas and beyond the reach: of a supply of: air; besides,:the temperature of the tubes vwhich are surrounded with water -is so low that the flame is soon cooled down below an igniting temperature. QUESTroN 391. What temperature is necessary to ignite coal gas or produce flame? Answer. A temperature considerably hotter than redhot iron is needed, as can easily be shown by the fact that a gas-light can not be ignited with a red-hot poker. QUESTION 392. Are there any parts of the fire-box where the temperature is probably below-'the igniting point? Answer. Yes; along the sides and ends near the plates, which are covered with water on the opposite side. At these points the coal is usually "dead" or incandescent, as it remains at too low a temperature to burn. For this reason, in some cases a space of from 8 to 12 inches on each side and still more at the ends of the grates, is- made of solid plates, without any; openings, and therefore called "dead-grates," so that no cold air can enter at those points..V These plates are made sloping downwards from the sides towards the centre of the fire-box,:so that the coal which falls,on them and is thus coked, can easily-be raked towards the middle of the fire. This arrangement of dead' plates-often improves the combustion and:results in greater economy of fuel.-. The reduction of the area of the openings between:-the grate-bars can usually be compensated by making the bars narrower or the spaces between them wider. QuESTION 393. What should be the condition of the coal when it is put on the fire? 388 Catechism of the Locomotive. Answer. It is true of the coal as well-as of the gases that the chemical action between it and the oxygen can only take place when the two are in intimate contact, and therefore -the rapidity and completeness of combustion and intensity of heat will be increased by -increasing te number- of points of contact, or by reducing the size of the fuel. The coal should therefore be broken up, but not so small as to fall between the grate-bars or be carried out of the fire-box by the blast. QUESTION 394. What amount of air must be admitted to the fire to effect perfect combustion? Answer. It was stated that average bituminous coal contains about 80 per cent. carbon, 5 per cent. of hydrogen and 15 per cent. of other substances. As a large proportion of the latter are incombustible, we will confine ourselves for, the present to the consideration of the combustion of the hydrogen and carbon alone. The hydrogen, as: has been e explained, unites with oxygen in the proportion:by; weight of 1 part of the former to 8 parts of the latter, and the product of this union is water,-or steam. As, 36 parts of air.contain only 8 of oxygen, IN ORDER TO B-URN:THE HYDROGEN IT MUST BE SUPPLIED.WITH 36: TIMES ITS WEIGHT OF AIR. In order to burn the carbon perfectly it must, as has been explained, be converted-into carbonic dioxide, which consists of 6 parts of carbon and 16 of oxygen; and as air consists of 28 parts of. nitrogen: to every 8 of oxygen, we must furnish 72 parts of air to every 6 of carbon, or, in other words, CARBON NEEDS 12 TIMES ITS WEIGHT OF AlR POR ITS PERFECT COMBUSTION. Combustion. 389 Every pound of average bituminous coal therefore requires 1.8 lbs. of air to burn its hydrogen, and 9.6 lbs. for the carbon, or 11.4 for both. As a portion of the other substances of which coal is composed, besides the oxygen and hydrogen, which others have been classed as impurities, are combustible, there will be no material error if we estimate -the amount of air required for the combustion of bituminous coal at 12 POUNDS PER POUND OF FUEL. As each cubic foot of air weighs 0.08072 lb., 12 pounds will be equal to 12 148.6 cubic feet of air, 0.08072 or for the sake of even figures and a quantity which can easily be remembered, we will say 150 cuBIc FEET OF AIR ARE NEEDED FOR THE COMBUSTION OF EACH POUND OF COAL. This is the theoretical quantity of air which is needed for combustion. Now, unfortunately, the process of combustion in the fire-boxes of locomotives is one in which any very exact combination of the substances which unite is not possible with the appliances which are now employed. If, therefore, we admitted the exact amount of air given above, while some portions of the fire where combustion was not very active might have mnore air than is needed, other portions would have too little; and if the air is not very thoroughly mixed, the flame and burning coal may be surrounded- with the products of combustion, which would exclude the air and thus reduce its effect upon the fire. For this reason, besides the air required to furnish the oxygen necessary for the complete combustion of the fuel, it is also necessary to furnish an additional quantity of air for the dilution 33* 390 Catechism of the Locomotive. of the gaseous products of combustion, which would otherwise. prevent the free access of air to the fuel. The more minute the division and the greater the velocity with which the air rushes among the fuel, the smaller is the additional quantity of air required for dilution. In locomotive boilers, although this- quantity has not been exactly ascertained, there is reason to believe that it may on an average be estimated at about one-ladlf of the air required for combustion.* We would therefore have as the quantity of air needed for combustion 150 150 + - - 225 cubic feet. This estimate is roughly made, but it is the nearest approximation at present attainable. It is probable that the supply of air required for dilution varies considerably in different arrangements of- the fire-box and for different kinds of fuel, and it is possible that by admitting the air for combustion in small enough jets, and deflecting the currents of smoke and gases so as to cause them to mingle with the air, the quantity required for dilution might be reduced below that indicated by the above calculation. Undoubtedly all the air which is admitted into-the fire-box which does not combine with the chemical elements of the fuel lessens the amount of steam generated in the boiler, both with reference to time, that is to say per minute, and to fuel, that is per pound of coal consumed. But with the present locomotive boiler it is simply a choice of two evils. If no more air is admitted than theory indicates to be needed for combustion, then, owing to *Rankine. Combustion. 391 the imperfect means which are usually employed to cause the air and fuel to combine, a portion of the latter will escape unconsumed; and if more air is admitted, the temperature of the products of combustion is lowered and their volume increased, the evils of which have already been pointed out. It therefore becomes a matter in which we are obliged to consult experience and determine by experiment what amount of air it is necessary to admit to the fuel to produce the most economical results. QUESTION 395. What proportion of the air should be admitted through the grate, and how much above the fire? Answer. This, too, is a question which can probably be answered best by consulting experience. The relative quantity of air required above and below the fire depends very much on the nature of the fuel. Coal which "runs together" or cakes very much or has a great deal of clinker in it, doubtless, will need more air above the fire than other coal which is said to be " dryer," for the reason that it will be found impossible to admit so much air through the caking coal in the grate as through the other kind. An idea of the relative quantity which should be admitted above and below the fire may be. found if we know how much air is needed to burn the solid carbon or coke which is left after the gas is expelled from it, and how much for the gas itself. The gas which is expelled from a pound of coal consists of about 0.05 lb. of hydrogen and 0.15 lb. of carbon. Now, it has been shown that hydrogen requires 36 times its weight of air to burn it perfectly, so that 0.05 lb. would need 0.05 X 36 1.8 lbs.; and carbon requires 12 times its weight of air, so that for 0.15 lb. of carbon 0.15 X 12 - 1.8 lbs. 392 Catechism of the Locomotive. is needed, so that for both 3.6 lbs. of air is required for perfect combustion. As has been shown, 12 lbs. is needed to consume the whole of the fuel, so that 30 per cent. of the whole supply is required for the combustion of the gas alone. If this is diluted in the same proportion as that required for the combustion of the carbon, and it probably should be even more so, we would have 30 per cent. of 225 = 67.5 cubic feet of air required for the combustion of the gas. It is certain, however, that the solid coke on the grates is not perfectly consumed, or, in other words, converted into carbonic dioxide, especially when the layer of it on the grates is very thick. When this is the case the air coming in contact with the lower layer of coke forms carbonic dioxide, but as it rises through the burning coke another equivalent of carbon unites with the carbonic dioxide, and thus forms carbonic oxide. If, now, enough air is admitted above the fire, this carbonic oxide will combine with it, and, as has been explained before, a second combustion will take place if there is time and opportunity for combination before thile gases enter the flues. It is therefore probable that more than 30 per cent. of the whole supply of air should be admitted above the fire. It is at any rate best to provide the means for admitting more, and also appliances for regulating the supply, so that it can be governed as experience may indicate to be best. QUESTION 396. Is it not possible byj enlarying the grate to admit enough air to the fire to produce perfect combustion? Answer. Yes; when no air is admitted above the fire, large grates are found to produce the best combustion. But while it is true that the same amount of (oimbustion. 393 iheat will be produced by the union of each equivalent of oxygen and fuel, yet if we can force more air and fuel to unite in the same place, a higher temperature is produced in that place, just as a fire in a blacksmith's forge is hotter because of the forced blast than that in an ordinary stove, or a smelting furnace than a parlor grate. If, then, we can concentrate the draft in the fire of a locomotive, we secure a greater intensity of combustion; and when the air is urged against the solid carbon with considerable force, it comes in contact with every point of its surface, and therefore less dilution of the air is needed, and consequently the products of combus-tion, have a higher temperature; and, as has been explained, a larger proportion of the heat is then transferred to the water than if the temperature is lower and the volume greater. Intensity of combustion also has the effect of maintaining an igniting temperature; whereas, if the same amount of fuel is burned slowly, its heat' may not be high enough to ignite the gases as they are produced. It is desirable, however, to have all the space that is possible in the fire-box, so as to give room for the mixing of the gases; but with a large fire-box and large grate a decided improvement and economy will often result by diminishing the effective area of the grate by covering a part of it with dead plates, but at the same time making provision for the admission of air above the fire. QUESTION 397. What is meant by the "Total Heat of Combustion?" Answer. It is the number of units of heat-given out by the combustion of a given quantity (usually a pound) of fuel. 394 Catechism of the Locomotive. QUESTION 398. How is this determined? Answer. The heat given out by the combustion of one pound of the chemical elements of which coal is composed has been determined by experiment, and from such data, knowing the substances of which fuel is composed, we call determine the amount of heat which would be developed if they were each perfectly consumed. Thus the total heat of combustion of one pound of hydrogen is 62,032 units, and of the same quantity of carbon 14,500 units.* Therefore, if a pound of coal contains 5 per cent. of hydrogen, the heat given out by the combustion of that element will be 62,032 xO.05=3,101.60 units, and if it has 80 per cent. of carbon, the combustion of the latter would develop 14,500x0.80=11,600 units, so that the total heat of the combustion of these two elements would be 3,101.6+11,600 —14,701.6 units. It was shown in answer to Question 40 that it required 1,213.4 units of heat to convert water at zero to steam of 100 pounds pressure. As steam is usually generated from water -at a temperature of about 60 degrees, the total heat required to convert it into steam of 100 pounds pressure would be 1,213.4-60=-1,153.4 units. A pound of average bituminous coal, therefore, contains heat enough to convert:12 lbs. of water into steam of 100 lbs. absolute pressure. Ordinarily only about half that amount of water is evaporated in locomotive boilers per pound of fuel. QUESTION 399. WIlhat are the chief causes of this waste of heat? Answer. It is due, first, to the waste of unburnt fuel s The experiments which have been made to determine these amounts do not agree exactly, but those given are thought to be the most trustworthy. Combustion. 395 in the solid state. This occurs when fuel whichis very fine falls through the grates, or is carried through the tubes and out of the stack in the form of cinders.* Second, to the waste of unburnt fuel in the gaseous or smoky state. The method of preventing this waste by a sufficient supply and proper distribution of air has been explained in the answer to preceding questions. N71ird, to the waste or loss of heat in the hot gases which escape up the chimney or smoke stack. The temperature of the fire in a locomotive fire-box in a state of active combustion is probably from 3,000 to 4,000 degrees. This heat is in part radiated and cQnducted to the heating surface of the fire-box, and it is found that more water is evaporated by this portion of the heating surface in proportion to its area thian by any other in the boiler. The gases when they enter the tubes transmit a portion of their heat to the surfaces with which they are first in contact. The amount of heat thus transmitted, as has been stated, is in proportion to the difference in temperature of the gases inside the tubes and that of the water outside. After passing over the part of the tube with which the gases are first in contact, they then arrive at another portion of the tube surface with a diminished temperature, and the rate of conduction is therefore diminished; so that each successive equal portion of the heating surface transmits a less and less quantity of heat, until the hot air at last leaves the heating surface and escapes up the chimney with a certain remaining excess of temperature above that of the water in the boiler, the heat corresponding to which excess * It should be remarked here that some and perhaps most of the cinders which are carried out of the stack are not comlblstible but are composed of the same materials that form clinkers on the grate. 396 Catechism of the Locomotive. is wasted.* It is, therefore, desirable to extract as much heat as possible from the gases before they escape from tthe tubes. Now it will be impossible to heat the water outside of the tubes hotter than the gases inside. When the temperature of the water is equal to that of the gases, no more heat will be transmitted from one to the other. If the temperature of the water is 350 degrees, that of the gases in the tubes will never be any lower, but will escape into the smoke-box with not less than that amount of heat. If, however, the cold water is introduced at the front end of the tubes, so that the surface with which the gases are last in contact has a temperature considerably lower than 350, then an additional amount of heat will be transmitted before they escape. It is, there-.fore, important that the cold feed-water should be admitted near the front end of the boiler, so that the products of combustion will be in contact with the coldest part of the heating surface last, and thus give out as much of their heat as possible before they escape. As a matter of fact, the gases escape at a much higher temperature. Experiments made by the writer showed that the temperature in the smoke-box of a locomotive when first starting was 270 degrees, and when working at its maximum capacity on a steep grade and with a heavy train it was as high as 675 degrees. The average temperature while running was, in three trials on different parts of the xoad, as follows: Average steam pressure, 9S 8 lbs.; average temneratire, 499.8 lbs. Average steam pressure, 106 lbs. average temperature, 585.1 lbs. Average steam pressure, 112.2 lbs.; average temperature, 551 lbs. In making these experiments a record was made of * Rallkine. Combustion. 397 the indications of a pyrometer and of the steam gauge once every minute while the engine was running. The distance run was 19 miles for the first experiment, 13 for the second and 6 for the third, with 30 loaded freight cars in the train. The last experiment was made while the engine was working on a heavy grade and very nearly up to its maximum capacity. It will thus be seen that a great deal of heat is wasted by escaping up the chimney. Fourth, by external radiation from the boiler. This occurs chiefly from the fact that it is not sufficiently well protected or covered with non-conducting material. The practice, or rather the neglect, of not covering the outside of the fire-box with lagging doubtless causes a very considerable loss of heat by radiation and convection from the hot boiler plates. QUESTION 400. What is the ordinaryform offire-box employed for burning bituminous coal? Answer. It is that represented in plate II and figs. 41 and 44, and is simply a rectangular box, and for that reason it is called a plain fire-box. Sometimes provision is made for admitting air into such fireboxes through hollow or rather' tubular stay-bolts, which are put into the sides and front. In most cases, too, the fire-box door has perforations for adiuitting air. QUESTION 401. What other appliances are used for burning bituminous coal? Answer. The most common appliance which is added to the plain fire-box is what is called a fire-brick arch. This is shown in fig. 214. B C is the arch which, as its name implies, is formed of fire-brick and extends backward and upward from a point in the tube-sheet below the tubes. In order to be self-supporting it is 34 398 Catechism of the' Locomotive. built ill the form of all arch, the two sides of the firebox acting as abutments for its support. The engraving represents with sufficient clearness the direction of the flames and smoke. These must take a more circuitous " run " as it is called, after leaving the fire, in order to reach the tubes. Time is thus given for the gases to combine and combustion'to take place.:: Fig. 21. Scale / in.=l foot. The fire-brick becomes heated, and thus to some extent prevents the gases from being cooled down below an igniting temperature by contact with the cold surface of the fire-box before combustion is complete. The fire-brick, however, soon burns out, and must be replaced, but owing to its cheapness and the ease Combustion. 399 with which it can be removed, this does not make a serious objection to its use. Air is nearly always admitted above the fire when the brick arch is used, either by tubular stay-bolts, a, a, a, or perforations in the door, or both. In order to avoid the inconvenience and expense of replacing the fire-brickl arch, what is known as the, _ Fig. 215. Scale X in.=1 foot. "Jauriet water-table" has been extensively used on some road.s. This is the invention of Mr. C. F. Jauriet anid is represented in fig. 215, and consists of a flat "table," B C, formed of two boiler plates placed about 4- in. apart, with tile space between filled with water. The two plates are stayed with ordinary stay 400 Catechisnz of the.Locomotive. bolts in the same way as tile sides of the fire-box. The form of the water-table is similar to that of the fire-brick, excepting that it is not arclied, this form jnot being necessary, as the plates are riveted to the sides of the fire-box. Air is admitted above the fire both by hollow stay-bolts and holes in the door, as shown at A. Tubes, f, are put into the front and lower portion of the water-table to allow the ashes and cinders, whllich would otherwise be deposited above, to fall down on the grates..When air is admitted at the furnae door of an ordinary fire-box, it is very apt to rush directly into the tubes without mingling with the gases. It was found by some of the firemen on English railroads that by placing a shovel over the top of the furnace door, the current of air which entered could thus be deflected downward, and in this way smoke could be almost entirely prevented. This led to thd adoption of a hood or deflector, A, fig. 216, which is made of sheet iron and is placed over the fire-box door and is arranged with a lever, B so that it can be raised in order to be out of the way when coal is thrown on the fire. It is suspended from a hook, C, from which it can easily be detached and taken out for repairs. This is frequently necessary, as the intense heat of the fire-box burns away the sheet iron of which it is made very rapidly. It can be made of old boiler plate, so that the expense of renewal is very:slight. When this plan is used, a double sliding door, shown in fig. 217, is commonly used with it. These doors are opened by the leversf d, and e g, which are all connected together. With these sliding doors the opening for the admission of air can easily be regulated, and the opening through Comnbustion. 401 which the lever, B, is attached to the deflector, A, can be arranged more conveniently than with a swinging Fig. 216. Fig. 217. Scale X in. = 1 foot. 34* 402 Catechism of the Locomotive. door. This plan has been employed by the Rogers Locomotive Works. Another plan of fire-box, which was designed and patented by Mr. William Buchanan, Master Mechanic of the Hudson River Railroad, and used extensively on that line, is shown in fig. 218. This consists of a __ -, Fifr. 218. Scale: in. = 1 foot. water-table, but it extends completely across the firebox from the tube sheet to the back-plate, thus dividing the fire-box into two compartments, I and N. In order to afford communication from the lower one to the upper one a round hole, D, about 24 in. in diameter, is put in the water-table in the position shown. It will thus be seen that all the currents of gas, smoke G(ombustion. 4~a' and air must unite in passing through this opening, and are thus brought into close contact with each other, After they enter the upper chazmber and before they enter the tubes, there is room and time for combustion. The position of the lower side of the table, it will be seen, is similar to that of the deflector shown in fig. 216, so that it acts in somewhat the same way, by directing the currents of air, which enter through the furnace door, downward on the fire. QUESTION 402. How do these different plans operate? Answer. They will all burn coal more perfectly, and therefore more economically, if they are carefully and skillfully managed, than is possible in ordinary plain fire-boxes; but, it is probable that more economy in the consumption of coal would result from the improvement of the practice and knowledge of firemen than can be expected from the use of any of. the appliances described, if they are used without care, or knowledge of the principles of combustion. QUESTION 403. In what respect does anthracite coal differfrom bituminous? Answer. It differs chiefly in the fact that it contains a much larger proportion of carbon and less of hydrogen, and in the fact that it consequently gives off very little or no coal gas. Its combustion is therefore more simple than that of bituminous coal, as there is very little else than solid carbon to burn. QUESTION 404. In what kind of afire-box is anthracite usually burned? Answer. It is usually burned in a very long grate, and as the heat is very intense, the grate-bars are usually made of iron tubes, through which a current of water circulates, so as to prevent them from melting. 40:4 -Catechism of the Locomotive.. QUESTION 405. Is it important to admit air above an anthracite fire to facilitate combustion? Answer. As there are no gases to be burned, it is not so important as it is with bituminous coal, but if the layer of anthracite on the grates is very thick, it will be impossible to get enough air through the coal to convert all the carbon into carbonic dioxide, and the carbon and oxygen will therefore unite so as to form carbonic oxide. If air is admitted above the fire, as has already been explained, another equivalent of oxygenwill unite with the carbonic oxide, and a second combustion will then take place above the fire, and the carbonic oxide will thus be converted into carbonic dioxide. If, under these circumstances, no air was admitted above the fire, the second combustion would not occur, and all the heat produced thereby would be lost. QUESTION 406. HOW can we determine the relative value of different kinds of fuel for use in locomotives? Answer. This can only be determined satisfactorily by actual experiment. The chemical composition, excepting so far as it indicates the presence of deleterious substances, such as sulphur, aslles, clinkers, etc., affords but little assistance in determining the value of fuel. Nealy the same quantities of elements in different fuels may arrange themselves, before and during combustion, so as to produce very different series of compounds. It is true that the composition of coal gives us some indication of its heat-producing capacity, but the extent to which that capacity can be converted into actual steam in locomotive boilers, depends to a very great extent upon the conditions under which the fuel is burned. It should also be remembered that the rapidity with which steam can be generated is a Combustion. 405 very important matter in locomotive practice. Whether a heavy freight train can be taken up a given grade, or a fast express make time, often depends upon the amount of steam which can be generated by the fuel in each second of time that the boiler is worked to its maximum capacity. Therefore any appliance for improving combustion, which reduces the quantity of steam which can be generated by the boiler in a given time, is quite sure to fall into disuse or be abandoned. It is of course often necessary to adapt the appliances for burning fuel to the fuel itself; and when a poor quality of the latter must be used, more boiler capacity must be given than is needed to do the same work with better fuel. The table in the appendix will no doubt be valuable as indicating the properties and relative value of several different kinds of fuel used in this country. The table is copied from a report made to the Navy Department of the United States by Professor Walter B. Johnson in 1844, and the conclusions are deduced from a series of very elaborate experiments made for the Navy Department. This report furnishes the most full and reliable data regarding the value of American fuel thus far (1874) published; but it contains little or no information concerning the fuels which are now used on railroads in our Western States. The first eight specimens of coal given in the table are anthracite; all the rest are bituminous coals. PART XX. THE RESISTANCE OF TRAINS. QUESTION 407. What is meant by the resistance of trains or cars? Answer. It is the power required to move them on the track. Thus if a rope, fig. 219, was attached to a car at one end, and the other passed over a pulley, a, and a sufficiently heavy weight, W, was hung on the end of the rope, it would move the car. The weight W would then be equal to the resistance of the car. QUESTION 408. How can the resistance of cars under diferent circumstances be determined? Fig. 219 Answer. It has been found that it takes a force of about 6 lbs. per ton (of 2,000 lbs.) to move a car slowly on a level and straight track after it is started. That is, if a car weighs 20 tons and a rope, fig. 219, is attached to it at one end and the other passed over a pulley, a, witfh a weight, W, suspended to it, it will require a The Resistance of Trains. 407 weight equal to 20 x 6 120 lbs. to keep the ca2 moving slowly. If two cars of the above weight were coupled together, it would require twice 120 or 240 lbs., and if three were attached to each other, three times 120, or 360 lbs., and so on. In other words, MULTIPLYING THE TOTAL WEIGHT OF THE CARS IN TONS (OF 2,000 LBS.) BY 6 WILL GIVE US THEIR RESISTANCE, OR THE FORCE REQUIRED TO KEEP THEM MOVING ON A LEVEL AND STRAIGHT TRACK AT A SLOW SPEED AFTER THEY ARE STARTED. The resistance is represented by the weight above, and the locomotive must exert a force equal to that weight to keep the tr-ain moving. As the speed increases the resistance increases, as' is shown by the following table. It should'be stated here, however, that our knowledge regarding this whole subject of the resistance of American cars and trains is exceedingly inaccurate and imperfect, and the data given in the books are nearly all based on experiments made in Europe, with cars of a different construction from thbose used here. There is reason for believing; however, that the resistance of American cars is less than that of European cars, and we hlave assumed it to be 6 lbs. per ton on a level at Very slow speed, which is less than the resistance which is usually given, but the following figures should be regarded merely as an approximation to the actual facts, of which we are still in ignorance: Velocity of trains ii miles per hour....5. 1015 20 25 33 35 40 45 560 70 Resistance on straight line in lbs. per ton (of 2,000 lbs.)....... 6.6 7. 38.39.(;11.213.115317. 8 6 27 34.6 Nov if we want to get the resistance at 30 miles,n hour of a trainl of ten cars weighing eaci 20 tons, 408 Catechism of the Locomotive. the calculation would be 10 X 20 X 11 — 2,250 lbs. This will give the resistance on a level and straight track. On an ascending grade the resistance is greater than that given above, because, besides pulling the car horizontally, it is necessary to raise it vertically a distance equal to the ascent of the grade. Thus if we have a grade with a rise of forty feet in a mile, the amount of energy required to simply raise the weight of a car would be equal to its weight in pounds multiplied by the vertical height of the ascent. Thus, supposing a car which weighs 40,000 lbs. to be run one mile oil a grade of forty feet ascent in that distance, then the energy expended in simply raising the car will be equal to 40,000 x 40 = 1,600,000 foot-pounds. Now, if it was necessary to raise that weight by a direct vertical lift or pull, it would require a force equal to or a little greater than the load to do it. But in pulling a car or train up a grade, which is an inclined plane, the force, which is the locomotive, instead of being exerted through the vertical distance is exerted through the horizontal distance, which in this case is one mile, or 5,280 feet. Therefore, if we divide the number of footpounds of energy required by the distance through which the power is exerted, it will give us the force exerted through one foot. That is, 1,600,000 - 151.5 lbs. 5,280 The resistance due to the ascent alone of a train on a grade or incline can therefore be calculated by MULTIPLYING THE WEIGHT OF THE TRAIN IN POUNDS BY THE ASCENT IN ANY GIVEN DISTANCE IN FEET AND DIVIDING THE PRODUCT BY THE HORIZONTAL The Resistance of Trains. 409 DISTANCE IN FEET. Thus in the above example the rate of the ascent is given in so many feet per mile; we therefore multiply by 40 and divide by 5,280, which is the number of feet in a mile. If the rate of the gradient had been given, as it sometimes is, as 1 in 132, we would simply have divided the weight of the train by the latter number. If we want to get the resistance per ton of train we substitute for its weight that of one ton in pounds; thus: 2,000 x 40 = 15.1 lbs. 5,280 If, now, we have the resistance which is due to the ascent or gravity alone, we must add to this the resistance on a straight and level track, at the speed at which the train runs, in order to determine the total resistance on the grade. On a level road at a speed of 5 miles per hour it would be 6.1 lbs. per ton, so that on a grade of forty feet to a mile at that speed the resistance would be 6.1 + 15.1 = 21.2 lbs., per ton, and at 10 miles it would be 6.6 + 15.1 = 21.7 lbs., and at 30 miles per hour on the grade the resistance would be 11.2 + 15.1 = 26.3 lbs. per ton. To get the total resistance on a grade for any speed, we ADD THE RESISTANCE FOR THAT SPEED ON A STRAIGHT AND LEVEL LINE TO THE RESISTANCE DUE TO THE ASCENT ALONE. The resistances for various rates of speed and grades has been calculated, and is given in the table in the appendix. The top horizontal row of figures of that table gives the rates of speed. The left-hand vertical row gives the rise of grade in feet per mile. The resistance for any given grade and speed is given where the vertical 35 410 Catechism of the Locomotive. row of figures under the rate of speed and the horizontal row opposite the rise of the grade intersect each other. Thus, for a grade of 30 feet per mile and a speed of 45 miles per hour, we follow the vertical column under the 45 downward, and the horizontal column opposite 30 to the right, and where the two intersect the resistance, 29.1 lbs. is given. QUESTION 409. What effect do curves have oin the resistance of trains? Answer. They increase the resistance, but in what proportion or to what degree is not known accurately. European authorities say that the resistance is increased, over what it would be in a straight and level line, about 1 per cent. for every degree of the curve occupied by a train. It is probable, however, that the resistance of American cars, which nearly all have double trucks, is not so great on curves as that of European cars, which nearly all have long and rigid wheel-bases, and whose wheels therefore can not adjust themselves so easily to the curvature of the track as they can when the American system of double trucks is used. QUESTION 410. What is meant by a degree of a curve? Answer. In order to measure circles, they are all supposed to be divided into 360 equal parts, which are called degrees. One degree of a curve is therefore xan of a complete circle; but if the curve has a long radius, one degree of such a curved track will be longer than one degree of a curve with a short radius, but each will have the same amount of "bend " or curvature. It is this latter which increases the resistance of trains, and the greater the number of degrees 6f a ii rve bccupied hy a train of cars, the The Resistance of Trains. 411 greater will be the " bend" of the track, and therefore the greater the resistance. QUESTION 411. What other causes affect the resistance of trains? Answer. The condition of the track and the force and direction of the wind. On a rough track the resistance is very much greater than on a smooth one, and a strong head-wind makes it much more difficult to pull a train than it is in calm weather. PART XXI. PROPORTIONS OF LOCOMOTIVES. QUESTION 412. In proportioning a locomotive to any given kind of work, what are the first facts which should be known? Answer. We should first know the weight of the train which the locomotive must draw; second, the speed at which it must run; and third, the steepest grades and the shortest curves of the road on which it must work. From these data the resistance of the train which the locomotive must overcome can be at least approximately determined. QUESTION 413. When the greatest resistance of the train is known, what is the next thing to be determined? Answer. As was stated in answer to Question 66, if the wheels revolve and their adhesion is greater than the resistance opposed to the movement of the locomotive, the latter will overcome the resistance; but if the latter is greater than the friction, the wheels will slip. It therefore follows that the adhesion must be somewhat greater than the resistance. As the adhesion is equal to about one-fifth* of the adhesive weight or pressure of the driving-wheels on the rails, obviously this weight should be five times the resistance. Thus, if we have a train weighing 400 tons which we want to take up a grade of 40 feet per mile at a speed of 20' See answer to Question 309. Proportions of Locomotives. 413 miles per hour, its resistance, calculated from the table given in the previous part, would be 9,360 lbs. Therefore, 9,360 x 5 = 46,800 lbs. = the required adhesive weight. QUESTION 414. What considerations determine the manner of distributing this weight on the wheels? Answer. It is found by experience that if too much weight is placed upon one wheel, the material of which the rails are made is partly crushed and injured, and they then wear out much more rapidly than they would if the weight was distributed on more wheels, and thus a smaller amount of weight rested on each point of contact with the rails. The amount of weight which can be carried on a single wheel depends upon the material of which the rails are made, and to some extent on their form and size, or as the latter is usually expressed, on their weight per yard. QUESTION 415. When the adhesive weight and the number (cf driving-wheels are known, how is the size of the latter and of the cylinders determined? Answer. The size of the wheels will to a certain extent depend upon the speed, because the larger the wheels, the further will the locomotive move in one revolution; but no exact rule can be given for their size. At present there is still a great diversity of opinion among engineers regarding the best sizes of wheels and cylinders for any given service. ProbablV the safest plan twill be to consult the best practice, and in the absence of any better reasons be guided for the present by that. In this country the most common size of locomotives used is that which we have solee.ted for our illustrations, that is. what are called five-feet wheels, and cylinders of 16 inches diameter and 24 35* 414 Catechism of the Locomnotive. inches stroke. More engines of these dimensions are used than of any other. For freight service the wheels are sometimes made of smaller and for passenger trains of larger diameter; but locomotives with drivingwheels and cylinders of the dimensions given are used for both passenger and freight service. It should be stated here that what are called five-feet wheels are usually about 11 in. larger in diameter than five feet. This arose from the fact that the tires which are now used are made thicker than they were on the first engines, and the practice thus established has been continiued. We will therefore take the diameter of what is called a five-feet wheel at what it really is, 61- in. Such locomotives also have about 40,000 lbs. of adhesive weight. Now, the circumference of such wheels is 193.2 in., and therefore in one revolution of the wheels, if they do not slip, the locomotive will move that distance on the rails. At the same time each piston will sweep through the cylinder twice, and therefore in one revolution 4 times one cylinder full of steam is used. Now a cylinder of 16 in. diameter and 24 in. stroke contains or will hold 4,8251 cubic inches, so that in one revolution of the wheels 4,825- X 4= 19,302 cubic inches of steam are used. As has been stated, in one revolution of the wheels, if they do not slip, the locomotive will move 193.2 in. If, now, we divide 19,302 by 193.2 it will give us the amount of steam used to move the locomotive and train one inch. Now, 19,302 -- 193.2 =99.9, which, for the sake of even figures we will call 100. We thus see that a locomotive with 40,000 pounds -or 20 tons (of 2,000 lbs.) of adhesive -weight requires 100 cubic inches of'cylinder Proportions of Locomotives. 415 capacity* to move it one inch. Now, if a locomotive had only half as much weight on the driving-wheels, it could pull only half as much load, and would therefore use only half as much steam, and consequently need only half the cylinder capacity of the other locomotive. If there was three-quarters or a third as much adhesive weight, the cylinder capacity should also be three-quarters or a third. We thus see that the cylinder capacity should be proportioned to the total adhesive weight. Now as 100 cubic inches of cylinder capacity are needed to move an engine with 20 tons adhesive weight one inch, if we divide 100 by 20 we will get the cylinder capacity needed for each ton. That is, 100+ 20 — 5 CUIC IN. CYLINDER CAPACITY PEla TON (of 2,000 lbs.) OF ADHESIVE WEIGHT IS NEEDED TO MOVE ANY LOCOMOTIVE ONE INCH. This quantity we have named the modulus of propulsion. Supposing now that it is required to calculate the cylinder capacity for a locomotive with 15 tons adhesive weight, and wheels 4} feet or 54 in. in diameter. We will first multiply 15 by the modulus of propulsion, 15 x 5=75 = the number of cubic inches of cylinder capacity required to move such a locomotive one inch. Multiplying the length of the circumference of the wheels, which in this case is 169.6 in. by 75, will give us the total cylinder capacity for one revolution. That is 169.6 x75-12,720 cubic inches of cylinder capacity, or the space which should be swept through by the two pistons. Dividing this by 4 will give us the cubical contents in inches of one of the cylinders. *The cylinder capacity is the space swept through by the two pistons. In the above illustrations what is meant is, that the average space in the cylinller swept through by the piston is 100 cubic inches for each inch that the locomotive advances. 416 Catechism of the Locomotive. Thus, 12,720 4 = 3,180 cubic inches = the capacity of one cylinder. Now as the capacity of a cylinder is calculated by multiplying the area of the piston by the length of the stroke, if we have the one we can easily determine the other. Thus, supposing it was intended to make the stroke of the pistons 22 in., dividing 3,180 by 22 will give us the area of the piston. Thus, 3,180 + 22 - 144.5 square inches. Now by the well-known rule in mensuration, if we DIVIDE THE AREA OF A CIRCLE BY 0.7854, THE SQUARE ROOT OF THE QUOTIENT WILL BE THE DIAMETER OF THE CIRCLE. Thus, 144.5 0.7854 = 183.9. The square root of 183.9 is 131 nearly, which should be the diameter of the cylinder. Instead of calculating the diameter of the circle, a more convenient way is to refer the area to a table of areas, and from it find the diameter. Of course if we have the diameter of the piston and want to get the stroke, we DIVIDE THE CUBICAL CONTENTS OF THE CYLINDER BY THE AREA OF THE PISTON. Thus, in the present illustration, if it was intended to have the piston 13- in. diameter, we would have divided 3,180 by the area of a piston 13- in. diameter, which is 143.1, so that we would have 3,180 ~ 143.1 - 22 nearly, = inches of stroke of piston. From the above considerations we can deduce the following RULE FOR CALCULATING THE CAPACITY OF THE CYLINDERS WHEN THE ADHESIVE WEIGHT IS KNOWN:MULTIPLY THE TOTAL WEIGHT ON THE DRIVINGWHEELS IN TONS (of 2,000 lbs.) BY 5, AND THEN BY THE CIRCUMFERENCE OF THE WHEELS IN INCHES, AND DIVIDE BY 4. THE QUOTIENT WILL BE THE CUBICAL CONTENTS IN INCHES OF EACH CYLINDER. Proportions of Locomotives. 417 From this, if either the diameter or stroke is given the other can easily be found, as lhas been explained. It should be remarkled -here that it is unimportant, so far as tile po\ver of the locomotive is concerned, whether the cylinders have a large diameter and a short stroke or a small diameter and a long stroke, provided the cubical contents are the same. Thus cylinders 17- in. in diameter and with 20 in. stroke would have almost exactly tlhe same capacity and the same power would be exerted with them as with cylinders 16x24 in.; the only difference would be that with the cylinder of the largest diameter the pressure on the piston and consequently on the crank-pin journal and the strain on the parts would be greater than with the smaller cylinder. The difference in pressure would, however, be exactly comlpensated by the loss or gain in the leverage exerted tllhrough the drivingwheels on the rails. QUESTION 4161 What circumstances should determine the size of locomotive boilers? Answer. They should be proportioned to the amount of adhesive weight, and to the speed at which the locomotive is intended to work. Thus, a locomotive with a great deal of weight on the driving-wheels could pull a heavier load and would, by tile above rule for proportioning the cylinders, have a greater cylinder capacity than one with little adhesive weight, and would therefore consume more steam, and therefore should have a larger boiler. It is also obvious that if a locomotive like that slhown in plates I and II should have a boiler just large enough to furnish steam when running at the rate of 20 miles an hour, it would be too small if the locomotive ran 40 miles an hour, the 418 Catechism of the Loconmotive. train resistance being the same in both cases. Drivingwheels 5 feet in diameter would at 20 miles per hour make 112 revolutions per minute, and would therefore consume 448 cylinders full of steam. At 40 miles per hour double the number of revolutions would be made, and consequently twice the quantity of steam would be used, and therefore the boiler should have twice the steam-producing capacity. If, therefore, we know the size of a boiler required for a given amount of adhesive weight and a given speed, we can easily calculate the boiler capacity for any other weight and speed. QUESTION 417. How can we determine the boiler capacity needed for an engine with a given amount of adhesive weight and for a given speed? Answer. This must be determined empirically, that is from experience. QUESTION 418. On what does the steam-generating capacity of a boiler depend? Answer. First, upon the size of its grate and firebox, because more fuel can be burned in a large fireplace than in a small one; second, on the amount of heating surface to which the products of combustion are exposed, and third, on the draft produced by the blast or exhaust steam. Of course the amount of steam generated is also dependent upon a great variety of other circumstances, such as the nature of the combustion, the firing, the arrangement of the firebox, grates, etc., and the condition of the beating surfaces; but these have nothing to do with the proportions or size of the boiler. QUESTION 419. What are the proportions of boilers uised in locomotives like that which has been illustrated in these articles and represented in Plates [and 1? Proportions of Locomotives. 419 Answer. The area of the grate is about 2,100 square inches and the total heating surface about 800 square feet, and the water capacity about 5,000 lbs., and the total weight of the boiler, including all the boiler attachlments and appliancesfor promoting combustion, about 30,000 lbs. QUESTION 420. At what speed are such engines usually run? Answer. The speed varies so much under different circumstances, that it is impossible to give even approximately the average speed of such engines. QUESTION 421. How then can we determine the proper proportions of a boiler for a locomotive intended for any given service? Answer. As stated before, this can only be done empirically. The safest method is to select a locomotive which is doing the best service, and learn the average speed at which it runs, the size of its grate and the amount of its heating surface, and its adhesive weight. Now MULTIPLY THE ABOVE SPEED IN MILES PER HOUR' BY THE ADHESIVE WEIGHT OF THE LOCOMOTIVE IN TONS (of 2,000 lbs.) AND DIVIDE THE PRODUCT INTO THE AREA OF THE GRATE IN SQUARE INCHES. THEN MULTIPLY THE ADHESIVE WEIGHT OF THE LOCOMOTIVE FOR WHICH THE BOILER IS TO BE PROVIDED BY ITS SPEED, IN MILES PER HOUR, AND BY THE QUOTIENT OBTAINED ABOVE. THE PRODUCT WILL BE THE AREA OF THE GRATE IN SQUARE INCHES FOR THE NEW ENGINE. To illustrate this, suppose an engine of the dimensions given to run at an average speed of 20 miles per hour. Now, multiplying that speed by the number of tons of adhesive weight and dividing the product into the area of the grate, we 420 Catechism of the Locomotive. have 20 x 20-400 and 2100 —400=5.25. We now want to determine the size of a grate for the boiler of a locomotive with 30 tons adhesive weight and to run at a speed of 15 miles per hour. We therefore multiply 15 by 30 and the product by the above quotient, or 15 x 30 X 5.25=2,362.5 = square inches of grate surface for the boiler. The required heating surface can be obtained in a similar way, by substituting it instead of the grate surface in the calculations. QUESTIoN 422. How is the size of locomotive boilers usually limited? Answer. By the weight of the locomotive and to some extent by the distance between the rails. It will be found often that it is impossible to make the boiler of the size indicated by a calculation similar to the above without at the same time making the weight of the locomotive and the adhesive weighlt greater than was assumed. The result of such a calculation indicates, therefoire, that too large a proportion of the weight of the locomotive is on the driving-wheels for the speed at which it is intended to work, and that either they should bear less weight or the speed be reduced. QUESTION 423. In what respects is the operation of locomotive boilers d&fferent from that of nearly all other steam boilers? Answer. The amount of steam generated in proportion to the amount of heating surface is much greater in locomotive boilers than in any other kind. To produce combustion which will be sufficiently active to generate the requisite quantity of steam, the fire must be stimulated by the blast created by the exhaust steam to a degree unknown in other kinds of boilers. So rapid is the movement of the products of combus Proportions of Locomotive$. 421 tion that a smaller proportion of the beat is imparted to the water contained in the boiler, and consequently a less amount of water is evaporated in proportion to any given amount of fuel than in boilers in which combustion is less violent. The combustion is also less perfect, because the strong draft does not allow time for a perfect combination of the gases which produce combustion. The supply of steam which a locomotive boiler must furnish is also much more irregular than the demands made upon any other kind of boiler. At one time the fire must be urged to the greatest possible intensity in order to furnish steam enough to pull a train up a steep grade. When the top is reached the demand ceases, and the boiler can be cooled. The load which a locomotive can pull over a given line of road is usually limited by the utmost capacity of the boiler to supply steam at these critical periods. QUESTION 424. What relation is there between this irregllar action and the size of the boiler? Answer. The smaller the boiler, or rather the larger the amount of steam which must be generated in a given time in proportion to the heating surface, the more must the fire be urged; and therefore the smaller the boiler in proportion to the work it must do, the less will be its economy. In order to produce a rapid combustion in a small boiler, it is necessary to contract the exhaust nozzles in order to create a draft strong enough. In doing this the back pressure on the pistons is very much increased, and when the blast becomes very violent a great deal of solid coal is carried through the tubes and escapes at the smoke-stack unconsumed. At the same time large quantities of un36 422 Catechism of the Locomotive. consumed gases escape, because there is not time for combustion to take place in the fire-box. The fact that with a violent draft the flame and smoke are in contact with the heating surface for a sensibly shorter period of time also has its influence; as less heat will be imparted to the water if the products of combustion are only -o~ of a second instead of T-o in passing through the tubes. There is another consideration which should be taken into account in this connection, which is, that if a boiler is so small that it is workled nearly up to its maximum capacity at all times, it will be impossible to accumulate any reserve power in it in the form of water heated to a high temperature to be used as occasion may require. With a boiler having a great amount of heating surface and capacity for carrying a large quantity of water, the latter can be heated at times when the engine is not working hard, and the heat thus stored up in the water can then be used when it is most needed. Thus we will suppose that to pull a train of cars on a level 250 lbs. of steam are consumed per mile. On a grade of 30 feet per mile the resistance will be three times what it is on a level, and therefore three times the quantity of steam will be consumed, so that the boiler must then evaporate 750 lbs. of water per mile. Now to convert 250 lbs. of water heated up to a temperature due to 130 lbs. of effective pressure, or 355.6 degrees, into steam of that pressure will require 216,575 units of heat. If at the same time that this steam is being consumed, we pump into the boiler 250 lbs. of water of a temperature of 60 degrees, 73,900 more units of heat will be needed to raise the water to the temperature due to 130 lbs. Proportions of Locomotives. 423 effective pressure, so that on the level part of the road it would be necessary to transmit to the water in the boiler 216,575+73,900=290,475 units of heat in a mile. If there is no room in the boiler for storing a surplus quantity of hot water, it will be necessary on a grade as fast as the steam is consumed to feed an equivalent amount of cold water to take the place of that which was converted into steam, so that on a 30 feet grade it would be necessary to convert at the rate of 750 lbs. of hot water into steam in a mile, which would require 649,725 units of heats, and at the same time heat an equal amount of cold water to a temperature due to the pressure of the steam, which would require 221,700 more units. So that it will be necessary to transmit at the rate of 871,425 units of heat to the water per mile. Now if the boiler was so large that more water could be pumped into it and heated than was used on the level portion of the road, and could there be stored up for future use, the pumps might be either partly or entirely shut off when the engine was working the hardest on the grade. In this way, instead of being obliged to convert hot water into steam, and at the same time heat an equal amount of cold feed-water, there would be a surplus of hot water stored up already heated. It would therefore only be necessary to convert this hot water into steam, which will require a transmission of heat to the water at the rate of 649,725 units of heat instead of 871,425. It must be remembered that on nearly all roads there are certain difficult places which practically limit the capacity of the locomotives on that line. If therefore the capacity of the engines can be increased at those points, their capacity over the whole line is increased. 424 Catechism of the Locomotive. It will be seen by the above illustration that by having a large boiler it is necessary for it to do very much less work at the critical period, when, as every locomotive runner knows, it is often of the utmost importance to make use of every possible available means in order to pull the trains. It is true that on a very long grade the supply of surplus hot water would soon be exhausted, but even in such cases there is usually one place, owing to a curve or other cause, which is more difficult to surmount than any other, in which case it will be necessary to use more steam for a short time than the locomotive can generate if the boiler is fed continuously. For such cases a surplus of water can be used. But even if the resistance is equal over the whole length of the incline, still the large boiler will have the advantage, because it call at all times generate more steam than a smaller one. It may therefore, we think, safely be assumed that locomotive boilers should always be made as large as the weight of the locomotive will permit. QUESTION 425. What effect does the size of the drivin7gwheels have upon the combustion and evaporation of locomotive boilers? Answer. As small wheels make more revolutions in running a given distance than large ones, there will be more strokes of the piston with the former than with the latter, if the locomotive in both cases runs at the same speed. As smaller cylinders are usually employed with small wheels, the blast up the chimney is then composed of a larger number of discharges of steam, but each one of less quantity, than when larger wheels and cylinders are used. In the one case the "puffs" of steam are many and small, and in the lat Proportions of Locomotives. 425 ter few and large. If the cylinders are proportioned by the rule which has been given for that purpose, the amount of steam discharged in running any given distance will be the same with engines having large and those with small wheels, the only difference being that it will be subdivided into a greater number of discharges in the one case than in the other. Now, it is found that the draft of engines is much more effective on the fire when the blast is thus subdivided, that is when small wheels and cylinders are used, than it is with large ones, and therefore more steam is generated with the former than with the latter. QUESTION 426. What relation is there between the size of the wheels and that of the boiler? Answer. As has been explained, the size of the boiler is limited by the weight of the locomotive. The boiler and its attachments of an American locomotive, when the former is filled with water, weigh about half as much as the locomotive; therefore unless we increase the weight of the latter or decrease the weight of the machinery, we can not increase the size of the boiler. Now, large wheels are heavier than small ones; they require larger cylinders, stronger connections, heavier frames, and in fact nearly all the parts of the machinery used with large wheels must be heavier than are required when small wheels are used. Therefore, by decreasing the size of the wheels all the other parts of the engine proper can be made lighter than is possible if large wheels are used, and thus the size and weight of the boiler can be increased without increasing the whole weight of the locomotive. There is of course a practical limit below which the size of the wheels can not be reduced, because the speed of 36* 426 Catechism of the Locomotive. the piston would become so great as to be injurious to the machinery. By reducing the stroke, however, with the diameter of the wheels, the evil referred to may be obviated to a great extent. A cylinder with a large diameter and comparatively small stroke has also the advantage that there is less surface exposed to radiation of heat than there is in a cylinder in which these proportions are reversed. PART XXII. DIFFERENT KINDS OF LOCOMOTIVES. QUESTION 427. Into what classes may locomotives be divided conveniently? Answer. 1. Locomotives for "switching,"'shunting" or "drilling" service, that is, for transferring cars from one place to another at stations; 2, for freight Itraffic; 3, for ordinary passenger traffic, and 4, for suburban or metropolitan railroads, where a great many light trains are run. QUESTION 428. What kinds of locomotives are used in this country for switching cars at stations? I............................... /: Fig. 220. Answer. Four-wheeled locomotives similar to that shown in Plate IV. In some cases they are made with six driving-wheels. Engines like that shown in Plate IV have separate tenders, but they are sometimes made so as to carry the water-tank and fuel on the locomotive itself, as' shown in fig. 220, and are 428 Catechism of the Locomotive. then called tank locomotives. Fig. 220 represents a switching engine built by the Taunton Locomotive Manufacturing Company. QUESTION 429. Why are four-wheeled locomotives used for switching? Answer. Because in such service it is constantly necessary to start trains, many of which are very heavy, and therefore a great deal of adhesion is needed. For this reason the whole weight of the locomotive and in the case of tank locomotives that of the water and fuel is placed on the driving-wheels. It is also necessary for such locomotives to run over curves of very short radius and into switches whose angle with the main track is very great, and therefore in order that they may do this and remain on the track, their wheel-bases must be very short, and consequently the wheels are all placed near together between the smokebox and fire-box. QUESTION 430. Why are such locomotives not suited for general trafic? Answer. Owing to the shortness of their wheel-bases they become very unsteady at high speeds, and acquire a pitching motion, similar to that of a horse-car when running rapidly over a rough track. This unsteadiness not only becomes very uncomfortable to the men who run the locomotive, but there is danger of the engine running off the track. As nearly all switching is done at very slow speeds, it is not so objectionable for that service as it would be on the "' open road "" at high speeds. * The term " open road" is a literal translation fromn the German, for which there is no corresponding English term, and means the road between stations where trains run fast. Different Kinds of Locomotives. 429 QUESTION 431. What kinds of locomotives are used for freight service? Answer. The greater part of the freight service of this country is performed by locomotives like that selected for the illustrations of these articles, and represented in Plates I, II and III. Such locomotives have been called " American " locomotives because they first originated in this country and are now more generally used here than anywhere else. Side elevations of locomotives of this kind, built by the Baldwin Locomotive Works, the Grant Locomotive Works, the Danforth Locomotive and Machine Company, the Mason Machine Works and the iinkley Locomotive Works -are represented in Plates V, VI, VII, VIII and IX. Such locomotives have been described in the preceding pages. QUESTION 432. What are the dimensions of such engines? Answer. The principal dimensions of the engines illustrated are given in the table in the appendix, but locomotives of this plan are built of much smaller and also of larger sizes than those represented by the engravings. Illn some cases such locomotives do not weigh more than 35 or 36,000 lbs., with cylinders from 8 to 12 inches in diameter. In other cases they weigh as much as 66,000 lbs., with cylinders 17 or 18 inches in diameter. The wheels vary from 4 to 6 feet in diameter, but the most common sizes are 4- and 5 feet QUESTION 433. When it is desirable to pull heavier loads than is possible with the adhesive weight that can be placed on four driving-wheels, what is done? Answer.,One or more pairs of driving-wheels are 430 Catechism of the Locomotive. added, as in the ten-wheeled locomotive represented in Plate X, the'"Mogul " engine, Plate XI, and the "Consolidation " engine, Plate XII. The ten-wheeled locomotive, it will be seen, is similar in construction to an ordinary American locomotive, excepting that it has another pair of driving-wheels in front of the main driving-wheels. It will be seen, however, that it is necessary to keep these close to the latter, because if they are brought further forward they will be too near the back truck-wheels. For this reason a truck consisting of a single pair of wheels, A, A, is placed in front of the cylinders, as represented in Plates XI and XII, is now much used. The front driving-wheels are then placed further forward, and thus bear a larger proportion of weight than they do in locomotives like that shown in Plate X. QUESTION 434. How are trucks with a single pair of wheels constructed? Answer. The truck frame is extended some distance behind the truck-axle, as shown in fig. 221, and the centre-pin, a, about which it vibrates, is placed at the back end. The weight of the locomotive, or that portion to be carried on the truck, is then made to rest over the centre of the axle, but in such a way that it can move laterally or crosswise over the track. Such trucks were first made so that the weight of the engine rested on slides on the truck frame, but recently they are nearly always suspended on links, so that they can swing like a pendulum, as shown in figs. 190 and 191. The weight of the engine then rests on the centre-plate, H H, which forms part of the plate, B B. This is suspended by links, L L, represented by dotted lines, which are attached by bolts to the cross-pieces, Diff erent Kinds of Locomotives. 431 m m, which are fastened to the truck frame. In this way the truck-wheels can move sideways independent of the engine itself. As the wheels and axles, A A, must move about the centre-pin, a, fig. 221, the axle assumes a radial position to the curves of the track. It does this, too, quite independent of the drivingwheels, as is shown in fig. 221, which represents a 432 Catechism of the Locomotive. plan of the wheels on a curve. It will be seen that the truck is not at all influenced by the position of the driving-wheels. This arrangement therefore gives great flexibility to the wheel-base, and enables the wheels to adjust themselves to any lateral curvature or alignment of the track. QUESTION 435. For what purpose are locomotives like that shown in Plates Xl and XII used? Answer. " Mogul " locomotives are often used for ordinary freight service where heavy trains must be hauled, and also on steep grades. Consolidation locomotives, represented in Plate XII, which have eight drivingwheels, are employed almost exclusively for traffic over heavy mountain grades. QUESTION 436. What other kinds of locomotives are used for freight traffic? Answer. Various kinds of tank locomotives, that is, locomotives which have no separate tenders, but carry the water-tanks and fuel on the frame and wheels of the locomotive itself, have been devised and are to some extent used. Plate XIII represents a locomotive of this kind on which the tanks are placed on each side of the boiler, and the fuel on a Bissell truck at the back end. A similar truck is placed at the front end, so that a locomotive of this kind can run equally well either way. The lateral movement of the two trucks also gives great flexibility to the wheelbase, so that such an engine will adjust itself easily to the curvature of the track. If, however, the two pairs of truck-wheels should both stand on an elevated part of the track, and the driving-wheels on a depression, the latter would evidently not carry as much and the truck-wheels would carry more of the weight of the Different Kinds of Locomotives. 433 engine than they did on a level part of the track. If the reverse condition of things should occur, that is, if the driving-wheels should be on an elevation and one or both pairs of the truck-wheels on a depression, then the latter would bear less weight than they did and the driving-wheels more. For this reason, in order to distribute the weight evenly on all the wheels, it is necessary to equalize the weight on the truck and driving-wheels, by connecting them with equalizing levers, similar to those which were described in answer to Question 301. These levers distribute any undue weight which may come on one wheel to that next to it. This is important, because if the drivingwheels bore less weight at some times than at others, their adhesion and their capacity to draw loads would be reduced in like proportion. It is evident, however, that if the water-tank or fuel is carried on the driving-wheels, there will be a greater weight on them when the tank is full than when it is empty, and that therefore there will either be so much weight on the wheels at one time as to be injurious to the rails, or else there will be too little for adhesion at another. Of course cases are conceivable, and doubtless exist in practice, where more adhesion is required to start a train and lihaul it during the first part of the " run " than will be needed - during the latter part. In such cases doubtless the variable character of the weight might be an advantage instead of the reverse, but for ordinary practice a variable load on the driving-wheels would lhave the disadvantages which have been described. For this reason tank locomotives have been built like that represented in Plate XIV. In. this it will be seen that 37 434 Catechism of the Locomotive. the weight of the water-tank rests on a four-wheeled truck at the back end. A Bissell or two-wheeled truck is, however, placed in front in the same position as in the engine represented in Plate XIII, and carries a portion of the weight of the boiler and nmachinery. In order to get all the advantages which a fourwheeled switching engine possesses in having its whole weight on the driving-wheels, and at the same time avoid the disadvantages which result from a short wheel-base, and also from a varying amount of weight on the driving-wlieels, a locomotive like that represented in Plate XV was designed by the writer with the whole weight of the boiler and machinery resting on the driving-wheels, and the water and fuel on a truck. By this means not only the objections to carrying the weight of the water on the driving-wheels is overcome, but at the same time the disadvantages arising from the short wheel-base of the switching locomotive, Plate IV, are also obviated. That is, all the permanent weight of the boiler and machinery of such a locomotive rests on the driving-wlceels, and is therefore all adhesive weight, as it is in the switching engine, and at the same time by extending the frame beyond the fire-box and placing the water-tank and fuel on this extension of the frame and supporting their weight on a truclr, the engine has a wheel-base which is as long and as flexible as that of ordinary -American engines, represented in Plates V, VI, VII, VIII and IX, and as the latter have only about twothirds of their weight on the driving-wheels, locomotives like that represented in Plate XV, of the same weight as the others, have fifty per cent. more adhesion, or they may be one-third lighter and.have thle Different Kinds of Locomotives. 435 same adhesion. As was explained in answer to Question 260, if an ordinary American locomotive runs backwards, that is, with the driving-wheels in front, the friction of their flanges against the rails on curves of short radius will be very excessive. To avoid this with locomotives of the design last described, they are run with the truck first, which, being at the opposite end of the boiler from the position which it usually occupies, reverses the position of the boiler and other parts relative to the motion of the engine. That is, the fire-box is then in front and the smoke-stack behind. Engines of this kind have been built and are now working and doing excellent service; but the prejudice which exists against running locomotives in the reverse direction to what bas been customary seems to be the chief obstacle in the way of their use. Another plan which possesses all the advantages of the locomotive described above and is free from the last objection is represented in Plate XVI. This plan was first adopted by Mr. Robert Fairlie in England, but has been introduced into this country and very much improved by Mr. William Mason, of Taunton, Mass. In these locomotives, the driving-wheels and cylinders are attached to a truck frame which turns around a centre-pin like any ordinary truck. The steam and exhaust pipes are connected to the boiler and cylinder with pipes which have flexible joints. By this means the truck can move independently of the boiler, and thus the driving-wheels can adjust themselves to the curvature of the track, just as the wheels of any other truck do, and therefore the driving-wheels can be run ahead just as well as the truck-wheels which carry the tank. This plan pos 436 Catechism of the Locomotive. sesses the additional advantage that the fire-box can be made as wide and as long as may be desired without interfering with the driving-wheels. The flexible pipes are, however, usually considered an objection; but with the improvements which have been made in their design and construction, the difficulties which were at first encountered have probably been overcome. At any rate if there is no other objection to the use of such locomotives, ingenuity and care should in time overcome that one. Plate XVII represents a locomotive of this plan, with six driving-wheels and a six-wheeled carrying truck under the tank. This latter plan of locomotive is intended for heavy freight traffic. QUESTTON 437. What kind of locomotives is used for passenger trains? Answer. Eigh-t-wheeled American locomotives are used almost exclusively for passenger service. Usually the driving-wheels of such locomotives are larger in diameter than are used for freight traffic. Their size varies fromn 5 feet to 5 ft. 9 in. in diameter. The locomotive by the Mason Machine Works represented in Plate VIII has 5- feet driving-wheels. For very heavy express trains locomotives with 17 X 24 inch cylinders and weighing 34 tons are now used on many through lines. QUESTIONT 438. What is meant by suburban and metropolitan railroads, what is the nature of their traffic, and whot kiads of locomotives are needed for it? Answer. The traffic of suburban railroads consists chiefly of the transportation of passengers who do business in the city to the latter in the morning and to their homes in the evening. As the largest num Different Kinds of Locomotives. 437 ber of passengers must be carried during a few hours in the morning and evening, it is necessary to run very heavy trains at those times. As the passengers must be distributed at many stations which are near together, it is necessary to stop often; and in order that the average speed may be reasonably fast the trains must run very rapidly between these stations. It is therefore necessary to have heavy locomotives, with more than the usual proportion of adhesive weight, so that the trains can be started quickly without slipping the wheels. The main valves should also have a liberal amount of travel, so that steam will be admitted to and exhausted from the cylinders quickly. In some cases it is thought desirable to have locomotives which will run equally well either way, so that it will not be necessary to turn them around at each end of the " run." By metropolitan railroads are meant railroads in large cities. They may be divided into two classes, one for carrying freight cars from the outskirts of cities to the warehouses and stores at their business centres, and also from the terminus of one road to that of another. Metropolitan railroads of this kind are usually branches of lines which extend from the city. Locomotives for such traffic must have great tractive power, in order to pull heavy trains, and as the speed is usually slow the wheels and the boiler capacity may be small. They must generally be capable of running through curves of very short radius; and as the traffic is usually carried through streets in close proximity to buildings, the locomotives should be as nearly as possible noiseless. The other class of metropolitan roads is for carrying passengers. The traffic of the latter is 37* 438 Catechism of the Locomotive. similar to that usually carried on horse railroads, and consists almost exclusively of passengers. At present (1874) there are only one or two metropolitan railroads in this country for carrying passengers which are operated by steam power. It seems certain, however, that their use will soon become very general in all large cities. Their traffic will consist of many light trains run at short intervals and at comparatively slow speeds, and therefore very light locomotives are required. QUESTION 439. What kinds of locomotives are used for suburban railroads? Answer. The ordinary American eight-wheeled locomotive is used more than any other kind; but a number of locomotives like that represented by fig. 222 have been built and are used for this traffic. These have one pair of driving-wheels in front of the main pair and a Bissell truck in front of the cylinder. With this arrangement the driving-wheels bear a larger proportion of weight than they do if arranged on the ordinary American plan with a four-wheeled truck. Another plan is that shown in Plate XVIII. Such engines, as will be seen, have a Bissell truck at each end, and therefore they run equally well either way. In some cases the tanks of such engines are carried on the top and sides of the boiler. WThen they are obliged to run only a short distance, and a small supply of water is needed, this arrangement answers very well; but it is impossible to carry a large supply of water in this way without overloading the wheels of the locomotive, and at the same time increasing the evils of a varying load on the drivingwh1eels. Fig 222. LIGHT PASSENGER AND FREIGHT LOCOMOTIVE, BY THE GRANT LOCOHOTIVE WORKS, PATERSON, N. J. 440 Catechism of the Locomotive. Locomotives like that shown in Plate XIV are also used for suburban traffic. As shown in the engraving they have a four-wheeled truck at one end and one with two wheels at the other, so that it is thought that they can be run safely either way. The fourwheeled truck carries the weight of the water and fuel. The plan of engine represented by Plate XV is very well adapted' for this kind of traffic. Excepting on curves with a very short radius it could.be run in either direction at any required speed, without encountering any other difficulty excepting the prejudices of those who run it. As double-truck locomotives similar to that shown in Plate XVI can adjust themselves to any curve, this objection could not be urged against their use. QUESTION 440. What kinds of locomotives are used on, metropolitan railroads? Answer. For freight traffic ordinary switching locomotives like that represented in Plate IV are often employed. In some cases these have the tanks on the locomotives. It often happens, though, that such traffic must be conducted in the streets of a city, and that the noise, especially of the exhausting steam, is thus liable to frighten horses,and disturb the occupants. It is, then, necessary either to condense the exhaust steam or render its escape noiseless, which is done by allowing it to escap6 into the water-tanks. Street locomotives which have a condenser similar to the surface condensers used on marine engines are used on the Hudson River Railroad in New York. The exhaust steam passes through these and then escapes into the tanks. The latter are long and nar -)ifferent Kinds of Locomotives. 441 row, so as to expose a great deal of surface to radiation, and in this way cool the water which becomes heated by the steam. The engines have four drivingwheels and vertical boilers. The cylinders are connected to a crank shaft with a pinion on it, which gears with another wheel of larger size on the drivingaxle. In this way the speed is reduced and great tractive power can be exerted. The whole of the engine is enclosed so. as to hide the machinery, the sight of which is supposed to frighten horses. The: engines were designed and patented by Mr. A. F. Smith, formerly Master Mechanic of that road. For roads in cities carrying passengers almost exclusively, an entirely different class of locomotives is needed. To suit passengers it is of course necessary to run a great many trains at very short intervals. When this is done the trains are necessarily very light, and therefore only light locomotives are needed. Plate XIX represents the locomotives employed on the Greenwich Street Elevated Railroad in New York. These engines weigh only 10,000 lbs., and the wheels are 30 in. diameter and the cylinders 7 x 10 in. The peculiarity in their construction consists in their having an intermediate shaft between the two pairs of driving-wheels. This shaft has two cranks inside of the frames and two outside. The cylinders are connected to the inside cranks, and the coupling-rods to those on the outside. The water is carried in a tank on top of the boiler. The fuel is anthracite coal. PART XXIII. CONTINUOUS TRAIN BRAKES. QUESTION 441. What are meant by automatic or continzuous train brakes? Answer. Continuous train brakes are brakes which can be applied to all the cars of a train by the locomotive runner on the locomotive. In some cases such brakes are arranged in such a way that they can also be applied from any car in the train, or are made selfacting in case of an accident, such as a car getting off the track or a train breaking in two. QUESTION 442. What are the principal systems of brakes of this kind in use? Answer. What is called, after its inventor, the Westinghouse atmospheric brake is now used more than any other. Next to this, Smith's vacuum brake is used most. Besides these two, Creamer's, Ward's, Loughridge's and Henderson's systems of brakes are used to a limited extent. The two first are, however, the only ones which have come into sufficiently extensive use as yet to justify us in describing them here. QUESTION 443. How does the Westinghowuse brake act and how is it constructed? Answer. As its name indicates, the medium employed for transmitting the power for operating the brakes is atmospheric air. This is compressed to any required density by a Crontinuot.s ]Trabi Brakces. 443 steam pump which is located between the drivingwheels, or in any other convenient place on the locomotive. This pump is shown in section in fig. 223 and consists of two cylinders, the upper one, A, the steam cylinder, the piston of which is connected by its rod with the piston in the lower cylinder, B. This latter is operated by the steam piston, and at each Fig. 223. Scale Y in.=l foot. stroke a quantity of air, equal to the space swept through by the lower piston, is compressed and thus forced into a cylindrical reservoir, which is usually placed under the foot-board of the locomotive, in which it is stored for use at any time when the brakes are to be applied. The air and steam cylinders are supplied 444 Catechism of the Locomotive. with suitable valves for admitting and releasing the air and steam. From this reservoir it is conducted back under the tender and cars by pipes, which are connected together between the engine and tender and between the cars by India rubber hose. Two pieces of hose are attached to the engine and also to each end of the tender and cars, so that in case one piece should break the others will act. Each of these pieces is united or coupled to the corresponding piece opposite to it by a peculiar coupling made for the purpose, so that they can be quickly disconnected if the cars, en'gine or tender are uncoupled. Under the tender and also under each car is a cylinder and piston. The compressed air is conducted to this cylinder in front of the piston when the brakes are to be applied. As the piston-rod is connected by a bell crank to the brake levers when the piston is forced out by the pressure of the air, the brakes are at once applied to the wheels. As the reservoir under the foot-board is connected by the pipes which have been described with the cylinders under each car and the tender, by simply opening communication between the reservoir and the pipes, the air at once rushes from the reservoir back through the whole length of the train, and so rapid is its motion and quick its action that only a second or two intervenes between the opening of communication and the application of the brakes. To relieve or "let off" the brakes it is only necessary to close the reservoir cock and open communication from the air-pipes to the external atmosphere, when the compressed air in the brake cylinders will escape, and the springs ordinarily used on car brakes will cause the pistons to resume their former positions. Continious Train Brakes. 445' For the purpose-of opening the connection from the reservoir to the brake cylinder, and closing this connection and opening one from the latter to the external air, a single three-way cock is commonly used. This is arranged at such a point as to be under the control of the engineer, so that he can at pleasure turn A K ]iD Fig. 224. Scale 1Y inch=1 foot. on the compressed air with any degree of force, instantaneously, or slowly, or with a varying power, or by another turn of the cock let it off as freely, still keeping it under the same complete control. 38 446 Catechism of the Locomotive. QUESTION 444. How does the vacuum brake act and how is it constructed? Answer. The power is applied to the brakes of the cars in this system by exhausting instead of compressing the air. This is done by means of an ejector, of which fig. 224 is a section. This operates somewhat like an injector. Steam is admitted into the pipe B, and escapes through the annular or circular opening a a. The effect of this is to create what is called an "induced current," or to draw the air from the pipe C' C, which, with the steam, escapes at A. This produces a partial vacuum in the pipe C, which extends back under the cars. The pipes under the cars are connected together by rubber hose, which are prevented from collapsing by coils of wire inside. Under the tender and under each car are India rubber cylinders with cast iron ends, one fastened to the car and the other movable. The rubber cylinders can be extended or compressed somewhat like the bellows of an accordeon. The rubber is supported by iron rings inside, placed from 4 to 6 inches apart, so as to prevent them from collapsing when the air is exhausted from them. When this is done the pressure on the movable cast iron end draws it towards the fixed one, and by attaching the former to the brake levers by a rod, the force of the pressure on the head is communicated to the brakes. The ejector is placed on top of the boiler, and when the brakes are to be applied the locomotive runner opens a valve, which admits steam into the ejector, which instantly begins to produce a partial vacuum and thus apply the brakes. When the pressure of the brakes is to be released, the release valve, D, is opened, Continuous Train Brakes. 447 which admits air into the pipe, C, through which it is conducted back to each of the India rubber cylinders, and thus counteracts the pressure on the ends and releases the brakes. Both the atmospheric and the vacuum brakes have recently been applied to the driving-wheels of locomotives with very excellent results. PART XXIV. PERFORMANCE AND COST OF OPERATING LOCOMOTIVES. QUESTION 445. What is the cost of operating ordinary locomotives per mile run? Answer. The average cost at the present time (1874) is from 20 to 25 cents per mile.* QUESTION 446. What items of cost are included in this, and what proportion do they each bear to the total cost? Answer. The items of cost and the percentage of each to the whole expense of operating locomotives, and also to the total of all the expenses of operating locomotives are given in the following table: 1U llll P-'o P, P-C4 Fuel................0 cts. 0.30.03 Oil and waste........... 0.4 cts. 0.02.004 Wages of locomotive runners and firemen 6.0 cts. 0.3..06 Repairs of locomotives...... 7.0 cts. 0.35.07 Cleaning locomotives...... 0.6 cts. 0.03.006 Total............. 120.0 cts. 1.00.20 From this table it will be seen that the locomotive * Deducting 10 per cent. from this amount will give very nearlv the gold value of the cost. The figures given above represent the cost in the depreciated promises to pay of the United States Government. Performance and Cost of Operating. 449 expenses are 20 per cent. of the whole cost of operating railroads. This cost of course varies under different circumstances. The above is probably somewhat lower than the average cost in this country. QUESTION 447. How many miles do locomotives ordinarily run per ton of coal and per cord of wood? Answer. This also varies greatly under different circumstanc3s. An average taken from the monthly reports of 52 different roads gives 38 miles run per ton of coal, and an average from the reports of 16 roads gives 471 miles run per cord of wood. No deductions should, however, be made from this of the relative value of wood and coal for fuel, because the trains which are run with wood for fuel are usually lighter than those hauled with coal-burning engines. The above figures are the average results during the month of May, 1871, of all the trains on the roads from whose locomotive reports it has been compiled. The following report of experiments, which were carefully made by the writer, will give the performance of a locomotive when great care is taken to produce good results. It should be stated, however, that the engine with which these experiments were made had been in service eighteen months, without receiving thorough repairs, and that the boiler at times primed badly, so that the rate of evaporation of water per pound of coal is not a fair indication of the performance of the engine in that respect. The coal used was known as Brazil coal, from Indiana, and in order to compare the performance of two engines only lumps of coal were used, so as to leave no room for question regarding the relative amount of fine coal used by each engine. The maximum grades on the road on which the 38* 450 Catechism of the Locomotive. experiments were made were 30 feet per mile, and the total ascent from the lowest to the highest point on the road was 374 feet. LOCOMOTIVE EXPERIMENTS. 1873. 1873. 1873. Date of experiment.July 21. July 28. August 2. Number of miles run.145 145 1-15 Number of cars hauled..... 41 31t 41 Total weight of cars, lbs......1,497,240 1,119,650 1,508 860 q'Ttal amount of coal burned, lbs.. 8.676 5,102 7,221 Total am'nt of water consumed. lbs. 63.531 45.719 52,609 Water evaporated per lb. of coal, lbs.. 7.32 8.02 7 04 Miles run per ton (of 2,000 lbs.) of coal. 33.4 50 8 38 8 Coal consumed per car per mile, lbs. 1 45 1.13 121 Average speed, including stops, miles. 11.1 13 13 8 QUTESTION 448. How can we determine the speed at which an engine is running? Answer. In the absence of any special instruments for the purpose, BY COUNTING THE NUMBER OF REVOLUTIONS OF THE DRIVING-WHEELS PER MINUTE, THEN MULTIPLYING THE LENGTH OF THEIR CIRCUMFERENCE IN INCHES BY THE NUMBER OF THEIR REVOLUTIONS PER MINUTE AND THE PRODUCT BY 60, AND DIVIDING THE LAST PRODUCT BY 63,360. THE QUOTIENT WILL BE THE SPEED IN MILES PER HOUR. Thus, supposing driving-wheels which are 611 in. in diameter, and whose circumference is therefore 193.2 in., should make 164 revolutions per minute, then 193.2 X 164 X 60. 63,360 =30, (nearly) miles per hour. PAiRT XXV. WATER-TANKS AND TURN-TABLES. QUESTION 449. How are locomotive tenders or tanks supplied with water? Answer. At suitable points, called water stations, along the line of the road, large tanks or reservoirs are Fig. 225. Scale 1 in = foot. the latter, or else the water is pumped in, leither by hand or by horse, wind, water or steam power. 452 Catechism of the Locomotive. These tanks are usually, when there is room for them, located near the track, as shown in fig. 225, so that the water can be conducted by a spout, a, direct from the tank to the man-hole of the tender. Communication to and from this spout is opened and closed by a valve, b, inside of the tank. The spout is usually attached to the tank by a hinged joint, so that it can be lowered to the tender and then raised up out of the way of the engine and train. It is generally balanced by a counterweight, suspended to one end of a rope, which passes over apulley and is fastened to the spout at the other end. Such tanks are now generally made of wooden staves like a tub or pail, and supported on a heavy frame, c c c, made of wood, as shown in the engraving, or on stone or brick masonry. Fig. 226. Scale 1 in.=1 foot. When there is no room for the tank or reservoir near the track, it is placed in any convenient position at some distance from it, and the water is then conveyed by an underground pipe to the place where the locomotive must take water. At the end of this pipe what is called a water-crane, fig. 226, is located. This consists of a vertical pipe, A, with a horizontal arm, B, which is made so as to swing around over the manhole of the tender when the latter is to be filled with Water-Tanks and Turn-Tables. 453 water. In some cases the horizontal arm alone swings around, but in others the vertical pipe turns with the horizontal one in a joint, C0, underneath the surface of the ground. The latter plan is thought to be preferable to the first, as the pipe is less liable to freeze fast in the joint when the latter is underground than when it is exposed above. A suitable valve, D, is also attached to the pipe below ground, so that the stream of water can be turned off or on at pleasure by the wheel E. QUESTION 450. What considerations should determine the source from which a supply of water should be drawn? Aisuwer. The first must of course be its convenience to the point where the water is to be used; but more attention should be given to the quality of the water than it ordinarily receives, as the use of impure water, or that which contains a considerable amount of mud or solid matter mixed with it, or in suspension as it is called, or has lime or other mineral substances chemically combined with it, will very soon coat the inside of the boiler with a covering of scale, which is a very bad conductor of heat, and consequently the boiler is much less efficient and much more heat is wasted than if the heating surfaces were clef. Besides this loss of efficiency, when boiler plates are covered with non-conducting scale, they are much more liable to be injured by thie action of the fire than when the water comes directly in contact with the metal of the plates. Some water, too, has a corroding effect on the metal of the boiler which is very destructive. QUESTION 451. How can the relative amount cf in 454 Catechism of the Locomotive. crustating substances in different kinds of water be determined? Answer. The relative quantity of solid matter or mud which is held in suspension can be at least approximately determined by simply filling vessels, say large clear glass bottles, with different kinds of water and letting them stand for some time until the solid matter settles to the bottom. An easy method of precipitating the lime and some other salts which are held in solution and which will not settle until they are converted into a solid form is the following: Dissolve in a goblet of pure water (distilled or freshly caught rain water) two or three teaspoonfuls of the oxalate of ammonia. Have equal quantities, say a goblet-full of each of the waters to be tested, ranged side by side and marked so as to be identified. Into each of these goblets stir equal quantities of the solution nientioned-about three teaspoonfuls will be enough-and let them stand for a day. The lime and some other salts will be precipitated and fall to the bottom as a powder; and the quantity of this precipitate in each glass will form a very good index of its relative injuriousness in the formation of scale. When the oxalate of ammonia cannot easily be procured, an experiment may be tried, in the same way, by dissolving common white soap, or other pure soap, in a goblet of pure water, and then stirring into the glasses of water to be tested a few teaspoonfuls of this solution. The comparative amount of lime in the water will be shown by the amount of coagulated matter which will be thrown down.* *Correspondent of the Railroa(l (Xazette. Water- Tanks and Turn- Tables. 455 QUESTION 452. How are locomotives tarned around on the track? Answer. The most common means employed for that purpose is a turn-table, fig. 227. This consists of two heavy beams made of wood, east or wrought iron, placed side by side and resting on a pivot in the centre, on which they turn. They are placed in a circular pit below the level of the track, so that when rails are laid in the ordinary way on top of the beams they will be exactly level with the track which leads up to the pit. By turning the beams on the central pivot so that the rails will come exactly in line with the perinanent track which leads up to the pit, the locomotive can be run on the turn-table, which is then revolved a half-revolution, which of course reverses the position of the locomotive and brings it opposite Fig. 228. Scale A in.=1 foot. the permanent track so that it can be run off from the table. In order to prevent the beams from tipping down when the engine first runs on or off of the turntable, wheels are placed at their outer ends which run on a circular track and bear any inequality of weight that may be thrown on them if the locomotive is not equally balanced on the central pivot. QUESTION\ 45 —3. How is the central pivot constructed? Fig. 227. Scale A, incifli root. 50-FooT TURN-TABLE, BY W' ILLIAMK SELLERS & CO.. PHILADELPHIA. 1 co~~~~~~~~~~~~~~~~~~o ie k139';O 458 Catechism of the Locomotive. Answer. It usually consists of a vertical post, A, shown in fig. 228, which is a transverse section through the centre of the turn-table, the end of which rests on hard cast iron or steel bearings. In some cases, as shown in figs. 227 and 228, which represent a turntable built by William Sellers & Co., of Philadelphia, the weight rests on conical steel rollers, m m, which revolve in a circular path formed in the top plates. Sometimes turn-tables are fitted with gearing and cranks, D, fig. 228; but if they are made so that the whole weight rests on the centre, and if they are of sufficient length so that an engine and tender can be moved on them sufficiently to be balanced over the centre, gearing will not be needed; but a simple lever fastened to the turn-table will be all that will be required to turn the table and the engine and tender on it.'rhe tables should be of such a diameter or length across the centre as will enable the class of engine in use on any road to be balanced. With light engines the 50-feet table is large enough; with the long, heavy engine now used on the great trunk lines, the engine and tender quite fill up the entire length of 50 feet, leaving no margin for adjustment. In such cases, the 54 feet, 56 feet, or, better, the 60 feet, should be employed. These large tables are also made heavier in proportion. The table should be of such a length that engines, with tender either empty or full, when run on the table can be so placed as to bring the centre of gravity immediately over the centre. When so balanced, one man can turn the loaded table with ease. In setting up turn-tables it is necessary that the foundation at centre, upon which the pivot rests, should be of the most substantial character, so as not to Water- Tanks and Turn-Tables. 459 be liable to settle. The circular track, which may be made of light rails, say 28 or 30 lbs. to the yard, should be level, and the table should be so adjusted as to swing clear of the circular track when loaded. The pit required is quite shallow near the edge and deepens towards the centre. Provision is made for covering the entire pit by a platform turning with the table, but this should be avoided whenever possible, as the best constructed cover does offer some resistance in turning. Even in roundhouses, where a covered pit might be considered preferable as presenting a smooth floor for crossing in any direction, it has been found advisable, in view of the greatest ease in turning and the facility offered by the open pit for cleaning, to dispense with the cover. The centre upon which the table turns is constructed of the best cast steel, and consists of conical rollers of steel between two steel plates grooved out to receive these rollers. This part of the table must be kept clean and well oiled, say with best sperm or lard oil and tallow of such a consistency as not to harden in cold weather. The top cap at centre is held in place by a circle of bolts. These bolts take the entire weight of the table and load; by slacking off the bolts the table can be lowered on the wheels on the circular track and the cap lifted off to gain access to the plates and rollers. These should be opened, examined and cleaned at least once every three months. Under the cap and between it and the top of the centre box are segments of wood. These can be altered in thickness to bring the table in proper adjustment. If the centre foundation settles, these segments should be thinned sufficiently to enable the table to 460 Catechism of the Locomotive. be screwed up to a proper height. With proper care such tables are practically indestructible.* QUESTION 454. Is there any other method of turning locomotives? Answer. Yes; what is called a Y is sometimes used. This consists of a system of tracks laid somewhat in the form of the letter Y, as shown in fig. 229, in which A B is the main track, with two curves, C and B C, laid as shown. If now it is desired to turn a locomotive which is standing in the position of the dart A, it is run on the curve A C to the position of the darts a and C. It is then run backward from C on the curve C B, as represented by the dart b, and when it reaches the main track in the position of the dart B it is evident that its position will be reversed, as is shown if we compare the direction of the dart A with that of B. * Wm. Sellers & Co.. PART XXVI. INSPECTION OF LOCOMOTIVES. QUESTION 455. What are the principal divisions of the work of operating or running a locomotive? Answer. They are: 1. Inspection and lubrication; that is, an examination of the parts to see that they are in good working order, and the application of oil to the journals and other parts subjected to wear. 2. Setting the engine in motion and starting the locomotive and train. 3. Management while running. 4. Stopping the engine and train. 5. Laying up. 6. Management in case of accident. 7. Cleaning the engine. QUESTION 456. When the locomotive is inspected, what should be especially observed about the boiler? Answer. In the first place, all new boilers should be tested by pressure before being used, and ALL boilers, whether new or old, SHOULD BE TESTED PERIODICALLY. The oftener the better. The ways of applying the pressure test are: 1, the cold-water test, that is, by filling the boiler with cold water and then forcing in an additional quantity with a force-pump so as to raise the pressure to that at which it is intended to test the boiler; 2, the warm-water test, by filling the boiler entirely full of cold water and then kindling a fire in the grate so as to warm this water. As water expands about one twenty-fourth in rising from 60 to 39* 462 Catechism of the Locomotive. 212 degrees, the rise in temperature will cause a corresponding increase in pressure; 3, by steam pressure. If the latter method were not so commonly used, it would seem the height of madness to test a boilerwhich is neither more nor less than an attempt to explode it-in the shop where it is built or repaired, and where the results of an explosion would be more disastrous and fatal than anywhere else, in order to see whether it will explole when put into service on the line of the road. The danger of explosion is also increased at such times by hammering and caulking at leaky rivets and joints.+ It would seem, therefore, very much more rational to test boilers first by hydraulic pressure. For a first test this is preferable, because cold water will leak through crevices which would be tight when the boiler is heated, so that leaks can be more surely detected with cold than with warm or hot water. It is, however, doubtless true that boilers are often strained muchl more by the unequal expansion of the different parts than by the actual pressure. It is therefore thought that after the hydraulic test has been applied the second or wari-water test should be used. This can be easily done, as the boiler must be filled full of water for the first test. When the boiler is subjected to the test pressure, it should be carefully examined to see whether any indications of weakness are revealed. Any material change of form or any very irregular change of pressure is indicative of weakness The flat stayed surfaces should be carefully examined by applying a straight edge to them before and after they are subjected to pressure, * \Wilson on Boiler Colnstruction. Inspection of Locomotives. 463 to see whether they change their form materially. One of the greatest dangers and most common accidents to locomotive boilers, as has been pointed out in a previous chapter, is the breaking of stay-bolts, to detect which, a locomotive runner and master mechanic should exercise constant vigilance. While the pressure is on, the outside surface of the boiler should be thoroughly examined with slight blows of a hammer, which will often reveal a flaw in the metal or a defect in workmanship. After the hydraulic and warmwater tests hlave been applied, the boiler should be emptied, and the inside examined carefully to see whether any of the stays and braces have been broken or displaced by the test. After this hlas been done, and not until then, should steam be generated in the boiler. In making the latter test it would doubtless be more safe to employ a pressure somewhaut lower than that employed with the cold and warm water. There is great diversity of opinion regarding the maximnum pressure which should be employed in testing boilers. It is doubtless true that a weak boiler might be injured and thus made dangerous by subjecting it to a very severe pressure, while without such a test it would lhave been safe. Recent experiments have indicated, however, that in most cases the ultimate strength of material is actually increased by subjecting it to a strain which even exceeds the elastic limit, provided such a strain is imposed only a few times. Although no absolute rule can be given to govern all such cases, it is thought that for the. hydraulic and warm-water tests, a pressure about 50 per cent. greater and for the steam test 25 per cent. greater than the maximum working pressure should be employed. 464 Catechism of the Locomotive. Before old boilers are tested, they should be very carefully examined, both inside and outside, to see whether they are injuriously corroded. It is to be regretted that the insides of locomotive boilers are usually made so difficult of access that it is impossible to discover the extent and the effects of corrosion without the most careful examination. This is not possible without getting inside of the boiler. Whenever this can be done, a prudent locomotive runner should use the opportunity of inspecting the boiler of his engine himself, and not depend upon the boilermakers who are employed for that purpose. He should remember that it is his life and not theirs which is exposed to danger by any weakness or defect in the construction of the boiler of the locomotive which he runs. Before starting the fire in a locomotive, the fire-box should be carefully examined to see if there are any indications of leaks, which will often reveal cracked plates, defective stay-bolts or flues. If the latter simplyleak at the joints, they can generally be made tight by caulking or the use of the tube expander. This is easily done when the engine is cold, but if not attended to may be very troublesome on the road. Leaks at other parts of the boiler should be examined, as they may reveal dangerous fractures. It is of the utmost importance, both for safety and for economy of working, that boilers should be kept clean, that is, free from mud and incrustation. In some sections of the country, especiallyin the Western States, this is the greatest evil against which locomotive runners and those having the care of locomotives must cntend. The cures which have been proposed Inspection of Locomotives. 465 are numberless, but that which is now chiefly relied upon is, first, the use of the best water that can be procured, and second, frequent and thorough washing out of the boiler. QUESTION 457. What sort of examination should be given to the boiler attachments? Answer. It should be observed whether the gratebars or drop-doors of the grate are properly fastened, and whether the ashes have been cleaned out of the ash-pan, and also whether the fire is clean, that is, whether the grates are free from cinders or clinkers. The height of water in the boiler should be observed by testing it with the gauge-cocks and by noticing it in the glass gauge, if one of the latter is used. It is also well to blow out the sediment and mud fromn the latter before starting, and to see that the valves which admit steam and water to the glass are open. They should, however, be opened only a very short distance, so that only a small quantity of steam or hot water will escape in case the glass tube should be broken. The injector, if one is used, should be tested to see that it is in working order, and as soon as the engine starts out of the engine house both of the pumps should also be tested, in order to see whether they are in good working condition. The safety-valves should be raised, so as to be sure that they are not ruste(d or otherwise fastened to their seats. There is no part of a locomotive more liable to disorder than the steam gauge. For this reason it should be frequently tested, and whenever there is any indication of irregularity in its action it should be examined. As the wire netting on the smoke-stack often has holes cut into it by the action of the sparks, it should be frequently ex 466 Catechism of the Locomotive. amined to see whether it is in good condition. It is also liable to be " gummed up," especially if too much oil is used in lubricating the cylinders and valves. As soon as holes are cut into the netting there is danger that the sparks which escape will set fire to the combustible material near the track, and if the netting is gummed up the draft will be obstructed and the engine will not make steam. The gummy matter can often be removed by building a wood fire on top of the netting. In this way the oil in the gummy matter is burned up, which leaves a dry material which can then, at least to some extent, be beaten out of the netting. QUESTION 458. How can it be known whether the pumps are working well? Answer. Their operation is indicated by the force of the stream which escapes from the pet-cock when it is open. When the pump is in good condition the water begins to escape promptly in a strong stream as soon as the pump-plunger begins its inward stroke, and continues to escape until the plunger completes its stroke. If the pump is not in good condition, this escaping stream is weak and is apt to continue during the outward stroke of the pump-plunger. It is difficult to tell, however, when the engine is running slowly, whether the pump will work well at higher speeds, and therefore a locomotive runner should always test the condition of the pumps during the previous run. QUEsTION 459. Fheat should be noticed in connection with the throttle-valve? Answer. As a failure of the throttle-valve to work. may be the cause of a most serious accident, it should Inspection of Locomotives. 467 be certain that it is in good working condition, that all the bolts, pins and screws and other accessories are in good -working order. It should also be known whether the throttle-valve is steamntight. This can be learned -by observing whether steam escapes from the exhaust-pipes- or cylinder-cocks when the latter are open, the reverse lever in full gear, and the throttle-valve closed. If the throttle-valve leaks, enough steam may accumulate in the cylinder, when there is no one on the engine, to start it, and in this way cause a serious accident. The throttle-lever should always be fastened with a set-screw or latch of some'kind when the engine is standing still. QUESTION 460. In inspecting the cylinders, pistons, guides and connecting-rods, to what points should the attention be directed? Answer. It should be known whether the piston packing is properly set out, that is, whether it is so tight that it will not "blow through," or leak steam from one end of the cylinder to the other, which of course will waste a great deal of steam. Of the two evils, it is, however, better to have piston-packing too loose than too tight, because if it is too tight, it is liable to cut or scratch the cylinders so as to make it necessary to rebore them, and at the same time if the packing-rings are lined with Babbitt metal, the heat created by the intense pressure and friction will melt the metal. In some cases the cylinders become heated to so high a temperature from this cause that the wood-lagging with which they are covered on the outside is burned. The packing of the piston-rods should be steamtight, and' it should be observed whether the rod and 468 Catechism of the Locomotive. the pump-plunger are securely attached to the crosshead. The utmost care must be exercised to keep the guides well oiled. The oil cups on the guide-rods or cross-heads, when they are placed on the latter, must be kept clean, so that the oil will flow freely, and yet not too rapidly, on the surfaces exposed to friction. The same thing is true of the oil-cups on the connectingrods. Attention should be given to the brass bearings of the connecting-rods to see that they are not so loose as to thump, nor keyed so. tight on the crank as to be liable to hbeat. The latter can be easily known by moving the stub-end lengthwise of the journal. They should never be so tight that they cannot be thus moved with the hand. Especial attention should be given to seeing that all the bolts and nuts on the connecting-rods are tight. There are no parts of a locomotive which require more careful attention in order to keep them lubricated, and thus prevent them from heating and being "cut," than the bearings on the crank-pins and the slides of the cross-head. Examination should be made to see that neither the piston-rods, pump-plungers, guides, connecting-rods nor crank-pins are bent or sprung. QUESTION 461.'How can it be known whether the piston-packing is too loose or'" blows through? " Answer. It can usually be noticed in the sound of the exhaust, which can be heard very distinctly on the foot-board when the furnace door is opened. If the packing is not tight, it produces a peculiar wheezing sound between and after each discharge of steam. If the packing leaks, it will also be indicated by the escape of steam from both the cylinder-cocks, if they are ~ Inspection of Locomotives. 469 open, just after the crank passes the dead point. This will usually show in which of the cylinders the packing is too loose. The same thing will occur, however, if either or both of the main valves leak, so that it is often hard to determine whether the " blow " is due to a leak from the valve or from the piston. Of course, it may sometimes happen that both leak, or that the piston on one side and the valve on the other-leak, so that often the diagnosis of the disease, as the doctors say, is extremely difficult. Careful observation and experience will, however, aid a locomotive runner in detecting such defects much more than any directions which can be given here. QUESTION 462. What is meant by " setting out packing," and how should it be done? Answer. " Setting out packing " is simply expanding the rings when they get too loose. With ordinary spring packing, figs. 96 and 97, which is now generally used, this is done by screwing up the nuts b, b, b, which, as was explained in answer to Question 169, compresses the springs a, a, a, and thus expands the rings A, A. In doing this, as already stated, great care must be exercised not to screw the nuts up too hard, and it is always better to have the packing too loose than too tight. - Care must also be taken to keep the piston-rod in the centre of the cylinder, otherwise there will be undue pressure and wear on the stuffingbox. After the nuts are screwed up, the position of the piston-head should be tested with a pair of callipers. This is done by placing one leg of the callipers against the side of the cylinder, and setting them so that the other leg will just touch the edge of the projection E, fig. 96, or the end of the piston-rod. Then 40 470 Catechism of the Locomotive. by placing the callipers above and' below, and on each side of the piston, it will appear whether it is too high or too low or too near either side; then by loosening the nuts on one side and tightening them on the other it can be moved to a central position. Ordinarily this work is intrusted to persons who are employed for the purpose. A young locomotive runner, fireman or mechanic will, however, always do well to familiarize himself with such duties, and, if possible, do it himself, under the direction of those who are skilled in that kind of work. QUESTION 463. If the stuffiny-box of the piston-rod leaks, what should be done? Answer. If the packing in it is in good condition, it can usually be made tight by simply screwing up the gland. In doing this, the nuts on the bolts should not-be screwed up more than is'necessary to make the packing steam-tight. Any greater pressure only increases the friction on the piston-rod unnecessarily. In doing this, the two bolts must be screwed up equally, otherwise the gland will be " canted," that is, inclined so as to "bind " or bear unequally and very hard against the piston-rod, and thus be liable to cut or scratch it. After packing has been in the stuffingbox a long time, it becomes very hard and compact, and sometimes partly charred. Then either it must be removed and new packing be put in, or, if in tolerably good condition, it can often be made to work well by simply reversing it, that is, by putting that which was at the bottom of the stuffing-box on top and vice versa. Before packing is put into a stuffing-box, the former should always be thoroughly oiled. Inspection of Locomotives. 471 QUESTIoN 464. WMien the slides of the cross-heads wear, how is the.lost motion taken ziup? Answer. When there are gibs on the cross-head,,the lost motion can be taken up by putting " liners" or " shims," that is, thin pieces of metal, between them ~and the cross-head, so that they will fill up the space between the guide-bars. When there are no gibs, the guide-bars must be taken down, and the blocks between them at each end must be reduced in thickness so as to bring the bars nearer together. In doing this, ~great care must be taken that the guides are accurately " in line" with the centre line or axis of the ~cylinder. This work should never be intrusted to any excepting skilled workmen, from whom those who are inexperienced should seek instruction. QUESTION 465. Wlhen the brass bearings of the connecting-rods become too loose on their journals, what should be done? Answer. They must be taken down, and the two surfaces in contact must be filed away so as to bring them closer together. In doing this they must be filed square with the other surfaces. otherwise they will not bear equally on the journals when they are keyed up. Before attaching them permanently to the rods, they should be keyed on the journal in the strap alone, so that it can be known by trial whether they move freely and yet are tight enough to prevent thumping on the journal. When they are attached to the rod, it is very important, especially with coupling or parallel-rods. that the correct length from centre to centre of the bearings be maintained. It is much better to leave coupling-rods loose on their journals, because, if the bearings are keyed up tight, the rods are 472 Catechism of the Locomotive. sure to throw an enormous strain on the crank-pins, as the distance between the centres of the axles is not always absolutely the same, owing to the rise and fall of the axle-boxes in the jaws. It is therefore always best to have a little play in the coupling-rods, and it is safe to say that much more mischief is done by meddling with the coupling-rod brasses than by neglecting them. QUESTION 466. What part of thle valve gear should receive attention when the engine is inspected? Answer. All the bolts, nuts and keys should be carefully examined to see that they are properly fastened. The bolts and nuts in the eccentric straps are especially liable to become loose, and as they are between the wheels, and therefore not easy of access, are often neglected. The oil-holes should all be seen to be clear, otherwise it will be impossible to keep the journals well oiled. The eccentric straps and the link blocks are very liable to be imperfectly oiled, and when the former become dry and cut, they throw a great strain on the eccentric-rods, which is liable to break them. When this occurs the strap and the portion of the rod which is attached to it revolve with the eccentric, and frequently a hole is thus knocked into the front of the fire-box, which disables the engine. The valve gear is, with the exception, perhaps, of the pumps and injector, the most delicate part of the locomotive, and more liable to get out of order than any other, and should therefore be watched with the greatest care. QUESTION 467. How can it be known whether the main valves of a locomotive are tight? Answer. As already indicated, the symptoms which manifest themselves when a valve leaks are very sim Inspection of Locomotives. 473 ilar to those which appear when the piston packing leaks. If the valve is moved to its middle position and steam is admitted into the steam-chest, and it then escapes from both cylinder-cocks, it is apparent that the valve is not tight. But the valve faces of locomotives usually wear concave, because the valves are worked most about half-stroke, so that they will often be tight when in the centre of the face, but will leak at the ends of the full stroke. This will become apparent by the peculiar wheezing sound, already referred to, when the engine is at work. As has been explained, it is, however, often very difficult to determine whether this sound is due to a leak at the pistons or the valves. If the packing of the valve-stem leaks, it can be remedied in the manner described for making that of the piston-rod tight. -- QUESTION 468. To what points of the running gear should attention be directed during inspection? Answer. All the wheels of the engine and tender should be carefully examined to see that they are sound. A fracture in a driving-wheel is usually apparent if the wheel is carefully examined. The condition of ordinary cast iron tender and truck-wheels is revealed on striking them with a hammer, when if they are sound they will give out a peculiar clear ring; whereas if they are fractured, the sound produced by the blow of the hammer will be dead, like that of a cracked bell. The flanges of the wheels should also receive attention to see that they are not broken, as such a fracture is not always revealed by the sound produced by a blow from a hammer. The axles too should be examined' to see that the wheels have not worked loose on the whleelseat, When this occurs it often becomes apparent by 474 Catechism of the Locomotive. the oil from the axle-boxes working through between the hubs of the wheel and the axle. This can be observed on the outside of the wheels when the bearings are inside, and inside the wheels when the bearing is outside. The springs should be examined to see that they are in good condition, and the oil-holes in the boxes must be kept clear, so that the oil can reach the bearings. The tender boxes are kept oiled by packing them with cotton or woolen waste saturated with oil. This should be taken out occasionally and renewed and the boxes cleaned. The working of the drivingboxes up and down the jaws will in time wear them so that there will be some lost motion in the jaws. This will be indicated by a thump when the cranks pass the dead point. A similar thump will, however, be produced by lost motion in the boxes of the main connecting-rod, so that it is difficult to determine, without special examination, the cause which produces the concussion. It is therefore best when an engine works with a thump at each revolution for the runner to stand by the side of it where he can touch the connecting-rods and driving-wheels, and then have the fireman open the throttle-valve so as to move the engine slowly. If the lost motion is in the connectingrods it can be felt by the jar as it passes the dead points. The same is true of lost motion in the jaws, which can be felt by touching the driving-wheels. When the jaws become worn the lost motion can be taken up by moving up one or both of the wedges. When this is done, great care must be taken to keep the centres of the driving-axles the same distance apart on both sides of the engine, and also to keep Inspection of Locomotives. 475 their centre lines square with the frames. There should always be centre-punch narks placed on the frames or guide-yokes on each side of the engine in front of the main axle, and at equal distances from its centres, so that wlheih the boxes or jaws become wornl the position of the axle call be adjusted with a trail from these mIlarks. Of course, if the main axle is square, it is easy to adjust the trailing axle from it with a tram. If the axles are not square with the frames and parallel witll each other, the engine will run towards one side or thle other of the trackl according to- the inclination of the axles. It sometimes happens that the bolts which hold up the wedges in the jaws are broken. When this occurs the wedge drops down, and of course the lbox has so much lost motion thbat it soon manifests itself in the working of the engine. These bolts, and also those which hold up the clamps on the frames at the bottom of the jaws, should be examined whlen the engine is inspected, so as to be sure they are in good condition. The bolts and nuts about both the engine and tender trucks should be watched to see thalt none are lost or work loose. The engine and tender should occasionally be lifted up from the centre plates of the truck, and the latter be lubricated with tallow. It often happens that these become dry, so that they are difficult to turn wllen the weiglht rests on them, and therefore they will not adjust thenmselves easily to the curves of the track. QuxESrToxN 469. [What otKpr parts of a locomotive shlould be examined bejore starting? Answer. It should be certain that the brakles on the tender are in good working condition, that is, that the 476 Catechism of the Locomotive. bolts, nuts and keys are all secure, the levers, rods and chains properly connected, and the shoes fastened and not too much worn. If either an atmospheric or vacuum brake is used, it should be tested before starting, to see that the pump or ejector is in good working condition. It is also well to apply the brakes to the train before starting, so as to see whether the connections are in good condition and properly connected. It is always best for the locomotive runner to examine the connections of the brake hose through the whole train himself, to be sure that they are properly made. The inside of the water-tank should also be examined occasionally, to see whether it is clean, and if not it should be thoroughly washed out. The man-hole should always be covered before starting, in order to prevent cinders and coal from falling in, which are liable to obstruct the pump valves. It is hardly necessary to say that it must always be certain before starting that there is enough water in the tank to feed the boiler until the next point is reached at which a supply can be obtained. The sand-box must also be filled, the bell rope in good condition, and if running at night the reflector of the head-light must be polished and the lamp supplied with oil and the wick trimmed so as to burn brilliantly. The locomotive runner must also see that the proper signals are displayed in front of his engine. QUESTIoN 470. What tools, etc., should every locomotive runner on the road carry Answer. A coal shovel, coal pick, long-landled hoed and poker, a pair of jacks, either screw or hydraulic, chains, rope and twine to be used in' case of accident, * These are of course not needed on wood-burning engines. Inspection of Locomotives. 477 a heavy pinch-bar for moving the engine, a small crow-bar, oil-cans with short and long spouts and another smaller one with spring bottom, a steel and a, copper hammer, a cold and a cape chisel, a hand-saw, axe and hatchet, one large and one small monliey-wrench and a full assortment of solid wrenches for the bolts and nuts of the engine, cast iron plugs for plugging tubes, with a bar for inserting them, two sheet iron pails or buckets, different colored lanterns and flags, according to the colors used for signals on the line, and a box with a half-dozen torpedoes. QUESTION 471. What duplicate parts should be carried with the engine? Answer. Keys, bolts and nuts for connecting-rods, split-keys, wedge bolts, bolts for oil-cellars of driving and truck boxes, driving and truck spring-hangers, wooden blocks for fastening guides in case of accident, blocks for driving-boxes and links, a half-dozen 4-in. bolts, from six inches to two feet long, to be used in case of accident, two extra water-gauge glasses, two glass head-light chimneys. QUESTION 472. What should be observed in lubricating a locomotive or any other machinery? Answer. The most important thing to observe is that the oil reaches the surface to be lubricated. It is of much greater importance that the lubricant should reach the right place than that a large quantity should be used. A few drops carefully introduced on a journal will do much more good than a large quantity poured on the part carelessly. For this reason all oil-cups and oil-holes should be kept clean so as to form a free passage for the oil. PART XXVII. RUNNING LOCOMOTIVES. Q UESTION 473. Before starting the fire in a locomotive, what must be observed? Answer. It must always be noticed, before kindling the fire, whether the boiler has the requisite quantity of water in it; that all cinders, clinkers and ashes are removed from the grates and ash-pan; that the grates and drop-door are properly fastened, and that the throttle-valve is closed and the lever secured. Locomotive boilers are sometimes seriously injured by building a fire in them when there is no water in the boiler. In filling a boiler it must be remembered, however, that when the water is heated it will expand, and that when bubbles of steam are formed they will mix with the water and thus increase its volume, so that after the water is heated its surface will be considerably higher than when it is cold. QUESTION 474. Ho-w should the ire in a locomotive be started? Answer. It should be started very slowly, so as not to heat any one part suddenly. Probably the greatest strains which a locomotive boiler has to bear are those due to the unequal expansion and contraction of its different parts. When the fire is started, of course the parts exposed to it are heated first, and consequently expand before the others. Now, if the fire is kindled Running Locomotives. 479 rapidly, the heating surfaces \-ill become very hot before the heat is communicated to the parts not exposed to the fire. Thus the tubes, for example, will be expanded so as to be considerably longer than the outside shell of the boiler, and therefore there will be a severe strain on the tube-plates, which will be communicated to the fire-box, stay-bolts, braces, etc. The inside plates of the fire-box will also become much hotter than those on the outside, and as it is rigidly fastened to the bar to which both the inside and the outside shells are fastened at the bottom, its expansion will all be upward, which thus strains the staybolts in that direction. As the motion due to this expansion is greatest near the top of the fire-box, the top stay-bolts are of course strained the most, and it is those in that position, as has already been pointed out, which are the most liable to break. When steel plates are used the expansion or contraction often cracks them, and sometimes, hours after the fire is withdrawn froml the fire-box, the inside plates will crack with a report like that of a pistol. It is therefore very important both to heat and cool a locomotive boiler very slowly, and the fire should always be kindled several hours before the engine starts on its run. QUESTION 475. What should be done when the locomotive leaves t]he engine-house and before the traicn is started? Answer. Before leaving the engine-house the cylinder cocks should be opened, so that all the water or steam which is condensed in warming the cylinders can escape. Before the engine is started from the engine-house the bell should be rung and time enough allowed for any workmen employed about the engine to get out of the way. This rule must be scrupulously 480 Catechism of the Locomotive. obeyed under all circumstances, and a locomotive should never be started without first giving such a signal. Without it there is always danger that some one about the engine will be hurt or killed. While running from the engine-house to the train the runner should observe very carefully the working of all the parts of his engine, and as far as possible see that they are in good working condition. The fireman should stay on the tender to handle the brake, as may be necessary, and - should assist in coupling the tender to the first car of the train. The junction with the train, especially when it is a passenger train, should be made very gently, as otherwise passengers may be injured by the shock. Before starting the runner should see himself that the engine and tender are securely coupled together, and the latter to the train, that the frictional parts are properly lubricated, as explained heretofore, that the fire is in good condition and that the requisite quantity of steam has been generated. If the steam is too low, the blower is started, which stimulates the fire. QUESTION 476. When the train is ready, how should the engine be started? Answer. After the signal to start is given by the conductor, the runner also gives a signal by either ringing the bell or blowing the whistle. The latter should, however, be used, especially at stations, as little as possible, on account of the risk of frightening horses and the shock which it produces on persons who are unaccustomed to hearing it, or are suffering from any nervous disorder. After giving the requisite signal, the runner places the reverse-lever so that the valve will work either in full gear or very near it. Running Locomotives. 481 He then opens the throttle slowly and cautiously-so as to start the train gradually. If the train is a very heavy one, it is best to back the engine so as just to " take up the slack. of the train," that is, to push the cars togetler so that there will be no space between them and thus compress the car draw-springs. When the cars stand in this way, those at the front end of tho train are started one after another, which makes the start easier than it would be if it were necessary to start them all at once. If the throttle is opened too rapidly, the driving-wheels are apt to slip, but with a very heavy train, even with the greatest care, this is liable to occur. If the train can not be started otherwise, the rails must be sanded by opening the valves in the sand-box. As little sand should be used as possible, because the resistance of cars running on sanded rails is greater than on clean rails, and thus the train is more difficult to draw after it reaches the rails to which sand has been applied. Thus the difficulty to be overcome may be increased by the means employed to overcome it. While the train is slowly set in motion the fireman and runner must ascertain by watching whether the whole train moves together, and that none of the couplings are broken in starting, and also whether ally signal is given to stop, as is sometimes necessary after the train has started. On leaving the station he should observe whether all the signals indicate that the track is clear and that the switches are set right, and also look out for obstructions on the track. Thle train should always be run slowly and cautiously until it has passed all the frogs, switches and crossings of the station yard, and not until thlen and when the 41 482 ( Catechism of the Locomotive. runner has seen that everything is in order should he run at full speed. As the engine gains in speed the reverse lever should be thrown back and nearer the centre of the quadrant or sector, so as to cut off " shorter." QUESTION 477. After the engine is started, how can it be rtun most economically? Answer. The advantage of using steam expansively hlas already been explained in Part V.; it is more economical to use steam of a high pressure which is done by keeping the throttle-valve wide open, and then regulating the speed by cutting off shorter-that is, expanding it more. If the speed is reduced by partly closing the throttle-valve, the steam is wiredrawn and, as was shown in answer to Question 59, it then produces much less useful effect than it would if it was admitted into the cylinder at full boiler pressure. It is found, however, that in many cases if the steam is cut off very short the final pressure when it escapes is so low that it does not produce blast enough to stimulate the fire, and therefore the boiler will not make enough steam. This is more liable to occur with engines which have small than with those which lhave large boilers, or when the boilers are in bad condition or the fuel is of poor quality. When it does occur it is necessary to work steam during a longer portion of the stroke, so as to increase the final pressure when it is exhausted and regulate the speed with the throttle-valve. Of course this is very wasteful, but it is often the best which can be done and pull the train, There is also another practical difficulty in uising Ratnning Locomotives. 483 steam of a high pressure and running with the throttle wide open and regulating the speed with the reverse lever alone. The link motion, as has already been explained, will not be effective in cutting off at a point below about one-quarter of the stroke. Now it often happens, even when cutting off at that short point, with light trains on a level or slightly descending grade, that the speed will be too great if the throttle is wide open and with full steam pressure in the boiler. When this is the case, it is absolutely necessary to reduce the speed either by partly closing the throttle, or reducing the pressure in the boiler. Undoubtedly if valve-gear for locomotives was so constructed that steam could be cut off effectively at a shorter point of the stroke, it would result in increased economy in the use of steam. The runner should aim to run at as nearly uniform speed as possible, and in order to do so should divide the distance between stopping points and the time given for running it into as small divisions as he conveniently can, so as to be able to tell as often as possible whether he is running too fast or too slow, and thus travel over the shorter spaces in corresponding periods of time. QUESTION 478. How should the boiler be fed? Answer. The feeding-of the boiler should if possible be continuous, and the quantity of water pumped into it should be adjusted to the amount of work which the engine is doing. Ordinarily one pump is more than sufficient for feeding the boiler, so that usually only the one on the right side of the engine, where tile runner stands, is used. The flow of the water is regulated by partly opening or closing the feed-cock. The 484 Catechism of the Locomotive. injector is commonly used only when the engine is standing still, when the pumps will not feed. In feeding the boiler it must be seen that the water is neither too high nor too low. ]f it is too low there will be danger of overheating tile crown-plates or even of an explosion; if it is too high, the steam space in the boiler is diminished unnecessarily, and will cause the water to rise in the form of a spray, and thus be carried into the cylinders with the steam, or the boiler will prime or foam, as it is called. This water, if it collects in the cylinder as already explained, may by the concussion produced by the motion of the piston break the cylinder. QUESTION 479. What is the cause of priming in a boiler. Answer. It is often caused by the difference in temperature and pressure in the water below and the steam above. Thus, if we have a boiler in which the water is heated to a temperature due to 100 lbs. effective pressure, or 338 degrees, and we then open the throttle-valve suddenly, so as to relieve the pressure on top of the water, there will at once be a rapid generation of steam in the water which will rush to fill the space from which the steam has been drawn. This newly generated steam will be forme: at the hottest part of the boiler first, that is, next to the heating surface. It will therefore happen that as soon as the pressure is relieved, bubbles of steam from all parts of the heating surface of the boiler will low to the point at which the steam escapes. The motion of these bubbles will be so rapid that large quantities of water will be carried with them. The same thing will also occur if the heat of the water is increased very rapidly. BRunning Locomotives. 485 The water will then become hotter than the temperature due to the pressure of the steam above it, and consequently there will be a rapid formation and escape of bubbles of steam from the water, which will thus have the same effect as they would have if the steam pressure was reduced. The amount of water carried up with the steam is increased if the escape of the latter is obstructed in any way, owing to imperfect circulation of water in the boiler, or by floating impurities, such as oil, on the surface. When this condition of things exists, the ebullition is, as it were, convulsive, and the water is thus carried up with the steam when it escapes. Priming is also probably due in some measure to the flow of steam over the surface of the water to the point of outflow,* carrying particles of water with it just as a high wind will, when blowing over the crests of the waves of the sea. When steam is drawn, as it usually is in locomotives, from the top of the dome to which the safetyvalves are attached, the tendency to prime is very much increased when they are blowing off, so that some engineers advocate the use of two domes, from both of which the supply of steam is sometimes drawn, and in other cases the safety-valves are mounted on one, and the steam-pipe is placed in another dome. Whenever the safety-valves begin blowing off steam, the pressure in the boiler should be reduced as soon as possible, not only because when they are blowing off it tends to produce priming, but because the steam which escapes from them is wasted. The pressure can be most economically reduced either by increasing * Wilson on Steam Boilers. 41* 486 Catechism of the Locomotive. the amount of water which is fed into the boiler or by opening the heater cocks and allowing the steam to escape into the tank and thus warm the water. If the boiler is too full, the former method cannot be employed, and in heating the water in the tank the runner must be careful not to get it too hot, because in that case neither the pumps nor the injectors will work satisfactorily, and the paint on the tenders is also liable to be blistered and destroyed by the heat. By feeling the tank with the hand it can soon be discovered whether the water is too hot. If the steam pressure cannot be reduced in any other way, the furnace door must be partly opened. The use of muddy water will also sometimes cause a boiler to prime. It is probable that priming is sometimes due to the formation of foam on the surface of the water, and therefore all priming is often called fowaning; whereas it is thought that often a boiler will prime when the water does not foam. More accurate information regarding the priming of boilers is, however, much needed, as many of the phenomena have thus far not been satisfactorily explained. The principal causes of priming in ordinary practice are, however, undoubtedly owing to defective circulation, too little steam room, impure water, or too much water in the boiler. QUESTION 480. How can it be known whether an engine is priming, and what should be done to prevent it? Answer. The priming of a boiler can be known by the white appearance of the steam which escapes from the smoke-stack and the cylinder cocks. Dry steam always has a bluish color. When an engine primes or works water into the cylinders, it is usually Running Locomotives. 487 indicated by a peculiar dead sound of the exhaust, which from this cause loses its distinctly defined and sharp sound.- Tliis-can be observed best when the furnace door is opened. It is also indicated by the discharge from the gauge-cock, as the water which then escapes from the lower cocks is mixed with steam, or, as runners say, is not " solid," and the steam from the upper cocks is not clear, but mixed with water. To use a phrase employed by practical men, the priming or foaming of the boiler may be known by the "flutter" of the gauge-cocks. As soon as there are any indications of priming, foaming, or that water is working into the cylinders, the cylinder cocks should be opened at once, otherwise the cylinders, cylinder heads or pistons may be broken. The throttle-valve should be either partly or entirely closed. When the latter is done the foaming will in most cases cease for the time, so that the runner can tell how much solid water there is in the boiler. If he finds that the boiler has too much water in it. it is best to shut off the pumps, and in many cases the blow-off cock is opened. The latter is, however, attended with some danger, because if any obstruction should get into the blow-off cock, or it should stick fast, so that it could not be closed, all the water would escape from the boiler, and with a heavy fire in the fire-box there would be great danger of overheating, and thus injuring the boiler or of "burning" it, as it is ordinarily termed. A much better method of affording relief in such cases is to place what is called a surface-cock in the back end of the fire-box, about half way between the upper and lower gauge-cocks. WVith such a cock, the water can be blown off from the surface instead of 488 Catechism of the Locomotive. from the bottom. As foaming or priming is often caused by oil, or other floating impurities on the surface, they can be blown out of the boiler with this arrangement, whereas, if the water escapes from the bottom of the boiler, the floating impurities will always remain after it is blown off. A perforated pipe, which extends for some distance along the surface of the water inside the boiler, is sometimes attached to the surface-cock, so that the water which is blown off will be drawn from a number of points along the surface. If the steam is rising rapidly when foaming begins, it will be well to cool the boiler off by opening the furnace door part way. This means of relief should, however, be used as little as possible, because there is always danger of causing the tubes or other parts of the boiler to leak, by either heating or cooling suddenly or rapidly. If the engine primes when there is but little water in the boiler, and at a time when the steam is rising rapidly, it may sometimes be remedied by increasing the amount of feed-water, and thus partly cooling the water inside. The use of pure water, careful firing so as to keep the steam pressure regular, feeding the boiler so that the level of the water will be nearly uniform, and then starting the engine carefully, that is, opening the throttle-valve gradually, are the most effective means in practice of preventing a locomotive boiler from priming. QUESTION 481. What is the economical effect of priming on the consumption of:fuel in locomotives? Answer. It causes a great waste of heat, first by the escape of that contained in the hot water which passes through the cylinders and which does no work, and Running Locomotives. 489 second, when steam is mixed with a great deal of water, it will not flow either to or from the cylinders as quickly or easily as dry steam will. Consequently the initial pressure on the piston, if the engine is running. even moderately fast, and is cutting off short, will not be so great as it would be if dry steam was used. Wet steam is also more difficult to exhaust from the cylinder than that which is dry, and therefore the back pressure on the piston is greater when the boiler primes than when dry steam alone is used. QUESTION 482. When running on the open road, what should the locomotive runner observe? Answer. Either he or the fireman should constantly watch the track in front of them, and also observe, from time to time, whether the train of cars, especially if it is a long one which he is handling, is in good condition. HE MUST OBSERVE EVERY SIGNAL SCRUPULOUSLY, AND SHOULD NEVER PASS ONE UNTIL HE IS SURE THAT HE IS AUTHORIZED TO DO SO. The well-known maxim, "be sure you are right; then go ahead," should be changed for locomotive runners to, DON'T GO AHEAD UNTIL YOU ARE SURE YOU ARE RIGHT, AND WHEN IN DOUBT ALWAYS CHOOSE THE SIDE OF SAFETY. In running through curves, the speed of the train should always be moderated in proportion to the sharpness of the curve, and before reaching it. In running through curves, the tendency of the train is to continue in a straight line, and there is thus danger of running off the track. The higher the speed, of course, the greater is the resistance which is required to prevent the train from running in a straight line, and consequently the greater is the strain which is thrown on the flanges of the wheels 490 Cateehis m of the Locomotive. and on the rails' and axles. In running through curves, it is also impossible, usually, to see further than a short distance ahead, and therefore, if the train is running very fast, it cannot be stopped in time, should there be any obstruction or danger on the track. QUESTION 483. What precautions should be observed in'running over steep grades Answer. On approaching an ascending grade the runner should see that the fire is inl good condition, and as much coal should be put on it as can be burned to advantage. He should also fill the boiler as full of water as he safely can, without danger of priming, and should heat this water as hot as possible without blowing off steam at the safety-valves. The object of this is to have a supply of water already-heated before reaching the grade. If, as often happens with a heavy train, the boiler will not make as much steam as the engine consumes, if there is a large supply of hot water in the boiler it can be used as a reserve, should it be necessary to do so, without danger of injury to the boiler. If there was so little water in the boiler that it would be dangerous to allow it to get lower, then it would be necessary to feed cold water as rapidly as the hot water escaped in the form of steam. It is often impossible to heat all this cold water as fast as it is pumped into the boiler, without reducing the steam pressure until there is then not sufficient power to pull the train. If, however, there is a supply of hot water in the boiler, at the critical point on the grade, where the engine is most liable to fail, the pump can be partly shut off, and thus less water will be pumped into the boiler, and the steam pressure be maintained Running Locomotives. 491 without danger. Undoubtedly it is better to feed locomotive boilers uniformly, if that is possible, but it often happens that a reserve supply of hot water in the boiler enables an engine to pull a train up the most difficult place, whereas, without such a supply, the locomotive would stick fast. As the capacity of lo oomotives is rated on nearly all roads by the number of cars they'can "pull up the hill," of course whatever aids them at the critical point increases their capacity. It is this fact which gives engines with large boilers so much advantage over those with small ones. In running up steep grades, allowance should always be made for the effect of the inclination of the track upon the position of the water surface in the boiler, and also the fact that as soon as the throttle-valve is closed, and steam shut off, the surface of the water will be considerably lower than when the engine was working'hard. On a grade of 50 feet to a mile, the front end of the tubes of an ordinary locomotive would be about 13 inches higher than the back end of the crown-sheet. If, then, on working hard up such a grade, it is succeeded by another of'equal descent; the front ends of the tubes would be 13 inches lower than they were while coming up, so that if the back end of the crown-sheet was covered with 13 inches of'water just before reaching the top, it would be exposed to the fire as soon as the engine'reached the descent. This exposure would be dangerous, because not only would the water be 13 inches lower over the crownsheet, but it would fall considerably more, when the throttle-valve was closed. These considerations will show the danger of running the water too low while ascending steep grades. 492 Catechism of the Locomotive. In pulling trains up steep grades, especial caution should be exercised to prevent any of the cars from breaking loose from the train, because such an accident may cause great disaster. As soon as the engine reaches the top of the grade, the fireman should oil the main valves, because it can only be done when steam is shut off, as the oil will not run into the steam-chest when there is a pressure of steam in it; and as the valves are always subjected to the severest wear while pulling up a steep grade, the valves and valve-faces are apt to become dry. As saturated steam to some extent prevents valves from cutting, it is not so important that they be lubricated while the engine is working with steam, but as soon as steam is shut off they should be oiled, otherwise there is danger of their being injured by their friction on the valve-seats. In running down grades, the runner has the greatest possible cause for using every precaution, because not only is the train much more difficult to control, but usually frequent sharp curves prevent a view of the track for any considerable distance ahead. He should, therefore, watch the track in front of him with the greatest vigilance, so as to be ready to give the requisite signals to the brakemen to apply the brakes, or, if the engine and train are provided with continuous brakes, to apply the latter, or even reverse his engine, in case of danger. QUESTION 484. How should an engine be run past those stations where the train does not stop? Answer. The speed of the train should be slackened in passing stations, especially if a clear view of the track and switch signals can not be obtained at some dis Running Locomotives. 493 tance before reaching the station. There is always a possibility that the switches may be turned wrong, or that there may be some obstruction on the track at stations, so that some caution should be exercised in running past them. The proper signal, either by the whistle* or the bell, should be given on approaching stations, and also at all common road crossings. QUESTION 485. What must be done on approaching a draw-bridge or a crossing of another'railroad at the same level? Answer. In many of the States it is provided by law that all trains must come to a dead stop before crossing a draw-bridge or another railroad at the same level. Whether such a law exists or not, the rule should always be observed. After coming to a stop, the train should under no circumstances be started until the signal has been given to start the train by the signal-man at the bridge or crossing. A runner should never assume that the signal has been given, nor take another person's word for it, but should see and know it himself. In some conditions of the weather and with the light falling on a signal in certain directions, it is sometimes difficult to determine its color or form. If there is any doubt about it, the testimony of another person should always be sought. There is good reason for believing that color-blindness, that is, an incapacity for distinguishing one color from another, is a much more common infirmity than is usually supposed. It is certain, too, that people who ordinarily distinguish colors very accurately are subject to color-blindness in certain condi* The methods of giving signals vary so much on different roads that no general direction that will suit all cases can be given. 42 494 Catechism of the Locomotive. tions of health, and that it is sometimes the result of overwork or great weariness; and a case is recorded of a person who was always color-blind after a debauch. There are, therefore, good reasons- why a locomotive runner should not always place too implicit confidence in what he "sees with his own eyes," but if he has any doubt, he should take the "benefit of the doubt," which should always lead him to take the side of safety. QUESTION 486. How should the engine and train be managed in running into a station? Answer. First of all when running into a station when the train stops, the speed must be checked so that the train will not enter with very great momentum. Therefore, at a distance varying from one to three-quarters of a mile, according to the nature of the grades and track, the steam should be shut off, so that the speed will be reduced so much that the train under any circumstances will be under full control. It is always better to enter a station at too low a speed than to run in too fast, because if it is necessary, more steam can always be admitted to the cylinders to increase the speed before coming to a stop; whereas it is not so easy to stop -the train if it is. running too fast, and it becomes necessary to check it before entering.the station. This will sometimes be necessary, because it may readily happen through negligence or accident at stations that in switching cars one or more may be left standing wholly or partly, on the track, which the arriving train must run over, in which.case a collision with its terrible consequences may be unavoidable. When a train is equipped with continuous brakes, Running Locomotives. 495 the control which they usually give to a locomotive runner over the train is so great that he is apt to approach stations, crossings or draw-bridges at a high rate of speed, and rely on such brakes to stop the train. This practice is always attended with great danger, because if it was found, on getting near to the station, crossing or draw-bridge, that the track was Lot clear, and that it was obstructed by a car or train, or the draw was open, if the runner should attempt to apply the brakes and from some cause they should fail to work, as sometimes occurs, then a collision or other disaster would be inevitable, because it would be impossible to stop the train with the ordinary hand brakes. For this reason a locomotive runner should always approach such places cautiously and with his train under sufficient control, so that if he finds there is danger ahead he can stop the train with the ordinary means, or at the worst by reversing the engine. Continuous brakes should always, excepting in cases of imminent danger, be applied gradually, so as not to check the cars with a jerk or too suddenly. The practice of opening the cock which admits air to atmospheric brakes suddenly, and then turning it back again as quickly, is almost sure to produce disagreeable and dangerous shocks to the cars. The cock shllould be opened gradually, so as to check the cars slowly at first. QUESTION 487. What must be attended to when running a locomotive at night? Answer. As soon as it begins to grow dark, thle head-light must be lighted and properly trimmed, and the proper lamp signals placed in front of the engine, if the rules of the road require the display of such 496 Catechism of the Locomotive. signals. A lamp should always be placed in the cab, so as to throw its light on the steam-gauge, but not into the runner's face, because he is unable to see distanlt signals so well if his eyes are exposed to the glare of a light near him. At night, as objects which are passed can not be seen distinctly, it is more difficult to tell the speed at which an engine is running than it is in the day time. A runner should therefore consult his watch frequently, and by counting the revolutions of the wheels, which he can do by the sound of the pump valve or other part of the machinery, he can tell from the rule given in the answer to Question 438 the speed at-which the locomotive is running. From this rule a table can easily be constructed for an engine with any size of driving-wheels, showing the speed for any given number of revolutions per minute. It will be a good exercise for a young locomotive runner to construct such a table, which will be found very convenient for reference if placed in a conspicuous place in the cab. QUESTION 488. What must be attended to in very cold weather? Answer. Great care must be exercised to prevent the water in the pumps, pipes and in the tender from freezing. If it does it will be almost certain to break the pump or burst the pipes. To avoid this the heater cocks must be opened so as to keep the water in the tender warm. In excessively cold weather the engine should be run with greater caution than at other times, as iron is then more brittle, and also more liable to break, owing to the frozen condition and consequent solidity of the track. Running Locom'otives. 497 QUESTION 489. In running a locomotive in severe snow or rain-stormls, what should be observed? Answer. Whenever it snows the pilot or cow catcher should be covered with boards, or, better still, with sheet iron, so as to act like a snow plow. Brooms made of steel wire should be placed in front of the front wheels of the engine, so as to sweep the snow from the rails. The front damper on the ash-pan should be kept closed so as to exclude the snow from the ash-pan, which would soon fill it up, and in this way obstruct the draft. If the fall of snow is very heavy or it blows into drifts, the train must of necessity run very slowly, and even if a part of the track is clear of snow, it is unsafe to run fast on it, as there would be danger of throwing the engine off the rails if it should run into a heavy drift at a high speed. In severe rain storms bridges, culverts and such portions of the track as are liable to be washed away should be approached cautiously, especially'at night. In both snow and rain-storms, and also in fogs, great caution is required, owing'to the difficulty of seeing signals. QUESTION 490. What is meant by a reserve engine or "helper. " Answer. A reserve engine is a locomotive which is not employed in hauling a regular train, but is kept as a "reserve" to go to the help of an engine which may be compelled to stop on account of an accident of any kind, or to assist engines in moving trains up heavy grades, or is used in clearing away a wrecked train, rebuilding bridges or other structures. QUESTION 491. What must be observed in running a reserve engine. 42* 498 Catechism of the Locomotive. Answer. As no special arrangements are usually made in preparing time-tables* for the running of reserve, or as they are usually called by railroad men, " wild" engines, it may very probably happen that it will be called upon to assist other engines when the road is not clear, and therefore its runner must constantly be on the look-out for signals to stop, which are often given suddenly. He must switch off with special caution in order to be sure to keep out of the way of regular trains running in the opposite direction on the same track. When he reaches the train or place where the assistance of the reserve engine is needed, he must approach it slowly and carefully, in order to avoid a violent shock. On the return from the assisted train, he incurs the same danger, and must pay close attention to any signal to stop made to him by any opposite train on the same track, and also on his part warn such trains by the. proper signals. When a train is run with two engines, both in front of it, the forward one always takes the management of the train. The runner of the hind engine must be guided by the signals of the runner of the forward engine. In starting, the forward engine must be set in motion first and then the one behind it. In stopping, the steam must be shut off first in the hind engine. Likewise in decreasing the speed during the trip, the hind engine must first regulate the flow of steam. If these precautions are not observed the forward engine may easily be thrown from the track by the faster motion of the hind one. When a train is assisted by a "helper " placed be* A time-table is a table which gives the time when each train shall arrive at the stations it passes, the stations at which it shall stop, and all the regulations by which it shall be run. ]Runnig Locomotives. 499 hind the train, and therefore pushing it, the forward engine must likewise be set in motion first, and steam should be let on in the hind engine only after a signal has been given by the runner of the head engine. During the run both engines must move with the same speed.* QUESTION 492. How should switching engines be managed? Answer. In pushing and switching the freight cars in the station-yard, they should be moved carefully and severe shocks must be avoided, as the cars, the goods with which they are loaded and the persons employed about them may be injured by violent concussions. The runner must also follow the instructions of his superior strictly and cheerfully, and should examine patiently and observe with discretion the suggestions of employes who are not his superiors. In this service it is also of special importance that the runner give a distinct signal with the whistle or bell before every movement of his engine, in order to warn in time those who at such times often stand on the track in the way of the engine or cars, or the persons engaged in loading, cleaning or repairing the cars, and thus give them time to get out of the way.t QUESTION 493. In firing a locomotive, what are the most important ends to be attained? Answer. That which is of first and chief importance is to make steam enough, so that the locomotive can pull its train and "make time "J; second, it must *Katechismus der Einrichtung und Betriebes der Locomtive, by Georg Kosak. t Georg Kosak. Tlle term make time means to run at the speed indicated on the timetable. 500 Catechism of the Locomotive. make the requisite quantity of steam with the least consumption of coal, and third, with the least production of smoke, although the latter, independent of the economy of combustion, is considered of importance only with passenger trains. What is frequently lost sight of in considering this subject is the fact that with all locomotives it often happens that it is a matter of extreme difficulty to make enough steam to do the work required of the engines. When a freight train is struggling up a grade with a heavy train, or an express engine is obliged to make time under similar conditions, it often depends entirely upon the quantity of steam which can be generated in the boiler in a given time whether the engine will fail or not. In firing, therefore, the most important end to be aimed at is often simply to produce the largest amount of steam possible in a given time, even at the sacrifice of economy or by producing any quantity of smoke. Any means of economizing fuel or of smoke prevention, which reduces the steam-producing capacity of boilers, is therefore quite sure to be abandoned in time. QUESTION 494. How can a boiler be made to produce the largest quantity of steam in a given time? Answer. By burning the greatest quantity of fuel possible on the grate in that time. This can be done by keeping the grates free from clinkers and the ashpan from ashes, and then distributing the coal evenly over the grates in a layer six to twelve inches thick. The thickness of the layer which will give the best results will, however, vary with the quality of the fuel, and must be determined by experience. If the layer is too thick, not enough air will pass through it Running Locomotives. 501 to burn the coal. If it is too thin, then so much air will pass through that the temperature in the fire will be reduced. The rapidity of combustion will also be promoted by breaking up the coal into lumps the size of a man's fist or smaller. If fine coal is used it should be wet, otherwise it will be carried into the flues by the blast before it is burned or caked or even reaches the grate. Experience will indicate the amount of air which can advantageously be admitted above the fire in order to secure the maximum production of steam. The best size of the exhaust nozzles and the position of the petticoat pipe must also be determined by experience. It will usually be found, however, that if enough air is admitted above the fire to prevent smoke, it will reduce the maximum amount of steam which can be generated in a given time. The fire should also be fed regularly and with comparatively small quantities of fuel at a time, although if the feeding is too frequent there is more loss from the cooling effect which results from the frequent opening of the furnace door than is gained from the regularity of the firing. In this, too, a fireman must consult experience to guide hlim. QuESTIox 495. How can a locomotl've be fired with the least consumption of coal? Answer. Two systems of firing are practiced in this country, one known as the " banking system" and the other the " spreading system." When the banking system is employed, the coal is piled up at the back part of the fire-box, as shown in fig. 218, and slopes down towards the front of the grate, where the layer of coal is comparatively thin and in an active state of incandescence. The heap of coal behind is 502 Catechism of the Locomotive. gradually coked by the heat in the fire-box and the gases are thus expelled. Openings in the furnace door admit air which mingles with the escaping gases, which then pass over the bright fire in front, and are thus supposed to be consumed. When the "bank" of coal behind becomes thoroughly coked, it is pushed forward on the bright fire and fresh coal is again put on behind to be coked. This system of firing is practiced on some roads with good results, but it is doubtful whether it could be used successfully with coal which cakes and clinkers badly. The spreading system is most commonly employed in the Western States, where the coal contains a great deal of clinker. When this is practiced, the coal is spread evenly over the whole of the grate in a thin layer, and its success and economy depend upon the regularity and evenness with which this layer of coal is maintained and the fire fed. The thickness of the coal must be adapted to the working of the engine. When it is working lightly, the layer of coal should be thin, but when the engine is pulling hard the layer of coal must be thicker, otherwise the violent blast may lift the coal off the grates. The success of this system, as was explained in answer to Question 388, depends upon the manner in which the thickness of the fire is regulated, on the admission of the proper amount of air above the fire, and on the frequency with which the fire is supplied with coal. When this system of firing is employed not more than two shovels-full of coal should be put into the fire-box at once, and if the engine is not working hard, one or even less will be sufficient. - The firemen must, however, determine by experience the thickness Running Locomotives. 503 of fire, amount of air which should be admitted and the frequency of firing which will give the best results in practice. Doubtless these will vary with different kinds of fuel and the construction of engines. Usually the greatest obstacle in the way of producing good results is the fact that firemen would rather "take things easy" than exercise that diligence and observation which will alone insure success in any occupation. QUESTION 496. How can, smoke be most effectually prevented? Answer. The means of preventing smoke were very fully explained in answer to Questions 379 and 388. It may be said briefly that this can be done only by properly regulating the supply of air which is admitted to the fire. The means of doing this have already been explained. QUESTION 497. What method of fring is employed when anthracite coal is used? Answer. The spreading system alone is then used. QUESTION 498. How may the rules which firemen should observe when bituminous coal is used be briefly stated? Answer. 1. Keep the grate, ash-pan and tubes clean. 2. Break the coal into small lumps. 3. Fire often and in small quantities. 4. Keep the furnace door open as little as possible. 5. Consult the steam gauge frequently, and maintain a uniform steam pressure, and if necessary to reduce the pressure do it by closing the ash-pan dampers rather than by opening the furnace door. QUESTION 499. On arriving at a station where a train stops longer thani a few m/inutes, what should the lMcomiotive runner and fireman attend to? 504 Catechism of the Locomotive. Answer. The runner should examine thoroughly all the parts of his engine, as has been heretofore explained. He should especially examine all the journals and wearing surfaces to see whether they are hot. This he can discover by feeling them. If any of them have become very much heated, they must be cooled by throwing cold water on them, and then thoroughly oiled. In oiling a hot journal mineral oil should never be used, as it is easily evaporated by the heat and then takes fire. Animal oil should therefore always be used on a hot bearing. The working parts should be thoroughly lubricated, as already explained. F The fireman should examine the tank and see whether it is necessary to take in a fresh supply of water. He should then examine the grates and ashpan, and clean the cinders and clinkers from the former, and the ashes from the latter. Neglecting to clean the ash-pan may result in melting and destroying the grate-bars, and by obstructing the admission of air to the grates the ashes prevent the combustion from being as complete as it would be otherwise. With some kinds of fuel it is necessary to clean the tubes frequently, which must often be done at stations where the train stops. During the stop, as thorough an inspection of the engine should be made by the runner and fireman as the time will permit; but any unnecessary waste of time must be avoided, and the firing should be so managed that-nothing need be done about it during the halt at the station. On starting again the same precautions should be exercised as on making the first start. QUESTION 500. After reaching the end of its run, how should an engine be cleaned and repaired? Runniing Locomotives. 505 Answer. Before reaching the last station the firing should be so managed that there will be. as little fire as possible remaining in the fire-box at the end of the run. After the arrival the engine should be run over a pit which is usually provided for the purpose, and the fire should-, be raked out of the fire-box by dropping the drop-door if there is one to the grate, or turning the grate-bars edgewise, or withdrawing one or more of them if it is necessary to do so. In this way the fire will fall into the ash-pan, from which it can easily be raked. After all the fire is withdrawn the dampers and furnace door should be closed so as not to allow the cold air to cool the fire-box and tubes too rapidly. IIn order to keep the boiler clean,-that is as free as possible from sand, sediment or incrustation, it is necessary to blow it out frequently if the water which is used contains much solid or incrustating matter. With " bad water " the boiler should be blown out as often as possible. On some roads this is done after.each:trip. In blowing a boiler out, the blow-off cocks.must be left open, and after all the water has escaped the engine should be left to stand until it is cooled off. If there is any considerable accumulation of mud or sediment the hand-holes at the bottom of the fire-box and the cover to the mud-drum should be taken off, and as much of the mud removed as can be scraped out through those apertures. A hose pipe attached to the hose of a force pump'should then be inserted through these same openings, and a strong stream of water forced. into the boiler. By this means much of the loose mud and scale will be washed out. The oftener this is repeated of course the. cleaner can a boiler be 43 506 Catechism of the Locomotive. kept. If a large amount of incrustation or mud has accumulated about the tubes, some or all of them must be taken out, so as to be able to remove the dirt. After an engine is blown out, under no circumstances excepting absolute necessity should it be filled with cold water until it is entirely cooled off. It should be rememberedi that any sudden change of temperature in a boiler subjects it to very great strains and incurs the danger of cracking the fire-box plates, or causing the tubes to leak. The tender should also be cleaned of the mud which settles in it from time to time, but it is not necessary to do this as often as it is to clean the boiler. All the plates and flues should have the soot which sticks to them thoroughly cleaned off. Although the cleaning of the boiler and the grates is usually committed to a special set of men, yet the locomotive runner should examine them personally to see that it is properly done. He should pay attention to the condition of the grate, and see whether it is level and smooth. As soon as one or more of the bars are bent crooked, they usually burn out. If one of the bars is burnt out the fire falls through the hole that it leaves into the ash-pan, and then: the fire under the grate will heat it red hot, and finally may melt every bar. Every grate-bar which is only a little damaged or bent must therefore be removed as quickly as possible and replaced with a new one. As soon as the engine is run into the engine-house, all superfluous grease which has escaped from the wearing surfaces and the dust or mud which adheres to the engine should be wiped off with cotton waste or rags. This is usually done by men employed for the Running Locomotives. 507 purpose. While they are doing this, they should examine every part thoroughly and observe whether it is in good condition, and if any defects are found they should be reported to the proper person whose business it is to have them repaired. As the faithfulness and skill of a fireman are often estimated by the good or bad: condition of his engine, he should, if for no other reason, take pains to keep it clean and everything in as good condition as possible. If the engine is taken to pieces in order to be thoroughly repaired, the runner, if he does not help to do this, should watch carefully the taking it apart and the putting it together again, as in this way he can become thoroughly familiar with the construction of the machine he runs. QUESTION 501. What precaution must be taken to prevent the water in a locomotive from freezing, if it is laid up? Answer. In very cold weather, if engines are laid up for any considerable time, no water must be left in the tender, boiler or any of the pipes. If, however, the engine must be soon used, and it is impracticable to let the water out of the boiler and tender, then, if exposed to the cold, a light fire must be kept in the boiler sufficient to make steam enough to warm the water in the tender. The water should, however, be drawn out of the pumps and the feed and supply pipes. This can be done by opening the pet-cocks, and closing the tender valves and uncoupling the hose, which will allow the water in the supply pipes to run out. By running the engine a few revolutions the pumps will then be emptied. The pipes and the pumps can also be prevented from freezing without 508 Catechism of the Locomotive. uncoupling the hose if the tender valves are closed and the pet-cocks opened, and steam is then admitted into the supply pipes by the heater-cocks. This forces part of the water which is in the pumps out of;the petcocks and warms the rest. This, however, requires constant watchfulness to prevent freezing, and in excessively'cold weather, if the engine must lay up for any considerable time, it is always best to empty the pumps and pipes. PART XXVIII. ACCIDENTS TO LOCOMOTIVES. QUESTION 502. What are the most serious accidents which may happen in running a locomotive? Answer. The most serious accidents are: 1. Collision of two trains approaching each other. 2. Collision of a moving with a standing train. 3. Collision of trains at the crossing of two railroads. 4. Running a train into the opening left by an open draw-bridge. 5. Escape of an engine without any one on it. 6. Running off the track. 7. Explosion of the-boiler. 8. Bursting or rather collapse of a flue. 9. Blowing out of a bolt, stud or rivet from the boiler. 10. Failure of the feed-pumps, injector or checkvalve. 11. Breaking or bursting of a cylinder, cylinderhead, steam-chest, or steam-pipe. 12. Breaking or getting loose of the piston or crosshead or bending of the piston-rod. 13. Breaking or bending of a connecting-rod or crank-pin. 14. Breaking of a tire, wheel or axle. 15. Breaking of a spring, spring-hanger or equalizer. 43* 510 Catechism of the Locomotive. 16. Breaking of a frame. 17. Breaking or getting loose of a part of the valvegear. 18. Failure of the throttle-valve. 19. Breaking of a coupling. QUESTION 503. What should be done to prevent a collision when two trains are approaching each other? Answer. The obvious thing to do is to stop the trains as soon as possible. This is done by applying the brakes at once with all their power, and then reversing the engine, although it is best not to do the latter until the train is somewhat checked, as there is always danger of bursting the cylinder or breaking the cylinder-heads, piston or connections if an engine is reversed suddenly at a high speed. Of course the higher the speed, the greater is the danger of injury from this cause, and therefore it is best, if there is time, first to check the speed of the train before reversing the engine. When the engine is reversed, the sand-valves should be opened so as to increase the adhesion of the wheels, so that when their motion is reversed they may check the speed of the train as soon as possible. On perceiving danger ahead the order of procedure should be as follows: 1. Shut the throttle-valve. 2. If the train is equipped with hand brakes alone, blow the danger signal for their application, or if the train has a continuous brake, apply it with its full force. 3. Reverse the engine and open the throttle and the sand valves. 4. If a collision is inevitable, shut the throttle-valve before the engines meet, because if it is left open, after Accidents to Locomotives. 511 the collision and when the speed of the train is checked, the engine, if not disabled, will by its own power crush through the wreck and thus do additional damage. QUESTION 504. What should be done if a standing train should see another train approach it and there should be danger of a collision? Answer. The locomotive runner of the standing train should start his engine in the same direction as the approaching train' is running, as quickly as possible, because the shock of the collision will be very much lessened if both trains are moving in the same direction compared with what it would be if one was standing still. QUESTION 505. What should be done to avoid a collision at a railroad crossing? Answer. As was explained in answer to Question 485, trains should always come to a dead stop before crossing another railroad on the same level. If, however, through any means danger of such a collision should be incurred, then evidently the one train should be stopped and the other moved out of the way as soon as possible. QUESTION 506. How can an accident by running into the opening at a draw-bridge be avoided? Answer. First by ALWAYS coming to a dead stop before reaching it, and second by not starting again until it is absolutely certain that the draw is closed. Of course if a locomotive runner of an approacling train finds a draw open, the only thing he can do is to stop as soon as possible. QUESTION 507.' What measures should be trtPten to prevent locomotives from escaping without a responsible perso n on: themn. 512 Catechism of the Locomotive. Answer. In the first place when a locomotive is left standing the throttle-valve should always be closed and,fastened, the cylinder cocks should also be opened so that if any steam leaks into the cylinders it will not accumulate there, but will escape, and the reverse lever should be placed in the centre of the sector, so that if by any accident the throttle should be opened the engine will not start. QUESTION 508. If a loconzotive should escape, what should be done, and how may it be captured? Answer. The first thing to be done is to telegraph to the stations towards which the escaped engine is running, either to keep the track clear, or, if there is a train approaching, to open a switch and thus let the engine run off the track. An escaped engine may be captured by a swifter engine following it, but this is always attended with great danger, as the first engine may leave the track or become wrecked. A safer plan is to telegraph ahead of the escaped engine and have an engine placed in a position where the track can be seen for a long distance in the direction in which the: runaway is expected. As soon as the latter comes in sight, the waiting engine should start in the same direction, so that when they get near to each other they will both be running in the same direction and at nearly the same speed. By regulating the speed of the front engine, the following one may be allowed to come up to it quite gently, and then a man can easily climb from the one engine to the other, and thus both be stopped. QUESTION 509. What should be done in case an engine gets off the track? A.tswer. The first thing to do is to close the throt Accidents to Locomotives. 513 tie-valve and " signal for brakes,"* or apply the continuous brakes if the train is equipped with them, and then reverse the engine.. If its position after it stops is much inclined, it is generally necessary to draw the fire to prevent injury to the heating-surface, a part of which is then usually exposed to the steam, and therefore not covered with water. QUESTION 510. How is a locomotive replaced on the track in case it gets off? Answer. It is impossible to give any directions for replacing locomotives on the track which will meet the great variety of circumstances which occur. in practice. If the engine has not run far from the rails, it can usually be run on again by placing blocks of wood under the wheels and thus running them up to their proper position, but if the engine falls on its side or runs down an embankment, it is usually necessary to send for the appliances which are now provided on nearly all roads for removing wrecks and replacing engines on the track. These appliances are generally stored in what is called a wrecking or tool car, which is placed at a convenient point on the road, from which it can be sent to any place where its services are likely to be needed. Such cars are generally provided with ropes, jack-screws, chains, crowbars, levers, etc., to be used in such cases, and generally a special set of men is sent with the wrecking car to direct and assist in replacing engines and cars on the track. It would lead us too far to describe all the methods of doing this employed under various circumstances; and as such work seldom forms part of the duties of a lo* This expression means, among railroad men, to signal to brakemen by blowing the whistle to have them apply the brakes. a5o14 catechism of the Locomotive. comotive runner, a complete description would be out of place here. QUESTION 511. After an accident which disables the engine, what is the first thing to do? Answer. The first thing to do is always to "protect the train; that is, to send out signal men in each (irection to stop approaching trains; otherwise they might run into the wrecked train, and thus cause a double accident. QUESTION 512. What is the chief cause of boiler explosions? Answer. The cause of all boiler explosions, as happily expressed by a prominent American engineer," is THAT THE PRESSURE INSIDE THE BOILER IS GREATER THAN THE STRENGTH OF THE MATERIAL OUTSIDE TO RESIST THAT PRESSURE. This may occur in two. ways: first, and most frequently with locomotives, from insufficient strength of the boiler to bear the ordinary working. pressure; and second, from the gradual increase of heat and pressure until the latter is greater.than the boiler was calculated to bear. Insufficient strength may be due: 1, to defects of the original design, owing to the ignorance of the strains to which the material of the boiler will be exposed, and its power of resistance; 2, to defective workmanship and material, which can usually be discoveredby careful inspection; 3, to the reduction of the original strength of the boiler by ordinary wear and tear or neglect, which can also usually be discovered by careful inspection. The first two causes have been fully discussed in * See Fifth Annual Report of the American Master Mechanics' Association. page 196. Accidents to Locomotives. 515 the part relating to boiler construction, and the last under the head of inspection of locomotives. Over-pressure is nearly always due to some defect of the safety-valve, or to the fact that it is overloaded. This latter often occurs when safety-valves are set by a defective steam gauge, which indicates too little pressure. Over-pressure may also occur by letting an engine stand alone with a large fire in its fire-box and possibly with the blower turned on. A boiler may, by suddenly.opening the throttlevalve, undoubtedly be subjected to very severe strain that may possibly be sufficient to cause its destruction, even though it had sufficient strength to bear the ordinary pressure at which the safety-valve blows off. Suddenly opening or closing the throttle-valve may produce a violent rush of steam and water against the part of the boiler whence the steam is drawn. The percussion of the water and steam in such cases has been known to shake the whole boiler, and to lift the safety-valve momentarily right off its seat.* The weakest parts of a locomotive are the two sides where the barrel joins the outside fire-box. Many boilers, especially those with a high wagon-top, have flat spaces at this point, which it is impossible to stay properly. It is at this point, too, that the expansion and contraction of the tubes and the outside shell exert their greatest strains, and it will therefore be found, generally, that the seams at this point begin to leak before any others, and for these reasons it is believed that all the seams which join the outside shell of the fire-box to the barrel should be doubleriveted. * Wilson on Boiler Construction. 516 Catechism of the Locomotive. The practice of ascribing steam-boiler explosions to obscure causes has been productive of much mischief, as it engenders a carelessness on the part of those having charge of them, who have been led to believe that no amount of care will avail against the mysterious agents at work within the boiler. Explosions are also, in the absence'of other convenient reasons, very generally attributed to shortness of water. This is often nothing more than a convenient method of shifting the responsibility from the builder or owner of the locomotive to the runner or fireman, who, if not killed by the explosion, in many cases might just as well be, so'far as his ability to defend himself is concerned.* QUESTION 513. Vhat should a locomotive runner and freman do to avoid and prevent explosions? Answer. 1. The height of the water in the boiler should always be maintained so as to cover the heating surfaces. 2. The boiler should be kept as clean, that is, as free from scale, mud and other impurities, as possible. 3. It should never be subjected to strains from sudden heating or cooling. 4. The steam-gauge and safety-valves should be examined and tested frequently, to be sure they are in order; and 5, they should- examine every part of the boiler which is accessible, but especially the stay-bolts,' to see that there is no fracture of any part or any injurious corrosion or other dangerous defect. QUESTION 514. What should be done in case of the bursting or collapse of a tube? Answer. As soon as possible after it occurs, the runner must stop the train, and close first the end of * Wilson on Boiler Construction. Accidents to Locomotives. 517 the flue in the fire-box, and then that in the smokebox, by driving in iron plugs, which are usually provided for the purpose. These plugs are attached to the end of a bar, with which' they are inserted into the tubes. If the escape of water and steam from the tube is so great as to make it difficult to see the end of the tube, the steam may sometimes Jbe drawn up the chimney by starting the blower.'If, however, the escape is so great as to'make it impossible to insert the plug, then the steam pressure must be reduced by running with both pumps on, or by starting the injector; or it may be necessary to draw the fire and cool off the engine. When a flue collapses, the front end of which is behind the steam or petticoat pipes, it is usually necessary to cool off the engine before a plug can be inserted, especially if any considerable amount of water and steam escape from it. While driving in the plug, the runner and fireman should always keep themselves'in such positions that the plug can not hit them in case it is blown out by the steam. If the engine is not supplied with iron flue-plugs, a wooden plug' can be cut of the proper size and driven in. This can be attached to the bar referred to and inserted; but if no such bar is carried with the engine, the wooden plug can be made on the end of a long pole and then cut nearly off. It is then inserted into the flue and driven in and broken off. It will be found that such plugs-will burn off even with the end of the flue, but will not burn entirely out. QUESTION 515. What should be done in case a bolt, stud or rivet blows out of the boiler andlthus allows the steam or hot water to escape? 44 518 Catechism of the Locomotive. Answer. If it is accessible, cut a plug on the end of a long pole and drive it in in the same way as described above. This will avoid the necessity of cooling off the engine; but in some cases it will be found that a plug can not be inserted or driven in without drawing the fire and cooling off the boiler. QUESTION 516. In case it is found necess try to draw the fire and cool off the boiler, and if so much water has escaped as to uncover the crown plate, what must be done? Answer. If the leak has been stopped or the fault remedied, one of the safety-valves should be taken off and water poured into the boiler with pails or buckets through the opening left by the removal of the safetyvalve until the crown sheet is covered. The fire may then be kindled again and the engine complete its journey. When bituminous coal is used for fuel, the necessity for drawing the fire in case of accident may often be avoided by completely covering or "banking"' the fire with fine coal which has been wet, and closing the dampers and opening the furnace door. In this way the fire may be smothered and the boiler cooled without putting the fire out, so that after the defect is remedied it will not be necessary to rekindle it. QUESTION 517. What must be done in case of the failure of one or both of the feed pumps or of the injector or check-valve? Answer. If one of the pumps fails the other one may be used, but the defect or obstruction to the first should be remedied as soon as possible, because the second may also fail. It will then be:necessary to depend upon the injector alone, if there is one, for feed Accidents to Locomotives. 519 ing the boiler. Only after all the appliances for feeding the boiler have failed and the water is so low as to be in danger of exposing the crown sheet, should the fire be drawn or banked, and the runner should then at once give the proper signals for warning and the protection of his train, and if he is unable to repair the pumps or injector, he must send for aid to the nearest accessible point. QUESTION, 518. In case a pump fails, how should it be examined in order to discover the defect? Ansuwer. As explained in the answer to Question 458, the working of a pump is usually indicated by the stream which escapes from the pet-cock. If, when this is opened, steam and water escape, it is an indication that the check-valve is not working properly. When this occurs hot water will escape if the petcock is opened when the engine is standing still, but the pump may still feed the boiler if the upper or pressure-valve works properly. When the check-valve does not work as it should, it is also indicated by the heating of the feed-pipe, owing to the escape of hot water from the boiler through the check-valve when the pet-cock is opened. If, when the plunger is drawn out of the pump, air is sucked in through the open pet-cock, then the upper or pressure-valve of the pump does not work, but the working of the pump may still be secured by the working of the checkvalve; but if the pump, air-chamber and feed-pipe then get' filled with air, the plunger may compress this air at each stroke, and as it can then follow the plunger during its outward stroke, the latter will not suck water, but will simply compress the air during the inward stroke, which will then expand during the 520 Catechism of the Locomotive. outward stroke. This will be indicated by the escape of air from the pet-cock when the plunger is moving inward, and the suction of air when the plunger is moving outward. This can be known by holding the hand in front of the pet-cock. Usually, however, the air is mixed with water so that the stream which escapes from the pet-cock is broken or irregular. If air escapes from the pet-cock during the inward stroke of the plunger, but none is sucked in during the outward stroke, it shows that there is a leak somewhere in the pump or pipes, and that it is pumping air instead of water. The leak may be in the stuffing-box of the plunger, the joints of the pump or pipes, in the hose or their connections with the supply-pipe or tender. If neither air nor water escapes from the pet-cock during the inward stroke of the pump plunger, or, if the stream of water at that time is weak, then it indicates that the suction or lower valve of the pump is not working properly. The same thing will occur if the pipe, pump or tender-valve is obstructed. If there is a cock, as there always should be, just above the suction-valve, it will aid us very. much to discover the fault when the pump will not work. If, when this cock is opened, cold water escapes from it, the fault is in the suction-valve; if hot water, then it is the pressure and check-valves which are leaky, obstructed or broken, and consequently the hot water from the boiler leaks back into the pump.: In the absence of such a cock, the fault can often be discovered by feeling the pump barrel with the hand. If the pump can not be made to work, and the fault is found to be in the lower valve, it must be taken out and examined; or if the fault is in the pipes, it can usually be easily Accidents to Locomotives. 521 remedied. If the pipes are burst with only a small fracture, it can usually be remedied by covering the aperture with canvas or rubber and wrapping twine around it tightly. The upper valve of a pump must, however, never be taken down without first being sure that the check-valve is tight, because if it is not, the person will be likely to be scalded in taking the pump apart. Directions for managing an injector, and also for taking care of pumps in cold weather, have already been given in the answers to Questions 142 and 488. QUESTION 519. What should be done in case of the breaking or bursting of a cylinder or cylinder-head? Answer. The main connecting rod must be taken down on that side of the engine. The piston should then be moved to the front or back end of the cylinder and wooden blocks be placed between the guides so as to fill up the space between the cross-head and the end of the guide-bars, and thus prevent the cross-head and piston from moving. The valve stem should then be disconnected from the rocker, and the valve moved to the middle of the valve face; so as to cover up both steam-ports. It must then be fastened in that position by screwing up one of the bolts of the stuffingbox of the valve stem, so as to make the gland bind against the valve stem. The train should then be run cautiously to the next station with the use of one cylinder. If the engine is not able to haul the train with one cylinder, then it should be uncoupled from the train and run to the, first telegraph station or other point where the aid of a helping engine can be Bobtained or.telegraphed for. In tlie meanwhile the train must be protected by the proper signals. Should 44* .522 Catechism of the Locomotive. the engine continue its journey with one cylinder, it must be started, if it should happen to be standing at the dead point, by pushing or by means of crow-bars. In so doing, however, the bars should not be put between the spokes of the wheels, as they may easily be caught in the wheels when the engine starts, and in this way the spokes be broken or the persons who are using the crow-bars be badly hurt. QUESTION 520. What must be done in case a steamchest or steam-pipe is broken? Answer. If a steam-chest is broken a block of wood should be bolted over the mouth of the steam passage, so as to prevent the escape of the steam from the steam-pipe on that side. It will sometimes require considerable ingenuity to devise means of fastening such a block or blocks of wood so as to cover the mouth of the steam passage. As cylinders are now usually made, the blocks can be fastened by cutting them to the proper form and size, and then placing a thick block on top, and bolting the steam-chest cover down on top of it. If the cover is broken, a part of it may be used or a piece of plank with a few holes bored into it be employed instead. In some cases a piece of board can be bolted over the end of the steampipe. When the latter is broken, it should be taken down and a piece of board or plank bolted over the opening of the T-pipe to which the steam-pitpe was attached. The engine can then be run with one cylinl der as before, although usually in such cases it is not necessary to disconnect any other parts than the valve stem. QUESTION 521. What must be done if a piston, crosshead, connecting-rod or crank-pin is broken or beat? Accidents to Locomotives. 523 Answer. If the piston, cross-head or main connecting-rod is broken, the same course must be pursued as when a cylinder is broken. If a coupling-rod or a crank-pin of a trailing-wheel is broken, then it is necessary to take down both the coupling-rods, but not to disconnect the main connecting-rods or their attachments, unless they are injured. QUESTION 522. If one coupling-r-od is broken or taken down, why must the other be taken down also? Answer. Because if only one rod is used there is then nothing to help the cranks of the trailing wheels:past the dead-points, so that in starting, or if they are moving slowly when they reach these points, they are quite as likely to revolve in one direction as the other. If they happen to turn in the reverse direction to that in which the wheels to which they are coupled are moving, then the crank-pins of one or the other pair of wheels are very liable to be broken or bent. QUESTION 523. What must be done if a driving-wheel tire or driving-axle breaks? Answer. If a tire on a main driving-wheel or the wheel itself breaks, the driving-box of the broken wheel or tire should be held up by putting a wooden block under the box. An ordinary American engine can then be run on three driving-wheels, but it must be run with the utmost caution. If the engine has more than four driving-wheels there is usually less difficulty in running it, if one of the main wheels is injured, than if there are only four. But it is almost impossible to give directions which will be applicable to all the accidents of this kind that may occur to different kinds of engines. If none of the connecting-rods, crank-pins or crank-pin bosses are injured, it is not 524 catechism of the.Locomotive. necessary to disconnect either side, but if the injury is of such a nature that the coupling-rod must be taken down onI one side, the one on the other side must be taken down too. If the main crank-pin and connecting-rod are not disabled, both cylinders may be used even if one of the main wheels or tires is broken. But even if one side of the engine must be entirely disconnected, the engine may still be run with one cylinder and by driving one wheel. If a main axle breaks the engine can usually be run, but great caution must be exercised. In such cases, however, if assistance or a telegraph office is near where the accident occurs, it is usually best to send for assistance at once, rather than take the risks which attend the attempt to run an engine so seriously injured. QUESTION 524. What must be done when a trailing or leading driving-wheel, tire or axle breaks? Answer. Very much the same course must be pursued as was described in the previous answer, although it is generally less difficult to run with a trailing or leading axle broken than it is when the main axle has met with such an accident. QUESTION 525. What must: be done if an engine-truck wheel or axle breaks? Answer. It is usually best to chain up the end of the truck-frame over the broken axle or wheel to the engine frame and place a cross-tie across the other end of the truck-frame, between it and the engine frame, so that the weight of the engine may rest on the crosstie. If a part of the flange or a piece of the wheel is broken out, the wheels should be-turned around so that the unbroken part will rest on the rail, and they should then be chained or otherwise fastened so that Accidents to. Locomotives. 525 they cannot revolve, and thus be made to slide on the rails and carry the weight of the engine in that way. The same plan is employed if a tender wheel breaks, but one end of a tender-truck frame must be chained up. It is usually necessary to place a cross-tie across the top of the tender, and fasten the chains to it. QUESTION 526. What must be done in case a drivingspring, spring-hanger or equalizing-lever breaks? Answer. As the breaking of a spring or springhanger may cause a more serious accident, the engine and train should be stopped as soon as possible after it occurs. If the hanger is broken and there is a duplicate on hand, it should be substituted in place of the broken one. If there is no duplicate, then the spring should be taken down, and a wooden block be placed between the top of the driving-box and the frame to support the weight which before rested on the spring. In order to insert this block, if it is a front spring which is broken, it is usually best to raise the engine with jack-screws or run the back wheels on inclined blocks of wood placed under each of the back wheels. This raises the weight off from the front-wheels, and the block can then be inserted between the box and frame. If it is one of the springs over the back wheels which is broken, the front wheels should be run on the wooden wedges. Such wedges can soonl be cut out of a cross-tie with an axe, or by sawing a square stick of wood diagonally it will make two such wedges. The end of the equalizing lever next to the broken spring must be supported by inserting a piece of wood under it. This will usually be held securely by the weight which is suspended from the opposite end, bearing the blocked end down on the block. 526 Catechism of the Locomotive. QUESTION 527. What should be done if an enginetruck or tender spring breaks? Answer. Very much the same course must be pursued that is employed when a driving-spring breaks, excepting that usually the weight can be lifted off from a truck-box easier by placing a jack under the end of the truck-frame than by the method described. Usually, too, each of the truck-springs supports the weight on two.of the wheels, so that the two boxes must be blocked up. QUESTION 528. What must be done in case the engineframe is broken? Answer. Usually very little need be done excepting to exercise more than usual caution in running, and to reduce the speed. Of course the breakage.of a frame may disable the engine, but ordinarily in such accidents that.is not the case. QUESTION 529. How can it be known if an eccentric has slipped on the axle? Answer. It is indicated at once by the irregular sound of the exhaust, or, as locomotive runners say, the engine will be "lame." QUESTION 530. When it is known that an eccentric has slipped, how can it be learned which is the one that is misplaced? Answer. This can usually be learned by examining the marks which should always be made on the eccentrics and on the axles. If no such marks have been made by the builder of the engine, the runner himself should make them, after the valves have been set correctly. The effect upon the valve when an eccentric slips is either to increase or diminish the lead. Therefore, by running the engine slowly with the link first Accidents to Locomotives. 527 in full forward and then in full back gear, and observing whether steam is admitted at each end of the cylinder just before the crank reaches the dead points, it can be known which eccentric has moved. If it has slipped in one direction the lead will be increased and steam will be admitted to the cylinder some time before the piston reaches the end of the stroke. If it has moved the opposite way, the lead will be diminished and steam will not be admitted until after the piston has reached the end of its stroke. The admission of steam will be indicated by its escape from the cylinder cocks. QUESTION 531. If by any means the valve stem or either of the eccentric rods should be lengthened or shortened, how can it be known? Answer. The crank on one side should be placed at one of the dead points and the cylinder-cocks opened; then admit a little steam to the cylinder, by opening the throttle-valve slightly, and throw the reverse lever from full gear forward to full gear backward, and observe whether steam escapes all the time from the end of the cylinder at which the piston stands. Then repeat the operation with the crank at the other dead point. If either of the eccentric rods or the valve stem have been lengthened or shortened, it will cause the valve to cover the steam-port either at the front or back end of the cylinder, so that no steam will escape from the cock at that end. If the length of one of the eccentric rods has been changed, then when the altered rod is in gear the valve will have too little or no lead at one end of the cylinder and too much at the other. If, therefore, this occurs when the forward rod is in gear and not in back gear, 528 Catechism of the Locomotive. it indicates that the length of the forward rod has been altered. If the reverse occurs it shows that it is the back-motion rod whose length has been changed. It must be observed that if the length of an eccentric rod is altered the lead will be changed only at that part of the link which is operated by the altered rod. That is, if the forward eccentric rod is too long or too short, the lead at the front and back ends of the cylinder in forward gear only will be affected. If the back eccentric rod is changed the valve will be affected only in back gear. If, however, the length of the valve stem is changed, the lead will be changed in both forward and back gear. The valves on each side of the engine can, of course, be tested in the same way. QUESTION 532. When it is discovered which eccentric has slippedl, how should it be reset? Answer. If it has been marked, it is simply turned back so that the marks correspond with each other again. This is done by first loosening the set-screws, and, after the eccentric is turned to the proper place, tightening them up again. When an eccentric slips it is often caused by the cutting of the eccentricstraps, valve or other part of the valve-gear, so that these should always be examined to see whether they are properly oiled. If the eccentrics have not been marked, the valve may be set by placing the crank at the forward dead-point, and the reverse lever in the front notch of the sector and the full part of the forward-motion eccentric above the axle. Then admit a little steam into the steam-chest, open the cylinder cocks, and move the forward-motion eccentric slowly forward until steam escapes from the front cylinder cock, which will show that the stealn-port is opened Accidents to Locomotives. 529 and the valve has some lead. To set the backwardmotion eccentric the crank is placed in the same position, but the reverse lever is thrown into the back notch and the full part of the eccentric is placed below the axle. Then move this eccentric forward until steam escapes from the front cylinder cock as before. In order to verify the position of the eccentrics the crank may be placed at the back dead-point and the reverse lever moved backward and forward, at the same time observing whether steam escapes from the back cylinder cock when the link is in back and forward gear. QUESTION 533. What should be done in case an eccentric-strap or rod, or rocker arm or shaft, or the valve stem breaks? Answer. If an eccentric-strap or rod breaks, the broken rod and strap should be taken down, and the valve-stem disconnected from the rocker and the valve fastened in the middle position of the valve face, and the engine should be run with one cylinder only. The same course must usually be pursued if a rocker breaks. If the valve-stem breaks, it is not necessary to disconnect the link and eccentric rods, but simply to fasten the valve in the centre of the valve face. QUESTION 534. If a link hanger or saddle, or a lifting arm should break, what may be done? Answer. The valve-gear may be used on that side of the engine by putting a wooden block in the link slot above the link block, so as to support the link near the position at which it works the valve full stroke forward. Of course the engine can then be run in only one direction, and should therefore be 45 530 Catechism of the Locomotive. run with the utmost caution. If, however, it should be necessary to back the train on a side track, it can be done by taking out the wooden block and substituting a longer one, so that tle link will be supported in a position near that at which it works the valve full stroke backward. These' blocks must be fastened in some way, either with rope or twine, so that they will be held in their position when the engine is at work. QUESTION 535. If the lifting shaft itself or its vertical arm, the reverse lever or rod, should break, what can be done? Answer. If it is impossible to devise any temporary substitute or method of mending them, both links can be blocked up as described above. QUESTION 536. In case the throttle-valve should fail, what should be done? Answer. If such an accident occurs, especially if it happens about a station, it is attended with great danger. If it is found that steam can not be shut off from the cylinders with the throttle-valve, then the reverse lever should be placed in the middle of the sector. If this does not prevent the engine from moving, the reverse lever should be alternately thrown into forward and then into back gear, and at the same time every aperture, such as the safetyvalve and heater cocks, should be opened, and every means be taken to cool the boiler as quickly as possible. The Areman should open the furnace door, close the ash-pan dampers, and start the blower so as to draw a strong current of cold air into the furnace and through the tubes. At the same time the injector should be started and the fire drawn as quickly as possible. After the boiler is cooled; the cover of the Accidents to Locomotives. 531 steam-dome may be removed and the valve examined if the defect call not be discovered in any other way. Of course if the accident occurs on the open road, the train must be at once protected by sending out signals in each direction. QUESTION 537. What must be done in case a coupling breaks? Answer. When a coupling between the cars or tender breaks, if the front end of the train is immediately stopped, there will be danger that the back end of it, which is broken loose, will run into the front end, and thus do great damage. As it always occurs, when a coupling of a passenger train breaks, that the signal bell in the cab is rung, the first impulse of a runner under such circumstances is to stop the engine. He should, however, be careful not to do so if on shutting off steam he finds that the train has broken in two, but should at once open the throttle in order to get the front end of the train out of the way of the rear end. The ease with which the speed of a train is arrested with continuous brakes has increased the danger of accident from this cause. Usually a runner learns by the sudden start of the engine that the train has separated, and when that occurs he should never apply the brakes. QUESTION 538. If from any cause the supply of water in the tender becomes exhausted, what must be done? Answer. It is best, if it can-be done without risk of injury to the engine, to run the train on a side track and then draw the fire. If no water can be obtained near enough to supply the tender with buclkets, help must be sent for; but if there is a well, stream or 532 Catechism of the Locomotive. pond of water near, the tender can be partly filled by carrying water. QUESTION 539. In case an engine becomes blockaded in a snow storm with plenty of fuel, but runs out of water, what can be done.? Answer. Snow should be shoveled into the tender and steam admitted through the heater cocks so as to melt the snow. QUESTION 540. If a locomotive without an injector should be obstructed in a snow storm or in any other way so that it could not move, and therefore could not work the pumps, what should be done in case the water in the boiler should get low? Answer. The weight of the engine should be lifted off from the main driving-wheels and the coupling rods disconnected from the main crank-pin, so that the main wheels can turn without moving the engine. These can then be run and the pumps thus be worked. The weight can usually be most conveniently taken off from the main wheels by running the trailing wheels on wooden blocks, and thus raising up the back end of the engine. QUESTION 541. If it is impossible, in a snow storm or in very cold weather, to keep steam in the. boiler without danger, what should be done? Answer. Draw the fire, blow all the water out of the boiler, empty the tanks, disconnect the hose and slacken up the joints in the pumps and injector so that all the water in them can escape, and thus prevent them from freezing up. PART XXIX. ACCIDENTS AND INJURIES TO PERSONS. QUESTION 542. In case an accident occurs and one or more persons are seriously injured, what can be done by those present. Answer. In such cases it very often happens that with knowledge and sufficient coolness to apply that knowledge, one or more non-medical persons who are present when an accident occurs can do as much or more toward saving life and allaying pain, before a doctor comes, than he can afterwards. The following cases cited by Dr. Howe in his book on " Emergencies " will illustrate this: "Case 1.-A machinist was admitted to a New York hospital suffering from wounds of the wrist and palm of the hand. On arriving at the hospital the entire clothing on one side of hlis body was saturated with blood, from the loss of which he was partly insensible. On making an examination, it was found by the surgeon that a folded handkerchief was bandaged over the centre of tlie wrist, and that the wound in the palm of the hand was untouched. The pad was placed on the wrist, as if the greatest care had been exercised to avoid pressing on either of the two arteries. The bleeding in this case could easily have been controlled if the bandage and pad had been properly applied. The patient, however, 45* 534, Catechism of the Locomotive. developed erysipelas, and, not having sufficient vitality to carry him through, died the fifth day." " Case 2.-A laborer fell from the front platform of a car at Harlem, and had his right foot crushed by one of the wheels. An ordinary bandage was placed on the limb without any compress over the vessels. In bringing the man to the hospital, the rough jolting of the carriage set the wound bleeding, and by the time he reached his destination he was apparently lifeless. The vessels were tied and stimulants administered, but he never rallied. Death occurred six hours after his admission. His injuries, independent of the bleeding, might indeed have terminated his life; still the chances would have been in his favor if a compress had been applied to the limb to prevent bleeding. The fact that such a thing was not done shows either culpable negligence or deplorable ignorance." Many similar cases constantly occur where a little intelligent timely action of those present would save the life of an injured person, who without such help must die before professional surgical aid can be obtained. QUESTION 543. When it is founct that one or more persons are seriously injured, what is the first thing to be done? Answer. The first thing to do is to extricate the person or persons from the danger, and at the same time send a messenger for a doctor. If it is doubtful if one can be obtained by sending in one direction, send two or more messengers in different directions. QUESTION 544. To what kind of injuries are locomo Accidents and Injuries to Persons. 535 tive runners -and other persons employed or traveling on railroads exposed? Answer. They are liable to be bruised or crushed in case of collision or running off the track, or of injury from falling off the train, or of being run over by a moving train. Brakemen and others whose duty it is to couple cars are liable to have their hands, arms or bodies crushed between the cars, and locomotive runners are sometimes burned or scalded if an accident happens to their engines. Tiain-men are also frequently exposed to very great cold in winter and heat in summer, and are thus liable to be frost-bitten or sun-struck. Passengers are seldom injured excepting through their own carelessness, unless in cases of collision or running off the track and the destruction of the cars. Strangers and even railroad employes are frequently run over by trains while walking on the track, and frequent accidents occur to deaf people in this way, and it is not very unusual to hear of trainmen who sit on the main track at night while their trains are waiting on the side-track for another train to pass, go to sleep while in that position, and then are run over by the passing train. QUESTION 545. When persons are crashed or dangerously wounded, what are the chief immediate sources of danger and death when their wounds are not necessarily fatal? Answer. First, excessive bleeding in case an artery is ruptured; second, the shock to the whole system, from which the sufferer may not have the strength to recover. QUESTION 546. Widen does bleeding from a wound become dangerous? 536 Catechism qof the Locomotive. Answer. Profuse bleeding is always dangerous, but it should be remembered that bleeding occurs from two sources: first fromt the arteries, which are the vessels which convey the blood from the heart, and second from the veins, through which the blood flows back to, the heart. The first is called arterial bleeding and the second venous bleeding. Now it must be remembered that the heart is the great force-pump of the body, and that it supplies all parts of the body with blood, somewhat as the feed-pump of a locomotive supplies the boiler with water. The arteries referred to fulfill the same purpose that the feed-pipe does to a locomotive pump-they convey the fluid from the pump to the place where it is needed. Now the blood is forced into these arteries with a certain amount of pressure, so that if any of them are cut or injured the blood will flow out in a jet or spurt just as the water will escape from a feed-pipe if that is ruptured. The blood which flows through the veins back to the heart may, on the other hand, be compared to the water in the supply pipes of a locomotive pump, that is, there is very little pressure on it, and therefore if they are injured the flow of blood from them is less rapid than from the arteries. It will therefore be seen that arterial bleeding is much more dangerous, because the blood flows from them under a pressure. QUESTION 547. How can arterial bleeding be distinguished from venous bleeding? Answer. The blood is of a bright scarlet color, and is forced out in successive jets; each jet corresponds with the movements of the heart. This characteristic spurting is caused by the intermittent force-pump action of the heart, driving out the blood. Venous Accidents and Injuries to Persons. 5317 bleeding is distinguished from arterial by the darkblue color of thle blood when flowing from the wound. It never flows in repeated jets, but oozes slowly from the wounded surfaces. Venous blood is traveling toward the heart, and there is consequently little force behind to cause a more rapid flow. This form of bleeding is comparatively harmless, unless occurring from very large veins.* QUESTION 548. How can the bleeding be stopped in case an artery is cut or ruptured? Answer. The most efficient and available method is the application of PRESSURE on the artery BETWE:EN THE WOUND AND THE HEART. Under ordinary circumstances this can be most effectively done with what is called a field tourniquet, which is simply a handkerchief passed around the limb above the wound, the ends of which are then tied together. A pad is then made, either of cloth rolled up, a piece of wood, or a round stone about the size of a hen's egg well wrapped, or any substance from which a firm pad can be quickly made, which is placed over the artery. The handkerchief is then placed over the pad and a short stick put through it on the opposite side of the limb and twisted around until the pad compresses the artery firmly. While the tourniquet is being prepared, some one should compress the artery with his fingers or thumb, so as to prevent as much loss of blood as possible. QUESTION 549. What is the position of the arteries in the bodly end how can their location be known? Answer. The position of the principal arteries is "Emergencies and How to Treat Them," by Joseph W. Howe, M. D. /? 6il a // Fig. 230. Accidents and Injuries to Persons. 539 shown in fig. 230. They proceed from the heart h with branches, a, a, and b, b, which extend along each limb. These branches subdivide again below the knees and elbows, and again in the hands and feet. The position of the arteries can be felt by their pulsation at almost any part of them, but when they are buried below the muscles it is more difficult than when they are near the surface. QUESTION 550. In case of a wound and rupture of the arteries in the arm, what should be done? Answer. The artery at a should be firmly compressed with the thumb until a bandage and pad from which a tourniquet can be made are prepared. The pad should then be applied over the artery and compressed as explained in answer to Question 548. The bleeding can also be stopped by placing a round piece of wood or other form of pad between the arm at a and the body and then tying the arm tightly against the body, so that the pad will be pressed against the arm. QUESTION 551. In case of rupture to an artery below the knee, where should the pressure be applied? Answer. The artery approaches near the surface at c, c, immediately back of the knee, where it is represented in dotted lines in fig. 230. Pressure should therefore be applied at that point first with the thumb until a tourniquet can be applied. The bleeding can also be stopped by elevating the leg and allowing it to rest on the back of a chair or other similar support. The weight of the leg will then bring sufficient pressure on the artery to stop the bleeding. A towel or other soft material should be placed over the back' of the chair, so that the pressure will not be too painful to the sufferer. 540 Catechism of the Locomotive. QUESTION 552. If an artery is ruptured in the leg above the knee, where should the pressure be applied? Answer. In the thigh at b, where the beating or pulsations in the artery can be distinctly felt. The reader should familiarize himself with the position of the arteries by feeling their location in his own body. By doing so he may be able to save the life of a companion or other person in case of accident, whereas without such knowledge the injured person would die. QUESTION 553. After the arterial bleeding has been stopped, if blood should continue to ooze out of the wound, what should be done? Answer. The wound should be filled with lint or cotton waste; and the limb then be bandaged by beginning at its extremity and wrapping the bandage closely and evenly around it so as to bring, as nearly as possible, an equal pressure on the whole of it. Bandaging the limb in this way up to the point where the pressure is applied to the artery, will prevent swelling, and the veins will be compressed so that the blood will not flow from their torn extremities. QUESTION 554. When the bleeding has been stopped, what should be done? Answer. The injured person should be laid in as comfortable a place as can be procured for him, and should be given a moderate drink of water. If much exhausted, two or three tablespoonsful of brandy or whisky, mixed with an equal quantity of water, should be given first, and smaller quantities, of not MORE THAN A TABLESPOONFUL at a time, should then be given every half hour. Usually wounded persons are given too much stimulant, so that fre Accidents and injuries to Persons. 541 quently they are injured more than they are benefited thereby. After a person has lost much blood, he feels an intolerable thirst, but if too much water is given him, he is apt to become sick and vomit, which weakens him still more. It is therefore best to give him very little water, say a teaspoonful at a time, after the first drink, or if ice can be obtained, give the sufferer pieces of ice frequently, which can be allowed to melt slowly in his mouth. QUESTION -555. When a person is insensible, what should be done for him? Answer. Lay him down in as comfortable a place as the circumstances will permit, and protect him from cold, rain or hot sun, as may be needed. A common error is to place injured and insensible persons in an erect position or in a chair. If he is insensible he should always be laid down with his head slightly lower than his body. Then water should be dashed two or three times on his face, and warm bricks, stones or pieces of iron, such as coupling links or pins, applied to his feet and in the arm-pits and between the thighs, being careful that the warm objects applied are not hot enough to burn. Then cover the person with blankets, heavy coats or anything else which will keep him warm. Wounded persons soon become cold and chilled, the effects of which are very injurious, and therefore especial pains should be taken to keep them warm. In very cold weather there is great danger that injured persons will be frost-bitten, which must be carefully guarded against. In case of shock, when the injured person lies pale, faint, cold and sometimes insensible, with feeble 46 542 Catechism of the Locomotive. pulse and labored breathing, anything like excitement must be avoided, as it tends to exhaust the patient. All assistance and attention should be given to a wounded person with the least noise and excitement, and all crowds and idle spectators should be driven away and every effort made to keep the sufferer comfortable and quiet. If food is given it should be in the form of beef tea or broth, and in small quantities at a time. QUESTION 556. In case any bones are broken, what should be done? Answuer. The limb should be supported as comfortably as possible until a doctor's services can be obtained. There is danger with a broken limb that the bones will protrude through the flesh and skin, to avoid which the limb should be placed in a natural position and laid on a pillow, car cushion or other soft object. This should then be wrapped around the limb and tied in this position, so as to prevent any movement of the broken bones. QUESTION 557. If a person is crushed or severely burned, what should be done? Answer. The immediate danger from such injuries arises from the " shock " to the system. It is usually best to bandage the part which is crushed until surgical aid can be obtained, and the sufferer treated as explained in answer to Question 548. QUESTION 558. What should be done for a person who has been burned or scalded? Answer. Lint or cotton waste saturated with molasses and water should be applied to the wound, or the latter should be dusted with wheat flour, and then dressed with lint or cotton waste, and loosely bandaged. Accidents and Injuries to Persons. 543 If the injury should be severe, a shivering followed by depression is very likely to come on. To check this, warmth in the form of hot applications and stimulants should be used, as already explained. QUESTION 559. What should be done for a frost-bite? Answer. Warmth should be applied to the frozen part very gradually by rubbing with snow or pouring cold water on it. The occurrence of stinging pain, with a change in color, is a signal to stop all rubbing or other measure which might excite inflammation. If the frozen part turns black the next day, a poultice should be applied. If persons exposed to the cold become very much exhausted or sleepy, stimulants should be given, as explained in answer to Question 554, and the body briskly rubbed with the hands and warm flannel or other woolen material. QUESTION 560. flow should a person be treated who has been sun-struck? Answer. Apply cold water or ice to the head, place the sufferer in a cool place, and make him comfortable. After being sun-struck the person should not work for some days or weeks thereafter, until his health and strength are fully recovered. PART XL. RESPONSIBILITY AND QUALIFICATIONS OF LOCOMOTIVE RUNNERS.* QUESTION 561. What are the dangers to which the runner and the fireman are exposed by their work on the engine? Answer. Runners and firemen are not only exposed to great bodily injury or even death by every accident which may happen to their engine, but unless they are very careful to preserve their health it is quickly destroyed by the constant changes of the weather to which their position exposes them, and also by the effect of the heat of the fire and by the smoke by which they are often surrounded. In order to protect themselves in a measure from the injurious effects of change of weather, smoke, cold, etc., frequent bathing and cleansing of the skin are absolutely necessary, and also the wearing of a woolen undershirt next the skin at all seasons. The gases of coal which pour out of the furnacedoor, if it is opened when the throttle is closed, have an especially injurious effect on the throat, lungs, etc. They should always see to it, therefore, that th3 blower is always started before the fire-door is opened, in order that these injurious gases, which have col* NOTE.-The greater part of this chapter is a translation from Prof. George Kosak's "Katechismus der Einrichtung und Betriebes der Locomoltive." Qualifications of Locomotive Runners. 545 lected during a halt, may be drawn forward and up the smoke-stack by the draft. The steady, loud clatter which the engine makes while running has an injurious influence on the nervous system. The runner should therefore endeavor to lessen these shocks of the engine as far as possible by keeping watch over it and keeping its parts accurately adjusted. In order to keep himself fresh and strong in his service, which is extremely exhaustive to body and mind, the runner must try to strengthen himself by regular, temperate living, and eating abundant nourishing food. The common use of strong drinks, which undermines the mental and physical strength of men, should be avoided by a person occupying the exhaustive and responsible position of a locomotive runner. If in ordinary life a drunken man is unfit for any simple work, how shall a drunken runner or fireman undertake the difficult management of so great, so delicate and so costly a machine as a locomotive? How can hundreds of men quietly trust their lives and limbs to such a man, whom no one can help despising? Rightfully, therefore, conscientious railroad managers place the greatest stress on the sobriety of the runners and firemen, and instantly discharge from their service those who give themselves up to a passion for drink. Owing to the demands which their daily labor makes upon their strength and endurance, locomotive runners should be careful not to increase the drain by dissipation, irregular hours or overwork. There seems to be something about the power of endurance of the human frame analogous to the capacity of a bar of iron or steel to resist strains. So long as the strains do 46* 546 Catechism of the Locomotive. not exceed the elastic limit, that is if the bar recovers its original length when the strain is removed, it will bear millions of such strains without becoming weaker; but if it is strained so hard that it is permanently stretched, then comparatively few applications of the force will rupture the bar. In a similar way, if the strain or fatigue which a man endures is no more than he will recover from after the ordinary rest, he can endure an almost unlimited number of such strains, but if the fatigue exceeeds his'" elastic limit," then he soon becomes permanently injured thereby. It often happens that an excessive amount of work is unavoidable, but when it can be avoided it should be by those who wish to preserve their health and strength. In order to save themselves from great injuries, runners and firemen should always act with the greatest caution, and never rush carelessly into danger. They should never adopt the principle of foolhardy and thoughtless people, who by the consciousness of continual danger fall into the habit of carelessly "trusting to their luck," etc. On the contrary, they should always face the danger with their eyes open and with the greatest conscientiousness. Many try to show great courage by scorning the danger, and some such even wish to meet a little in order to be able to show their pluck. These should bear in mind that they have a great responsibility laid, upon them, and that it is not alone their own well-being or life which is at stake in case of any mishap, but that by their careless behavior they may wound or 1kill the helpless people who are committed to their -care, cause incalculable misery by robbing families of their sole support and of their children; and bring great Qualifications of-,Locomotive Runners. 547 sorrow and mourning to their fellow-men. The thought of the curse and the despair of the survivors may give sleepless hours even to a locomotive runner who knows himself to have been without any fault regarding an accident; how much more must it be with him who cannot give himself this assurance? There are not wanting instances in which the runner who caused such an accident by his thoughtlessness, driven to despair by his own heavily-burdened conscience, went miserably to ruin. QUESTION 562. What requirements and duties should every locomotive runnerfilfill? Answer. Every locomotive runner should fulfill the following requirements and duties: 1. He should lhave an exact knowledge of the engine intrusted to him, and a general knowledge of the nature and construction of steam engines generally. Likewise, he should be perfectly familiar with the management of the boiler, the running of the engine, and the way of keeping the working parts in good condition; also, with the forms and peculiarities of the line of road on which he runs, the rules which govern the running of trains and with the signal system adopted. 2. Health and bodily strength he must have in abundant measure in his position, which is exhausting and in which he is exposed to all sorts of weather. 3. He should have a good, plain common-school education, and be ready at reading, writing and arithmetic. 4. HIe should always carry out exactly and cheerfully the regulations of the service, or the instructions given him by special orders from the officers over him. 548 Catechism of the, Locomotive. 5. Faithfulness, frankness and honesty, which characterize an upright man in ordinary life, and also the strictest temperance in the use of strong drink, he should possess in a high degree in his very responsible position. 6. He should have acquired a certain degree of skill in putting together and taking apart locomotives, and also in repairing separate parts of them. It is desirable that he should always be present when his own engine is taken apart, put together or repaired, in order that he may acquire a thorough knowledge of its condition and learn to understand properly the imnportance of its various parts. 7. In caring for his engine he must preserve perfect cleanliness and order, and in using fuel he must manifest the greatest care and rigid economy. 8. Whenever there is danger, coolness and selfpossession are indispensably necessary, and any thoughtlessness or recklessness is to be strictly avoided. 9. Towards his superior officers his behavior should be respectful and obliging; towards those under him, patient and kindly, and at all times he should avoid profanity and all intemperate language. He should endeavor, as far as possible, to instruct the fireman who accompanies him and make him familiar with the construction and management of the engine, and should see that he does his work strictly in accordance with his instructions. It is the fireman's duty to follow the runner's instructions strictly, and in case of any sudden disability of the runner he must stop the engine in accordance with the instructions given him, and then give Qualifications of Locomotive Runners. 549 the proper signals for help, until another runner arrives. In the meanwhile the engine is to be kept at a halt with all the usual precautions. 10. The runner should try to keep himself informed of the progress and improvement of locomotives by reading suitable books and technical periodicals, and when possible acquire some skill in geometrical and mechanical drawing, in order to accustom himself to accurate work and sound and systematic thinking. QUESTION 563. What studies should mechanics, locomotive runners and firemen take up, and what technical books should they read? Answer. As already stated, they should know how to read and write their own language, and understand arithmetic and have some knowledge of geography. Every locomotive runner and fireman has a good deal of spare time, a part of which he can devote to study, and all of them, even if they have not had the advantage of early education, could by industry and perseverance acquire a knowledge of " reading, writing and ciphering." The assistance of a good teacher should always be procured, if possible. With so much knowledge, some book on natural philosophy can be read to advantage, and then some book on mechanics. The following list of books is given, which the student will do well to read in the order in which they are named. It should always be remembered, however, that the mere buying of books contributes very little knowledge to the owner. It is the reading and understanding them which " increases knowledge." 550 Catechism of the Locomotive. LIST OF BOOKS FOR MECHANICS, LOCOMOTIVE RUNNERS, FIREMEN, ETC. A Hand Book of the Steam Engine, by John Bourne; published by Longmans, London; $2.00. A Catechism of the Steam Engine, by John Bourne; published by Longmans, London; $2.00. Lessons in Elementary Physics, by Balfour Stewart; published by Mactmillan & Co., New York; $1.50. Experimental Mechanics, by Prof. Ball; published by Macmillan & Co., New York; $6 00. The New Chemistry, by Prof. J. P. Cooke; published by Appleton & Co., New York; $2 00. Elementary Treatise on Heat, by Balfour Stewart; published by Macmillan _& Co, New York; $3.00. Combustion of Coal, by C. Wye Williams; published by Lockwood & Co., London; $1.20. A Treatise on Steam Boilers, by Robert Wilson; published by Lockwood & Co., London; $3.00. Link-Valve Motion, by Wm. S. Auchincloss; published by D. Van Nostrand, New York; 83.00. The Conservation of Energy, by Balfour Stewart; published by Appleton & Co., New York; $1.50. Richards' Steam Engine Indicator, by Charles T. Porter; published by Longmans, London; $2.50. PiLATES. PLATE IV. DIMENSIONS, WEIGHT, ETC., OF FOUR-WHEELED SWITCHING LOCOMOTIVE, BY THE HINKLEY LOCOMOTIVE WORKS, BOSTON, MASS. Gauge of Road................................ 4 ft 8 in. Number of Driving-Wheels......................4........... 4 Number of Front Truck-Wheels............................None. Number of Back Truck-Wheels...........................None. Total Wheel Base........................................6 ft. 9 in. Distance between Front and Back Driving-Wheels...... 6 ft. 9 in. Total Weight of Locomotive in working order........... 48,ooo lbs. Total Weight on Driving-Wheels..................... 48,000 lbs. Diameter of Driving-Wheels.............................50 in. Diameter of Truck-Wheels............................N...one. Diameter of Cylinders..................................... I5 in. Stroke of Cylinders...........................................22 Outside Diameter of smallest Boiler ring....................443,4 in. Size of Grate.........................................3 X 3% ft. Number of Tubes,..............................................2 Diameter of Tubes...................................... 2 in. Length of Tubes.....................................o...... ft. Square Feet of Grate surface.................................... II Square Feet of Heating surface in Fire-Box.............7 Square Feet of Heating surface in Tubes.....................580 Total Feet of Heating surface.................6................656 Exhaust Nozzles - single or double....................... Double. Diameter of Nozzle............................... 3..,2 in Size of Steam Ports.................................o X I X in. Size of Exhaust Ports......................... 2.z in. Throw of Eccentrics................................... 4 in. Outside Lap of Valve............................ 4 in. Inside Lap of Valve....................................... None. Size of Main Driving-axle Journal...................... 6 X 7 in. Size of other Driving-axle Journal......................6% X 7 in. Size of Truck-axle Journal........................... None. Diameter of Pump Plunger............................... I in. Stroke of Pump Plunger................................... 22 in. Capacity of Tank..................................,2oo gallons. ~~~ —-— I~~~~~-. Plate IV. FOUR-WHEELED SWITCHING LOCOMOTIVE, BY THE HINKLEY LOCOMOTIVE WORKS, BOSTON, MASS Scale,'8 in.= - ft. _.j 554 PLATE V. DIMENSIONS, WEIGHT, ETC., OF EIGHT-WHEELED "AMERICAN" LOCOMOTIVE BY THE BALDWIN LOCOMOTIVE WORKS, PHILADELPHIA. Gauge of Road............................. 4 ft. 8. in. Number of Driving-Wheels....................................4 Number of Front Truck-Wheels...................4............... Number of Back Truck-Wheels............................. None. Total Wheel Base...................................... 2I ft. 9 in. Distance between centres of Front and Back Driving-Wheels... 96 in. Total Weight of Locomotive in working order............ 65,00ooo lbs. Total Weight on Driving-Wheels..................42,000 lbs. Diameter of Driving-Wheels......................6o03 in. Diameter of Truck-Wheels..................................28 in. Diameter of Cylinders................................... in. Stroke of Cylinders................................... 24 in. Outside Diameter of smallest Boiler Ring.....................48 in. Size of Grate.......................................65 X 34'/ in. Number of Tubes...................................44 Diameter of Tubes....................................2 in. Length of Tubes...................................o ft II in. Square Feet of Grate surface............................ 5........5 Square Feet of Heating surface in Fire-Box.................. 6.oo. 6 Square Feet of Heating surface in Tubes.....................825.4 Total Feet of Heating surface..............................926 Exhaust Nozzles - single or double........................ Double. Diameter of Nozzle............................. 23 to 3 in. Size of Steam Ports............................... X 5 in. Size of Exhaust Ports.......................... 2......2 X 15 in. Throw of Eccentrics..................................... 5. in. Outside Lap of Valve........................................ in. Inside Lap of Valve..................................... I-32 in. Size of Main Driving-axle Journal................. 7 in. dia. x 8 in. Size of other Driving-axle Journal..................7 in. dia. x 8 in. Size of Truck-axle Journal..........................4 X 7% in. Diameter of Punmp Plunger..........................2 in. Stroke of Pump Plunger....................................24 in. Capacity of Tank...........................2,000 gallons. I_ _ Plate V. EIGHT-WHEELED "AMERICAN" LOCOMOTIVE, BY THE BALDWIN LOCOMOTIVE WORKS, PHILADELPHIA. Scale, V7 in.= x ft. L* ____J _- ~~___~ _~ 556 PLATE VI. DIMENSIONS, WEIGHT, ETC., OF EIGHT-WHEELED "AMERICAN" LOCOMOTIVE By THE GRANT LOCOMOTIVE WORKS, PATERSON, N. J. Gauge of Road.......................................4 ft. 8I2 in. Number of Driving-Wheels.................................... 4 Number of Front Truck-Wheels............................4..... Number of Back Truck-Wheels....................... None. Total Wheel Base..................................... 2i ft. 9 in. Distance between centres of Front and Back Driving-Wheels.... 8 ft. Total Weight of Locomotive in working order............62,coo lbs. Total Weight on Driving-Wheels........................42,coo lbs. Diameter of Driving-Wheels............................6I in. Diameter of Truck-Wheels..................................28 in. Diameter of Cylinders...................I...................6 in. Stroke of Cylinders.........................................24 in. Outside Diameter of smallest Boiler Ring.....................48 in. Size of Grate..........................................60 X 34 in. Number of Tubes............................................I40 Diameter of Tubes..........................................2 in. Length of Tubes.......................................... ft. Square Feet of Grate surface................................. 4 Square Feet of Heating surface in Fire-Box......................98 Square Feet of Heating surface in Tubes.................85 Total Feet of Heating surface................03...............03 Exhaust Nozzles - single or double..................D.....ouble. Diameter of Nozzle.................................34 to 334 in. Size of Steam Ports..............................I... X 4 in. Size of Exhaust Ports..........................2 X 14 in. Throw of Eccentrics.....................................5 illn. Outside Lap of Valve....................................... in. Inside Lap of Valve................................ None. Size of Main Driving-axle Journal................63 dia. X 734 in. Size of other Driving-axle Journal.................6 -dia. X 734 ill. Size of Truck-axle Journal.........................43 dia. X 8 in. Diameter of Pump Plunger...................2 in. Stroke of Pump Plunger..................................24 in. Capacity of Tank...................................z,ooo gallons. _j Plate VI - EIGHT-WHEELED "AMERICAN" LOCOMOTIVE, BY THE GRANT LOCOMOTIVE WORKS, PATERSON, N. J. Scale, / n. I ft L ------- ------ — ~ —~~ —------- ~ -- -~-~ —-~ —-----— ~ —-— ~- ~ —-~-~ —~~~~~~~~~- ------- PLATE VII. DIMENSIONS, WEIGHT, ETC., OF EIGHT-WHEELED "AMERICAN " LOCOMOTIVE BY THE DANFORTH LOCOMOTIVE AND MACHINE CO., PATERSON, N. J. Gauge of Road.......................................4 ft. 8y in. Number of Driving-Wheels..................................... 4 Number of Front Truck-Wheels................................ 4 Number of Back Truck-Wheels.........................None. Total Wheel Base....................................2I ft. 2 in. Distance between centres of Front and Back Driving-Wheels, 7 ft. 9 in. Total Weight of Locomotive in working order............60,200 lbs. T6tal Weight on Driving-Wheels........................38,350 lbs. Diameter of Driving-Wheels..........................5 ft. 7Y8 in. Diameter of Truck-Wheels........................ a... 2 ft. 6 in. Diameter of Cylinders.................................... I5 in. Stroke of Cylinders.........................................24 in. Outside Diameter of smallest Boiler Ring.................3 ft. Io in. Size of Grate......................................56 X 34S in. Number of Tubes........................................... I36 Diameter of Tubes...........................a........... 2 in. Length of Tubes.......................................... II ft. Square Feet of Grate surface.................................. 3.5 Square Feet of Heating surface in Fire-Box.....................86 Square Feet of Heating surface in Tubes......................775 Total Feet of Heating surface............................ 86s Exhaust Nozzles - single or double........................Double. Diameter of Nozzle................................23 in. Size of Steam Ports.............................. I X I3 in. Size of Exhaust Ports............................. 2 X I3 in. Throw of Eccentrics....................................... 5 in. Outside Lap of Valve.................................... Y8 in. Inside Lap of Valve.............................8 in. Size of Main Driving-axle Journal.................6.......... in. Size of other Driving-axle Journal.......................... 6 in. Size of' Truck-axle Journal................................. 4 in. Diameter of Pump Plunger................................ 28 in. Stroke of Pump Plunger......................24 in. Capacity of Tank........................... I, 800oo gallons. i. -_ _ _ _ _ _ _ _ _ _ _ _ _ _ __ _ _ _ _ _ _ _ _ _ _ _ _ _ __ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Plate VII. C.WRIHT.N.Y. EIGHT-WHEELED "AMERICAN" LOCOMOTIVE, BY THE DANFORTH LOCOMOTIVE AND MACHINE CO., PATERSON, N. J. Scale, Y8 in.= I ft. L -.1 560 PLATE VIII. DIMENSIONS, WEIGHT, ETC., OF EIGHT-WHEELED "AMERICAN" LOCOMOTIVE BY THE MASON MACHINE WORKS, TAUNTON, MASS. Gauge of Road.........................i.....n.....4 ft. 8 in. Number of Driving-Wheels........................4............. Number of Front Truck-Wheels.................................4 Number of Back Truck-Wheels.............................None. Total Wheel Base.........................................22 ft. Distance between centres of Front and Back Driving-Wheels.... 8 ft. Total Weight of Locomotive in working order.......... 62,00ooo lbs. Total Weight on Driving-Wheels............00..........40,ooo lbs. Diameter of Driving-Wheels.............................5 ft. 6 in. Diameter of Truck-Wheels...............................2 ft. 9 in. Diameter of Cylinders........................ I ft. 5 in. Stroke of Cylinders.....................................2 ft. Outside Diameter of smallest Boiler Ring................ 3 ft Io in. Size of Grate........................................ 66 X 3534 in. Number of Tubes.................................55 Diameter of Tubes................................... 2 in. Length of Tubes....................................... II ft. 2 in. Square Feet of Grate surface...............................i6.38 Square Feet of Heating surface in Fire-Box................ 05 Square Feet of Heating surface in Tubes.......................906 Total Feet of Heating surface............................ IoI Exhaust Nozzles - single or double.....................Single. Diameter of Nozzle..............................33 in. Size of Steam Ports................... I5 X I in. Size of Exhaust Ports..........I.......... I5 X 23/4 in. Throw of Eccentrics..................................... 42 in. Outside Lap of Valve................................ Y8 in. Inside Lap of Valve.......................... I-I6 in. Size of Main Driving-axle Journal.....................6 X 7y in. Size of other Driving-axle Journal............................ Size of Truck-axle Journal...........................34 X 62 in. Diameter of Pump Plunger................................I34 in. Stroke of Pump Plunger......................24 in. Capacity of Tank............2.......................,250 gallons. * The Boiler is made conical, 46 in. diameter at the Smoke-Box and 50 in. at the Fire-Box. Plate VIII. EIGHT-WHEELED "AMERICAN" LOCOMOTIVE, BY THE MASON MACHINE WORKS, TAUNTON, MASSACHUSETTS. Scale, Y8 in. = I ft. 562 PLATE IX. DIMENSIONS, WEIGHI', ETC., OF EIGHT-WHEELED "AMERICAN" LOCOMOTIVE BY THE HINKLEY LOCOMOTIVE WORKS, BOSTON, MASS. Gauge of Road...........................ft....... 4 ft. 8.. in. Number of Driving-Wheels..................................... 4 Number of Front Truck-Wheels.........................4........ Number of Back Truck-Wheels.............................None Total Wheel Base....................................2I ft. 4', in. Distance between centres of Front and Back DrivingWheels............................................ 7 ft. 6 in. Total Weight of Locomotive in workling order............63,000 lbs. Total Weight on Driving-Wheels........................ 4,0oo lbs. Diameter of Driving-Wheels................................68 in. Diameter of Truck-Wheels..................................30 in. Diameter of Cylinders......................................6 in. Stroke of Cylinders......................................24 in. Outside Diameter of smallest Boiler Ring.............46 in. Size of Grate.........................................3 ft. X 5 ft. Number of Tubes...................................... o.....150 Diameter of Tubes..........................................2 in. Length of Tubes............................................ ft. Square Feet of Grate surface...................................15 Square Feet of Heating surface in Fire-Box..................... oo Square Feet of Heating surface in Tubes.................755 Total Feet of Heating surface................................. 855 Exhaust Nozzles - single or double........................Double. Diameter of Nozzle......................................... 3 in. Size of Steam Ports............................. I4 X I S in. Size of Exhaust Ports..................................... 23 in. Throw of Eccentrics........................................ 5 in. Outside Lap of Valve...............................I3-I6 in. Inside Lap of Valve.................................None. Size of Main Priving-axle Journal.......................7 X 7 in. Size of other Driving-axle Journal........................7 x 7 in. Size of Truck-axle Journal.............................4% X 7 in. Diameter of Pump Plunger................................I in. Stroke of Pump Plunger.............................. 24 in. Capacity of Tank................................... 2,000 gallons. L -1~~~~~~~~~~~~~~ Plate IX. EIGHT-WHEELED "AMERICAN" LOCOMOTIVE, BY THE HINKLEY LOCOMOTIVE WORKS, BOSTON, MASSACHUSETTS. Scale,'/ in.=-I ft. -----— ~ —-— c~~~~ —U I —-—.~~~.2 564 PLATE X. DIMENSIONS, WEIGHT, ETC., OF TEN-WHEELED LOCOMOTIVE, BY THE BALDWIN LOCOMOTIVE WORKS, PHILADELPHIA. Gauge of Road....................................... ft. 8 in. Number of Driving-Wheels....................................6 Number of Front Truck-Wheels.................................4 Number of Back Truck-Wheels.............................. None. Total Wheel Base.................................... 23 ft. 6 in. Distance between centres of Front and Back Driving-Wheels....88 in. Total Weight of Locomotive in working order............78,000 lbs. Total Weight on Driving-Wheels........................58,ooo lbs. Diameter of Driving-Wheels................................54 in. Diameter of Truck-Wheels................................... 6 in. Diameter of Cylinders.................................... I8 in. Stroke of Cylinders.........................................24 in. Outside Diameter of smallest Boiler Ring.....................50 in. Size of Grate...................................... 60 X 34~ in. Number of Tubes............................................I52 Diameter of Tubes.........................................2 in. Length of Tubes.......................................2 ft. 9 in. Square Feet of Grate surface................................I4.37 Square Feet of Heating surface in Fire-Box......................94 Square Feet of Heating surface in Tubes................ 0..14. o14 Total Feet of Heating surface................................. Io8 Exhaust Nozzles - single or double........................Double. Diameter of Nozzle.................................. 3 to 3A in. Size of Steam Ports.............................. X 6 in. Size of Exhaust Ports................................. 2 X i6 in. Throw of Eccentrics.....................................5 in. Outside Lap of Valve....................................... it. Inside Lap of Valve.................................... I-32 n. Size of Main Driving-axle Journal.................7 in. dia. X 8 in. Size of other Driving-axle Journal..................7 in. dia. x 8 in. Size of Truck-axle Journal........................... 43 X 72 in. Diameter of Pump Plunger.................................2 in. Stroke of Pump Plunger................................. 24 in. Capacity of Tank........................... o.....2,200 gallons. Plate X..1. TEN-WHEELED LOCOMOTIVE, BY THE BALDWIN LOCOMOTIVE WORKS, PHILADELPHIA, Scale, s iln.= I ft. 566 PLATE XI. DIMENSIONS, WEIGHT, ETC., OF "MOGUL" LOCOMOTIVE, BY THE BALDWIN LOCOMOTIVE WORKS, PHILADELPHIA. Gauge of Road.........t....................4 ft. 8 in. Number of Driving-Wheels.................................... 6 Number of Front Truck-Wheels................................2 Number of Back Truck-Wheels............................None. Total Wheel Base.................................... 22 ft. 8 in. Distance between centres of Front and Back Driving-Wheels..96 in. Total Weight of Locomotive in working order..........77,0oo lbs. Total Weight on Driving-Wheels............6..........,ooo lbs. Diameter. of Driving-Wheels....................52 in. Diameter of Truck-Wheels.......................30 in. Diameter of Cylinders..................................... i8 in. Stroke of Cylinders.................................... 24 in. Outside Diameter of smallest Boiler Ring...................50 in. Size of Grate........................... 66 x 34Y in. Number of Tubes..............................16.............. Diameter of Tubes........................................2 in. Length of Tubes...................................... I ft. 3 in. Square Feet of Grate surface................................. Square Feet of Heating surface in Fire-Box.......... 10.......2.7 Square Feet of Heating surface in Tubes......................948 Total Feet of Heating surface............................... Exhaust Nozzles-single or double.................Double. Diameter of Nozzle.............................3 to 3 in. Size of Steam Ports...............................s.. X i6 in. Size of Exhaust Ports............................... X I6 in. Throw of Eccentrics...................................... in. Outside Lap of Valve......................... in. inside I,ap of Valve...................................... -32 in. Size of Main Driving-axle Journal...............7 in. cia. x 8 in. Size of other Driving-axle Journal...............7 in. dia. x 8 in. Size of Truck-axle Journal........................5 in. dia. X 8 in. Diameter of Pump Plunger..............................2 in. Stroke of Pump Plunger..................................24 in. Capacity of Tank............................. 2,200 gallons. L J. Plate XI. ira I -- "MOGUL" LOCOMOTIVE, BY THE BALDWIN LOCOMOTIVE WORKS, PHILADELPHIA. Scale, ~8 in.- I ft. By =- - ~ 568 PLATE X DIMENSICNS, WEIGHT, ETC., OF "CONSOLIDATION" LOCOMOTIVE, BY THEDANFORTH LOCOMOTIVE AND MACHINE CO., PATERSON, N. J. Gauge of Road........................................4 ft. 8'/ in. Number of Driving-Wheels.....................................8 Number of Front Truck-Wheels................ 2............2 Number of Back Truck-Wheels............................None. Total Wheel Base.................................... 23 ft. 2 in. Distance between centres of Front and Back DrivingWheels............................ 5 ft. 7 in. Total Weight of Locomotive in working order............ 96,55 lbs. Total Weight on Driving-Wheels.....................86,430 lbs. Diameter of Driving-Wheels.................... 4 ft. 2 in. Diameter of Truck-Wheels.........................2 ft. 7 in. Diameter of Cylinders................................ 20 in. Stroke of Cylinders.........................................24 in. Outside Diameter of smallest Boiler Ring................ 4 ft. 2 in. Size of Grate............2...... C.....2c X 34Y3 in. Number of Tubes.........65................. 65 Diameter of Tubes.................................. 2 z4 in. Length of Tubes.................................... I3 ft. 9gI in. Square Feet of Grate surface...............................29 Square Feet of Heating surface in Fire-Box.................... 39 Square Feet of Heating surface in Tubes...................... I370 Total Feet of Heating surface...................5............ I509 Exhaust Nozzles-single or double......................... Double Diameter of Nozzle.................................. in. Size of Steam Ports....................... I X I5 in. Size of Exhaust Ports........................... 23 X I5 in. Throw of Eccentrics................,........ s.....5 in. Outside Lap of Valve..............s.............. in. Inside Lap of Valve....................... None. Size of Main Driving-axle Journal......................63, in, Size of other Driving-axle Journal................ 63,4 in. Size of Truck-axle Journal............................5 in. Diameter of Pump Plunger.................................2% in. Stroke of Pump Plunger............................. 24 in. Capacity of Tank.............. 2,400 gallons. _ __ __~~~ _______ _ __ _____~ ___ ____.1 Plate XII. "CONSOLIDATION" LOCOMOTIVE, BY THE DANFORTH LOCOMOTIVE AND MACHINE CO., PATERSON, N. J. Scale, ys in.= I ft. 570 PLATE XIII. DIMENSIONS, WEIGHT, ETC., OF DOUBLE-END TANK LOCOMOTIVE, BY THE ROGERS LOCOMOTIVE AND MACHINE WORKS, PATERSON, N. J. Gauge of Road,..............,.............. 4 ft. 8. in. Number of Driving-Wheels.....................................6 Number of Front Truck-Wheels............................... 2 Number of Back Truck-Wheels.................................2 Total Wheel Base................................24 ft. 7/2 in. Distance between centres of Front and Back Driving-Wheels.. I2 ft. Total Weight of Locomotive in working order...........84,000 lbs. Total Weight on Driving-Wheels....................... 68,ooo lbs. Diameter of Driving-Wheels.............................. 4o0 in. Diameter of Truck-Wheels..................................26 in. Diameter of Cylinders................,,.................. I5 in. Stroke of Cylinders.............,........................ 20 in. Outside Diameter of smallest Boiler Ring.................. 46 in. Size of Grate..........................................34 x 48 in. Number of Tubes............................................32 Diameter of Tubes..........................................2 in. Length of Tubes.......................,..... ft. g in. Square Feet of Grate surface...........e.............. II. 7 Square Feet of Heating surface in Fire-Box..................... 67 Square Feet of Heating surface in Tubes........................ 608 Total Feet of Heating surface.................................675 Exhaust Nozzles-single or double........................Double. Diameter of Nole....................................2 to 23/8 in. Size of Steam Ports............................3 X I 3-I6 in. Size of Exhaust Ports.233....................3 X 2 7-I6 in. Throw of Eccentrics....................................... 43 in. Outside Lap of Valve................................. X -64 in. Inside Lap of Valve......................................I-I6 in. Size of Main Driving-axle Journal...................... 6 X 7y, in. Size of other Driving-axle Journal...................... 6 X 7y4 in. Size of Truck-axle Journal.............................4% X 8 in. Diameter of Pump Plunger................................ I in. Stroke of Pump Plunger....................................20 in. Capacity of Tank................................. i,6oo gallons. L.__ _ ____ Plate XIII. DOUBLE-END TANK LOCOMOTIVE, BY THE ROGERS LOCOMOTIVE AND MACHINE WORKS, PATERSON, N. J. Scale, Y,/ in.= I ft. ~~~~~~~ii i lil... 572 PLATE XIV. DIMENSIONS, WEIGHT, ETC., OF DOUBLE-END TANK LOCOMOTIVE, BY THE ROGERS LOCOMOTIVE AND MACHINE WORKS, PATERSON, N. J. Gauge of Road............................ 2 4 t. 8.X in. Number of Driving-Wheels...................................... Number of Front Truck-Wheels.................................2.. Number of back Truck-Wheels...........................4....... Total Wheel Base................................. 25 ft. 183 in. Distance between centres of Front and Back Driving,-Wheels.6 ft. 6 in. Total Weight of Locomotive in working order........... 75,00ooo lbs. Total Weight on Driving-Wheels....................... 40,00ooo0 lbs. Diameter of Driving-Wheels.............................4834 in. Diameter of Truck-Wheels.............................30 and 26 in. Diameter of Cylinders...................................I5 in. Stroke of Cylinders........................................ 22 in. Outside Diameter of smallest Boiler Ring:.................. 43 in. Size of Grate............................. 34 X 50 in. Number of Tubes................................... I39 Diameter of Tubes.................................... 2 in. Length of Tubes....................................8 ft. ioy in. Square Feet of Grate surface................................ 8 4 Square Feet of Heating surface in Fire-Box...................... 82 Square Feet of Heating surface in Tubes.2........................ 7 Total Feet of Heating surface.................................793 Exhaust Nozzles-single or double...................Double. Diameter of' Nozzle.................................. 2 to 2X8 in. Size of Steam Ports......a........................33 X I 3-I6 in. Size of Exhaust Ports.............................I334 X 2 7-I6 in. Throw of Eccentrics..................................... 4 in. Outside Lap of Valve...............................5/8 X I-64 in. Inside Lap of Valve...................................... I-I6 in. Size of Main Driving-axle Journal.......................6 X 73 in. Size of other Driving-axle Journal..............6 X 73 in. Size of Truck-axle Journal...........................43 X 73 in.t Diameter of Pump Plunger................................. Y8 in. Stroke of Pump Plunger:....................................22 in. Capacity of Tank.t....................................ooo gallons. t Above is the Front Truck-exle Journal. That of the Back Truckaxle is 43 X 73 in. Plate XIV. DOUBLE-END TANK LOCOMOTIVE, BY THE ROGERS LOCOMOTIVE AND MACHINE WORKS, PATERSON, N. J. Scale, Y8 in. = I ft. L _. _._.... 574 r PLATE XV. DIMENSIONS, WEIGHT, ETC., OF IMPROVED TANK LOCOMOTIVE, DESIGNED BY M. N. FORNEY, 73 BROADWAY, NEW YORK. Gauge of Road...................................... 4 ft. 8, in. Number of Driving-Wheels..........4.............. Number of Front Truck-Wheels............4............ 4 Number of Back Truck-Wheels..................None. Total Wheel Base................................... 20 ft. 9 in. Distance between centres of Front and Back DrivingWheels.............................................6 ft. 8 in. Total Weight of Locomotive in working order............60,ooo lbs. Total Weight on Driving-Wheels....................... 44,000 lbs. Diameter of Driving-Wheels................................50 in. Diameter of Truck-Wheels..................................26 in. Diameter of Cylinders................................... 14 in. Stroke of Cylinders....................................20 in. Outside Diameter of smallest Boiler Ring....................46 in. Size of Grate....................................54 X 36-8 in. Number of Tubes............................................ 139 Diameter of Tubes................................... 2 in. Length of Tubes...................o................ io ft. I'I in. Square Feet of Grate surface...................................14 Square Feet of Heating surface in Fire-Box......................78 Square Feet of Heating surface in Tubes....................... 734 Total Feet of Heating surface................................. 812 Exhaust Nozzles-single or double........................Double. Diameter of Nozzle................................... 2 in. Size of Steam Ports....................................2 X IX4 in. Size of Exhaust Ports.................................12 X 2y in. Throw of Eccentrics...................................5 in. Outside Lap of Valve........4.............................3/5 in. Inside Lap of Valve...-.i........................ I-32 in. Size of Main Driving-axle Journal........................ 6 X 7 in. Size of other Driving-axle Journal........................ 6 X 7 in. Size of Truck-axle Journal............................33, X 7 in. Diameter of Pump Plunger...................................4 in. Stroke of Pump Plunger...........................s.....5 in. Capacity of Tank................................1,500 gallons. L -J 575 F -— ~ — ~ ----— "- i- --- m~~~~~~~~~~~.o; I~_ IE!:k~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~.... Z 00 0 t'! ~~Y8i~ 1Il~llj~ o O~~~~~~~~~~~~~~~~~_ 576 PLATE XVI. DIMENSIONS, WEIGHT, ETC., OF DOUBLE-TRUCK NARROW-GAUGE TANK LOCOMOTIVE, BY THE MASON MACHINE WORKS, TAUNTON, MASS. Gauge of Road...................................3 ft. Number of Driving-Wheels.....................................4 Number of Front Truck-Wheels................................ 4 Number of Back Truck-Wheels..................4.............. Total Wheel Base..................................... I ft. 6 in. Distance between centres of Front and Back Driving-Wheels....5 ft. Total Weight of Locomotive in working order................ Total Weight on Driving-Wheels.......................24,000 lbs. Diameter of Driving-Wheels............a................. 2 ft. 9 in. Diameter of Truck-Wheels............................... 2 ft. 6 in. Diameter of Cylinders.. _................................. Io in. Stroke of Cylinders...................................I ft. 3 in. Outside Diameter of smallest Boiler Ring...ft............ 3 ft. Size of Grate...................................... 4I X 31 in. Number of Tubes.............................................81 Diameter of Tubes........................................2 in. Length of Tubes....................................... 8 ft. 2 in. Square Feet of Grate surface................................8.93 Square Feet of Heating surface in Fire-Box.................... 56 Square Feet of Heating surface in Tubes..................... 346 Total Feet of Heating surface..4...0.................402 Exhaust Nozzles- single or double........................Single. Diameter of Nozzle................................... in. Size of Steam Ports.................................X 2 x /8 in. Size of Exhaust Ports x................................. X 2 in. Throw of Eccentrics....................................... 33 in. Outside Lap of Valve...................................... 3in. inside Lap of Valve.........................................I-I6 Size of Main Driving-axle Journal.......................5 X 7 in. Size of other Driving-axle Journal............................... Size of Truck-axle Journal..............3... 6. in. Diameter of Pump Plunger.................................. Stroke of Pump Plunger........................................ Capacity of Tank......................800o gallons. -__- __ __ --- _______________I Plate XVI. DOUBLE-TRUCK NARROW-GAUGE TANK LOCOMOTIVE, BY THE MASON MACHINE WORKS, TAUNTON, MASS. Scale, Y in.=- x ft..L ~ ~~DOBE-RC NARWGUETN OOOIE 578 PLATE XVII. DIMENSIONS, WEIGHT, ETC., OF DOUBLE-TRUCK TANK FREIGHT LOCOMOTIVE BY THE MASON MACHINE WORKS, TAUNTON, MASS. Gauge of Road..................................... 4 ft. 8y in. Number of Driving-Wheels..................................... 6 Number of Front Truck-Wheels.................................. 6 Number of Back Truck-Wheels.................................. 6 Total Wheel Base..................................1.........3 ft. Distance between centres of Front and Back Driving-Wheels.... 8 ft. Total Weight of Locomotive in working order...................... Total Weight on Driving-Wheels........................66,ooo lbs. Diameter of Driving-Wheels............................. 3 ft. 6 in. Diameter of Truck-Wheels............................... 2 ft. 6 in. Diameter of Cylinders.........................I ft. 4 in. Stroke of Cylinders.......................................... 2 ft. Outside Diameter of smallest Boiler Ring....................... 4 ft. Size of Grate...................................... 66 x 483Y in. Number of Tubes............................................54 Diameter of Tubes.......................................... 2 in. Length of Tubes...................................... I. ft. 6 in. Square Feet of Grate surface.................................. 22. 17 Square Feet of Heating surface in Fire-Box......................26 Square Feet of Heating surface in Tubes....................... 927 Total Feet of Heating surface...............................I053 Exhaust Nozzles-single or double......................Single. Diameter of Nozzle......................... Variable. Size of Steam Ports....................................5 X I % in. Size of Exhaust Ports.................................. 5 X 234 in. Throw of Eccentrics........................................ 8 in.* Outside Lap of Valve....................................... in. Inside Lap of Valve..............I-....................i... 6 in. Size of Main Driving-axle Journal.....................62 X lo in. Size of other Driving-axle Journal................................ Size of Truck-axle Journal.........................4 X 8 in. Diameter of Pump Plunger...................................... Stroke of Pump Plunger.................................. Capacity of Tank......................... 2,530 gallons. * This engine has Walschacrt's valve gear, which is worked by a crank of 8 inches throw. L - Plate XVII. DOUBLE-TRUCK TANK FREIGHT LOCOMOTIVE BY THE MASON MACHINE WORKS, TAUNTON, MASSACHUSETTS. Scale, s3 in.= i ft. 580 PLATE XVIII. DIMENSIONS, WEIGHT, ETC., OF DOUBLE-END LOCOMOTIVE, BY THE GRANT LOCOMOTIVE WORKS, PATERSON, N. J. Gauge of Road................................. 8 in. Number of Driving-Wheels.................. 4 Number of Front Truck-Wheels.......a.................. 2 Number of Back Truck-Wheels................................. 2 Total Wheel Base.......................9............. ft. 9 in. Distance between centres of Front and Back Driving-Wheels..... 7 ft. Total Weight of Locomotive in working order............52,000 lbs. Total Weight on Driving-Wheels................ 4....... 42,o0o lbs. Diameter of Driving-Wheels................................. 56 in. Diameter of Truck-Wheels...................28 in. Diameter of Cylinders.................1.................I4 in. Stroke of Cylinders.............................. 22 in. Outside Diameter of smallest Boiler Ring.............42 in. Size of Grate.................................73 x 34 in. Number of Tubes.............................................24 Diameter of Tubes........................................ 2 in. Length of Tubes....................................... 7 ft. io in. Square Feet of Grate surface................................. 6.5 Square Feet of Heating surface in Fire-Box.................... 80.8 Square Feet of Heating surface in Tubes..................... 468.5 Total Feet of Heating surface................................549.3 Exhaust Nozzles-single or double......................... Double. Diameter of Nozzle................................. 22 to 3Y8 in. Size of Steam Ports.................................1.4 X I/8 in. Size of Exhaust Ports.................................I4 X 274 in. Throw of Eccentrics................................. 5 in. Outside Lap of Valve........................................ in. Inside Lap of Valve.................................. None. Size of Main Driving-axle Journal..................6 dia. X 734 in. Size of other Driving-axle Journal..................6 dia. X 72 in. Size of Truck-axle Journal........................4 dia. X 8 in. Diameter of Pump Plunge r.................... 3 in. Stroke of Pump Plunger.....................................5 in. Capacity of Tank...................................,6oo gallons. Plate XVIII. DOUBLE-END LOCOMOTIVE, BY THE GRANT LOCOMOTIVE WORKS, PATERSON, N. J. Scale, Y8 in.-I ft.; _....................... _.. _. I PLATE XIX. DIMENSIONS, WEIGHT, ETC., OF LOCOMOTIVE FOR THE N. Y. ELEVATED R. R. DESIGNED BY D. W. WYMAN, SUPERINTENDENT. Gauge of Road....................................... 4 ft. io in. Number of Driving-Wheels......................... 4 Number of Front Truck-Wheels...................None. Number of Back Truck-Wheels.............................None. Total Wheel Base.......................................... 5 ft. Distance between centres of Front and Back Driving-Wheels.... 5 ft. Total Weight of Locomotive in working order.............. 8,00o lbs. Total Weight on Driving-Wheels.......................... 8,ooo lbs. Diameter of Driving-Wheels.....................30 in. Diameter of Truck-Wheels.................................. None. Diameter of Cylinders...................................... 7 in. Stroke of Cylinders.........................................o in. Outside Diameter of smallest Boiler Ring.................... 28 in. Size of Grate..........................................28 x 28 in. Number of Tubes.............................................I40 Diameter of Tubes.......................................i in. Length of Tubes............................3 ft. Square Feet of Grate surface.....f............................ ft Square Feet of Heating surface in Fire-Box................ 25 ft. Square Feet of Heating surface in Tubes...............i26 ft. Total Feet of Heating surface....................I5 ft. Exhaust Nozzles-single or double.........................Double. Diameter of Nozzle...................................... 2 in. Size of Steam Ports.......................... 6 X X in. Size of Exhaust Ports............................... 6 X 2 in. Throw of Eccentrics....................................... 2 in. Outside Lap of Valve................................... in. Inside Lap of Valve..............................-32 in. Diameter of Main Driving-axle Journal.......................3 in. Size of other Driving-axle Journal................................. Size of Truck-axle Journal........................................ Diameter of Pump Plunger..............................I3Y in. Stroke of Pump Plllnger.............................. I...io in. Capacity of Tank......09....................o..... gallons. Plate XIX LOCOMOTIVE FOR THE NEW YORK ELEVATED RAILROAD, DESIGNED BY D. W. WYMAN, SUPERINTENDENT Scale, Y8 in. —= ft. 1. Appendix 1. 585 PROPERTIES OF SATURATED STEAM.,~ ta g. j 0 r' L. b. L: Deg. eg.. L. 1.. 102.1,1144.5.0030 28b2 2.. 126.3 1151.7.0058 10721 R3.. 141.6 1156.6.0085 7322 4.. 153.1 1160.1.0112 5583 5.. 1 162.3 1162.9 ].0138 4527 6.. | 170.2 1165.3.0163 3813 7.. 176.9 1167.3.0189 3298 8.. 182.9 1169.2.0214 29,9 12.. 202.0 1175.0.0314 1986 13.. 205.9 1176.2.0338 1812 14. 209.6 1177.3.0362 1720 14.7 0. 212.0 1178. 1.0380 16142 15.3 213.1 1178.4.:0387 1610 16 1.3 216.3 1179..0411 1510721 17.3 219.6 1180.3.0085 1431 i8 3.3 222.4 1181.2.0459 1357 19 4 3 225.3 116082.1.0148312 58390 20 5.3 228.0 1182.9.050137 122 21. 6 3 230.6 1183.7.0531 1174 22 7 3 233.1 118467..0555 1123 23.3 235.5 118569.2.058 1075 24 9.3 237. 1185.9.039601 103 25 10.3 240.1 1186.6.0625 996 26 11. 242.3 1 1187.3.0650 92358 27 12.3 244.4 1187.8.0673 19286 28 1 3. 246.4 1188.4.0696 1895 29 14.3 248.4 1189.1.0719 1866 33 1.3 250.4 1189..0743 3 80 16 31 16.3 252.2 1190.4.0766 813 32 i.3 21354.1 119078.9.0789 78 1633 1.3 255.9 119..0812 7671515 3- 2.193 21957.6 1192.0.0835 746 311 24.3 2259.3 1192.5.08583 726 23 21.3 260.9 1193..00881 707 37 1 22.3 262.6 11936..0905 99688 37 223 2 6 2. 6 1193. 5.0905 688 586 Appendix I. PROPERTIES OF SATURATED STEAM - CONTINUED. 3 w 2. 0 i 4 H 0 20 50t 3 Lb. Lb. Deg. De3. I Lb. -1 38 23.3' 264.2 1 1194.0.0929 1 671 39 24.3 i 265. 8 1 1194.5.0952 1 655 40 25.3 267.3 1194.9.0974 6 0 4 1 26.3 268.7 1 195.4.0996 1 625 42 27.3 270.2 2 1195 8.1020 611 43 28.3 271.6 1196.2.1042 598 44 29.3 273.0 1196.6.1065 585 45 1 30.3 11 274.4 1197.1!.1089! 572 46 31.3' 275.8 1197.5.1111 561 47 32.3' 277.1 1197.9.1133 550 48 33.3 298.:4 1198.3.1156 539 49 1 34.3 279.7 i 1198.7.1179 529 so 35.3 281.0 1 1199.1.1202 518 51 36.3 282.3 1199.5.1224 509' 52 37.3 233.5 1199.9.1246 500 53 38.3 i 284.79 1 200. 3.1269 491 541 39.3 285.9 1200.6.1291 482 55 40.3 287.1 1201.0.1314 474 56 41.3 288.2 1201.3.1336 466 57 42.3 289.3 i 1201.7.13614 458 58 43.3 290.4 1202.0.1380 451 59 44..3 i 291.6 i 1202.4 1.1403 441 60 45.3 292.7 1202.7 1.1425 437 61 46 3 293.8 1203.1 1.1447 430 62 47.3 294.8 1203.4.1469 42-1 63' 48.3 295.9' 1203.7.1493 417 64 49.3 296.9 1204.0.1516 411 65 50.3 298.0 1204.3.1538 -05 66 1 51.3 j 299.0 1204..1560 339 67 52:3 300.0 1204.9.1583 3903 68 1 53.3 300.09 1205. 2.1605 33o 69 I 54.3 301.9' 1205.5.1627 383 70 I 55.3 3 332.0 1205.8.1648 I 378 71 1 56.3 333.9' 1206.1'.1670 373 72 57.3 301.8 1206.3.1692 360 73 83'95.7 1206.6.1714 363 74 59.3 306.6 1206. 9.1736 359 75 60.3 307. 5 1207.2.1759 353 Appendix L. 587 PROPERTIES OF SATURATED STEAM —CONTINUED., _ L Lb. Peg. Peg. -Lb 76 4361.3 308.4 1207.4.1782 349 77 1 - 62.3 309.3 1207.7.1804 345 78 1 63.3 310.2 1208.0.1826 341 79 64.3 311.1 1208.3.1848 337 65.3 312.0 1208.5.1869 333 66.3 312.8 1208.8.1891 329 82 67.3 313.6 1209.1.1913 325 83 68.3 314.5 1209.4.1935 321 84 69.3 315.3 1209.6.1957 318 85 70.3 316.1 1209.9.1980 314 86 71.3 316.9 1210.1.2002 311 87 72.3 317.8 1210.4.2024 308 88 73.3 318.6 1210.6.2044 305 89 74.3 319.4 1210.9.2067 i 301 90 75.3 320.2 1211.1.12089 298 91 76.3 321.0 1211.3.2111 295 92 77.3 321.7 1211.5.2133 292 93 78.3 322.5 1211.8.2155 289 94 79.3 323.3 1212.0.2176 286 95 80.3 324.1 1212.3.21981 283 96 81.3 324.8 1212.5.2219 281 97 82.3 325.6 1212.8.2241 278 98 83.3 326.3 1213.0.2263 275 99 84.3 327.1 1213.2.2285 272 100 85.3 327.9 1213.4.2307 270 101 86.3 328.5 1213.6.2329 267 102 87.3 329.1 1213.8.2351 265 103 88.3 329.9 1214.0.2373 262 l 104 89.3 330.6 1214.2.2393 260 105 90.3 331.3 1214.4.2414 257 106 91.3 331.9 1214.6.2435 255 107 92.3 332.6 1214.8.2456 253 108 93.3 333.3 1215.0.2477 251 109 90.3 334.0 1215.3.2499 249 110 95.3 334. 1215.5.2521 247 111 96.3 335.3 1215.7.2543 245 112 97.3 336.0 1215.9.2564 243 113 98.3 336.7 1216.1.2586 241 108 9.3 33.3 215..217 25 588 AAppendix 1. PROPERTIES OF SATURATED STEAM —CONTINUED. l='~' 9!.,33. - 3 23 00 114 99.3 337.4 1216.3.2607 239 115 10.3 1 338.0 1216.5.2628 237 116 101.3 1 338.6 1216.7.2649 23 117 102.3 339. 3 1216.9.2674 233 118 103.3 339.9 1217.1.2696 231 119 104.3 340.5 1217.3.2738 229 120 105.3 341.1 1217.4.2759 227 121 106.3 341.8 1217.6.2780 225 122 107. 3 342.4 1217.8.2801 224 123 108.3 343.0 1218.0.2822 222 124 109.3 343.6 1218.2.2845 221 125 110.3 344.2 1218.4.2867 219 126 111.3 344. 8 1218.6.2889 217 127 112.3 345.4 1218.8.2911 215 128 113.3 346.0 1218.9.2933 214 129 114.3 346.6 1219.1.2955 212 130 115.3 347.2 1219.3.2977 211 131 116.3 347.8 1219.5.2999 209 132 117.3 348.3 1219.6.3020 208 133 118.3 348.9 1219.8.3046 206 131 119.3 349.5 1220.0.3060 205 135 120.3 350.1 1220.2.3080 203 136 121.3 350.6 1220.3.3101 202 137 122.3 351.2 1220.5.3121 200 138 123.3 351.8 1220.7.3142 199 139 124.3 352.4 1220.9.3162 198 140 125.3 352.9 1221.0.3184 197 141 126.3 353.5 1221.2.3206 195 142 127.3 354.0 1221.4.3228 194 1243 128.3 354.5 1221.6.3250 193 144 129.3 355.0 1221.7.3273 192 145 130.3 355.6 1221.9.3294 190 146 131.3 356.1 1222.0.3315 189 147 132.3 356.7 1222.2.3336 188 148 1233.3 357.2 1222.3.3357 187 149 134.3 357.8 1222.5.3377 186 150 135.3 358.3 1222.7 3397 184 155 140.3 361.0 1223.5.3500 179 Appendix L 589 PROPERTIES OF SATURATED STEAM-CONTINUED. i,'- {. C: ~.:. _... _ _ CD.' Lb. Lb. Deg. Deg. Lb. 160 145.3 363.4 1224.2.3607 174 165 150.3 366.0 1224. 9.3714 169 170 155.3 368. 2 1225. 7.3821 164 175 160.3 370.8 1226.4.3928 159 180 165.3 372.9 1227.1.4035 155 185 170.3 375.3 1227.8.4142 151 190 175.3 377.5 1228.5.4250 148 195 180.3 379.7 1229.2.4357 144 200 185.3 381.7 1229.8.4464: 141 210 195.3 386.0 1231.1.4668 135 220 205.3 389.9 1232.3.4872 129 230 215.3 393.8 1233.5.5072 123 249 225.3 397.5 1234. 6.5270 119 250 235.3 401.1 1235.7.5471 114 260 245.3 404.5 1236.8.5670 110 270 255.3 407.9 1237.8.5871 106 280 265.3 411.2 1238.8.6070 102 290 275.3 414. 4 1239.8.6268 99 300 285.3 417.5 1240.7.6469 96 590 Appendix II. Table of Hyperbolic Logarithms. _ I Num. Loga- i Loga- Loga- Num. Logarithms. rtis. rithms. rithnis. - - I _ _ -- -! 1.01.0099 1.46.3784 1.91.6471 2.36.8586 1.02.0198 1.47.3852 1.92.6523 i 2.37.8628 1.03.0295 1.48.3920 1.93.6575 2.38.8671 1.04.0392 1.49.3987 1.94 -.6626 2.39.8712 1.05.0487 1.50.4054 1.95.6678 2.40.8754 1.06 [.0582 1.51.4121 1.96.6729 2.41.8796 1.07.0676 1.52.4187 1.97.6780 2.42.8837 1.08 [.0769 1.53.4252 1.98.6830 2.43.8878 1.09.0861 1.54.4317 1.99.6881 2.44.8919 1.10.0953 1.55.4382 2.00.6931 2.45.8960 1.11.1043 1.56.4446 2.01.6981 2.46.9001 1.12.1133 1.57.4510 2.02.7030'.47.9042 1.13.1222 1.58.4574 2.03.7080 2.48.9082 1.14.1310 1.59.4637 2.04.7129 2.49.9122 1.15.1397 1.60.4700 2.05.7178 2.50.9162 1.16.1484 1.61.4762 2.06.7227 a2.51.9202 1.17.1570 1.62.4824 2.07.7275 2.52.9242 1.18.1655 1.63.4885 2.08.7323 2.53.9282 1.19.1739 1.64.4946 2.09.7371 2.54.9321 1.20.1823 1.65.5007 2.10.7419 2.55.9360 1.21.1962 1.66.5068 2.11.7466 2.56.9400 1.22.1988 1.67.5128 2.12.7514 2.57.9439 1.23.2070 1.68.5187 2.13.7561 2.58.9477 1.24.2151 1.69.5247 I2.14.7608 2.59.9516 1.25.2231 1.70.5306 2.15.7654 2.60.9555 1.26.2341.1.71.5364 2.16.7701 2.61.9593 1.27.2390 1.72.5423 2.17.7747 2.62.9631 1.28.2468 1.73.5481 2.18.7793 2.63.9669 1.29.2546 1.74.5538 2.19.7839'2.64.9707 1.30.2623 1.75.5596 2.20.7884 2.65.9745 1 1.31.2700 1.76.5653 2.21.7929 2.66.9783 1.32.2776 1.77.5709 2.22.7975 2.67.9820 1.33.2851 1.78.5766 2.23.8021 2.68.9858 1.34.2926 1.79.5822 2.24.8064 2.69.9895 1.35.3001 1.80.5877 2.25.8109 2.70.9932 1.36.3074 1.81.5933 2.26.8153 2.71.9969 1.37.3148 1.82.5988 2.27.8197 2.72 1.0006 1.38.3220 1.83.6043 2.28.8241 2.73 1.0043 1.39.3293 1.84.6097 2.29.8285 2.741 1.0079 1.40.3364 1.85.6151 2.30.8329 2.75 1.0116 1.41.3435 1.86.6205 2.31.8372 2.76 1.0152 1.42.3506 i1.87.6259 2.32.8415 2.77 1.0188 I 1.43.3576 1.88.6312 2.33.8458 2.78 1.0224 1.44.3646 1.89.6365 2.34.8501 2.79 1.0260 1.45 1.37151 1.901.6418 2.35.8544 2.80 1.0296 Appendix I. 591 Table qf Hyperbolic Logarithms-Continued. u Loga- Log- Loga- Num. LogaNum. riths Nu. oo'. N' u. -rithmns. rithms. I rithms. rithms. _II _I _ _ _ 2.81 1 1.0331 3.26 1.1817 3.71 1.3110 4.16 1.4'255 12.82 1.0367 3.27 1.1847 3.72 1.3137 4.17 1.4279 2.83 1.0402 3.28 1.1878 3.73 1.3164 4.18 1.4303 2.81 1.0438 i 3.29 1.1908 3.74 1.3190 4.19 1.4327 2.85 1.0473 3.30 1.1939 3.75 1.3217 4.20 1.4350 2.86 1.0508 3.31 1.1969 3.76 1.3244 4.21 1.4374 2.87 1.0543 i 3.32 1.199.9 3.77 1.3271 4.22 1.4398 2.88 1.0577 I 3.33 1.2029 3.78 1.3297 4. 23 1.4422 2.89 1.0612 3.34 1.2059 3.79 1.3323 4.24 1.4445 2.90 1.0647 1 3.35 1.2089 3.80 1.3350 4.25 1.4469 2.91 1.0681 3.36 1.2119 3.81 1.3376 4.26 1.4492 2.92 1.0715 3.37 1.2149 3.82 1.3402 4.27 1.4516 2.93 1.0750 3.38 1.2178 3.83 1.3428 4.28 1.4539 2.94 1.0784 1 3.39 1.2208 3.84 1.3454 4.29 1.4562 2.95 1.0818 1 3.40 1.2237 3.85 1.3480 4.30 1.4586 2.96 1.0851 3.41 1.2267 3.86 1.3506 4.31 1. 4609 2.97 1.0885 3.42 1.2296 3.87 1.3532 4.32 1.4632 2.98 1.0919 3.43 1.2325 3.88 1.3558 4.33 1.4655 2.99 1.0952 3.44 1.2354: 3.89 1.358i 4.34 1.4678 3.00 1.0986 3.45 1.2387 3.90) 1.3609 4.35 1.4701 3.01 1.1019 3.46 1.2412 3.91 1.3635 4.36 1.4724 3.02 1.1052 3.47 1.2441 3.92 1.3660 4.37 1.4747 3.03 1.1085 3.48 1.2470 3.93 1.3686 4.38 1.4778 3.04 1.1118 3.49 1.2499 3.94 1.3711 4.39 1.4793 3.05 1.1151 3.50 1.2527 3.95 1.3737 4.40 1.4816 3.06 1.1184 3.51 1.2556 3.96 1.3726 4.41 1.4838 3.07 1.1216 3.52 1.2584 3.97 1.3787 4.4-2 1.4838 3.08 1.1249 3.53 1.2612 3.98 1.3812 4.43 1.4883 3.09 1.1281 3.54 1.2641 3.99 1.3837 4.44 1.4906 3.10 1.1314 3.55 1.2669 4.00 1.3862 4.45 1.4929 3.11 1.1346 9.56 1.2697 4.01 1.3887 4.46 1. 4914 3.12 1.1378 3.57 1.2725 4.02 1.3912 4.47 1.4973 3.13 1.1410 1 3.58 1.2753 14.03 1.3937 4.48 1.4996 3.14 1.1442 3.59 1.2781 4.04 1.3962 4.49 1.5018 3.15 1.1474 3.60 1.2809 4.05 1.3987 4.50 1.5040 3.16 1.1505 1] 3.61 1.2837 4.06 1.4011 1 4.51 1.5062 3.17 1.1537 3.62 1.2864 4.07 1.4036 l} 4.52 1.5085 3.18 1.1568 3.63 1.2892 4.08 1.4060 1 4.53 1.5107 3.19 1.1600 3.64 1.2919 4.09 1. 4085 i 54: 1.5129 3.20 1.1631 3. 65 1.2947 4.10 1.4109 4.55 1.5151. 321 1.1662 3.66 1.2974 4.11 1.4134 4.56| 1.5173 3.22 1.1693 3.67 1.3001 4.121 1.4158 I 4.57 1.5195 13.23 1.1724 3.68 1. 3029 4.13 1.4182 -4.58 15216 3241 1.1755 3.69 1.3056 1 4.14 1.4206 4.59 1.5238 25 1 1.1786 I 3.70 1.3083 4.:15 i 1.4 31 4.60 1.5260 592 Appendix I. hble of Hyperbolic Logarithms —Continued. Iunl. _UM. Num.. rithms. rithms iths.. ithlms..... - L~o o/~Zg-/a - Lg- L 4 61! 1.5 8 5.06 1.6213 5.51 1.7065 5 96 1.7850 4.62 1.5303 5.07 1.6233 5. 52 1.7083 5.97 1.7867 4 63 1. 5325 5.08 1.6253 5 53 1. 7101 5.98 1.7884 4 64 1.5347 5.09 16272 5 54 1,7119 5 99 1.7900 4 651 1.5368 5.10 1 6292 5.55 1 7137 6.00 1.7917 4 jG 66 1 53930 5 11 1 6311 5.56 1 7155 6.01 1 7934 4.67 1 5411 S.12 1.6331 5.57 1.7173 6 02 1.7950 4.63 1.5432 5 i3 1.6351 5 58 1.7191 6.03 i 7667 4.69 1. 5454 5.14 1.6370 5.59 1.7209 6.04 1 7984 4793 1.5475 5.15 1.6389 5.60 1.7227 6.05 1.8001) 4.71 1.5496 5.16 1.6409 5 61 1 7245 6 06 1.80i7 4 72 1 5518 5.17 1.6428 5.62 1. 7263 6 U7 1.8033 4.73 1.5539 5 18 1 6448 5 63 1,7281 6.08 1.8:)5 ) 4.74 i.5560 5.19 1.6463 5 64 1.7293 6.09 1 8066 4.75 1.5581 5 20 1.6486 5.65 1.7316 6.10 1.8382 4.76 1.5602 5.21 -1.6505 5.66 1.7334 6.11 1.8393 4. 77 1.5623 5.22 1. 6524 5 67 1.7351 6. 12 1.8115 4.78 1 5644 5.23 1. 6544 5 68 1 7369 6.1 3 1.8131 4.79 1.56,5 5 24 1.6563 5 69 1.7387 6 14 1.8148 4.80 1.5686 5.25 1 6 2 5 7) 1 7404 6.15 1.8164 4.81 1.5706 5. 2 1.6601 5.71 1.7122 6.16 1 8180 4.82 1.5727 527.6820 5.72 1.7439 6 17 1.8196 4.83 1. 5748 5'8 1 6639 5.73 1.7457 6.18 1.8:213 4.84 1.5769 5.29 1 6658 5 74 1.7474 6.19 1.8229 4.85 1..5789 5.30 1.6677 5 75 1.7491 6.20 1.8245 4.86 1 580 L 5.31. 6695 5.76 1.7539 6.21 1.8261 4.87 1.5830 5 32 1.6714 5.77 1.7526 6.22 1.8277 4.88 1.5851 5.33 1.6733 5 78 1.7541 6.23 1.8293 4 89 1.5870 5.34 1.6752 5.79 1.7561 6 24 1.83U9 4.90 1.592 5 35 1. 6770 5.80 1.7578 6.25 1.8325 4 91 1 5912 5.36 1.6789 5.81 1.7595 6.26 1.8341 4 92 1 5933 5 37 1.6808 5.8' 1.7613 6.27 1.8357 4,93 1-.5953 5.38 1.6826 5 83 1.7630 6 28 1 8373 4.94 1.5973 5.39 1 6845 5 84 1.7617 6 29 1.8389 4 95 1.5993 5. 4 1.6863 5 85 1 7661 6.30 1.8405 4 96 1.6014 5.41 16882 5 86/ 1.7681 6.31 1.8421 4 97 1.6(034 5 421 1.6900 5.87 1.7698 6.32 1.8437 4 98 1.6054 5.43| 1.691 5.88 1. 7715 6.33 1.8453 4 99 1.6074 5.44 1.6937 5.89 1.7732 6 34 1.8168 5.00 1.6094 5.45 1.6956 5.90 1.7749 6.35 1.8484 5 01 1.6114 5.46 1.6974 5.91 1.7766 6.36 1.8300 5 02 1.6134 5.47 1.6992 5.921 1.7783 6.37 i 1.8515 5.03 1 6154 5.48 1.7011 5 93 1.7800 6.381 1.8531 5 01 1.6174 5.49 1. 709 5 91 1.7317 6 39 1.8547, 5 05 1 61.93 55 1.70471 5 951 1.7833 6.40 1: i5c i Table Showi,,g the V4/lute,(ld Proiperties of Vatrious Kinds of Coal. D/af500-',,'- -. D'.' "j -. A ~_-., DESIaver Meadow, s OCOAL. 5................Pa. 56.19 9.86 0.60 61.210.59 1, i!I 5.15! C)8 6.74 Beaver Meadow, slope No. 3............... Pa. 51493:4 40.78 2.38188.94 7 11 9.21 l1.961 1.01 112 4110. 462 Beaver Meadow, slope No. 5..........PI.. a. 56.191 39.86 2.66 91.47 5.15 9.88 6.74 0.60 61.2 10.592 Forest improvement................... Pa. 53.66 41.75 3.07 9075 4.41 10.06 6.97 0.81 40.2 10.807 Peach Mountain........................Pa. 53 79 41.64 2.96 89.02 6.13110.11 6.91 3.03 26.6 10.871 Lehigh................................ Pa. a55.32[ 4o0.50 5.28 89.15 5.56 8.93 7.22 1.08 36.1 9.626 Lackawanna............................. 45.82 391874 6 99 8.93 1.24 57.2 10.764 Lyken's Valley........................Pa. 48.56 46.13 6.88 83.84 9.25 9.46 12.24 4.40 18.0 10.788 Beaver Meadow (Navy Yard)................ Pa. 55. 08 40. 65 8.10 9. 08 8. 10. 1.40 107. 1 9s. 881 Natural coke of Virginia..................Va. 46.64 48.03:12.44 75.08 11.83 8.47118.461 5.31 60.9110.389 Coke of Midlothian co:1l................ Va. 32 70 68.501.....16.55 8. 63:16. 54'10.51 53.2 10.343 Coke of Neff's (Cumberlacni) coal........... Md. 31.57 70.95.......... 13 34 9.00113.34 3.55 43.7 10.381 Mixtur3 1-5 Canmb. anrd 4-5 B.3aver Meadow...... 54.29 41.261........ 8.88 8.86 8.88 4.91 9.5 9.725 Mixture 1-5 Cumab. and 4-5 Beaver Meadow.... 54.51 41.09....... 8.18 9.181 8.18 3.09 16.0 9.997 New York and Maryland Mining Company's.Md. 53.70 4.71 12.31 73.50 12.40 9.78 12.711 5.43 10.1111.208 Neff's Cumberland................. Md. 54.29 41.26 12.67 74.53110.34 9.44 10.961 4.53 6.1 10.604 Easby's " coal in store".................Md. 5347 41.90 14.98 76.26 8.08 10.02 8.38 1. 33 18 210 935 A Atkinson & Templeman's................... Md. 52.92 42.33 15.53 76.69 7.33 10.70 7.961 2.12 5.111.624 Easby&d Smith's-.-. -............. M.....N ld.'51.16 43 78115.52 74.291 9.30 9.96 9.69 3.04. 5.3111.034 Cumberland (Navy Yard)............M d. 53.29 42.04 14.87 70.85 14.98. 14.53 2.29 13.51...... Dauphin& Susquehann&............... Pa. 50.54 44.32 13.82 74.24i11.49 9. 34 16.36 3.50 23.7 11171 Blossburg................. Pa. 53.05 42.22 14.78 73.11 10.77 9.72 11. 20 3.40 13.7110.956 Lycoming Creek....Pa......4.4...5 1..1...a. 55.38 40.45 13.84 71.53 13.96 8.91 16.9'2 3.26 46.2!10.724 Qain's Run...........................Pa. 50.34 44.50 17.97 72.79 8.41 10.27 8.94 1.31 14.7 1 275 Karthaus.............. Pa. 52.54 42.63 19.53 73.77 7.00 9.09 7.89 3.66 52.5 9.887 Cambria County........................ Pa 53.46 41.90 20.52 69.37 9.15 9.24 9.75 3.48 14.8 10.239 Barr's Deep'.... Va.;3.17 42. 13 19. 78 67.96 10. 47 9.02 11.07 4.78 6. 4 110.142 Crouch & Sn ead's...5....................... Va. 53.59 41.8 24. 38 59.98114.28 8.34 14.34 5.37i 6.0 9 740 Midlothian (900 feet shaft)...... Va. 50.52 4.4 3427.28 61.08110.47 8.58 10.70 6.47 5.9 9.611 Creek Company's coal................Va. 46.50 48. 7132.47 60.30 8.57 8.42 8.64 4.41 10.5 9.211 Clover Hill............................ Va. 45.49 49.25132.21 56.83 10.13 7.67 10.60 3.86 11.5 8 588 Chesterfield Mining Company's........... Va. 45.55 49.18132.63 58.79 8.63 9.00 9.07 4.19 10.51 9.896 Midlothian (averae)............................ Va. 54.04 41.45129.8653.01 14.74 8.29 14.83 8.821 6.4 9.741 Tippecanoe............... Va. 15. 1.0 49.67134.54154.62 9.37 7.75 9.72 4.03 11.2 8.583 Midlothian (new shaft)..................... Va. 47.90 46.76135.77|56.40 9.44 8.7510.26 4.21 17.1 9 751 S Midlothian (scree-ed).....................Va. 45.72 48.99134.70 54.06 9.66 8.94 10.27 3.33 14.8 9.970. Midlothian (Navy Yard)................... 54.47 41.13'29.12156.11 14.14 - -. 4.42 43.2 Pictou (from New York)......N. S. 53.55 41.83 27.83156.98113.39 8.41 13.37 6.13 5.7 9.710 Sidney.....N.........S 47.44 47.22,23.81167.57 5.49 7.99 6.01 2.24 5.9 8.497 Pictou (Cunards)...... N. S. 149. 5 45.48125.97 60.74 12.51 8.48 12.06 6.191 3.7 9.648 Liverpool.......... Eng.4788. 4678 39.96 54.90 4.62 7.48 5.04 1.86; 11.1 8 255 Newcastle...............................En50.82 44.0835.8357.00 5.40 8.66 5.68 3.14 10.7 9.178 Scotch..............8.... Scotland 51.09 43.84 39. 19 48.81 9.34 6.95110.10 5.63 5.7 7.719 Pittsburg..................... Pa 46 81 47 8536.76154.93 7.07 8.20 8.23 0.941 9.9 8.942 Cannelton...........................Ind. i47.65 47.01133.99 58.44 4.97 7.84, 5.12 1.641 6.4 7.734: Dry Pine Wood 121.01 10. 02..... 0.... 3 0.30 4.691 0.30.1.....1 4.707 ~~.b.._................ Table o lResistanrces of Railroad Trains withl biffirent. Grades and Sp)eeds. -.:Z~ao o o o o o _' o oc l-, l -,,__ 0 6.1 6.6 78 8.3 9.6 11.2 13.1 15.3 17.8 20.6 j 27.0 34.6 2.......... 1.8 7.9 8;4 9 1 10.1 114 13.0 14.9 17.1 13.6 22 4 28 8 3614 10.......... 3.7 9.8 10.3 11.0 12.0 13.4 14.9 16 8 19.0 21.5 24 3 30.7 38.3 15.......... 5.6 11.7 12.2 12.9 13.9 15.2 16.8 18 7 21.9 24.4 27 2 33.6 41.2 20........ 7.5 13.6 14.1 14.8 15.8 17.1 18 7 20.6 22.8 25.3 28.1 34.5 42.1 25.......... 9.4 15 5 16.0 16.7 17.7 19.0 20.6 22 5 24.7 27.2 31.0 37.4 450 30.......... 11.3 17.4 17 9 18.6 19.6 21.9 22.5 24 4 26.6 29 1 31.9 38.3 45.9 35......... 1.2 19.3 19.8 20.5 21.5 22.8 244'26.3 28.5 31.0 2a3.8 40.2 47.8 40......... 15.1 21 2 21.7 22.4 23.4 24.7 26.3 28.2 30.4 32.9 35.7 42.1 49 7 45o.......... 1.0 23 23.6 24 2.3 26.6 28 2 30.1 32 3 34 8 37 6 44.0 51.6 560..1.....9 1 18.9 25.0 25 5.26.2 27.2 28.5 30.1 32 0 34.2 36.7 39.5 45.9 53.5 60...o.... 22 7 28.8 29.3 30.0 31.0 32.3 33 9 35.8 38.0 40.5 43.5 49.9 57.5 70....... 26.5. 32 6 33.1 33.8 34.8 36.1 37.7 39 6 41 8 44.3 47.1 53.5 61.1 80......... 30.3 tl 36.4 36.9 87. 38.6 39 9 9 40.5 42.4 44.6 47.1 i 49.9 56.3 63 9 90.......... 34.0 41.0 40.6 41.3 42 3 4'3.6 45.2 47.1 49.3 51.8 54 6 61.0 68 6 100..........,87.8 43,9 44.4 45.1 46.1 47.4 49.0 51.9 51.1 56.6 59.4 65.8 73.4 110.......... 41.6 4 7.7 48.2 48.9 49.9 51.2 52.8 54.7 56.9. 59.4 62.2 68.6 76 2 120.......... 4.5.4 51.5 52. 0 52.7 53.7 55 0 06 6 58.5 60,7 63.2 MO1 72.4 80.0 130.......... 49.2 5.5,3 55.8 56.5 57 5 58.8 60 4 62 3 6-1.5 67.0 69.8 76.2 830.8 140.......... 53.0 59.1 59.6 60.3 61 3 6,2.6 6.4.2 66.1 68.3 70.8 73.6 80.0 87 6 150.......... 56,8 62.9 630.4 64.1 65 I 66 4 68.0 69. 721 796 7. 83.8 91.4 160.......... 60.6 66.7 67.2 67.9 68.9 702 71.8 3.7 7 5. 784s. 7G6 93. 1 7........ 64.3 70.4 710.9 71.6 72. 6 70 9 75.5 77 4 796 8. 49 91.3 98.9 180.......... 68,1 74.2 74.7 75.4 76.4 77.7 79.3 81.2 834 8. 87 95 1 102.7 190.......... 71.9 78.0 78 5 79.2 80.2 81,5 83 I8 85.0 872 8. 25 98 9 106 5 200.......... 75.7 81.8 82 3 83.0 84.0 85.3 86.9 88.8 910 93 63 102.7 110.3 210.......... 79.5 185. 6 86.1 86.8 87.8 89.1 90.7 92~ 6 48 973 10 106.5 114.1 220.......... 83.3 89.4 89.9 90.6 91 6 92 9 94.5 96 4 986 111 I0" 110.3 1 1 7.6 230.......... 87.1 93.2 93.7 94.4 9.54 96.7 98,3 100.2 1024 149 1077 11i 121.7 240.......... 90.8 96.9 97.4 98.1 99.1 100.4 102.0 10;3.9 101 186 114 117 8 12-5.4 250.......... 94.6 100.7 101.2 101.9 102.9 103.2 105.8 107.7 109 i24 152 121.6 12902 260.......... 98.4 104.5 105.0 105.7 106.7 107.0 108.6 110.5 127 152 80 124.4 132 0 270.......... 102.2 108.3 108 8 109.5 110.5 111l13. 115.3 11295 20136. 28)........ 106.0 112.1 112.6 1 13.-3 114.3 115,6 117.2 119.1 113 238 266 13-30 140.6 290.......... 109.8 115.9 116.4 117.1 118.1.119.4 121. 12729 138D 4 300......113.6 119.7 120.2 120 9 121.9 123.2 124.8 126.7 1289 114 3. 40 6 148.2 INDEX. THE FIGURES BELOW REFER TO THE NUMIBERS OF THE PAGES. Absolute pressure, 13. Accidents to locomotives, 509. Accidents and injuries to persons, 533; danger from, 535. Actual energy, 24. Adhesion, 62, 319; amount of, 320; proportion of to resistance, 412. Adhesive weight, 32t. Admission, depends on,-222; how affected, 255; how equalized, 249; of steam, 30; period of, 249. Admission line, 236, 237. Air, admission of to fire-box, 380; control of supply of, 384; forces of. 8; method of admitting to the fire-box, 382; pressure of, 8, 9; quanltity necessary for combustion, 381, 388; quantity leedled for o(illition of gases, 389; quantity to be admitted through the grate and above the tire, 391; weight of, 8. Air chamber, 117. Alarm check, 126. Algebra, x. Algebraic symbols, x. Allen valve, 221. American locomotive, 429; engraving of, 555. 557, 569 561. 563. American Railway Master Mlechanlics' Association, 260, 288. Angular advance, 251. Animal oil, 504. Anthracite coal, 112. 152, 403; firing with, 503. Aquafortis, 368. Arganld-burner, 326 Arterial bleeding, 536. Artery, 536; injury to, 537, 539; position of, 537. Ash-pan, 67; construction of, 81. Ash-pan dampers, 81; operation of, 153. Atmospheric line, 48. Automatic brakes, 442; management of. 495 Axle, atijustmnent of, 475; breaking of, 509. 523; how made to assumne; radical position, 278. 282; maiu driving, 63. Axle box, arrangement of, 296; bearing of, 290; driving, 290; for tenders, 355; wear of, 297. Babbitt's metal, 173, 175, 180. Baclk elevation. xiv. Back pressure, 56, 163; line of, 236, 243. Backl view, xiv. Backward motion or gear, 187. Baldwin Locomotive Works, 429; locomotive by, 555, 565, 567. Ball joint, 160. Bearings, brass, 177; for driving axles, 290; for tender axles. 351; for truck axles, 292; proportions of, 362; wear oi;, 19. Bearing bars, 152. Index. 599 Bad(-casting, 161. Betl-plate, 146. Bell, 335; use of, 479. Bissell truck, 432. Bituminous coal, 368; composition of, 369, 388; use of, 503. Blast orifice, 71; (see also exhaust nozzle). Bleeding, danger from. 535; stopping of, 537, 540. Blower, 149; use of, 480. Blower cock, 149. Blow-off cock, 148. Block, link, 185; (see link block). Boiler, 66, 71; advantages of large size, 422; calculations of, 419; capacity of, 71, 418; cleaning of, 147 505; emptying of, 147; expatisimti ot, 90, 295, 478; explosion of, 509, 514; feeding of, 483; filling of, 506; inspection of, 461; irregular action of, 421; organs of, 66; operation of, 420; proportions of, 419; size of,: 417, 420; strains on, 85, 478; testing of, 461. Boiler attachments, 115; examination of, 465.; Boiler plate, fastenings of, 90; resistance of, 95; strength of, 89, 95; unequal strain on, 92. Boiler pressure, 223; difficulty of maintaining in cylinders, 223. Boiler seams, form of, 103; strength of, 93, 106. Boiling, 10. Boiling point, II. Bones, injury to, 542. Boolcs, list of, 550. Boss, 207. Boxes, for driving axles, 290; for tender axles, 355; for truck axles, 292. Braces, 80, 107; for frames, 292; prop)ortiols of, 108. Brakes, continullous train, 442; for tenders, 336; inspection of, 475; reliance on, 494. Brass bearings, 177; (see bearings). Brasses, 177. Breakintl joinlts, 173. Bridges, 31; widtlh of, 260. Buchanan, William, see preface, 402. Bumper-tinmber, 292. Bunsen burner, 374. Burns, treatmellt of, 542. Bushling, 174, 180. Butt-joints, 106. Cages, 116. c(,alrile, 375; flame of. 375. Carbon, 369, 371; air required for combustion of, 388; total heat of combustion, 380. Carbonic-acil gas 378. Carbonic dioxide, 378. Carbonic oxi(le, 378. Carburetted hydrogen, 369. Carrying wheels, 268. Cars. resistance of, 406. Casing, for cylinders, 170. Caulling, 106; effect of, 107. CaulkIilng c(lge, 106. Centre bearing, 3)6; lubrication of, 475. Centre of g avity. calculation for, 329, 330, 331. Centre-pin, 2;9, 271, 316. Centre-lflate, lower, for truck, 316; lubrication of, 475; upper, 316. Check -chainsi 310, 350. Check-valve, ftilure of, 509, 518; for injector, 120; for pump, 117. Chemical element, 365; combination of, 366. Chemical equivalent, 367. 600 Index. Chilling, 291. Chimney, 66; construction of. 112. Cleuarance, of piston. 221; effect of. 228; of valve, 42. Coal, amount of water evaporated by, 73, 894; condition of when put on tire, 387; value and properties of, 591. Cock, blower, 149; blow-off, 148; cylinder, 171; feed. 119; frost, 119; gauge, 130; heater. 149; oil, 169; pet, 118; try, 130. Co-efficient of friction, 359 Coke, 379; air needed for combustion of, 392. Cold weather, 496. Color blindness, 493. Collision. 509; prevention of, 510. Combustion, 365; air required for, 380, 388; chemical process of, 379; effect on of enlarging the grate, 392; how expblailedl. 370; ill locomotive fire-box, 377; intensity of, 393; in tabes, 36t; products of, 378; rate of, 73, 365; total hleat of, 380.;'93; whlen compllte, 373. Compression, 44, 221; calculation of, 243; effected by, 228; effect of, 247; line or curve of, 236. Compressive strain, 89. Combining tube, 31. Condensation, 17. Conduction, 18; of heat through heating surfaces. 395. Cone, 112; cone of wlheel, efifect of, 274, 277; adlvantage of, 285. Connecting rod, 5, 164; angularity of, 45, 175; breakill of, 509; construction of, 177; eftfect of, 44; inspection of, 467, 471; main, 177; pressure of, 174; welar of, 177. Consolidation locomotive, 430, 569. Continuous train brakes, 442, Convection, 111, 118. Coulnterbalance weights, (see counterweights.) Counterlsunk jointl, 156. Counlterweights, 289, 328; calculation for, 328, 831, 333; construction of, 333. Coupling, breaking of, 510, 531; engine to tender, 4S0. Coupling-pinl, 350. Coupling-rodl, 177; whvlly taken down, 523. Covering strip. 100, 103. Cow-catcher, 294, 338. Crank, 5, 63. Crank-pin, 64; breaking of, 509, 522; construction of, 288; how fastened, 28S; inspection of, 463; pressure on, 214. Creamer's brake, 442. Crow-feet, 107. Cross-head, 174; accident to. 5(9; inspection of, 471. Crossing,:approach to, 493, 511. Crovwn-bars, 80. Crown-shcet. or crown-plate, 75 85. Crushing. 93, 98; treattmenlt of, 542. Curve, degree of,t; 410; resisalnce on, 410; running through, 489. Culrve of compression. 236. Curve of expansion, 236. Cut-off; 16, 4l; advant'age of, 483; effect of link on, 217; effect of throw of eccentric on, 252. Cushion, 38 230. Cylinder, 163, 164; breakling of. 509, 521; cnnstruction of. 164; distance btetweeln. 69; inspectionl of, 63; location of, 63; protection of, 170; size of, 69, 413. Cylindler capacity. 414; calculation for, 415, 416. Cylinder casing, 17O. Cylinder cocks, 171; use of. 479. Cylitnder-he:lds, 165; lbreaking of, 521. Cylinlder-headl covers, 170. Cylinder laggi,lg, 170. Index. G60t Da mpers, for asl-pan, 81. 153. Danfolrth Locornotive atud It achine Co.. 429; loclm,tive by, 559 569. ])angers to which locomotive r'unners are exposed, 544. Dead-point, 5. Deal grate, 387. Dellctor, tfor tire-box door, 400; for sparks, 112. D)elivery-tube. 120. Diaphragtm, 140. I)itfrellt kinds of locomotives. 427 D)ilution of gtises, air neede(l for, 389. Distribution of steam, 220; d(efects of. 248: effect of, 231. l)istribution of weight, on driving wheels, 4.3. D)ome, 1 10; location of, 11). Double-enl tanilk locomotive, 571, 573, 581. ])ouble poppet vatlve. 155. D)oluble triuck locomotive, 435, 577, 579. Draft 67, 72. Draw-bar. 334. Draw-bridge, approach to, 493; running into, 509, 5It. Dra-wings, xiii. Drilled( holes, 92. 96, 98, 103. Drilling cars. 427. Drip-Pile. t32. )lrivilg-axle. breaking of. 523; main. 70; (see also,axlt). Drivini-axle boxes, 290; bearing of. 290. Driving-wheels, 70, 268; action of, 323; atdhesion of. 62. 319; breakilng of. 523; coInstructionl of, 285; distance betweenl 68; effict of their size on combustil and evaporatiol, 424; friction of, 62, 319.; how falstened, 28q; nmotioni of arotind culrves 284: relatio betweei size of aeld that of boiler, 425; size of, 68, 413, 425; weight on, 69. Drop-door. 1.53. D)ry-pipe, 111. Duplicate parts, 477. Dust guard, 356. Ebullition, 11. 485. Eccentric, 6; effect of throw of, 252, 255; how set, 1S2; 528; motion how comtnmunicated to valve. 1,5; motion sa:me as that of cranlk, 31; slipping of, 526, 528; throw of, 31, 251; with varying lap, 258. Eccentric-rod, 7; breaking of. 527 529. Eccentric-strap, 6; breaking of, 529. Effective pressure, 14. Eight-wheeled American locomotive, 555, 557, 559 561, 563. Ejector, 446. Elasticity, limit of, 89, 302; of spring, 302. Elastic strength, of spring. 302. Elementary substalnces. 365. Enlergy, 22, 23; actual, 24, 29; of repulsion, 28; possible or potential, 28. Endiurance, 545. Equalizing lever. 309; advantages of, 313; brealding of, 509. 525; qonstruction of, 310; distribution of weight by. 310; of truck, 316. Evaporation, amount required, 72; latent lieat of. 26. Exhlaust of steam. 3', 67; how affected by link, 217, 249. Exhaust line; 23i. 242. Exhaust-nozzle, 68, 71. Exhaust passage, 165. Exhaust pipe, 162. Exihaust-port, 5;, width of, 260. Exhaust steam, action of, 71, 72. Expander, 84. Expansion, 16, 221; advantages of, 55, 60, 482; liwuits of econ:omy, C0. Exlpansiont clamps, 294., Expansion curve or line, 51. 602 Index. Experiments with locomotives, 450. Explosion of boiler, 509; cause of, 514; prevention of, 516. Fairlie engine, 435. Feed-cock, 119, 149. Final pressure. 56, 482. Fire, depth or thickness of, 383; management of, 500; method of feedlilg. 383; method of starting, 478. Firing, 499. 501. Fire-box. 66. 67; construction of, 75; expansion of, 479; form of 3.)7; size of, 69; Fire-brick arch, 397. Flame, length of, 376; nature of, 371, 375. Flange of wheel, 278; friction of, 281. Flue, 66, 67; arrangement of, 81; bursting or collapse- of, 509, 516; fastening of, 83. Flue expander, 84. Flutter of water, 487. Fly-wheel, 5. Foaming. 484; cause of, 486; effect of, 488; prevention of, 486. Follower bolts, 172. Follower plate, 172. Foot-board or plate, 261, 338; effect of weight of, 339. Foot pound, 2:3. Force-pump, 115. Forney locomotive, 434, 575. Forward motion or gear, 187. Four-wheeled locomotive, 428; disadvalltages of. 428; engraving of. 553. Frames, 65, 292; attachment to the fire-box, 295; breaking of, 510, 526; fastening of, 294. Franklin Institute, system of screw threads, 342. Freezing of water in boiler, 507; in. pumps, 119, 507, 532. Freight locomotive, 429. Freight traffic, 427, 429. Friction, 358; depends on, 358; co-efficient of, 359; effect of pressure and velocity of surfaces oil, 361; effect of area of surfaces in contact, 364; law of, 363; of wheel flanges, 281; of wheels, 62, 319. Front view, xiv. Front:el!wation, xiv. Frost-bite, treatment of, 543. Frost-cock, 119. Fuel, value of, 404; waste of, 394. Fulcrum of driving wheel, 312. Furnace door, 67, 80, 149. Gas, 368; combustion of, 376. Gas-light, 371. Gauge of road. 75. Gauge-cocks, 130. Gibs, 175. Gland, 173. Glass water-gauge, 130; inspection of. 465. Grades, effect of on water level, 491; resistance on, 408; running on, 490. Grant Locomotive Works, 429; locomotive by, 557. Grate, 67, 73, 8t, 149; dead, 387; inspection of, 465; management of, 504, 506; rocking, 152; shaking, 152; surface, 419; water, 152. Grate-bars, 150. Greenwich Street Elevated Railroad, 441. Guide-blocks, 176. Guide-rods or bars, 164; inspection of, 467; object of, 174; wear of, 176. Guide-yoke, 175. Index. 603 Half-gear, 195. Hand-holes, 148. Hand-rails, 337. Head-light, 336; inspection of, 476; use of, 495. Heat, conduction of, 74: convertible into work, 25; equivalent of, 24; latent, 26; loss of, 395; mechanical equivalent of, 22; total of, steam, 29, 585; transmission of, 381, 395, 423; waste of, 18, 395. Heater-cocks, 149; use of, 486. Heating surface, 67; amount needed, 73, 419, 420. Heat of evaporation or gasification, 369. Helper, 497. Henderson's brake, 442. Hinkley Locomotive Works, 429; locomotive by, 553, 563. Hood for fire-box door, 400. Horizontal section, xiv. Hose, 350. Hudson River Railroad, locomotives used on, 440. Hydrogen, 369, 371; air required for combustion of, 388. Hyperbolic curve, 51, 237. Hyperbolic logarithms, 54; table of, 590. Hyponitrous acid, 368. Igniting temperature, 370, 376; of coal gas, 387. liucrustating substances. 454. Indicator, steam, 47, 231; method of attaching, 234. Indicator, diagram, 51, 233; form of, 235, 240, 241, 247. Induced current, 374. Initial pressure. 60. Injector, 120; action of, 120; action of fixed nozzle injector, 123; action of hot water on, 123; fixed nozzle, 120; failure of, 509, 518; inspection of, 465; location of, 127; self-regulating, 124. Injuries to persons, E33. Insensibility. treatmeunt of, 541 Inside pipe, 113. Inspection of locomotives, 461. Intensity of combustion, 393. Internal disturbing forces, 328. Introduction, ix. Inverted plane, xv. Jauriet, C. F.; water tables, 399. Jaws. 292. Johnson, Walter B., experiments on coal, 405. Journal. 177; effect of ilcreased diameter, 362; heating of, 504; oiling of, 179; of driving axle, 290; of truck axles, 292. Journal bearing, of driving axle, 290; of tender axles, 351; of truck axles, 354. Keys, 179. Lagging, 111; for cylinders. 169. Lamp, 373; for head-light, 336, 376. Lap, 40, 25i; inside, 40; effect of, 4l; outside, 40; effcct of, 41, 44; effect. of reducing, 255; effect of varying, 258. Latent heat, 26; of evaporation, 26, 29. Lateral motion, 317, 430. Laughing gas, 368. Lead, 38, 220, 249, 253; cause of, 218; effect of, 44; how affeicted by-liink, 218; how equalized, 249; inside, 38; necessity for, 221. Lift of prump valves, 117. Lifting arm, 66; breaking of, 529. Liftinlg shaft, 185; breaking of, 530; position of, 250. Limit of elasticity, 89; of spring, 302. 604 Indetx. Line and line, 237. Linear adlvance. 252. Lille of back-press.ure, 236, 243. Line of compression. 236. Line of expansion, 236. Liners, 175. Linlk, 66, 185; motion of, 189; radius of, 200.,iik-block, 185. Link-hlanger, 185, 250; breaking of, 529. Link inotioll, 181, 196. 248. Link-saddle, 187; breaking of, 529.,ist of books, 550.,ive ste:am, 229. Locomotive. 62; advance of 323; capacity of, 421; cleaning and repairing of, 50(5; cost of operating, 448; difierent kinds, 427; dimellsions of, 68, 429; escnape of, 50(9, 51 1; experiments wit h, 4.50; general description of. 62; how turnel arotiind, 455; inspection of, 461; list of parts of, 69; noumber of miles run to a toll of coal, 44.; principal p;Llts of, (62; proportions of. 412; resistance of, 62; speed of. 419; starting of, 4S0; weight of, 67. Longitudinal section, xv. Lost motion, 180. Lotlghridge's bralke, 442. Lubricant. 360; imanner of applying, 860. Lubrication. 358; effect of pressure and velocity of surfaces on, 361; method of, 477. Man-hole, 349. Malsonl Machlie Works, 429, 436; locomotive by, 561, 577, 579. afsoni. William. 435. Master Mlechliaics' Association. 260. 288. Mechanical equivalent or heat. 22. Mlctlropolitan railroads, 427, 437; locomotives for, 436, 438, 440. Miid-gear, 195. -'Miles ntill to ton of coal, 449. Mineral oil, 504. Miscollanieous, 335. Model of valve-gear. 204. Modlulus ot proptlsioll, 415. Mogul locouotive, 430. 567. Molecular activity. 376. Momentum of liston, 230, 244; creates resistance to turning of crank, 216. Motion, reciprocating, 5; rotary, 5. Motion curves, 84. 196; how drawn, 197, 204, 208. Motion diagram, 213, 214. Mud-drum, 148. Mud-holes, 148. New York elevated railroad, 441; locomotive for, 583. Nitric acid, 368. Nitrogen, 368. Nitrous acid, 368. Nitrous oxide, 365. Nuts, 341; proportions of, 348. Oil, 360; animal, 504; manner of applying, 360; mineral, 504. Oil boxes, for tender, 354. Oil cellars. 179, 290. Oil-cock, 169. Oil-cup, 176. Open-road. 428; running on, 489. Operating locomotives, cost of, 448. Index. 605 Outside shell of fire-box, 75. Overflow, 120. Overflow-lnozzle, 121. Oxalate of ammonia, 451. Oxygen, 368, 370. Packing, 173. Packingr-bolts, 173. Packing-nuts, 132. 173. Packin-ringlfs, 172; inspection of, 468; setting out, 459. P;acking-sprinlgs, 172. l'arablic reflector. 337. P;ar:Lllel noolion. 233. Parallel-rods, 177. Passenger traffic, 427; locomotive for, 4330. Perforated pipe, 488. Pertolrmance and cost of operating locomotives, 448. Periods of distribution of steam, 220. Periphery of wheel, 277. Pet-cock, 118, 149. Petticoat-pipe. 113. Pile-driving machine, 28. Pilot, (see cow-catcher,) 294, 339. Piston, 1; accident to, 509, 522; diameter of, 69, 164, 416; constructio'l of, 172; how oiled(, 169; inspection of, 467; momentum of, 38, 2.;U, 241; stroke of, 416. Piston-llead, 172. Piston-rodl, 2; action of, 174; breaking of, 509; construction of, 171. Pitch of screw-threads, 341, 343. Plan, xiv. Plates, 551. Potential energy, 24, 28. Pre-admission, 197, 220, 237, 240. Preface, iii. Pre-release, 221, 226, 249. Pressure-valve, 115. Priming, 170, 484; cause and prevention of, 486; effect of, 488. Properties of saturated steamn, table of, 585. Proportions of locomotives, 412. Prosser's expander, 84. Pump, 115; construction of, 115; failure of. 509 518; freezing of. 120), 507, 532; inspection of, 466; location of, 119; regulation of, 119; working of 176; in a bnow storm, 532. Pump-barrel. 115. Punip-lug, 177. Pumllp-plunger, 155, 177. Pump-valve, 115. Punched holes, 9. 93, 103. Punching holes, 91, 93. Puslling-bar. 338. Pyrometer, 397. Quadrants, 261. Radiation, 18, 11l; from boiler, 397. Rtain stormi, running in, 49 IReceiving-ttube. 120. tReciprocating motion, 5. ]eflector, 337. Rele[ase of steam, 41, 221; governed by, 227; how affected by link, 217. ]el,pulsion of piarticles, 28. Reqtuirements and duties of locomotive runners, 54;. Resierve engine, 497. 606 Index. Resistance of trains, 406; on curves, 410; on grades, 408; table of, 407, 596. Responsibility and qualifications of locomotive runners, 544. Reverse-lever, 66, 187; breaking of, 530; construction and location of, 261; length of, 263. Reverse-rod, 187, 261; breaking of, 530. Reversing gear, 264. Richardson safety valve, 140. Richard's steam engine indicator, 231. Riveted seams, 91; strength of, 93, 65, 106. Riveting, chain, 100; double, 100; machine, 97; single, 95; strength of, 103; strongest form of, 99. Rivets, 90; arrangement of, 91; crushing of, 95, 98; diameter of, 93; proportions of, 91; shearing of, 94; staggered, 101; strength of, 94; zigzag, 101. Rocker, 7; accident to, 529. Rocker-arm, breaking of, 529; length of, 204. Rocker-pin, 185. Rocking grate, 152. Rogers Locomotive Works, 402, 571, 573. Rotary motion, 5. Running-board, 337. Running-gear, 268; inspection of, 473. Running locomotives, 478. Running off the track, 509, 512. Russia iron, 111. Saddles, 296. Safety chains, 340, 350. Safety-valve, 134; effect of blowing off, 485; inspection of, 465; pressure on, 136; Richardson's, 140. Safety-valve lever, 135. Safety-valve seat, 139. Sand box. 335; use of, 481. Saturated steam, 13; properties of, 585. Scalds, treatment of, 542. Scale, 453. Screw-threads, 341; form of, 313; proportions of, 345; system of, 312; table of, 348. Seams, riveted, 91; strength of, 95. Section, xiv. Sectional view, xiv. Sectors, 261; arrangement of notches in, 263. Sellers, William, 342; system of screw-threads, 342, 344. Sellers, William & Co., turn table by, 456. Setting out packing, 469. Set-screws, 179. Shaking grate, 152. Shearing, 94, 98. Shock, treatment of, 541. Shoes, 297. Shuntitg, 427. Side-bearing, 356. Side elevation, xiv. Side rods, 177. Side view. xiv. Signals, 447; observance of, 481, 489, 493. Slack of the traill. 481. Slides, 174; how oailed. 176; wear of, 175. Slide-valve, 6, 30; ad vance of, 38; conditions which it must fulfill, 30; disadvantaZes of first form of, 37; first form of, 30; how made steam tilht. 169; inspection of, 472; lap of, 40; middle position of, 184; motion of modified by the proportions of link motion. 248; oiling of, 169, 492; proportions of, 260; setting of, 264; travel of, 88. Index. 607 Smith, A. F., 441. Smithll's vacuum brake, 442. Smoke. 368; cause of, 372; prevention of, 503. Smoke-box, 66, 111; temperature inll., t96. Smoke-stack, 66; construction of, 112; inspection of, 465; proportions of, 112; size of, 69. Snow, 497; melting of, 532. Snow storm, blockade by, 532; running in, 497. Sobriety, importance of, 545. Soot, 371. Spacing rivets, 96, 98. Spark deflector, 112. Speed of locomotives, 450. Spherical joints, 160. Spider, 172. Spread of wheels, 285. Spring, 295, 297; breaking of, 509, -525; construction of, 297; curvatulre of, 301, 307; elasticity of, 297, 3)3, 306; necessity fto, 295; ulltlber of plates of, 306; proportions of, 304; span of, 306; strength of, 303. Spring balance, 137. Spring balance lever, 138. Spring hanger, 297; attachment of, 308; breaking of, 509. Spring strap, 300. Staggered rivets, 101. Starting-valve, 126. Stations, running into, 494; running past, 492; stop at, 503. Stay-bolts, 76; brleaking of, 79, 463; strain on, 78. Steam, 10; absolute pressure of, 13, 585; admission of, 30,. 155; advantages of using expansively, 55; application of. 1; condensation of, 17; cut-off, 41; effective pressure of, 14; exhaust of, 3,'; expansion of, 14, 41, 47; expansive force of. 1; generation of greatest amounlt of, 500; pressure in cylinders, 47, 52, 53, 223; pressure, limit of, 134; pressure of, 11; pressure'of after expansion, 16; properties of. 56, 585; quantity required, 420; release of, 41; saturated, 13; superheated, 13; total heat of, 29, 57, 585; temperature of, 585; weight of, 585; volume of, 14, 163, 585; wire drawn, 59. Steam-dome, 110; location of, 110 Steam-chest, 6; bursting of, 509, 522; construction of, 169; protection of, 170. Steam-chest cover, 169. Steam-gauge, 140; connection of, 145; inspecting of, 465; testing of, 145. Steam indicator, 231; method of applying, 234. Steam line, 236. Steam passage, 165. Steam pipes, 111, 155; bursting of, 509, 522; construction of, 158. Steam ports. 5; opening of, 217. Steam space, 109. Steam ways, 5, 122; effect of, 223 Steam whistle. 146. Steel plates, 479. Straps, 177. Stroke, 16. Stub-end, 179. Studies for mechanics, locomotive runners, &-c., 549. Stuffing-box, 173; illspection of. 470. Suburban railroads, 427; locomotives for, 436, 438. Suction-pipe, 115. Suction-valve, 115. Sun stroke, treatment of, 543. Superheated steam, 13. Surface-cock. 487. Suspending-link, 250. 608 Index. Suspension, point of, 249. Suspension-links, 318. Switch. 269. Switching locomotive, 427, 428; running of, 499; engraving of, 553. Tangent, 209. T''ank, 6G, 319; capacity and weight of, 69, 346, 359; how strengtlhanld, 350. Tank locomotive, 428, 432, 571, 573, 575, 577, 579, 581, 583.'tauntonl Locomotive Mlanlutfacturing Company, 428. Temperature ili tire-box, 887; necessary to igiite coal gas, 387. Tendcr,68; capacity and weight cf, 69, 349, 357; construction of, 349.'lender trucks, 35u, 356.'lendelr-v lve, 350. Tensile strail, 89. Ten-wheeled locomotive, 430, 565. Tlestin of boilers, 461; of steam gauges, 145. Threads (of screws); see screw-threads, 341. Three-legged principle, 317. Throttle-pipe, 111. T'hrottle-valve, 155; failure of, 510, 530; inspection of, 466; operation of, 158; use of, 481. Throttle-valve lever, 158.''lhrow of eccentric, 31. Thumb tool, 84. T'ires, 6:3, 285; breaking of, 509, 424; how fastened, 286; standard size of, 288. Tools for engine, 476. Top view, xiv. Total heat of combustion, 380, 393; of steam, 29, 57. Total pressure of steam, table of, 585.'lourniquet, 537. T pipe, 159. T'raction, 319. Tractive power, 321. Traffic, freighlt and passenger, 427. Trailing wtheels, 65; breaking of, 524. Train, protection o1; 514. Tr'ansverse section, xv. Travel of valve, 38; effect of changing, 42, 195, 214, 216; how changed, Tread of wheel, 277. Truck, 268; construction of, 314; effect of on movement of locomotive around curves, 273; for tender, 356; lateral lmotion. of, 317, re.-istalnce to rolling, 280; use of, 269; with single pair of wheels, 271, 439. Truck axle, 283; breaking of, 524.''Truck boxes, 292, 314.'f'ruck fratne, 314. Truck springs, 314. Truck wheels, 65, 263; breaking of, 524; construction of, 291; size of, 68; slit, oi, 273; weight on. 69; why two are used, 269. Truss-bars, 316. Try-cocks, 130. Tubes, 66; arrangement o,f. 81; bursting or collapse of, 509, 516; fastening of, 83; number andl sze of, 69, 74. Tube-expandler, 84. l'urn-table, 451; construction of, 455. Unguent, 360. Ultimate strengthl, 90; of springs, 302. Unit of heat, 58. Unit of workl 23. United States standard for screw-threads, 343, Index. 609 Vacuum brake, 442; construction of, 446. Vacuum line, 48. Valve, slide, 6. (See slide-valve). Valve, Allen's, 224. Valve-face, 40. Valve-gear. 181; construction of, 181; dimensions of, 216; injury to, 510; inspection of, 472; model of, 250. Valve-rod, 7. Valve-seat, 5. Valve-stem, 7; accident to, 529. Vapor, 10. Variable exhaust, 163. Venous bleeding, 536. Vertical section, xiv. Volume, 14. Wagon top, 109. Waist of boiler, 67. Ward's air brake, 442. Water, amount evaporated per pound of coal, 73, 394; freezing of, 507; height of in boiler, 130, 484; muddy, 486; "solid," 487; supply exhausted, 531. Water crane, 452. Water gauge, 130, 132. Water grate, 152. Water space, 67; size of, 69, 75. Water supply, 453. Water table, 399. Water tank, effect of carrying weight of on driving-wheels, 433, 451. Wedges, 294, 297; bolts for, 475. Weight, distribution of, 413. Welt, 100, 103. Westinghouse brake, 442. Wheels, driving, 268; adhesion of, 62; breaking of, 509, 524; carrying, 268; size of, 68; trailing, 65; truck, 65, 268. Wheel-base, 69, 285. Wheel centres, 63, 286. Wheel guards, 340. Wild engine, 498. Wire drawn, 59, 197, 482. Wire netting, 465; method of cleaning, 466. Work. 22; convertible into heat, 25, Working water, 170. Wrist-pinl, 175. Wyman, I). W., locomotive by, 583. Y, 460. Zigzag rivets, 101. ADVERTISEMENTS. PUBLISHED EVERY SATURDAY. The Railroad Gazette contains: ENGRAVINGS of valuable improvements or new designs made ill locomotives or other railroad equipments or machinery, and of engineering works which possess features of interest to railroad men or engineers. ARTICLES on all the details of railroad business, written by practical railroad men. The " Catechism of the Locomotive" and the " Road-Master's Assistant" were first published in this paper in weekly parts. Articles of a similar nature on these and other departments of railroading are found in its columns. 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English versus Amlerican Bridges:- A pamphlet of 32 pages, being a discussion by eminent English and American engineers of the comparative merits of the English and American systemls of bridge building. Price, postage paid, 25 cents. Concerning the Cost of Transportation on Railroads, by L. P. MOREHOUSE, Assistalnt Engineer of the Illinois Central Railroad:-A pamphlet of 18 pages, being a thoroughly scientific analysis of this important subject. Price, postage paid, 25 cents. Catechisin of the Locomotive, by M. N. FORNEY, Mechianical Engineer:-A book of 650 pages, with 250 engravings and twenty full-page plates of various styles of locomotives. The most complete treatise on the construction and operation of the locomotive. Price, postage paid, $2.50. Address, THE RAILROAD GAZETTE, 73 Broadway, New York. BALDWIN LOCOMOTIVE WORKS. _ --- I-T;= Burntbama Pary, ia ~ Co. MANIUFACTUURERS OF LOCOMOTIVE ENGINES Adapted to every variety of service, including MINE LOCOMOTIVES and LOCOM[ OTIVES FOR NARROW GAUGE RAILWAYS. All work accurately fitted to gauges and thoroughly interchangeable. Plan, Materials, Workinanship, Finish and Efficiency fLlly guaranteed. GEO. BURNHASI. CHARLES T. PARRY, EDWARD LONGSTRETH, EDWARD H. WILLIAMIS. WILLIAM P. HENSZEY, JOHN H. CONVERSE. THE HINKLEY LOCOMOTIVE WORKS, Manufacturers of Locomotives, Boilers, Tanks, Iron and Brass Castings. 439 ALBANY STREET, BOSTON. ADAMIS AYER, President. FRANK D. CHILD, Sup't. F. L. BULLARD, Treasurer. H. L. LEACH, General Manager. GEO. F. CHILD, Secretary. MASON MACHINE WORIKS, TAUNTON, MASS., VIIILIAM:lAGf SON. President, v RG~ m ~P;e~~r\~~~~-.' Builders of All Kinds of TLOCOIMOTIVsE INCLUDING Double Truck Locomotives for Wide or.Narrow-Gauge Railroads; also, All Kinds of Cotton Machinery. -~~~~~~~~~~~ ~ ~~~.....- TALUNTONT LOCOMNOTIVE MANUFACTURING CO. [ESTABLISHED IN 1846.] P. I. PERRIN, Superintendent. HARRISON TWEED, Treasurer. TAIUNTON, MASS. DANFORTH LOCOMOTIVE AND MACHI:NE CO. JOHN COOKE President. New York Office, 52 WALL STREET. J. T. BLAUVELT, Vice-President. PANewTE York ce, 52 WALL STREET, A. J. BIXBY. Secretary and Treasurer. SON, N. J, JAMES COOKE, Superintendent. H. A. ALLEN, Agent. ROGERS LOCOMOTIVE AND MACHINE WORKS, Paterson, New Jersey. ) -m - R1o Locomotive Engines, and other Varieties of Railroad Machinery. J. S. ROGERS, President. THOMAS ROGERS Treasurer Rt. S. HUGHES, Secretary. PATERSON, N. J. WM. S. HUDSON, Supt. 44 Exchange Place, New York. MANCHESTER LOCOMOTIVE WORKS, MANUFACTURERS OF LOCOA'lOTIVE ENG INE i. All work accurately fitted to ga.uges. All parts dupllicates a]ld guaranteed of best nmaterial and worlklallship. JOHN A. BUItNIH-AM, PRESIrENT. WAr. G. G. MEANS. T]lIA.S., BOSTON, IASS. ARtETAS BLOOD, AGENT, MANCHESTER, N. H. PITTSBURGH Locomotive and Car Works, IPITTSBUEKGHE. I: A. -Manufacturers of LOCOMOTIVE ENGINES -FORBROAD OR NARROW GAUGE ROADS, From Standard Designs, or according to Specifications, to suit Purchasers. Tanks, Locomotive or Stationary Boilers, furnished at short notice. P. O. Address, Works, 410 Beaver Avenue, PITTSBURGH, PA. ALLEGHENY CITY. D. A. Stewart, Pres. Wilson Miller, Sec. and Treas. LOCOMOTIVE SELF OILERS -FOr, — Steam- Chest, Crank-Pins and Rods. NATHAN & DREYFUS, 108 LIBERTY STREET, N. Y. Perfect lubrication with the utmost economy. One ounce of oil on main connections or rod cups sufficient for an average run of 2,000 miles. Twelve ounces of melted tal.'ON-LIFTIrN low or oil, in cylinder lubrica. TIJECTOR. tors, will run engines with heavily loaded trains 120 miles. Sole manufacturers of the s world-renowned Friedmann Injectors, g for Locomotives and Station- ry Boilers. These injectors feed more water, and at a higher temperature, with less steam, than any others. RIICI-IARD DTJDGEON, 24 Columbia Street, New York, Maker and Patentee I ___ hS W OF IMIPROVED HYDRAULIC JACKS, Punches, Boiler-Tube Expanders, and Direct-Acting Steam H'ammers. Communications by letter will receive prompt attention. Jacks for pressing on Car Wheels or Crank Pins made to order. THOMAS T. TASKER, JR. STEPHEN P. Xt. TASKER. MORRIS, TASKER & CO., PASCAL IRON WORKS, PHILADELPHIA, TASKER IRON WORKS, New Castle, Delaware. Office, FIFTH and TASKER STREETS, Philadelphia. Office and Warehouse, No. 15 GOLD STREET, TNew York. Office and Warehouse, No. 36 OLIVE1R STREET, Boston. lrianufacturers of WROUGHT IRON WELDED TUBES, Plain, Galvanized and Rubber-coated, FOR GAS, STEAM AND WATER. Lap-Welded Charcoal Iron Boiler Tubes. Oil Well Tubing and Casing. Gas and Steam Fittings, Brass Valves and Cocks. Gas and Steam Fitters' Tools. Cast Iron Gas and Water Pipe. Street Lamps, Posts and Lanterns. Improved Coal Gas Apparatus. Improved Sugar Machinery, &c. We would call special attention to our Patent Vulcanized Rubber-coated Tube. OFFICE, 15 South St. WORKS, Cor. Essex and Burke Sts. BALTIMORE, MD This Company uses ONLY the best quality of Charcoal Iron, made from the celebrated hematite ores found within and around the City of Baltimore. The great ductility and tenacity of this iron, its admirable chilling qualities, its freedom from the defect of "spotting" on the tread, to which most of the best chilling irons are liable, make it peculiarly suitable for wheels. The first chilled wheels ever made were of Baltimore Iron, and some of them are still in service. All wheels made by this Company are annealed by their Patent Central Flue System, used exclusively by them, and believed to be the most perfect system of relieving wheels from strain. The advantage of their immediate proximity to the Baltimore orebeds and Blast Furnaces, and thegrat facilities for shipment from Baltimore by rail or by —-water to al In eble the Baltimore Car Wheel Company.-t-o offer s e ality at comparatively low pyes T e d f` odersIfoW s ttuo 6 yo, F:Vr _T0, o.+) Wheels of all4, Specimen of Baltimore Iron in Pig, 3 3,3 20 lbs. per sq. in.,ot axes M " after two years service, ) 33'900 ~. W S G B. S. G. BAKER President. J.M. LAWFORD, Secretary. i 74 b a rhn ~tl U s i o other severe te' st s, an le; ii~: to the utmost capacity Of t e,~~~~~~~~ CENTRAL FLUE SYSTEM,::i:~;z-::;;~j~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~j~:~~~~~~^ tJ.;:~:-::::: r:: r fi v l x sililz2-~:l::=:: = 0: 7: _ -- q 20 * -_ = E f =:C:: _::j: X;ll:. f::. f - f=::~ - - - _:: = _ _ -= - j - j = —- = - --- --- t ~~-; —, j I -''i.fi-t,: p:(:: i::-:::~ i',::: -~- ff; <: fL. -'-:-:D_' =iI-. — - -:.- —'-':-: -:7 —-'':~::' -! — 7 —-!:-7 -: i: -~ —: -': -- i- 4 -; —. —........ —:-. -;:........ -: -!. —0 -. —. -:~.::7i =BALTIMORE CAR'VVH E EL COMPAN'NY". WILLIAM B. BEMENT & SON, INDUSTRIAL WORKS, PHILADELPHIA, U. S. A,, M1anufacturers of Machine Tools, OTEHER EQUIPMENTS Locomotive and ailroad ShopsT Locomotive and Railroad Shops. MACIK'S PATENT INJECTOR. iii Manufactured by the TATTIOITATL TTBEIE WORKBV ZS O. N A'ITIONALr T UBE W\ORKS CO., BCSTON, MASS, AND McKEESPORT, PENN. MANUFACTURERS OF BEST LAP'WELDEDU Iron Boiler Tubes, STEAM AND GAS PIPE, Artesian and Oil Well Tubing, COASING-, "MACK'S" PATENT INJECTOR, (See cut opposite,) IMPROVED PIPE-SCREWING MACHINES, ETC. OFFICES AN1D tVAREHO USES: NEW YORK,..... No. 78 WILLIAM STRnIET. BOSTON....... No. 8 PEMBERTON SQUARE. BUFFAIO,...... NO. 218 MAIN STREET. CHICAGO,..... Nos. 112, 114, and 116 LAKE STREET. CINCINNATI..... Nos. 119, 121, and 123 PEARL STREET. McKEESPORT, PA..,. NEAR PITTSBURGH. CLEVELAND, O.... NO. 63 CENTRE STREET. Silver MIedacls awarded to us at the Cincinnati and Boston State Fairs, andrl American Institute Fair, in New York, and we challenge any and all Injectors ill the Ilarket to a public trial of superiority. We gualrantee every purclhaser of an INJECTOR against any claims for illfringelellt of ally other patellts. BEST TOOL STEELI MACHINERY, SPRING AND FROG STEEL, Steel Tires, Open Hearth Steel, ALL KINDS OF FORGINGS8, ETC.,if! ro~~~~I - WORKS, OFFCE, AND P. ADDRESS, Nicetown, Philadelphia, Pa. ESTABLISHED 1848. WM. SELLERS & CO., PIHILADELPHIA, MANUFACTURERS OF Machinists', Founders', Smiths' -ANDBOILER-MAKERS' TOOLS, Railway Equipments, T-urning anild Transfer Tables, -ANDPIVOT BRIDGES, GIFFARD INJECTORS, Poth Adjustable and Self-Adjusting, For Feeding Boilers with Water, -ANDSHAFTING AND MILL GEARING, Being the Originators of the BALL AND SOCKET HANGERS, VICE COUPLINGS, AND THE Interchangeable System of Shafting. SCALE IN STEAM BOILERS. LORD'S BOILER-CLEANSING COMPOUND, For removing SCALE IN STEAM BOILERS; For preventing the FORMATION OF SCALE IN BOILERS; For neutralizing MINE AND SULPHUR WATERIS. I will remove and prevent scale in any steam boiler, and make no charge until the work is found satisfactory. Send for any pamphlet, in which is given full particulars, with directions for use, and references and recommendations from many of the largest establishments in the United States, where I have accomplished the work with entire satisfaction. This compound will preserve iron from anything which Inay be found in water acting injuriously. If desired, I will send you positive proof of this, free of charge. Send for Pamphlet to GEORGE W. LORD, Philadelphia, Pa. THE PRATT & WHITNEY CO., HARTFORD, CONN., MANUFACTURERS OF ENGINE LATHIES, With Slate's Patent Taper Attachment; Planers, Drills, Boring Mills, Shaping Machines, and other Machinists' Tools; Drop Hammers of improved construction, Blacksmiths' Shears, Broaching, Stamping and Trimming Presses, Iron Shop Cranes, Friction Clutch Pulleys, Water Miotors, And a large variety of Gun and Sewing Machine Machinery. For simplicity, convenience. thoroughness of construction, correct workling, aind completeness of equipment with the most valuable modern attachments, the machinery made by this Company is unsurpassed. Photographs and descriptions furnished on application. A MISTAKET It is a nmistake to think that Solid Einery Wheels and Emery Grinding Machinery have nothing to do with Railroad ilnterests, just because THE TANITE CO. do not furnish a variety of Machiniery specially adapted for Railroad work. Thus far we have aimed to make the SOLID EMERY WHEEL popular, and to demonstrate its advantages, by supplying cheap and simple machines for general work. We now offer a CAR-BOX GRINDER, which perfectly finishes Car Brasses, so cheaply that every Coal Car and Truck can afford finished Brasses. We also offer an automatic EMERY PLANiER, which does exact and fine work, more cheaply than the Planer, Milling Machine, or Shaper. But what we urge is that while these machines and all our standard goods should be freely bought for the general uses of Railroad work, every Master Mechanic and Locomotive and Car Builder should become his own inventor and introducer of Emery Grinding Machinery. We can not furnish machinery for every branch of work; but every branch of metal and wood work can use this class of goods to advantage. We find this year (174) a Locomotive Factory in Austria, buildig Locomnotives in eret by the aid of Solid Wheels and Emrery Grinding Machinery of their own invention, on whose use the very existence of their works is said to depend. For Catalogues, &c., address THE TANITE CO., STROUZDSBURG, MIONROE CO., PA. AMERICAN TUBE WORKS, BOSTON, Sole Manufacturers in America of Green's & Alston's Patent Seamless Drawn BRASS TUBES, -AND- Adams's Patent Seamless Drawn COPPER TUBES, For Locomotive, Marine, Stationary Boilers, and other purposes. Heater Tubes, l ems Steam Pipes, Worms for Stills, Condensers, Paper Rolls, Feed Pipes, Bilge Pipes, Sand Pipes, Hand Rail, 4i% Pump Rams, Pump Chambers, Printers' Moulds, Window Guards, Plumbing Tubes. SEAMLESS DRAWN. WTM. C. COTTON, Treasurer, 97 State Street, Boston. W. H. BAILEY, AGENT, 180 Pearl Street, Nevv Yo.rlr H. S. MANNI:NG & CO. 111 Liberty Street, New York, GEINERAL AGENTS New York Tap and Die Co. Goods, WORCESTER MACHINE SCREW CO., MANNING'S BOLT CUTTER. NEW YORK AGENTS KEYSTONE PORTABLE FORGE CO., Machine Auger Bits, ONEIDA AND CUSHMAN LATHE CHUCKS, AND DEALERS IN Machinists' and IRailroad Supplies. GOLD MEDAL OF THE Mass. Charitable Mechanics' Association Exhibition, 1874, AWARDED THE BAY STATE IRON COMPANY, FOR THEIR HOMOGENEOUS STEEL BOILER -AND — FIRE-BOX PLATES. Also, Manufacturers. of PLATE IRON, PIG IRON AND RAILROAD IRON. JOHNT -I. REED & CO., Agents, No. 2 Pemberton Square, Boston, Mass. P. J. POTTERl. JOHN W. HOFFMAN. W3I. TOOTIIE. SOUTIIARD HIOFFMAN. POTTER, HOFFMAN & CO, 110 LIBERTY STREET, NEW YORK, General Railroad Supplies. AGENTS FORI Bay State Iron Co., Boston, Mlass. Homogeneous Plates, Rails, &c. Crucible Steel Tires, Axles, Forgings, &c. Chrome Tool Steel and Spring Steel. Sax, Kear & Co's Patent Steel Tired Wheels. CHROME STEEL CO., BROOKLYN, MANUFACTURERS OF ALL DESCRIPTIONS OF TRADE MARIK. C S Cast C\\ Steel. ADAMANTINE. Office, 110 Liberty Street, NEW YORK. WBr. ARTHUR, Pres't. C. P. HAUGITAN, SUp't. C. D. SCHUBARTH, Sec'y and Treas. Wer. TOOTHE, Gen'l Agesnt. JACKSON & SHARP COMPANY, WILMINGTON, DEL., Manufacturers of every variety of Passenger, Freight and Construction Cars, For Broad and Narrow Gauge Railways. Regular working force, 1,000 men. Photographic views of cars furnished on application, free of cost. CAST-STEEL WORKS -OF — FRIED. KRUPP, Essen, Germany. TIRES, AXLES, SPRING STEEL, CRAiNK PINS, CONNECTING RODS, PISTON RODS, &c., &c. Special Tool Steel, Very Superior Article, Suitable for All Kinds of Cutting Tools, Dies, &c. Represented by THOS. PROSSER & SON, 15 Gold Street, New York. RAMAPO WHEEL AND FOUNDRY CO., MANUFACTURERS OF WHEELS -FORDrawing-Room and Sleeping Coaches, Locomotives, Tenders, Passenger and Freight Cars, Wheels for NARRow-GAUGE and TRAM-ROADS, using exclusively the celebrated Irons from the Richmond and Salisbury Mines. Axles furnished and wheels fitted. RAMAPO, ROCKLAND COUNTY, N. Y, TURN TABLES, Pivot-Bridges, SELF-CLOSING PIVOT CANAL BRIDGES, -AND — First-Class Saw-Mill MIachinery of All Kinds, Manufactured by SNYDER BROTHERS, FOUNDERS AND MACIINISTS, WILLIAMSSPORT, PR. I~~(tit~~~ii ~~ ~~~etJRI~~~~2 S17d'It HAS.A. We, have the best and most complete assortment of Machinists' Tools ithout Chargeo In the Country, For Patterns, Comprising all those e R WI used in with our Patent ounlding MACHINE, LOCOMOTIVE, Mlachine.'1. It. REPA SHOPS. ~ 5 For Photographs, Prices and Description, etc., address''"~ -- ~ ~ NE'W YOiE'STEAX ETN.I'E C00., NTo. 4 Car Wheel Borer. 9 8 Chambers Street, New York, NICHOLS, PICKERING & C0., Manufacturers of CAST STEEL IRAILWAY SP RINGS, PHILADELPHIA. WXM.. ICHOLS. CHAS. W. PICKERING. . Phoenixville. Bridge. Works. CLARKE. REEVES. &. CO..Office. No. 410. Walnut. Street. Philadelphia,. ENGINEERS. &. CONSTRUCTORS. OF. IRON. BRIDGES. ROOFS. &. VIADUCTS. OF. EVERY. DESCRIPTION N. B.-An illustrated Album, showing different styles of construction, will be mailed on application to above address, on receipt of 75 cents.