The steam engine familiarly explained and illustrated; with an historical sketch of its invention and progressive improvement; its applications to navigation and railways; with plain axioms for railway speculators

Front matter

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JUST PUBLISHED, IN ONE VOLUME, 8VO.

Preface

THE AMERICAN EDITOR.

Several of the additions which were made by the Editor to the first American edition, have been superseded by the great extension which the original has from time to time received from its author. This is more particularly the case with the sections which had reference to the character of steam at temperatures other than that of boiling water ; to the use of steam in navigation ; and to its application to locomotion. These sections have of course been omitted. A few new sections and several notes have been added, illustrative of such points as may be most interesting to the American reader.

Columbia College, Neio York, March, 1836.

a2

PREFACE

THE FIFTH EDITION.

This volume should more properly be called a new work than a new edition of the former one. In fact, the book has been almost rewritten. The change which has taken place, even in the short period which has elapsed since the publication of the first edition, in the relation of the steam engine to the useful arts, has been so considerable as to render this inevitable.

The great extension of railroads, and the increasing number of projects which have been brought forward for new lines connecting various points of the kingdom, as well as the extension of steam navigation, not only through the seas and channels sur rounding and intersecting these islands, and through out other parts of Europe, but through the larger waters which are interposed between our dominions in the East and the countries of Egypt and Syria have conferred so much interest on the application of steam to transport, that I have thought it advisable to extend the limits of the present edition considerably beyond those of the last. The chapter on

PREFACE.

railroads has been enlarged and improved. Three chapters have been added. The twelfth chapter contains a view of steam navigation ; the thirteenth contains several important points connected with the economy of steam power, which, when this work was first published, would not have offered sufficient interest to justify their admission into a popular treatise; and the fourteenth chapter contains a series of compendious maxims, for the instruction and guidance of persons desirous of making investments or speculating in railway property.

London, December, 1835.

PREFACE

THE FIRST EDITION.

There are two classes of persons whose attention may be attracted by a treatise on such a subject as the Steam Engine. One consists of those who, by trade or profession, are interested in mechanical science, and who therefore seek information on the subject of which it treats, as a matter of necessity, and a wish to acquire it in a manner and to an extent which may be practically available in their avocations. The other and more numerous class is that part of the public in general, who, impelled by choice rather than necessity, think the interest of the subject itself, and the pleasure derivable from the instances of ingenuity which it unfolds, motives sufficiently strong to induce them to undertake the study of it. Without leaving the former class altogether out of view, it is for the use of the latter principally that the following lectures are designed. ■

To this class of readers the Steam Engine is a subject which, if properly treated of, must present

2 9

10 PREFACE.

strong and peculiar attractions. Whether we consider the history of its invention as to time and place, the effects which it has produced, or the means by which it has caused these effects, we find every thing to gratify our national pride, stimulate our curiosity, excite our wonder, and command our admiration. The invention and progressive improvement of this extraordinary machine, is the work of our own time and our own country; it has been produced and brought to perfection almost within the last century, and is the exclusive offspring of British genius fostered and supported by British capital. To enumerate the effects of this invention, would be to count every comfort and luxury of life. It has increased the sum of human happiness, not only by calling new pleasures into existence, but by so cheapening former enjoyments as to render them attainable by those who before never could have hoped to share them. Nor are its effects confined to England alone ; they extend over the whole civilized world ; and the savage tribes of America, Asia, and Africa, must ere long feel the benefits, remote or immediate, of this all-powerful agent.

If the effect which this machine has had on commerce and the wealth of nations raise our astonishment, the means by which this effect has been produced will not less excite our admiration. The history of the Steam Engine presents a series of contrivances, which, for exquisite and refined ingenuity, stand without a parallel in the annals of human invention. These admirable contrivances, unlike other results of scientific investigation, have

PREFACE. 11

also this peculiarity, that to understand and appreciate their excellence requires little previous or subsidiary knowledge. A simple and clear explanation, divested as far as possible of technicalities, and assisted by well selected diagrams, is all that is necessary to render the principles of the construction and operation of the Steam Engine intelligible to a person of a plain understanding and moderate information.

The purpose for which this volume is designed, as already explained, has rendered necessary the omission of many particulars which, however interesting and instructive to the practical mechanic or professional engineer, would have little attraction for the general reader. Our readers require to be informed of the general principles of the construction and operation of Steam Engines, rather than of their practical details. For the same reasons we have conlined ourselves to the more striking and important circumstances in the history of the invention and progressive improvement of this machine, excluding many petty disputes which arose from time' to time respecting the rights of invention, the interest of which is buried in the graves of their respective claimants.

In the descriptive parts of the work, we have been governed by the same considerations. The application of the force 'of steam to mechanical purposes has been proposed on various occasions, in various countries, and under a great variety of forms. The list of British patents alone would furnish an author of common industry and application with matter to

12 PREFACE.

swell his book to many times the bulk of this volume. By far the greater number of these projects have, however, proved abortive. Descriptions of such unsuccessful, though frequently ingenious machines, we have thought it advisable to exclude from our pages, as not possessing sufficient interest for the readers to whose use this volume is dedicated. We have therefore strictly confined our descriptions either to those Steam Engines which have come into general use, or to those which form an important link in the chain of invention.

December 26, 1827.

Chapter I. Preliminary Matter

Paga Motion the Agent in Manufactures. — Animal Power. — Power depending

on physical Phenomena. — Purpose of a Machine. — Prime Mover. — Mechanical Qualities of the Atmosphere. — Its Weight. — The Barometer. — Fluid Pressure. — Pressure of rarefied Air. — Elasticity of Air. — Bellows. — Effects of Heat. — Thermometer. — Method of making one. — Freezing and Boiling Points. — Degrees. — Dilatation of Bodies. — Liquefaction and Solidification. — Vaporization and Condensation. — Latent Heat of Steam. — Expansion of Water in evaporating. — Effects of Repulsion and Cohesion. — Effect of Pressure upon Boiling Point — Formation of a Vacuum by Condensation 17

CHAPTER n.

FIRST STEPS IN THE INVENTION.

Futility of early Claims. — Watt the real Inventor. — Hero of Alexandria. — Blasco Garay. — Solomon De Caus. — Giovanni Branca. — Marquis of Worcester. — Sir Samuel Morland. — Denis Papin. — Thomas Savery ... 38

Chapter III. Engines Of Savery And Newcomen

Savery's Engine. — Boilers and their Appendages. — Working Apparatus. — Mode of Operation. — Defects of the Engine. — Newcomen and Cawley. — Atmospheric Engine. — Accidental Discovery of Condensation by Jet. —

Potter's Discovery of the Method of working the Valves 51

14 CONTENTS.

Chapter IV. Engine Of James Watt

Page Advantages of the Atmospheric Engine over that of Captain Savery. — It

contained no new Principle. — Papin's Engine. — James Watt. — Particulars of his Life. — His first Conceptions of the Means of economizing Heat. — Principle of his projected Improvements 69

Chapter V

Expansive Principle applied. — Failure of Roebuck, and Partnership with Bolton. — Patent extended to 1800. — Counter. — Difficulties in getting the Engines into Use 80

Chapter VI. Double-acting Steam Engine

The Single-acting Engine unfit to impel Machinery. — Various Contrivances to adapt it to this Purpose. — Double Cylinder. — Double-acting Cylinder. — Various Modes of connecting the Piston with the Beam. — Rack and Sector. — Double Chain. — Parallel Motion. — Crank. — Sun and Planet Motion. — Fly Wheel. — Governor 91

Chapter X. Locomotite Engines On Railways

High-pressure Engines. — Leupold's Engine. — Trevithick and Vivian. — Effects of Improvement in Locomotion. — Historical Account of the Locomotive Engine. — Blenkinsop's Patent. — Chapman's Improvement. — Walking Engine. — Stephenson's first Engines. — His Improvements. — Liverpool and Manchester Railway Company. — Their preliminary Proceedings. — The great Competition of 1829. — The Rocket. — The Sanspareil. — The Novelty. — Qualities of the Rocket. — Successive Improvements. — Experiments. — Defects of the present Engines. — Inclined Planes. — Methods of surmounting them. — Circumstances of the Manchester Railway Company. — Probable Improvements in Locomotives. — Their Capabilities with respect to Speed. — Probable Effects of the projected Rail-roads. — Steam Power compared with Horse Power. — Railroads compared with Canals 145

Chapter XI. Locomotive Engines On Turnpike Roads

Railway and Turnpike Roads compared. — Mr. Gurney's Inventions. — His Locomotive Steam Engine. — Its Performances. — Prejudices and Errors. — Committee of the House of Commons. — Convenience and Safety of Steam Carriages. — Hancock's Steam Carriage. — Mr. N. Ogle. — Trevithick's Invention. — Proceedings against Steam Carriages. — Turnpike Bills. — Steam Carriage between Gloucester and Cheltenham. — Its discontinuance. — Report of the Committee of the Commons. — Present State and Prospects of Steam Carriages. 213

Chapter XII. Steam Navigation

Propulsion by Paddle Wheels. — Manner of driving them. — Marine Engine. — Its Form and Arrangement. — Proportion of its Cylinder. — Injury to Boilers by Deposites and Incrustation. — Not effectually removed by blowing out. — Mr. Samuel Hall's Condenser. — Its Advantages. — Origi-

16 CONTENTS.

Page nally suggested by Watt. — Hall's Steam Saver. — Howard's Vapour

Engine. — Morgan's Paddle Wheels. — Limits of Steam Navigation. — Proportion of Tonnage to Power. — Average Speed. — Consumption of Fuel. — Iron Steamers. — American Steam Raft. — Steam Navigation to India. — By Egypt and the Red Sea to Bombay. — By same Route to Calcutta. — By Syria and the Euphrates to Bombay. — Steam Communication with the United States from the west Coast of Ireland to "St. Johns, Halifax, and New York 241

Chapter XIII. Seneral Economy Of Steam Power

Mechanical Efficacy of Steam ; proportional to the Quantity of Water evaporated, and to the Fuel consumed ; independent of the Pressure. — Its mechanical Efficacy by Condensation alone ; by Condensation and Expansion combined; by direct Pressure and Expansion; by direct Pressure and Condensation ; by direct Pressure, Condensation, and Expansion. — The Power of Engines. — The Duty of Engines. — Meaning of Horse Power. — To compute the Power of an Engine. — Of the Power of Boilers. — The Structure of the Grate Bars. — Quantity of Water and Steam Room. — Fire Surface and Flue Surface. — Dimensions of Steam Pipes. — Velocity of Piston. — Economy of Fuel. — Cornish Duty Reports « 277

CHAPTER XIV. Plain Rules for Railway Speculators 307

THE

STEAM ENGINE

EXPLAINED AND ILLUSTRATED.

Chapter I. Preliminary Matter

Motion the Agent in Manufactures. — Animal Power. — Power depending on physical Phenomena. — Purpose of a Machine. — Prime Mover. — Mechanical Qualities of the Atmosphere. — Its Weight. — The Barometer. — Fluid Pressure. — Pressure of rarefied Air. — Elasticity of Air. — Bellows. — Effects of Heat. — Thermometer. — Method of making one. — Freezing and boiling Points. — Degrees. — Dilatation of Bodies. — Liquefaction and Solidification. — Vaporization and Condensation. — Latent Heat of Steam. — Expansion of Water in evaporating. — Effects of Repulsion and Cohesion. — Effect of Pressure upon boiling Point. — Formation of a Vacuum by Condensation.

(1.) Of the various productions designed by nature to supply the wants of man, there are few which are suited to his necessities in the state in which the earth spontaneously offers them : if we except atmospheric air, we shall scarcely find another instance : even water, in most cases, requires to be transported from its streams or reservoirs ; and food itself, in almost every form, requires culture and preparation. But if, from the mere necessities of physical existence in a primitive state, we rise to the demands of civil and social life — to say nothing of luxuries and refinements — we shall find that every thing which contributes to our convenience, b2 3 17 or ministers to our pleasure, requires a previous and extensive expenditure of labour. In most cases, the objects of our enjoyment derive all their excellences, not from any qualities originally inherent in the natural substances out of which they are formed, but from those qualities which have been bestowed upon them by the application of human labour and human skill.

In all those changes to which the raw productions of the earth are submitted in order to adapt them to our wants, one of the principal agents is motion. Thus, for example, in the preparation of clothing for our bodies, the various processes necessary for the culture of the cotton require the application of moving power, first to the soil, and subsequently to the plant from which the raw material is obtained : the wool must afterward be picked and cleansed, twisted into threads, and woven into cloth. In all these processes motion is the agent : to cleanse the wool and arrange the fibres of the cotton, the wool must be beaten, teased, carded, and submitted to other processes, by which all the foreign and coarser matter may be separated, and the fibres or threads arranged evenly, side by side. The threads must then receive a rotatory motion, by which they may be twisted into the required form ; and finally peculiar motions must be given to them, in order to produce among them that arrangement which characterizes the cloth which it is our final purpose to produce.

In a rude state of society, the motions required in the infant manufactures are communicated by the immediate application of the hand. Observation and reflection, however, soon suggest more easy and effectual means of attaining these ends : the strength of animals is first resorted to for the relief of human labour. Further reflection and inquiry suggest still better expedients. When we look around us in the natural world, we perceive inanimate matter undergoing various effects in which motion plays a conspicuous part : we see the falls of cataracts, the currents of rivers, the elevation and depression of the waters of the ocean, the currents of the atmosphere ; and the question instantly arises, whether, without sharing our own means of subsistence with the animals whose force we use, we may not equally, or more effectually, derive the powers required from these various phenomena of nature ? A difficulty, however, immediately presents itself : we require motion of a particular kind ; but wind will not blow, nor water fall as we please, nor as suits our peculiar wants, but according to the fixed laws of nature. We want an upward motion ; water falls downward : we want a circular motion ; wind blows in a straight line. The motions, therefore, which are in actual existence must be modified to suit our purposes : the means whereby these modifications are produced, are called machines. A machine, therefore, is an instrument interposed between some natural force or motion, and the object to which force or motion is desired to be transmitted. The construction of the machine is such as to modify the natural motion which is impressed upon it, so that it may transmit to the object to be moved that peculiar species of motion which it is required to have. To give a very obvious example, let us suppose that a circular or rotatory motion is required to be produced, and that the only natural source of motion at our command is a perpendicular fall of water : a wheel is provided, placed upon the axle destined to receive the rotatory motion ; this wheel is furnished with cavities in its rim ; the water is conducted into the cavities near the top of the wheel on one side ; and being caught by these, its weight bears down that side of the wheel, the cavities on the opposite side being empty, and in an inverted position. As the wheel turns, the cavities on the descending side discharge their contents as they arrive near the lowest point, and ascend empty on the Other side. Thus a load of water is continually pressing down one side of the wheel, from which the other side is free, and a continued motion of rotation is produced.

In every machine, therefore, there are tnree objects demanding attention : — first, The power which imparts motion to it, this is called the prime mover ; secondly, The nature of the machine itself ; and thirdly, The object to which the motion is to be conveyed. In the steam engine, the first mover arises from certain phenomena which are exhibited when heat is applied to liquids ; but in the details of the machine and in its application there are several physical effects brought into play, which it is necessary perfectly to understand before the nature of the machine or its mode of operation can be rendered intelligible. We propose, therefore, to devote the present chapter to the explanation and illustration of these phenomena.

(2.) The physical effects most intimately connected with the operations of steam engines are some of the mechanical properties of atmospheric air. The atmosphere is the thin transparent fluid in which we live and move, and which, by respiration, supports animal life. This fluid is apparently so light and attenuated, that it might be at first doubted whether it be really a body at all. It may therefore excite some surprise when we assert, not only that it is a body, but also that it is one of considerable weight. We shall be able to prove that it presses on every square inch* of surface with a weight of about 15lb. avoirdupois.

(3.) Take a glass tube a b (fig. 2) more than 32 inches long, open at one end a, and closed at the other end b, and let it be filled with mercury, (quicksilver.) Let a glass vessel or cistern c, containing a quantity of mercury, be also provided. Applying the finger at a so as to prevent the mercury in the tube from falling out, let the tube be inverted, and the end, stopped by the finger, plunged into the mercury in c. When the end of the tube is below the surface of

* As we shall have frequent occasion to mention this magnitude, it would be well that the reader should be familiar with it. It is a square, each side of which is an inch. Such as a b c d, fig. 1.

the mercury in c (fig. 3) let the finger be removed. It will be found that the mercury in the tube will not, as might be expected, fall to the level of the mercury in the cistern c, which it would do were the end b open so as to admit the air into the upper part of the tube. On the other hand, the level d of the mercury in the tube will be about 30 inches above the level o of the mercury in the cistern.

(4.) The cause of this effect is, that the weight of the atmosphere rests on the surface c of the mercury in the cistern, and tends thereby to press it up, or rather to resist its fall in the tube ; and as the fall is not assisted by the weight of the atmosphere on the surface d, (since b is closed,) it follows, that as much mercury remains suspended in the tube above the level c as the weight of the atmosphere is able to support.

If we suppose the section of the tube to be equal to the magnitude of a square inch, the weight of the column of mercury in the tube above the level c will be exactly equal to the weight of the atmosphere on each square inch of the surface c. The height of the level d above c being about 30 inches, and a column of mercury two inches in height, and having a base of a square inch, weighing about one pound avoirdupois, it follows that the weight with which the atmosphere presses on each square inch of a level surface is about 151b. avoirdupois.

An apparatus thus constructed, and furnished with a scale to indicate the height of the level d above the level c, is the common barometer. The difference of these levels is subject to a small variation, which indicates a corresponding change in the atmospheric pressure. But we take 30 inches as a standard or average.

(5.) It is an established property of fluids that they press equally in all directions ; and air, like every other fluid, participates in this quality. Hence it follows, that since the downward pressure or weight of the atmosphere is about 151b. on the square inch, the lateral, upward, and oblique pressures are of the same amount. But, independently of the general principle, it may be satisfactory to give experimental proof of this.

Let four glass tubes a, b, c, d, (fig. 4,) be constructed of sufficient length, closed at one end end a, b, c, d, and open at the other. Let the open ends of three of them be bent, as represented in the tubes b, c, d. Being previously filled with mercury, let them all be gently inverted so as to have their closed ends up as here represented. It will be found that the mercury will be sustained in all,* and that the difference of the levels in all will be the same. Thus the mercury is sustained in a by the upward pressure of the atmosphere, in b by its horizontal or lateral pressure, in c by its downward pressure, and in d by its oblique pressure ; and as the difference of the levels is the same in all, these pressures are exactly equal.

(6.) In the experiment described in (3), the space b d (fig. 3) at the top of the tube from which the mercury has fallen, is perfectly void and empty, containing neither air nor any other fluid : it is called therefore a vacuum. If, however, a small quantity of air be introduced into that space, it will immediately begin to exert a pressure on d, which will cause the surface i> to descend, and it will continue to descend until the column of mercury c d is so far diminished that the weight of the atmosphere is sufficient to sustain it, as well as the pressure exerted upon it by the air in the space b d.

The quantity of mercury which falls from the tube in this case is necessarily an equivalent for the pressure of the air introduced, so that the pressure of this air may be exactly ascertained by allowing about one pound per square inch for every two inches of mercury which has fallen from the tube. The pressure of the air or any other fluid above the

* This experiment with the tube a requires to be very carefully executed, and the tube should be one of small bore.

mercury in the tube, may at once be ascertained by comparing the height of the mercury in the tube with the height of the barometer ; the difference of the heights will always determine the pressure on the surface of the mercury in the tube. This principle will be found of some importance in considering the action of the modern steam engines.

The air which we have supposed to be introduced into the upper part of the tube, presses on the surface of the mercury with a force much greater than its weight. For example, if the space b d (fig. 3) were filled with atmospheric air in its ordinary state, it would exert a pressure on the surface d equal to the whole pressure of the atmosphere, although its weight might not amount to a single grain. The property in virtue of which the air exerts this pressure is its elasticity, and this force is diminished in precisely the proportion in which the space which the air occupies is increased.

Thus it is known that atmospheric air in its ordinary state exerts a pressure on the surface of any vessel in which it is confined, amounting to about 15lb. on every square inch. If the capacity of the vessel which contains it be doubled, it immediately expands and fills the double space, but in doing so it loses half its elastic force, and presses only with the force of 711b. on every square inch. If the capacity of the vessel had been enlarged five times, the air would still have expanded so as to fill it, but would exert only a fifth part of its first pressure, or 3lb. on every square inch.

This property of losing its elastic force as its volume or bulk is increased, is not peculiar to air. It is common to all elastic fluids, and we accordingly find it in steam ; and it is absolutely necessary to take account of it in estimating the effects of that agent.

(7.) There are numerous instances of the effects of these

properties of atmospheric air which continually fall under

our observation. If the nozzle and valve-hole of a pair of

. bellows be stopped, it will require a very considerable force

to separate the boards. This effect is produced by the diminished elastic force of the air remaining between the boards upon the least increase of the space within the bellows, while the atmosphere presses, with undiminished force, on the external surfaces of the boards. If the boards be separated so as to double the space within, the elastic force of the included air will be about 7^ lb. on every square inch, while the pressure on the external surfaces will be 15lb. on every square inch ; consequently, it will require as great a force to sustain the boards in such a position, as it would to separate them if each board were forced against the other with a pressure of 7§lb. per square inch on their external surfaces.

When boys apply a piece of moistened leather to a stone, so as to exclude the air from between them, the stone, though it be of considerable weight, may be lifted by a string attached to the leather : the cause of which is the atmospheric pressure, which keeps the leather and the stone in close contact.

(8.) The next class of physical effects which it is necessary to explain, are those which are produced when heat is imparted or abstracted from bodies.

In general, when heat is imparted to a body, an enlargement of bulk will be the immediate consequence, and at the same time the body will become warmer to the touch. These two effects of expansion and increase of warmth going on always together, the one has been taken as a measure of the other ; and upon this principle the common thermometer is constructed. That instrument consists of a tube of glass, terminated in a bulb, the magnitude of which is considerable, compared with the bore of the tube. The bulb and part of the tube are filled with mercury, or some other liquid. When the bulb is exposed to any source of heat, the mercury contained in it, being warmed or increased in temperature, is at the same time increased in bulk, or expanded or dilated, as it is called. The bulb not having sufficient capacity to contain the increased bulk of mercury, the liquid is forced up in the tube, and the quantity of expansion is determined by observing the ascent of the column in the tube.

An instrument of this kind, exposed to heat or cold, will fluctuate accordingly, the mercury rising as the heat to which it is exposed is increased, and falling by exposure to cold. In order, however, to render it an accurate measure of temperature, it is necessary to connect with it a scale by which the elevation or depression of the mercury in the tube may be measured. Such a scale is constructed for thermometers in this country in the following manner : — Let us suppose the instrument immersed in a vessel of melting ice : the column of mercury in the tube will be observed to fall to a certain point, and there maintain its position unaltered : let that point be marked upon the tube. Let the instrument be now transferred to a vessel of boiling water at a time when the barometer stands at the altitude of 30 inches : the mercury in the tube will be observed to rise until it attain a certain elevation, and will there maintain its position. It will be found, that though the water continue to be exposed to the action of the fire, and continue to boil, the mercury in the tube will not continue to rise, but will maintain a fixed position : let the point to which the mercury has risen, in this case, be likewise marked upon the tube.