Treatise on the steam engine

Front matter

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Preface

The second edition of the " Treatise on the Steam Engine," has been carefully revised, and many parts of it have been either re-written or much extended. Since the publication of the first edition, great improvements have taken place in the manner of using steam, and in two of its most important applications. The expansive action of steam, which was employed only in a few boats on the Hudson, has received a development in practice fully equal to what the author had anticipated, w T hile the value of this mode action has been illustrated by the publication of its results in the pumping engines of Cornwall. The views of the author in respect to the defects of the existing theory of the motion of steam vessels have been confirmed, and new illustrations, derived from actual experiment, have been given in their proper place. The navigation of the ocean by steam, the practicability of which was denied by many, has been proved to be safe and certain. Finally, the use of. steam in locomotion, which in 1830 was little more than in embryo, has been much extended and improved. The additions

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IV PREFACE.

which, have been made to the work have reference chiefly to these important subjects. For much valuable information in respect to steam navigation, acknowledgment is due to Mr. Haswell 3 the engineer of the U. S. Ship Fulton.

Although the imperfection of the theories of Robiscn and Tredgold has long been apparent, it has not been thought proper to abandon them altogether. It was, however, in contemplation to have attempted an exposition of a theory more consistent with true mechanical principles. This attempt has been rendered unnecessary by the successful investigations ofPambour, which are inserted in the form of an Appendix. It is still thought too early, in a work intended for practical men, to take this theory as the basis of our inference. The mode of proceeding in the former edition has in consequence not been altered.

Columbia College. ) 1st June, 1839. f

PREFACE

TO THE FIRST EDITION.

The Treatise which is now submitted to the public does not pretend to the merit of originality. Ali that has been attempted is to exhibit in a succinct, and, as far as possible, popular form, the present state of our knowledge on the interesting subject of which it treats. From this the sole exceptions are the theories of the expansive action of the steam engine, and of steamboats. To the former has been added the consideration of the physical circumstances that were left out of view in the investigations of Watt and Robison ; and the latter has been examined upon principles that, so far as the author is aware, although of frequent application in other branches of practical machines, have never been taken into account in this particular case.

Preparing the work for the American public, and as a substitute for treatises either too expensive or too rare to be of frequent occurrence, the author has not scrupled to avail himself of the labours of his European predecessors. The authors that have been most frequently consulted, are : Peclet, from whose TratU de Chaleur much valuable matter has been drawn ; Farey - and Tredgold ; while the researches of Stuart have

VI PREFACE.

been of great service in the compilation of the historical parts.

The author has also derived much information from the friendly aid he has received in various ways from the most eminent manufacturers of the steam engine who were within his reach. To the West Point Foundry Association, to 3Ir. Allaire, and Mr. Sabbaton, of New-York, and to Messrs. Rush and Muhlenburg of Philadelphia, he takes this opportunity to return his acknowledgments for the liberal manner in which their practical knowledge has been laid open to him.

To Captain Bunker, of the steam-boat President, and to Mr. R. L. Stevens, he has also been under obligation for the facts in relation to steam-boats which he has adduced as the test of his theory.

From Dr. McNiven he has received important facts in relation to the preliminary experiments of Fulton at Paris, and the first trial of his boat on the Hudson, at both of which that gentleman had the good fortune to be present. Had not the work been extended beyond the size originally intended, this communication would have been inserted entire in the Appendix.

Should the present work be successful in extending the knowledge of the principles and mode of action of the most important of the instruments by which the power of man is extended ; and particularly, should it have an influence of bringing into use those precautions and apparatus by which the risk to which human life is exposed, may be lessened, the object of the author will be fully accomplished,

Columbia College.

Chapter I

MECHANICAL AND PHYSICAL PRINCIPLES THAT ARE APPLICABLE TO THE CON- STRUCTION OF THE STEAM ENGINE-

Page Division of Material substances. — Forces which determine the state in which they exist. — Forms which all bodies are capable of assuming. — Difference in the mode of action of solids and fluids. — Forces and Motion. Centres of Gravity, Inertia, Percussion, Oscillation, and Gyration. — Motions found in natural agents, and in the parts of Machines. — Mechanical properties of fluids. — Specific Gravities — Pressure of the Atmosphere and Barometer. — Heat and its effects. — Thermometer. — Expansion of bodies by heat. — Specific Heat. — Latent Pleat. — Evaporation. — Radiation of Heat. — Conducting Power of bodies. — Mode in which liquids carry off heat. Cooling effect of gases. — Distribution of Heat among the particles of a solid. 1

Chapter II. Combustion

Definition of Combustion. — Oxygen. — Flame. — AtmospherieAir. — Currents of Air produced by Combustion. — Increase of Weight in the process of Combustion. — Temperature of Flame, and modes of burning of Solids, Gases, and Liquids. — Different species of Fuel. — Properties and chemical nature of Fuel. — Carbon and Hydrogen. — Comparative value of different kinds of Fuel. — Parts of Furnaces. — Ashpit. — Grate. — Body of the Furnace. — Flues. — Chimneys. — Damper. — Furnace doors. 32

Chapter III. Boilers

Materials of which boilers are constructed. — Figure of Boilers. — Strength and thickness of Boilers. — Apparatus for showing the level of the water. —Feeding Apparatus. — Proof of Boilers.— Safety Valves^— Air Valves.—

VI GONTENTS.

Page.

Steam Guages. — Self- regulating Damper.— Common Damper and Register. — Dangers arising from the fire-surface becoming bare of water. — Thermometer. — Plates of fusible metal. — Valves opening at the limit of temperature. — Deposits of solid matter, and modes of lessening and removing them. — Steam-pipes. — Generator of Perkins. 53

Chapter IV. General View Of The Double-acting Condensing Engine

Of Prime Movers in general. — Principles of the action of Machines. — Modes of applying Steam as a prime-mover. — Application of Steam to the Double-Acting Condensing Engine. — Modes of removing Water of Condensation and Vapour. — Modes of changing the reciprocating Rectilineal Motion of the Piston-Rod into a reciprocating circular motion. — Method of changing the reciprocating circular motion into a continuous one. Mode of regulating the varying motion of the Engine, and making it produce one with uniform velocity. — Other methods of obtaining a rotary motion. — Effect of the joint action of two Engines. — Water used to produce condensation. Water that has been employed in condensation applied to feed the boiler. — Manner ot ascertaining the state of the Vacuum formed by condensation. — Mode of regulating the supply of Steam. — Accumulation of Steam in the boiler, and mode of preventing it. — Double-acting condensing Engine considered as self-acting. — Packing and Cements. — Estimate of the power of the double-acting Condensing Engine. — Estimate of the quantity of water evaporated for each unit of force. — Estimate of the supply of water for the boiler. 97

Chapter V. Description Of The Double-acting Condensing Encine

Usual form of Double-Acting Condensing Engine. — Steam-pipe. — Jacket. — Side Pipes. — Slide Valve. — Puppet Valve. — Cylinder. — Cylinder Lid- — Cylinder Bottom. — Piston. — Woolf's Piston. — Cartwright's Metallic Packing. — Condenser. — Air Pumps. — Delivering door. — Air pump Bucket.— Hot Water Cistern and Pump. — Cold Water Cistern.— Injection Cock.— Water of Condensation.— Cold Water Pump.— Parallel Motion. —Lever Beam.— Pump Rods.— Connecting Rod.— Crank.— Fly Wheel. — Tumbling Shaft. — Eccentric— Double Eccentric. — Adjustment of Eccentric— Governor.— Throttle Valve.— Other forms of Double-Acting Condensing Engine. — Mode of setting these Engines in motion. 124

Chapter VI

GENERAL VIEW OF CONENSINC ENGINES ACTING EXPANSIVELY, OF HIGH-PKES- SURE, SINGLE-ACTING, AND ATMOSPHERIC ENGINES, PARTICULAR DESCRIPTION OF HIGH PRESSURE ENGINES.

Regulation of sieam by the valves of Condensing Engines.— Expansive force £»f steam, supposing the temperature to remain constant.— Expansive force

CONTENTS. Vll

Page, of steam of a given tension and in a given engine, on the same hypothesis. — Expansive action of steam of a given tension and constant temperature, when the friction and resistance are taken into view. — Expansive action at increasing tensions, and with temperatures varying according to the law of specific heat. — Effects of steam acting expansively, as usually employed. — Action of high pressure steam when not condensed. — Cases in which high pressure engines are useful. — Reconsideration of the precautions to be used in boilers generating high steam. — General view of the high pressure engine, its steam pipes, side pipes, and valves. — Calculation of the power of high pressure engines, their working beam, parallel motion, throttle valve, governor, and forcing pump. — General view of the single-acting condensing atmospheric engines. — Particular description of a high pressure engine, with a beam, and of long and short slide valves. — Particular description of a horizontal high pressure engine. 149

Chapter VII. Early History Of The Steam Engine

Introduction. — Statue of Memnon. — Hero of Alexandria — Eolipyle. — Anthemius and Zeno. — Cardan. — Mathesius. — Baptista de Porta.— De Causs. — Brancas. — WilkinsandKircher. — Marquis of Worcester. — Hautefeuiile — Papin's first plan. — Savary.— Papin's Engine for the Elector of Hesse. — Newcomen and Cawley. — Potter's Scoggan. — Beighton's Hand-Gear. — Smeaton. — Leupold. 176

Chapter VIII. Conclusion Of The History Of Thf, Steam Engine

Power and Defects of Newcomen's Engine.— Birth and education of Watt. — Professor .Robison. Watt's first experiment. — Professor Anderson. — Watt's second Experiment. — Inferences. — Separate Condenser. — Steam applied as the moving power. — Packing. — Jacket and Air Pump. — Working Model. — Dr. Roebuck. — Experimental Engine. — Watt's first patent. — Gainsborough's claim. — Boring apparatus. — Form of Watt's first Engine. Saving of Fuel. — Projects for rotary motion. — Fitzgerald, Stewart, and Clark. — Double-acting Engine of Watt. — Washborough and Pickard. — Crank. — Sun and Planet Wheel. — Other Inventions and Improvements by Watt. — Hornblower. — Watt's patent extended. — Governor. — Introduction of steam into various mechanic arts. — Expiration of Watt's patent. — Cartwright and Sadler. — Murray, Maudslay,and Fulton. — Wooli. — Oliver Evans. — Trevithick and Vivian. — Rotary Engines. — Conclusion. 203

Chapter IX. Applications Of The Steam Engine

•General view of the application of the Steam Engine. — Raising water. — Grinding corn. — Cotton Spinning. — Navigation. — Bossut's laws of the compact of fluids. — Principles of the action of Paddles. — Juan's laws of the action of fluids on solids moving in them. — Maximum speed of vessels.

X CONTENTS.

— Power required to propel paddles. — Relation between the power and the surface of the Paddles. — Laws of the motion of Steam-boais. — Theory of paddle wheels. — Comparison between theory and observation. — Suggestions for the improvement of Steam navigation. — Practical Rules. — Steam-boat engines. — History of Steam navigation. — ^Navigation of the Ocean by Steam. — Rules for boilers of Steam-boats. — Application of Steam to Locomotion. — History of the Steam-Carriage. — Conclusion. 231

TREATISE, &c

Chapter I

MECHANICAL AND PHYSICAL PRINCIPLES THAT ARE APPLI- CABLE TO THE CONSTRUCTION OF THE STEAM ENGINE.

Divisioyi of Material substances. — Forces which determine the state in which they exist. — Forms which all bodies are capable of assuming. — Difference in the mode of action of solids and fluids. — Forces and Motion. — Centres of Gravity , Inertia, Percussion, Oscillation, and Gyration. — Motions found in natural agents, and in the parts of Machines. — Mechanical properties of fluids. — Specific Gravities. — Pressure of the Atmosphere and Barometer. — Heat and its effects. — Thermometer. — Expansion of bodies by heat. — Specific Heat. — Latent Heat. — Evaporation. — Radiation of Heat. — Conducting Power of bodies. — Mode in which liquids carry off heat. — Cooling effect of gases. — Distribution of Heat among the particles of a solid.

The material substances with which we are acquainted are either Solid or Fluid.

Fluids are again subdivided into two classes, those which are incompressible, and those which are elastic : the former are called Liquids, the latter Aeriform Fluids.

Elastic or aeriform fluids may either be capable of being readily condensed into the liquid form, and are then called vapours or steam ; or can only be reduced to that form with great difficulty, resisting in some cases all the means, whether mechanical or physical, that have hitherto been applied for that purpose. The latter are styled gases, or permanently elastic bodies.

2 PRINCIPLES OP MECHANICS.

The last-named class may, however, when in chemical combination, assume both the liquid and solid form, and there are but few that have not, in recent experiments, been converted into liquids, by pressures of greater or less intensity. Still, however, although nearly the whole class are now known to be condensible, the distinction between vapours and gases maybe here retained with propriety, inasmuch as there is a wide difference in the manner in which they are applied in practical mechanics.

2. Two great antagonist forces are concerned in determining in which of these mechanical states a body shall exist : these are, Attraction and Heat. To that species of attraction which takes place between the particles of one and the same body, whether it be simple or compound, in its chemical character, the name of Attraction of Aggregation has been given. When the intensity of the attractive forces, exerted mutually by the particles of a body, is greater than the action which heat exerts to separate them, the body will exist in the solid state : when the action of attraction and heat exactly balance each other, the body is a liquid ; and when the repulsive force of heat predominates, the body passes into the state of an elastic fluid.

We know, however, of no perfect liquids ; in them all there remains a greater or less preponderance of the attraction of aggregation. This is manifested by the tendency they have, when minutely divided, to form small globular masses, or drops. And hence the motion of their particles among each other meets with a slight resistance, which is said to be due to the viscidity of the fluid.

3. It may be considered as a general rule, that all bodies in nature are capable of existing, when properly influenced by heat, in either of the three mechanical forms. Thus, if we cannot, by mechanical or physical means, reduce the lighter gases to the solid form, still we find them assuming it in chemical combinations ; while nearly all, even of the most refractory solids, have been melted and rendered volatile under the intense heat of the Galvanic Deflagrator, or of the Compound Blowpipe.

4. The general principles of mechanics applyequally to solid and fluid bodies, but are modified in their action by the peculiar nature of each. Solid bodies, having their particles firmly connected together, act as if all the matter they contain were collected in a single point. When the body presses merely by its own weight, or when the motion is rectilineal, this point is the Centre of Gravity, or of Inertia ; if the body oscillates around a fixed point, it is the Centre of Oscillation or Percussion ; and when it revolves around an axis, it is the Centre of Gyration. The properties of these points, along with the general principles of motion, and the causes that produce it, are of constant value in considering the structure of the steam-engine and its parts. And although these are to be found in all books on the theory of mechanics, it has been considered proper to recapitulate them in a succinct manner, in order that they may be referred to in the course of the work.

5. The cause which would tend to set a body in motion, whatever be its nature, is called a force.

A body moves in the direction of the force impressed, and with a quantity of motion equal to the intensity of the force.

A body set in motion by a force, and then abandoned to itself, would continue to move uniformly forwards in a straight line, were not its direction and the intensity of its motion to be changed by the action of other forces. Thus, near the surface of the earth, the friction of other bodies, and the resistance of the air, act continually to retard and finally destroy the motion of bodies, while the attraction of the earth constantly tends to change the direction of the motion, and bring the body back to the'surface.

When a body is set in motion by a force which acts during the whole continuance of the motion, it will still describe a straight line, but the spaces described in equal times will gradually increase. If the force act with equal intensity upon the body, whether it be in rest or in motion, the motion is uniformly accelerated, and the force is said to be constant. All forces that act continually, whether constant or not, are called accelerating forces.

When more than one force acts upon a body at the same instant of time, the direction and intensity of the motion will depend upon the joint action, and we may imagine it to be the effect of a single force, whose direction and intensity correspond with the motion given to the body. Such a force, which, were the forces that really act withdrawn, would produce the same effect that they do, is called their Resultant ; the forces that it would thus identically replace, are called the Components.

The resultant of two forces that act in the same straight line, and in the same direction, is equal to their sum ; if in the same straight line, and in opposite directions, it is equal io their difference : generally, the resultant of any number of forces acting in the same straight line is equal to their algebraic sum, the difference of direction being denoted by the use of the positive and negative signs.

The resultant of two forces whose directions are inclined to each other, and which meet in a point, is represented in magnitude and direction by the diagonal of a parallelogram whose sides represent the direction and magnitude of the forces. The resultant of three forces is found, by taking, first, the resultant of two of them, and then combining this resultant with the third. The resultant of three forces thus found may be combined with a fourth, in order to find the resultant of four, and so on for any number of forces.

When in a machine a force acts obliquely, no more of the force is effective than that which would be a component of the force in the line of direct action ; the other component is a loss of power, so far as the mechanical effect to be produced is concerned. It is, however, in general, worse than a mere loss of power ; for the whole of the force decomposed in this last direction acts upon the machine itself, and generally to wear away or dislocate its parts.

Motions are capable of being resolved or decomposed in the same manner as forces, and the investigation may in this way be extended to the case of forces that continue to act during the whole duration of the body's motion.

A motion which grows out of the combination of two other oblique motions, is in the direction of the diagonal of theparallelogram whose two sides represent the magnitude and direction of the two forces, and the intensity of the motion is represented by the magnitude of the diagonal. When two oblique forces act, one of which abandons the body, and would thus produce an uniform motion, while the other continues to act during the whole duration, we conceive the motion to be divided into a great number of very small portions, during each of which the motion and direction remain constant : the body would then tend to go on in a straight line, at the end of each of the small intervals in which the small portions of the motion are performed, but is, during each of them, deflected into the diagonal of a parallelogram by the active force. In this way a polygon is formed, which, as the sides are inappreciably small, coincides with a curve. When, therefore, two motions oblique to each other are combined, one of which is uniform and the other accelerated, curvilinear motion is the consequence.

If two accelerating forces act, in which the rate of acceleration is the same, the motion is rectilineal ; but if it be different, the motion is still curvilinear.

Wiien two parallel forces act upon a body, the resultant divides the line that joins the points to which the forces are applied, into parts that are inversely proportioned to the intensity of the two forces, and the resultant is equal in magnitude to the sum of the forces. The resultant of three such forces is found by taking first the resultant of two of them, and combining it with the third ; this may again be combined with a fourth, and so on to any number.

The resultant of any number of parallel forces continues of the same intensity, and passes through the same point, whatever be the direction of the forces ; hence it is called the Centre of Parallel Forces. When the body is moving forwaid in a straight line, under the action of forces other than gravity, it is called the Centre of Inertia ; when the body is acted upon by gravity, it is called the Centre of Gravity.

6. By gravity, or the attraction of gravitation, is meant that force, by virtue of which all bodies fall towards the earth in lines perpendicular to its surface. Although these directions

O PRINCIPLES OF MECHANICS.

are neither absolutely parallel, nor the forces, at different parts of the earth, or different distances from its surface, equal ; still the convergence of the lines is so small, and the variation so slow, that there is no impropriety in considering every particle of the body as acted upon by an equal and parallel force. The resultant of all these forces is the Weight of the bodv, and its place of action is the Centre of Gravity.

When the centre of gravity is supported, the body is supported also; when the centre of gravity is not supported, the body will fall until the centre of gravity reaches the lowest possible point. The supporting force may be applied to the centre of gravity, or it may act at a point vertically above, or vertically beneath that centre. In the first case the position of the body is indifferent, and it will remain at rest, however placed around the point of support ; in the second case, the body, if once disturbed, will fall or move around the point of support, until this be vertically above the centre of gravity ; in the third case, if the body be disturbed, it will oscillate until it return to rest in the position it orig nally held.

The centre of gravity of a straight line bisects it

The centre of gravity of a cylinder, or of a spindle of symmetrical form, bisects the axis.

The centre of gravity of a circle corresponds with its centre, as does that of a sphere.

The centre of gravity of a triangle is in the line which joins its vertex to the point that bisects its base, and at the distance of two-thirds of this line from the vertex.

When the centre of gravity of a triangle is known, that of a quadrilateral figure may be determined by dividing it into two triangles, and finding their respective centres of gravity, whence the common centre may be determined, as it will divide the line that joins the two, into parts inversely proportioned to the size of the two triangles. The centre of gravity of a pentagon is found by dividing it into three triangles, and thus for any polygon whatsoever.

The centre of gravity of a triangular pyramid is in the line which joins the vertex of the pyramid to the centre of gravity of the base, and at a distance of three-fourths of this line from the vertex.

When the centre of gravity of a pyramid is determined, we have the means of finding that of any solid body bounded by plane surfaces, for it may be divided into triangular pyramids.

The centre of gravity of a solid cone is in the line which joins its vertex to the centre of its base, and at the distance of three-fourths of that line from the vertex. But the centre of gravity of the surface of a cone is at the distance of two-thirds of that line from the vertex.

The centres of gravity of an ellipsis and an ellipsoid of revolution correspond with their respective geometric centres.

When a body is attached to a fixed point and oscillates, the action is no longer such as would take place if the whole of the matter were collected in the centre of gravity ; but the point, in which, if all the matter were collected, the action would be the same as actually takes place, is farther from the place of suspension ; this point is called the centre of oscillation.

The centre of oscillation of a straight line is distant two-thirds of its length from the point of suspension.

The centre of oscillation of a triangle is at the distance of three-fourths of its height from the vertex.

The centre of oscillation of a cone, right angled at the vertex, is in the middle of the base.

The centre of percussion is that point in a striking body, at which the whole of the motion would be communicated to the body struck.

When the striking body moves round a fixed point, the centre of oscillation and centre of percussion are identical.

A body suspended from a fixed point, and oscillating under the action of gravity, is called a Pendulum.

The centre of Gyration is that point in a revolving body, in which, if all the matter were collected, the quantity of rotary motion would remain the same as before.

The centre of gyration of a straight line, moving around an axis passing through one of its extremities, is at a distance from that axis, which bears to the length of the line the ratio of one to the square root of three, 1 : V3.

The distance of the centre of gyration of a circle or circular sector from its centre of rotation and curvature, is to the radius of the circle, as one to the square root of two, 1 : V2.

The motions which we find in the parts of machines, and in the great natural agents that are employed to propel them, are either rectilineal or rotary. Rectilineal motion may be either continuous or reciprocating, and rotary motions may in like manner either go on continually, or the moving points may oscillate within certain limits, and thus reciprocate.

Among these four species of motion, taken by pairs, there are ten possible combinations, and these might therefore occur in the changes which a machine makes upon the original motion of the moving power, or which one part of a machine causes in the motion of another ; no more than eight of these combinations, however, are to be met with in practice.

a. A continuous rectilineal motion is sometimes converted into another continuous and rectilineal motion, in an opposite direction.

b. A continuous rectilineal motion is sometimes changed into a continuous rotary motion, or,

c. Into a reciprocating rotary motion.

d. A continuous circular motion is sometimes changed into an alternating rectilineal motion.

e. A continuous circular motion is sometimes changed into another continuous circular motion, in an opposite direction, or,

/. Into a reciprocating circular motion.

g. A reciprocating rectilineal motion is sometimes changed into a reciprocating circular motion.

h. A reciprocating circular motion is sometimes changed into another reciprocating motion in an opposite direction.

8. The particles of fluid bodies, having no, or at most an insensible, attraction of aggregation, act independently of each other. Hence, we cannot refer the motion of a fluid mass to either of the Centres of which we have spoken, but each particle moves freely under the forces that are impressed, whether they act immediately upon it, or through the intervention of the adjacent particles.

Fluids thus transmit any force applied to one of their surfaces equally in all directions ; and if a fluid be inclosed in a vessel, and a force act upon any portion of its surface, as by means of a piston perforating one of the sides of the vessel that contains it, the pressure upon every remaining portion of the vessel will be equal, upon an equal surface, to that acting upon the piston : thus, if the piston be a square inch, and be acted upon by a force equivalent to a pound, every square inch of the surface of the vessel will also have to sustain a pressure equivalent to a pound.