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Transcriber's note:
Text enclosed by underscores is in italics (_italics_).
The notation "^{n}" means that n is superscript. The notation
"_{n}" means that n is subscript.
Text that was in small capitals has been converted to all
capitals.
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[Illustration: WATT.
Engraved by H. Adlard, from a Drawing by H. Corbould, taken with
the permission of James Watt, Esq.
FROM THE STATUE BY CHANTREY.
London: Taylor & Walton, Upper Gower Street.]
THE STEAM ENGINE EXPLAINED AND ILLUSTRATED;
With an Account of Its Invention and Progressive Improvement,
and Its Application to Navigation and Railways;
Including also a Memoir of Watt.
by
DIONYSIUS LARDNER, D.C.L. F.R.S.
&c. &c.
SEVENTH EDITION,
Illustrated by Engravings on Wood.
London:
Printed for Taylor and Walton,
28. Upper Gower Street.
MDCCCXL.
London:
Printed by A. Spottiswoode,
New-Street-Square.
TO
THE RIGHT HONOURABLE
HENRY LORD BROUGHAM AND VAUX,
FELLOW OF THE ROYAL SOCIETY,
AND
MEMBER OF THE NATIONAL INSTITUTE OF FRANCE,
AS A MARK OF PUBLIC RESPECT
AND
A TESTIMONY OF PRIVATE REGARD,
THIS WORK
INSCRIBED, BY HIS ATTACHED FRIEND,
THE AUTHOR.
ADVERTISEMENT.
The Drawings for several of the Cuts in this Volume have been
taken, by the permission of Mr. Weale, from the admirable Plates
annexed to the last edition of Tredgold on the Steam Engine and on
Steam Navigation. This acknowledgment is especially due for the
Illustrations which abound in this Volume.
_London, June, 1840._
[Illustration: LONDON ENTRANCE TO THE BIRMINGHAM RAIL-ROAD.]
CONTENTS.
CHAPTER I.
PRELIMINARY MATTER.
Page
The Steam Engine, a Subject of popular Interest 4
Effects of Steam 5
Great Power of Steam 7
Object of this Work 9
Disputes respecting the Invention 11
Hero of Alexandria's Machine 13
Blasco De Garay's Proposition to propel Vessels
by a Machine 16
Solomon De Caus 17
Giovanni Branca proposes to work Mills by Steam 22
Marquis of Worcester 23
Mechanical Properties of Fluids 25
Elastic and Inelastic Fluids 25
Elasticity of Gases 28
Effects of Heat 29
Application of these Principles to the Engines
of Hero, De Caus, and Lord Worcester 30
Sir Samuel Morland 34
Denis Papin 36
Atmospheric Pressure 38
Weight of Air 39
Pressure of Air 41
Barometer 41
Elastic Force of Air and Gases 42
Force obtained by a Vacuum 43
Common Pump 43
Rarefaction by Heat 44
Process of filling Thermometers 44
Papin's Method of producing a Vacuum 44
His Discovery of the Condensation of Steam 45
Thomas Savery 47
CHAP. II.
ENGINES OF SAVERY AND NEWCOMEN.
Savery's Engine 49
Boilers and their Appendages 50
Working Apparatus described 51
Mode of Operation 52
Defects of Savery's Engine 58
Newcomen's Engine described by Papin 62
Newcomen and Cawley obtain a Patent for
Atmospheric Engine 65
Accidental Discovery of Condensation by Injection 69
Potter's Discovery of the Method of working
the Valves 71
His Contrivance improved by the Substitution
of a Plug Frame 72
Advantages of the Atmospheric Engine over that
of Savery 72
The Power of Savery's Engine restricted 73
It contained no new Principle 73
Its practical Superiority 73
CHAP. III.
EARLY CAREER AND DISCOVERIES OF JAMES WATT.
Atmospheric Engine improved by Beighton 75
Smeaton's Improvements in the Atmospheric Engine 76
Brindley obtains a Patent for Improvement in 76
Invents the Self-regulating Feeder 76
Infancy of James Watt 77
His Descent and Parentage 77
Anecdotes of his Boyhood 78
His early Acquirements 79
Goes to London 80
Returns to Glasgow 80
Appointed Instrument-maker to the University 81
Opens a Shop in Glasgow 81
His Friends and Patrons 81
Professor Robison's Remarks on Watt's personal
Character 82
His industrious and studious Habits 82
His Attention first directed to Steam 83
Experiments on High-pressure Engine 83
Repairs an Atmospheric Model 84
Experimental Inquiry consequent on this 84
Its Results 84
Observes great Defects in the Atmospheric Engine 85
His first Attempt to improve it 85
His early Experiments on Steam 87
Discovery by Experiment of the Expansion which
Water undergoes in Evaporation 90
Discovers the latent Heat of Steam 91
Informed by Dr. Black of the Theory of latent Heat 93
His Improvement not due to Black 93
CHAP. IV.
EXPOSITION OF PHYSICAL PRINCIPLES.
Construction of Thermometer 98
Method of graduating it 99
Freezing and boiling Points 99
Latent Heat of Water 101
Quantity of Heat necessary to convert Ice into
Water, first noticed by Dr. Black 101
Examination of the analogous Effects produced
by the continued Application of Heat to Water
in the liquid State 102
Process of Boiling 104
Reconversion of Steam into Water 104
Conversion of Water into Steam 105
Latent Heat of Steam 107
Boiling Point varies 108
Different in different Places 109
Inquiry whether a Diminution of Pressure will
produce a corresponding Effect on the boiling
Point 112
Table showing the Temperature at which Water
will boil under different Pressures of the
Atmosphere 113
Mechanical Force of Steam 115
Facts to be observed in 117
CHAP. V.
FURTHER DISCOVERIES OF WATT.
Watt finds that Condensation in the Cylinder
is incompatible with a due Economy of Fuel 119
Conceives the Notion of condensing out of the
Cylinder 120
Discovers separate Condensation 121
Invents the Air Pump 123
Substitutes Steam Pressure for Atmospheric
Pressure 123
Invents the Steam Case, or Jacket 124
His first Experiments to realise these
Inventions 125
His experimental Apparatus 125
His experimental Models fitted up at Delft
House, in Glasgow 128
Difficulties of bringing the improved Engines
into Use 129
Watt first employed by Roebuck as a Civil
Engineer 130
His Partnership with Roebuck 130
His first Patent 130
Experimental Engine at Kinneal 131
Abstract of the Act of Parliament for the
Extension of his Patent 132
Description of his single-acting Steam Engine 133
CHAP. VI.
WATT'S ENGINES.
Correspondence of Watt with Smeaton 145
Failure of Condensation by Surface 146
Improvements in Construction of Piston 147
Method of Packing 148
Improvements in boring the Cylinder 149
Disadvantages of the new compared with the old
Engines 150
Greatly increased Economy of Fuel 150
Economy of the Engine 151
Expedients to force the new Engines into Use 151
Correspondence of Boulton 153
Correspondence with Smeaton 155
Efficiency of Fuel in the new Engines 156
Discovery of the expansive Action of Steam 157
Watt states it in a Letter to Dr. Small 157
Its Principle explained 158
Mechanical Effects resulting from it 162
Computed Effect of cutting off Steam at
different Portions of the Stroke 163
Produces a variable Power 163
Expedients for equalising the Power 164
Expansive Principle in Watt's Engines limited 165
Its more extensive Application in the Cornish
Engines 165
CHAP. VII.
DOUBLE-ACTING ENGINE.
Common Steam 168
Superheated Steam 170
Laws of Dalton and Gay Lussac 171
Law of Mariotte 171
Relation between Temperature and Pressure of
common Steam 171
Effects of the Expansion of common Steam 173
Mechanical Effects of Steam 173
Method of equalising the expansive Force 174
Hornblower's Engine 175
Woolf's Engine 176
Watt's Attempts to extend the Steam Engine to
Manufactures 178
Papin's projected Applications of the Steam
Engine 178
Savery's Application of the Engine to move
Machinery 180
Jonathan Hull's Application to Water Wheels 180
Champion of Bristol applies the Atmospheric
Engine to raise Water 181
Stewart's Application of the Engine to
Mill-work 182
Wasbrough's Application of the Fly-wheel and
Crank 183
Reasons why Watt's single-acting Steam Engine
was not adapted to produce continuous uniform
Motion of Rotation 184
Watt's Second Patent 186
Sun-and-Planet Wheels 187
Valves of double-acting Engine 189
CHAP. VIII.
DOUBLE-ACTING ENGINE.
Methods of connecting the Piston-rod and Beam
in the double-acting Engine 193
Rack and Sector 194
Parallel Motion 195
Connection of Piston-rod and Beam 195
Connecting Rod and Crank 203
Fly-wheel 205
Throttle-valve 207
Governor 209
Construction and Operation of the
double-acting Engine 216
Eccentric 225
Cocks and Valves 227
Single-clack Valves 227
Double-clack Valves 228
Conical Valves 228
Slide Valves 229
Murray's Slides 229
D Valves 230
Seaward's Slides 235
Single Cock 238
Two-way Cock 239
Four-way Cock 239
Pistons 242
Common hemp-packed Piston 242
Woolf's Piston 243
Metallic Pistons 244
Cartwright's Engine 245
Cartwright's Piston 247
Barton's Piston 248
CHAP. IX.
BOILERS AND FURNACES.
Analysis of Coal 252
Process of Combustion 253
Heat evolved in it 254
Form and Structure of Boiler 255
Waggon Boiler 255
Furnace 256
Method of feeding it 257
Combustion of Gas in Flues 260
Williams's Patent for Method of consuming
unburned Gases 260
Construction of Grate and Ash-pit 261
Magnitude of heating Surface of Boiler 262
Steam-space and Water-space in Boiler 263
Position of Flues 264
Method of feeding Boiler 265
Method of indicating the Level of Water in
Boiler 266
Level Gauges 266
Self-regulating Feeders 267
Steam Gauge 270
Barometer Gauge 272
Watt's Invention of the Indicator 274
Counter 278
Safety-valve 279
Fusible Plugs 280
Self-regulating Damper 281
Brunton's Self-regulating Furnace 283
Gross and useful Effect of an Engine 285
Power and Duty of Engines 287
Horse-power of Steam Engines 289
Evaporation proportional to Horse-power 290
Sources of Loss of Power 292
Absence of good practical Rules for Power 292
Common Rules followed by Engine-makers 292
Duty distinguished from Power 294
Duty of Boilers 294
Proportion of Stroke to Diameter of Cylinder 295
Duty of Engines 296
Cornish System of Inspection 297
Table showing the Improvement of Cornish Engines 298
Beneficial Effects of Cornish Inspection 299
Successive Improvements on which the increased
Duty of Engines depends, traced by John Taylor
in his "Records of Mining" 299
CHAP. X.
LIFE OF WATT.
Watt's Friends and Associates at Birmingham 302
His Invention of the Copying Press 302
Heating Apartments and Buildings by Steam 303
Watt's Machine for drying Linen 303
His Share in the Discovery of the Composition
of Water 303
The Merit of this Discovery shared between
Cavendish, Lavoisier, and Watt 305
Anecdote of Watt's Activity of Mind 309
His Introduction of the Use of Chlorine in
Bleaching 310
One of the Founders of the Pneumatic
Institution at Clifton 310
His first Marriage 311
Death of his first Wife 311
His second Marriage 311
Death of his younger Son 311
Extracts from his Letters 312
Character of Watt by Lord Brougham 313
Extract from Sir Walter Scott's "Monastery" on
the Character of Watt 314
Sketch of the Life of Watt from the "Scotsman"
by Lord Jeffrey 315
Occupation of his old Age 318
His Invention of Machine for copying Sculpture 318
His last Days 318
Monuments to his Memory 319
Inscription by Lord Brougham on the Pedestal
of the Monument in Westminster Abbey 320
CHAP. XI.
LOCOMOTIVE ENGINES ON RAILWAYS.
Page
High-pressure Engines 322
One of the earliest Forms of the Steam Engine 322
Description of Leupold's Engine 323
Non-condensing Engine of Messrs. Trevethick
and Vivian 324
Construction of a Machine for moving Carriages
on Railroads 328
Effects of Railway Transport 329
Moral and political Consequences of 334
History of the Locomotive Engine 337
Construction of Locomotive Engine by Blinkensop 337
Messrs. Chapman's Contrivance 337
Walking Engine 337
Mr. Stephenson's Engines at Killingworth 339
Liverpool and Manchester Railway 342
The Directors offer a Prize for the best
Locomotive Engine 344
Experimental Trial 344
The "Rocket," "Sanspareil," and "Novelty" 344
Admirable Arrangement in the Rocket 345
Description of the "Sanspareil" 347
Description of the "Novelty" 349
The Superiority of the "Rocket" 350
Method of subdividing the Flue into Tubes 353
Progressive Improvement of Locomotive Engines 354
Dr. Lardner's Experiments in 1832 357
Adoption of Brass Tubes 360
Great Expense of Locomotive Power 361
Mr. Booth's Report 362
Detailed Description of the most improved
Locomotive Engines 365
Substitution of Brass for Copper Tubes
ascribed to Mr. Dixon 370
Power of Locomotive Engines 379
Position of the Eccentrics 379
Pressure of Steam in the Boiler 401
Dr. Lardner's Experiments in 1838 406
Resistance to Railway Trains 407
Dr. Lardner's Experiments on the Great Western
Railway 408
Experiments on Resistance 409
Restrictions on Gradients 410
Compensating Effect of Gradients 412
Experiment with the "Hecla" 412
Disposition of Gradients should be uniform 415
Methods of surmounting steep Inclinations 415
CHAP. XII.
LOCOMOTIVE ENGINES ON TURNPIKE ROADS.
Railways and Stone Roads compared 420
Gurney's Steam Carriage 423
The Boiler of Gurney's Engine 423
His Method of cleansing Boilers 428
Convenience and Safety of Steam Carriages 432
Two Methods of applying Locomotive Engines
upon common Roads 434
Horse Carriages compared with Steam 435
Extract from Mr. Farey's Evidence before the
House of Commons 435
Hancock's Steam Carriage 436
How it differs from that of Mr. Gurney 437
Ogle's Locomotive Carriage 438
Dr. Church's Steam Engine 439
CHAP. XIII.
STEAM NAVIGATION.
Form and Arrangement of Marine Engines 441
Arrangement of the Engine-room 446
Marine Boilers 448
Effects of Sea Water in Boilers 450
Remedies for them 451
Blow-off Cocks 452
Indicators of Saltness 453
Seaward's Indicator 454
His Method of blowing out 454
Field's Brine Pumps 456
Tubular Condensers applied by Mr. Watt 457
Hall's Condensers 458
Substitution of Copper for Iron Boilers 460
Process of Stoking 462
Watt's Expedient of attaching Felt to the
Boiler Surface 463
Means of economising Fuel 463
Number and Arrangement of Furnaces and Flues 463
Howard's Marine Engine 464
Application of the expansive Principle in
Marine Engines 466
Recent Improvements of Messrs. Maudslay and
Field 467
Humphrey's Marine Engine 470
Common Paddle-wheel 472
Feathering Paddles 474
Galloway's Patent for a Paddle-wheel with
movable Paddles 476
Split Paddle 478
Proportion of Power to Tonnage 480
Improved Efficiency of Marine Engines 482
Iron Steam Vessels 483
Steam Navigation to India 484
CHAP. XIV.
AMERICAN STEAM NAVIGATION.
Steam Navigation first established in America 487
Circumstances which led to it 488
Attempts of Fitch and Rumsey to apply the
single-acting Engine to the Propulsion of
Vessels 489
Stevens of Hoboken commences Experiments in
Steam Navigation 489
Experiments of Livingstone and Fulton 489
Fulton's first Boat 490
The Hudson navigated by Steam 491
Extension and Improvement of River Navigation 492
American Steamers 494
Difference between them and European Steamers 494
Steamers on the Hudson 494
American Paddle-wheels 495
Sea-going American Steamers 496
Speed attained by American Steamers 497
Lake Steamers 499
The Mississippi and its Tributaries 499
Steam-boats navigating it 500
Their Structure and Machinery 500
New Orleans Harbour 503
Steam Tugs 503
APPENDIX.
_On the Relation between the Temperature, Pressure, and_
_Density of Common Steam._
Empirical Formula of Biot, showing the
Relation between the Pressure and Temperature 505
Empirical formula of Southern 506
Tredgold 506
Mellet 506
De Pambour 506
MM. Dulong and Arago 506
Law of the Expansion of elastic Fluids,
discovered by Dalton and Gay Lussac 506
Formula for the Relation between the Volumes
and Temperatures 507
Law of Mariotte 507
Table of Pressures, Temperatures, Volumes, and
Mechanical Effects of Steam 509
Empirical Formulæ for the Relation between the
Volume of Water and that of the Steam produced
by its Evaporation under given Pressures 511
Formula of Navier 511
Modified by De Pambour 511
_On the Expansive Action of Steam._
Mechanical Effect produced during a given
Extent of Expansion 511
Mechanical Effect produced during Evaporation
and subsequent Expansion 512
Application to double-acting Engines 513
Formula for Pressure of Steam in Cylinders 514
Formula for total Mechanical Effect per Minute
of Steam when cut off at any proposed Part of
the Stroke 514
Formulæ exhibiting the Relation between the
Resistance of the Load, the Resistances of the
Engine, the Evaporation, the Speed of the
Piston, and the Magnitude of the Cylinder 515
Formulæ showing the Relation between the Power
of the Engine, the Evaporation, and the useful
Load 516
Formulæ for the _useful Effect_ and the _Duty_ 517
Estimates of the several Sources of
Resistances 518
Tables to facilitate the Computation of the
Effects of Expansive Engines 519
Table of the Areas of Pistons 520
EXAMPLES of the Application of these Formulæ 521
INDEX. 523
[Illustration: VIADUCT, NEAR WATFORD, BIRMINGHAM RAIL-ROAD.]
[Pg001]
THE STEAM ENGINE.
[Pg003]
[Illustration: HERO OF ALEXANDRIA.]
CHAPTER I.
THE STEAM ENGINE, A SUBJECT OF POPULAR INTEREST. — THE OBJECT
OF THIS WORK. — DISPUTES RESPECTING THE INVENTION. — HERO. — DE
GARAY. — DE CAUS. — BRANCA. — MARQUIS OF WORCESTER. — PHYSICAL
PRINCIPLES. — ELASTIC AND INELASTIC FLUIDS. — THEIR
PROPERTIES. — APPLICATION OF THESE PRINCIPLES TO THE ENGINES
OF HERO, DE CAUS, AND LORD WORCESTER. — SIR SAMUEL MORLAND. —
PAPIN. — ATMOSPHERIC PRESSURE. — THE WEIGHT OF AIR. — LESS AT
GREATER HEIGHTS. — BAROMETER. — PRESSURE OF AIR. — ELASTIC
FORCE OF AIR AND GASES. — FORCE PRODUCED BY A VACUUM. — COMMON
PUMP. — RAREFACTION BY HEAT. — PAPIN'S METHODS OF PRODUCING A
VACUUM. — HIS DISCOVERY OF THE CONDENSATION OF STEAM. —
SAVERY.
(1.) That the history of the invention of a piece of mechanism,
and the description of its structure, operation, and [Pg004]
uses, should be capable of being rendered the subject matter of a
volume, destined not alone for the instruction of engineers or
machinists, but for the information and amusement of the public in
general, is a statement which at no very remote period would have
been deemed extravagant and incredible.
Advanced as we are in the art of rendering knowledge popular, and
cultivated as the public taste is in the appreciation of the
expedients by which science ministers to the uses of life, there
is still perhaps but one machine of which such a proposition can
be truly predicated: it is needless to say that that machine is
the STEAM ENGINE. There are many circumstances attending this
extraordinary piece of mechanism which impart to it an interest so
universally felt. Whether we regard the details of its structure
and operation, the physical principles which it calls into play,
and the beautiful contrivances by which these physical principles
are rendered available;—or, passing over these _means_, we direct
our attention to the _ends_ which they attain, we are equally
filled with astonishment and admiration. The history of the steam
engine offers to our notice a series of contrivances which, for
exquisite and refined ingenuity, stand without any parallel in the
annals of mechanical science. These admirable inventions, unlike
other results of scientific inquiry, have also this peculiarity,
that, to understand their excellence and to perceive their beauty,
no previous or subsidiary knowledge is necessary, save what may be
imparted with facility and clearness in the progress of the
explanation and development of the machine itself. A simple and
clear exposition, divested of needless technicalities and aided by
well-selected diagrams, is all that is necessary to render the
construction and operation of the steam engine, in all its forms,
intelligible to persons of plain understanding and moderate
information.
But if the contrivances by which this vast power is brought to bear
on the arts and manufactures, be rendered attractive by their great
mechanical beauty, how much more imposing will the subject become
when the effects which the steam engine has produced upon the
well-being of the human race are considered. It has penetrated the
crust of the earth, and drawn from beneath it boundless treasures
[Pg005] of mineral wealth, which, without its aid, would have been
rendered inaccessible; it has drawn up, in measureless quantity,
the fuel on which its own life and activity depend; it has relieved
men from their most slavish toils, and reduced labour in a great
degree to light and easy superintendence. To enumerate its present
effects, would be to count almost every comfort and every 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 could
never have hoped to share them: the surface of the land, and the
face of the waters, are traversed with equal facility by its power;
and by thus stimulating and facilitating the intercourse of nation
with nation, and the commerce of people with people, it has knit
together remote countries by bonds of amity not likely to be
broken. Streams of knowledge and information are kept flowing
between distant centres of population, those more advanced
diffusing civilisation and improvement among those that are more
backward. The press itself, to which mankind owes in so large a
degree the rapidity of their improvement in modern times, has had
its power and influence increased in a manifold ratio by its union
with the steam engine. It is thus that literature is cheapened,
and, by being cheapened, diffused; it is thus that Reason has taken
the place of Force, and the pen has superseded the sword; it is
thus that war has almost ceased upon the earth, and that the
differences which inevitably arise between people and people are
for the most part adjusted by peaceful negotiation.
Deep as the interest must be with which the steam engine will be
regarded in every civilised country, it presents peculiar claims
upon the attention of the people of Great Britain. Its invention
and progressive improvement are the work of our own time and our
own country; it has been produced and matured almost within the
last century, and is the exclusive offspring of British genius,
fostered and sustained by British enterprise and British capital.
The steam engine is a mechanical contrivance, by which coal, wood,
or other fuel is rendered capable of executing any [Pg006] kind
of labour. COALS are by it made to spin, weave, dye, print and
dress silks, cottons, woollens, and other cloths; to make paper,
and print books upon it when made; to convert corn into flour; to
express oil from the olive, and wine from the grape; to draw up
metal from the bowels of the earth; to pound and smelt it, to melt
and mould it; to forge it; to roll it, and to fashion it into
every desirable form; to transport these manifold products of its
own labour to the doors of those for whose convenience they are
produced; to carry persons and goods over the waters of rivers,
lakes, seas, and oceans, in opposition alike to the natural
difficulties of wind and water; to carry the wind-bound ship out
of port; to place her on the open deep ready to commence her
voyage; to throw its arms around the ship of war, and place her
side by side with the enemy; to transport over the surface of the
deep persons and information, from town to town, and from country
to country, with a speed as much exceeding that of the ordinary
wind, as the ordinary wind exceeds that of a common pedestrian.
Such are the virtues, such the powers, which the steam engine has
conferred upon COALS. The means of calling these powers into
activity are supplied by a substance which nature has happily
provided in unbounded quantity in every part of the earth; and
though it has no price, it has inestimable value: this substance
is WATER.
A pint of water may be evaporated by two ounces of coals. In its
evaporation it swells into two hundred and sixteen gallons of
steam, with a mechanical force sufficient to raise a weight of
thirty-seven tons a foot high. The steam thus produced has a
pressure equal to that of common atmospheric air; and by allowing
it to expand, by virtue of its elasticity, a further mechanical
force may be obtained, at least equal in amount to the former. A
pint of water, therefore, and two ounces of common coal, are thus
rendered capable of doing as much work as is equivalent to
seventy-four tons raised a foot high.
The circumstances under which the steam engine is worked on a
railway are not favourable to the economy of fuel. Nevertheless
a pound of coke burned in a locomotive engine [Pg007] will
evaporate about five pints of water. In their evaporation they
will exert a mechanical force sufficient to draw two tons weight
on the railway a distance of one mile in two minutes. Four horses
working in a stage-coach on a common road are necessary to draw
the same weight the same distance in six minutes.
A train of coaches weighing about eighty tons, and transporting
two hundred and forty passengers with their luggage, has been
taken from Liverpool to Birmingham, and back from Birmingham to
Liverpool, the trip each way taking about four hours and a
quarter, stoppages included. The distance between these places by
the railway is ninety-five miles. This double journey of one
hundred and ninety miles is effected by the mechanical force
produced in the combustion of four tons of coke, the value of
which is about five pounds. To carry the same number of passengers
daily between the same places by stage-coaches on a common road,
would require twenty coaches and an establishment of three
thousand eight hundred horses, with which the journey in each
direction would be performed in about twelve hours, stoppages
included.
The circumference of the earth measures twenty-five thousand
miles; and if it were begirt with an iron railway, such a train as
above described, carrying two hundred and forty passengers, would
be drawn round it by the combustion of about thirty tons of coke,
and the circuit would be accomplished in five weeks.
In the drainage of the Cornish mines the economy of fuel is much
attended to, and coals are there made to do more work than
elsewhere. A bushel of coals usually raises forty thousand tons of
water a foot high; but it has on some occasions raised sixty
thousand tons the same height. Let us take its labour at fifty
thousand tons raised one foot high. A horse worked in a fast
stage-coach pulls against an average resistance of about a quarter
of a hundred weight. Against this he is able to work at the usual
speed through about eight miles daily: his work is therefore
equivalent to one thousand tons raised one foot. A bushel of coals
consequently, as used in Cornwall, performs as much labour as a
day's work of one hundred such horses. [Pg008]
The great pyramid of Egypt stands upon a base measuring seven
hundred feet each way, and is five hundred feet high, its weight
being twelve thousand seven hundred and sixty millions of pounds.
Herodotus states, that in constructing it one hundred thousand men
were constantly employed for twenty years. The materials of this
pyramid would be raised from the ground to their present position
by the combustion of about four hundred and eighty tons of coals.
The Menai Bridge consists of about two thousand tons of iron, and
its height above the level of the water is one hundred and twenty
feet. Its mass might be lifted from the level of the water to its
present position by the combustion of four bushels of coal.
The enormous consumption of coals produced by the application of
the steam engine in the arts and manufactures, as well as to
railways and navigation, has of late years excited the fears of
many as to the possibility of the exhaustion of our coal-mines.
Such apprehensions are, however, altogether groundless. If the
present consumption of coal be estimated at sixteen millions of
tons annually, it is demonstrable that the coal-fields of this
country would not be exhausted for many centuries.
But in speculations like these, the probable, if not certain
progress of improvement and discovery ought not be overlooked; and
we may safely pronounce that, long before such a period of time
shall have rolled away, other and more powerful mechanical agents
will supersede the use of coal. Philosophy already directs her
finger at sources of inexhaustible power in the phenomena of
electricity and magnetism. The alternate decomposition and
recomposition of water, by magnetism and electricity, has too
close an analogy to the alternate processes of vaporisation and
condensation, not to occur at once to every mind: the development
of the gases from solid matter by the operation of the chemical
affinities, and their subsequent condensation into the liquid
form, has already been essayed as a source of power. In a word,
the general state of physical science at the present moment, the
vigour, activity, and sagacity with which researches in it are
prosecuted in every civilised [Pg009] country, the increasing
consideration in which scientific men are held, and the personal
honours and rewards which begin to be conferred upon them, all
justify the expectation that we are on the eve of mechanical
discoveries still greater than any which have yet appeared; and
that the steam engine itself, with the gigantic powers conferred
upon it by the immortal Watt, will dwindle into insignificance in
comparison with the energies of nature which are still to be
revealed; and that the day will come when that machine, which is
now extending the blessings of civilisation to the most remote
skirts of the globe, will cease to have existence except in the
page of history.
(2.) The object of the present volume will be to deliver, in an
easy and familiar style, an historical view of the invention of the
steam engine, and an exposition of its structure and operation in
the various forms in which it is now used, and of its most
important applications in the arts of life, especially in transport
by land and water. It is hoped that the details of these subjects
may be rendered easily intelligible to all persons of ordinary
information, whether urged by that natural and laudable spirit of
inquiry awakened by contemplating effects on the material and
social condition of our species, so rapid and so memorable as those
which have followed the invention of the steam engine, and by the
pleasure which results from the perception of the numerous
instances of successful contrivances and beautiful applications of
science to art which it unfolds,—or impelled by the exigencies of
trade or profession to acquire an acquaintance with a machine on
which, more than any other, the prosperity of our commercial and
manufacturing interests depends. It will be our aim to afford to
the former class all the information which they can require; and,
if this work be not as comprehensive in its scope, and as minute in
its details, as some of the latter may wish, it will at least serve
as an easy and convenient introduction to other works more
voluminous, costly, and detailed, but less elementary in their
matter, and less familiar in their style.
In explaining the different forms of steam engine which have been
proposed in the course of the progressive improvement [Pg010] of
that machine from its early rude and imperfect state to its
present comparatively perfect form, it will be necessary to advert
to various physical phenomena and mechanical principles, which,
however obvious to those who are conversant with matters of
science, must necessarily be at least imperfectly known by the
great majority of our readers. To refer for information on such
topics to other works on Mechanics and general Physics, would be
with most readers ineffectual, and with all unsatisfactory. In
former editions of the present work, we consigned these necessary
general principles of physics and mechanics to a preliminary
chapter; but it appears, on the whole, more convenient not to
remove the exposition of the principle from the place where its
application is required. We shall therefore pause as we proceed,
where these difficulties occur, to give such explanation and
illustration as may seem best suited to render them intelligible
and interesting to the unscientific reader.
The history of the arts and manufactures affords no example of any
invention the credit for which has been claimed by so many
different nations and individuals as that of the steam engine. The
advocates of the competitors for this honour have urged their
pretensions, and pressed their claims, with a zeal which has
occasionally outstripped the bounds of discretion, and the contest
has not unfrequently been tinged with prejudices, national and
personal, and characterised by a degree of asperity altogether
unworthy of so noble a cause, and beneath the dignity of science.
"When a question is clearly proposed, it is already half resolved."
Let us see whether a careful attention to this maxim will aid us
in the investigation of the origin of the steam engine. The source
of the power of that machine is found in the following natural
phenomena.
_First._ When fire is applied to water, the liquid swells into
vapour, and in undergoing this change exerts, as has been already
stated, a considerable amount of mechanical force. This force may,
by proper means, be rendered applicable to any purpose for which
labour or power is needful.
_Second._ The vapour so produced is endowed with the property of
elasticity, in virtue of which it is capable of [Pg011] swelling
or expanding into increased dimensions, exerting, as it expands, a
force, the energy of which is gradually diminished as the
dimensions of the vapour are increased. This mechanical force is
likewise capable of being applied to any useful purpose for which
labour or power is necessary.
_Third._ This vapour is capable, by proper means, of being
reconverted into water; and when so reconverted, it shrinks into
its original dimensions, deserting the large space which it
occupied as vapour, and leaving that space a vacuum. It is known
in physics, that when a vacuum is produced, surrounding bodies
have a tendency to rush into it with a definite amount of force.
Consequently any agent which produces a vacuum, becomes a source
of a considerable amount of mechanical power. By its reconversion
into water, therefore, steam again becomes a mechanical agent.
Such are the natural phenomena in which are found the original
sources of all steam power. In some forms of steam engine one of
these is used, and in some another, and in some the application of
all of them is combined; but in no existing form of steam engine
whatever is there any other source of mechanical power.
Neither these nor any other natural forces can be applied
_immediately_ to any useful purpose. The interposition of
mechanism is indispensable; on the invention and contrivance of
that mechanism depends altogether the useful application of these
natural forces.
The world owes the steam engine then partly to _discovery_, and
partly to _invention_.
He that discovered the fact, that mechanical force was produced in
the conversion of water into steam, must be justly held to be a
sharer in the merit of the steam engine, even though he should
never have practically applied his discovery. The like may be said
of him who first discovered the source of the mechanical power
arising from the expansion of steam.
The discoverer of the fact, that steam being reconverted into
water greatly contracted its dimensions, and thereby produced a
vacuum, is likewise entitled to a share of the credit. [Pg012]
The mechanism by which these natural forces have been rendered so
universally available as a moving power, is very various and
complicated, and cannot be traced to one inventor. "If a
watchmaker," says M. Arago, "well instructed in the history of his
art, were required to give a categorical answer to the question,
Who has invented watches? he would remain mute; but the question
would be divested of much of its difficulty if he were required
separately to declare who discovered the use of the main spring,
the different forms of escapement, or the balance wheel." So it is
with the steam engine. It is a combination of a great variety of
contrivances, distinct from each other, which are the production
of several inventors. If, however, one name more than the rest be
entitled to special notice; if _he_ is entitled to the chief
credit of the invention who by the powers of his mechanical genius
has imparted to the steam engine that form, and conferred upon it
those qualities, on which mainly depends its present extensive
utility, and by which it has become an agent of transcendant
power, spreading its beneficial effects throughout every part of
the civilised globe, then the universal voice will, as it were by
acclamation, award the honour to one individual, whose pre-eminent
genius places him far above all other competitors, and from the
application of whose mental energies to this machine may be dated
those grand effects which render it a topic of interest to all for
whom the progress of civilisation has any attractions. Before the
era rendered memorable by the discoveries of JAMES WATT, the steam
engine, which has since become an object of such universal
interest, was a machine of extremely limited power, inferior in
importance and usefulness to most other mechanical agents used as
prime movers; but, from that epoch, it is scarcely necessary here
to state, that it became a subject not of British interest only,
but one having an important connection with the progress of the
human race.
HERO OF ALEXANDRIA, 120 B. C.
[Illustration: _Fig._ 1.]
(3.) The discovery of the fact, that a mechanical force is
produced when water is evaporated by the application of heat,
[Pg013] must be considered as the first capital step in the
invention of the steam engine. It is recorded in a work entitled
_Spiritalia seu Pneumatica_, that Hero of Alexandria contrived a
machine, 120 years before the Christian era, which was moved by
the mechanical force of the vapour of water. The principle of this
machine admits of easy explanation: When a fluid issues from any
vessel in which it is confined, that vessel suffers a force equal
to that with which the fluid escapes from it, and in the opposite
direction. If water issues from an orifice, a pressure is produced
behind the orifice corresponding to the force with which the water
escapes. If a man discharge a gun, the gases produced by the
explosion of the powder issue with a certain force from the
muzzle, and his shoulder is driven backwards by the recoil with a
corresponding force. If the muzzle, instead of being presented
forwards, were turned at right angles to the length of the gun,
then, as the gases of explosion would escape sideways, the recoil
would likewise take place sideways, and the shooter, instead of
being driven backward, would be made to spin round as a dancer
pirouettes. This was the principle of Hero's steam engine. A small
globe or ball was placed on pivots at A and B (_fig._ 1.), on
which it was capable of revolving: steam was supplied through one
of these pivots from one of the tubes D C E F, which communicated
with the boiler. This steam filled the globe A I B K, and also the
arms I H and K G. A lateral orifice, represented at G, near the
end of these arms, allowed the steam to escape in a jet, and the
reaction, producing a recoil, had a tendency to drive the arm
round. A small orifice at H, on the other side of the tube,
produced a like effect. In the same manner, any convenient number
of arms might be provided, surrounding the globe and communicating
with its interior like the spokes of a wheel. Thus these arms,
having lateral orifices for the escape of the steam, all placed so
that the recoil may [Pg014] tend to turn the globe in the same
direction, a rotatory motion might be communicated to any
machinery which it was desired to move.
After having been allowed to slumber for nearly two thousand
years, this machine has recently been revived, and engines
constructed similar to it are now working in these countries. In
the proper place we shall describe Avery's Rotatory Engine, which
it will be seen is, not only in its principle, but almost in its
details, the machine of HERO OF ALEXANDRIA.
Although the elastic force of steam was not reduced to numerical
measure by the ancients, nor brought under control, nor applied to
any useful purpose, yet it appears to have been recognised in
vague and general terms. Aristotle, Seneca, and other ancient
writers, accounted for earthquakes by the sudden conversion of
water into steam within the earth. This change, according to them,
was effected by subterranean heat. Such tremendous effects being
ascribed to steam, it can scarcely be doubted that the Greeks and
Romans were acquainted with the fact, that water in passing into
vapour exercises considerable mechanical power. They were aware
that the earthquakes, which they ascribed to this cause, exerted
forces sufficiently powerful to extend the natural limits of the
ocean; to overturn from their foundations the most massive
monuments of human labour; to raise islands in the midst of seas;
and to heave up the surface of the land of level continents so as
to form lofty mountains.
Such notions, however, resulted not as consequences of any exact
or scientific principles, but from vague analogies derived from
effects which could not fail to have been manifested in the arts,
such as those which commonly occurred in the process of casting in
metal the splendid statues which adorned the temples, gardens, and
public places of Rome and Athens. The artisan was liable to the
same accidents to which modern founders are exposed, produced by
the casual presence of a little water in the mould into which the
molten metal is poured. Under such circumstances, the sudden
formation of steam of an extreme pressure produces, as is well
known, explosions attended with destructive effects. The Grecian
[Pg015] and Roman artisans were subject to such accidents; and the
philosopher, generalising such a fact, would arrive at a solution
of the grander class of phenomena of earthquakes and volcanoes.
Before natural phenomena are rendered subservient to purposes of
utility, they are often made to minister to the objects of
superstition. The power of steam is not an exception to this rule.
It is recorded in the Chronicles, that upon the banks of the Weser
the ancient Teutonic gods sometimes marked their displeasure by a
sort of thunderbolt, which was immediately succeeded by a cloud
that filled the temple. An image of the god _Busterich_, which was
found in some excavations, clearly explains the manner in which
this prodigy was accomplished by the priests. The head of the
metal god was hollow, and contained within it a pot of water: the
mouth, and another hole, above the forehead, were stopped by
wooden plugs; a small stove, adroitly placed in a cavity of the
head under the pot, contained charcoal, which, being lighted,
gradually heated the liquid contained in the head. The vapour
produced from the water, having acquired sufficient pressure,
forced out the wooden plugs with a loud report, and they were
immediately followed by two jets of steam, which formed a dense
cloud round the god, and concealed him from his astonished
worshippers.[1]
Among other amusing anecdotes showing the knowledge which the
ancients had of the mechanical force of steam, it is related that
Anthemius, the architect of Saint Sophia, occupied a house next
door to that of Zeno, between whom and Anthemius there existed a
feud. To annoy his neighbour, Anthemius placed on the ground floor
of his own house several close digesters, or boilers, containing
water. A flexible tube proceeded from the top of each of these,
which was conducted through a hole made in the wall between the
houses, and which communicated with the space under the floors of
the rooms in the house of Zeno. When Anthemius desired to annoy
his neighbour, he lighted fires under his boilers, and the steam
produced by them rushed in such quantity and with [Pg016] such
force under Zeno's floors, that they were made to heave with all
the usual symptoms of an earthquake.[2]
BLASCO DE GARAY, A. D. 1543.
(4.) In the year 1826, M. de Navarrete published, in Zach's
Astronomical Correspondence, a communication from Thomas Gonzales,
Director of the royal archives of Simancas, giving an account of
an experiment reported to have been made in the year 1543, in
which a vessel was propelled by a machine having the appearance of
a steam engine.
Blasco de Garay, a sea captain, proposed in that year to the Emperor
Charles V. to propel vessels by a machine which he had invented,
even in time of calm, without oars or sails. Notwithstanding the
apparent improbability attending this project, the Emperor ordered
the experiment to be made in the port of Barcelona, and the 17th of
June, 1543, was the day appointed for its trial. The commissioners
appointed by Charles V. to attend and witness the experiment were
Don Henry of Toledo, Don Pedro of Cardona, the treasurer Ravago, the
vice chancellor and intendant of Catalonia, and others. The vessel
on which the experiment was made was the Trinity, 200 tons burthen,
which had just discharged a cargo of corn at Barcelona. Garay
concealed the nature of his machinery, even from the commissioners.
All that could be discovered during the trial was, that it consisted
of a large boiler containing water, and that wheels were attached to
each side of the vessel, by the revolution of which it was
propelled. The commissioners having witnessed the experiment, made a
report to the king, approving generally of the invention,
particularly on account of the ease and promptitude with which the
vessel could be put about by it.
The treasurer Ravago, who was himself hostile to the project,
reported that the machine was capable of propelling a vessel at the
rate of two leagues in three hours; but the other commissioners
stated that it made a league an hour at the least, and that it put
the vessel about as speedily as would be accomplished with a galley
worked according to the common [Pg017] method. Ravago reported that
the machinery was too complicated and expensive, and that it was
subject to the danger of the boiler bursting.
After the experiment was made, Garay took away all the machinery,
leaving nothing but the framing of wood in the arsenals of
Barcelona.
Notwithstanding the opposition of Ravago, the invention was
approved, and the inventor was promoted and received a pecuniary
reward, besides having all his expenses paid.