Popular Science Monthly/Volume 12/November 1877/The Growth of the Steam-Engine I
By Professor R. H. THURSTON,
OF THE STEVENS INSTITUTE OF TECHNOLOGY.
Fig. 1.—The Grecian Idea of the Steam-engine.
THE STEAM-ENGINE AS A SIMPLE MACHINE.
["A machine, receiving at distant times and from many hands new combinations and improvements, and becoming at last of signal benefit to mankind, may be compared to a rivulet, swelled in its course by tributary streams until it rolls along a majestic river, enriching in its progress provinces and kingdoms. In retracing the current, too, from where it mingles with the ocean, the pretensions of even ample subsidiary streams are merged in our admiration of the master-flood. But, as we continue to ascend, those waters which, nearer the sea, would have been disregarded as unimportant, begin to rival in magnitude, and divide our attention with, the parent stream; until, at length, on our approaching the fountains of the river, it appears trickling from the rock, or oozing from among the flowers of the valley. So, also, in developing the rise of a machine, a coarse instrument or a toy may be recognized as the germ of that production of mechanical genius whose power and usefulness have stimulated our curiosity to mark its changes and to trace its origin. The same feelings of reverential gratitude which attached holiness to the spots whence mighty rivers sprung, also clothed with divinity, and raised altars in honor of the saw, the plough, the potter's wheel, and the loom."—Stuart.]
[. . . . "And, last of all, with inimitable power, and 'with whirlwind-sound,' comes the potent agency of steam. In comparison with the past, what centuries of improvement has this single agent comprised in the short compass of fifty years! Everywhere practicable, everywhere efficient, it has an arm a thousand times stronger than that of Hercules, and to which human ingenuity is capable of fitting a thousand times as many hands as belonged to Briareus. Steam is found in triumphant operation on the seas; and, under the influence of its strong propulsion, the gallant ship
'Against the wind, against the tide,
Still steadies with an upright keel.'
It is on the rivers, and the boatman may repose on his oars; it is on highways, and exerts itself along the courses of land-conveyance; it is at the bottom of mines, a thousand feet below the earth's surface; it is in the mill, and in the workshops of the trades. It rows, it pumps, it excavates, it carries, it draws, it lifts, it hammers, it spins, it weaves, it prints. It seems to say to men, at least to the class of artisans: 'Leave off your manual labor; give over your bodily toil; bestow but your skill and reason to the directing of my power, and I will bear the toil, with no muscle to grow weary, no nerve to relax, no breast to feel faintness!' What further improvement may still be made in the use of this astonishing power it is impossible to know, and it were vain to conjecture. What we do know is, that it has most essentially altered the face of affairs, and that no visible limit yet appears beyond which its progress is seen to be impossible."—Daniel Webster.]
SECTION I. The Period of Speculation. Hero to Worcester, b. c. 200 to a. d. 1700.—1. The history of the steam-engine is a subject that interests greatly every intelligent mind.
As Religion has always been, and still is, the great moral agent in
civilizing the world, and as Science is the great intellectual promoter of civilization, so the steam-engine is, in modern times, the most important physical agent in that great work.
It would be superfluous to attempt to enumerate the benefits which it has conferred upon the human race, for such an enumeration would include an addition to every comfort, and the creation of almost every luxury that we now enjoy.
"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."
2. The wonderful progress of the present century is, in a very, great degree, due to the invention and improvement of the steam-engine, and to the ingenious application of its power to kinds of work that formerly tasked the physical energies of the human race. We cannot examine the methods and processes of any branch of industry without discovering somewhere the assistance and support of this wonderful machine.
Relieving mankind from manual toil, it has left to the intellect the privilege of directing the power formerly absorbed in physical labor into other and more profitable channels. The intelligence which has thus conquered the powers of Nature now finds itself free to do brain-work; the force formerly utilized in the carrying of water and the hewing of wood is now expended in the Godlike work of thought.
What, then, can be more interesting than to trace the history of the growth of this wonderful invention, the greatest among the many great creations of one of God's most beneficent gifts to man, the power of invention.
3. While following the records and traditions of the steam-engine, I propose to call to your attention the fact that its history illustrates the very important truth that great inventions are never, and great discoveries are seldom, the work of any one mind.
Every great invention is really an aggregation of minor inventions, or the final step of a progression. It is not usually a creation, but a growth, as truly so as is the growth of the trees in the forest.
Hence the same invention is frequently brought out in several countries and by several individuals simultaneously.
Frequently, an important invention is made before the world is ready to receive it, and the unhappy inventor is taught, by his failure, that it is as unfortunate to be in advance of the age as to be behind it.
Inventions only become successful when they are not only needed, but when mankind is so far advanced in intelligence as to appreciate and to express the necessity for them, and at once to make use of them.
4. About a half-century ago, an able New England writer, in a communication to an English engineering periodical, described the new machinery which was built at Newport, Rhode Island, by John Babcock and Robert L. Thurston, for one of the first steamboats that ever ran between that city and New York. He prefaced his description with a frequently-quoted remark to the effect that, as Minerva sprang, mature in mind, in full stature of body, and completely armed, from the head of Jupiter, so the steam-engine came forth, perfect at its birth, from the brain of James Watt.
But we shall see, as we examine the records of its history, that, although James Watt was an inventor, and probably the greatest of the inventors of the steam-engine, he was still but one of the many men who have aided in perfecting it, and who have now made us so familiar with its tremendous power and its facile adaptation to labor, that we have almost ceased to admire it, or to wonder at this product of the workings of the more admirable intelligence that has so far perfected it.
5. Twenty-one centuries ago, the political power of Greece was broken, although Grecian civilization had risen to its zenith.
Rome, ruder than her polished neighbor, was growing continually stronger, and was rapidly gaining territory by absorbing weaker states.
Egypt, older in civilization than either Greece or Rome, fell but two centuries later before the assault of the younger states, and became a Roman province. Her principal city was at this time Alexandria, founded by the great soldier whose name it bears when in the full tide of his prosperity. It had now become a great and prosperous city, the centre of the commerce of the world, the home of students and of learned men, and its population was the wealthiest and most civilized of the then known world.
It is among the relics of this ancient Egyptian civilization that we find the first record of the early history of the steam-engine.
6. In Alexandria, the home of Euclid, the great geometrician, and possibly contemporary with that talented engineer and mathematician Archimedes, a learned writer, Hero, produced a manuscript which he entitled "Spiritalia seu Pneumatica."
The work is still extant, and has been several times republished. In it are described a number of interesting though primitive forms of water and heat engines, and, among the latter, that shown in Fig. 2, an apparatus moved by the force of steam.
This earliest of steam-engines consisted of a globe, a, suspended between trunnions, G L, through one of which steam enters through pipes, C M, F E, from the boiler, D, below.
The hollow bent arms, H and K, cause the vapor to issue in such a direction that the reaction produces a rotary movement of the globe, just as the rotation of reaction water-wheels is produced by outflowing water.
It is quite uncertain whether this machine was ever more than a toy, although it has been supposed by some authorities that it was actually used by the Greek priests for the purpose of producing motion of other apparatus in their temples.
Fig. 2. Hero's Engine, b. c. 200.
7. It seems sufficiently remarkable that, while the power of steam had been, during all the many centuries that man has existed upon the globe, so universally displayed in so many of the phenomena of natural change, mankind lived almost up to the Christian era without making it useful in giving motion even to a toy; but it must excite still greater surprise that, from the time of Hero, we meet with no good evidence of its application to any practical use for many hundreds of years.
Here and there, in the pages of history and in special treatises, we find a hint that the knowledge of the force of steam is not forgotten; but it is not at all to the credit of biographers and of historians that they have devoted so little time to the task of seeking and recording information relating to the progress of this and other important inventions and improvements in the mechanic arts.
8. In the year 1825, the Superintendent of the Royal Spanish Archives at Simancas furnished an account, which had been there discovered, of an attempt made in 1543, by Blasco de Garay, a Spanish navy-officer, under Charles I., to move a ship by paddle-wheels, driven, as was inferred from the account, by a steam-engine.
It is impossible to say to how much confidence the story is entitled; but, if true, it was the first attempt, so far as is now known, to make steam useful in developing power for practical purposes. Nothing is known of the form of the engine employed, it only having been stated that a "vessel of boiling water" formed a part of it.
The account is, however, in other respects, so circumstantial that it has been credited by many, but it is looked upon as very doubtful by the majority of writers upon the subject. It was published in 1825 by M. de Navarrete, in the form of a letter from Tomás Gonzales, Director of the Royal Archives at Simancas, Spain.
9. In 1601 Giovanni Battista della Porta, in his work "Spiritali," described an apparatus by which the pressure of steam might be made to raise a column of water, and the method of operation included the application of the condensation of steam to the production of a vacuum into which the water would flow. He used a separate boiler. Fig. 3 is copied from an illustration in a later edition of his work.
Fig. 3. Porta's Apparatus, a. b. 1601.
10. In 1615 Salmon de Caus, who had been an engineer and architect under Louis XIII. of France, and later in the employ of the British Prince of Wales, published a work at Frankfort, entitled "Les Raisons des Forces Mouvantes avec diverses machines tant utile que plaisantes," in which he illustrated his proposition, "Water will, by the aid of fire, mount higher than its level," by describing a machine designed to raise water by the expanding power of steam. (See Fig. 4.)
This consisted of a metal vessel partly filled with water, and in which a pipe was fitted leading nearly to the bottom and open at the top.
Fire being applied, the steam, formed by its elastic force, drove the water out through the vertical pipe, raising it to a height depending upon either the wish of the builder or the strength of the vessel.
11. In 1629 Giovanni Branca, of Lovetto, an Italian town, described, in a work published at Rome, a number of ingenious mechanical contrivances, among which was a steam-engine (Fig. 5), in which the steam, issuing from a boiler, impinged upon the vanes of an horizontal wheel.
This it was proposed to apply to many useful purposes.
Fig. 4.—De Caus's Apparatus, a. d. 1615.
12. In illustration of the singular manner in which old inventions disappear only to reappear in latter times, it may be remarked that this contrivance was brought forward quite recently by a sanguine inventor, who spent a considerable sum in building what he considered a great improvement upon existing forms of steam-engines.
The engine of Hero also has been frequently reinvented, and, under the designation of "steam turbine," it has been applied with some satisfactory effect to the production of very high velocity of rotation.
13. We now come to the first instance in which the expansive
Fig. 5.—Branca's Steam-Engine, a. d. 1629.
force of steam is supposed to have actually been applied to do important and useful work.
In 1663, Edward Somerset, second Marquis of Worcester, published a curious collection of descriptions of his inventions, couched in obscure
Edward Somerset, Second Marquis of Worcester.
and singular language, and called a "Century of the Names and Scantlings of Inventions by me already practised."
One of these inventions is an apparatus for raising water by steam. The description was not accompanied by a drawing, but the sketch here given (Fig. (j), probably resembles his contrivance very closely.
Steam is generated in the boiler D, and thence is led into the vessel A, already nearly filled with water. It drives the water in a jet out through a pipe, F or F' . The vessel A is then shut off from the
boiler and again filled "by suction" after the steam has condensed through the pipe G, and the operation is repeated, the vessel B being used alternately with A.
The instruments of Porta and of De Caus were "steam fountains," and were applied, if used at all, merely for ornamental uses.
That of the Marquis of Worcester was used for the purpose of elevating water for practical purposes at Vauxhall, near London. It was still earlier used at the home of Worcester, Raglan Castle, where the openings cut in the wall for its reception are still to be seen, as in Fig. 7.
14. The separate boiler, as here used, constitutes a very important improvement upon the preceding forms of apparatus, although the idea was original with Porta.
The "water-commanding engine," as its inventor called it, was, therefore, the first instance in the history of the steam-engine in which the inventor is known to have "reduced his invention to practice."
It is evident, however, that the invention, important as it was, does not entitle the marquis to the honor claimed for him by many authorities of being the inventor of the steam-engine. Somerset was simply one of those whose works collectively make the steam-engine.
Section II. The Period of Application of the Early Type of Steam-Engine. Morland, Savery, and Desaguliers.—14. The invention of the Marquis of Worcester was revived twenty years later, by Sir Samuel Morland, but in what form is not now known.
In a memoir, which he wrote upon the subject in 1683, he exhibited a degree of familiarity with the properties of steam that could hardly have been expected of any one at that early date.
In his manuscript, now preserved in the Haarlem Collection of the British Museum, he states the size of the cylinders required in his machine to raise given quantities of water per hour, and gives very exactly the relative volumes of equal weights of water and of steam under atmospheric pressure.
He tells us that one of his engines, with a cylinder six feet in diameter and twelve feet long, was capable of raising 3,240 pounds of water through a height of six inches, 1,800 times an hour.
15. From this time forward the minds of many mechanicians were earnestly at work on this problem—the raising of water by aid of steam.
Hitherto, although many ingenious toys, embodying the principles of the steam-engine separately, and sometimes, to a certain extent, collectively, had beeu proposed and even occasionally constructed, the world was only just ready to profit by the labors of inventors in this direction.
But, at the end of the seventeenth century, English miners were beginning to find the greatest difficulty in clearing their shafts of the vast quantities of water which they were meeting at the considerable depths to which they had penetrated, and it had become a matter of vital importance to them to find a more powerful aid in that work than was then available.
They were, therefore, by their necessities, stimulated to watch for, and to be prepared promptly to take advantage of, such an invention when it should be offered them.
16. The experiments of Papin, and the practical application of known principles by Savery, placed the needed apparatus in their hands.
When Louis XIV. revoked the Edict of Nantes, by which Henry IV. had guaranteed protection to the Protestants of France, the terrible persecutions at once commenced by the papists drove from the kingdom some of its greatest men.
Among these was Denys Papin, a native of Blois, and a distinguished philosopher. He studied medicine at Paris, and, when expatriated, went to England, where he met the celebrated philosopher Boyle, who introduced him into the Royal Society, of which Papin became a member, and to whose "Transactions" he contributed several valuable papers.
He invented, in 1680, the "Digester," in which substances, unaffected by water boiling under atmospheric pressure, can be subjected to the action of water boiling under high pressure, and thus thoroughly "digested," or cooked.
The danger of bursting these vessels caused him, in 1681, to invent
and apply the lever safety-valve, now an indispensable appurtenance to every steam-boiler.
17. In 1690 he constructed a working model of an engine, consisting of a steam-cylinder with a piston which was raised by steam-pressure, and which descended again when the condensation of the steam produced a vacuum beneath it.
This apparatus the inventor proposed to use as a motor for working pumps and for driving paddle-wheels; but he never built a successful working machine on this plan, so far as we can ascertain; and he did not then propose a separate boiler, but made the same vessel serve at once as a boiler, steam-cylinder, and condenser, evaporating water in the cylinder itself; and, after raising the piston, removing the cylinder from the fire, or the fire from under the cylinder, to effect condensation by the gradual loss of heat by radiation.
18. The most important advance in actual construction was made by Thomas Savery.
The constant and embarrassing expense, and the engineering difficulties presented by the necessity of keeping the British mines, and particularly the deep pits of Cornwall, free from water, and the failure of every attempt previously made to provide effective and economical pumping machinery, were noted by Savery, who, July 25, 1698, patented the design of the first engine which ever was actually employed in this work.
A working model was submitted to the Royal Society of London, in 1699, and successful experiments were made with it.
This engine is shown in Fig. 8, as described by Savery himself in 1702, in the "Miner's Friend."
L L is the boiler, in which steam is raised, and through the pipes O O it is alternately let into the vessels P P.
Suppose it to pass into the left-hand vessel first. The valve M being closed and r being opened, the water contained in P is driven out and up the pipe S to the desired height, where it is discharged.
The valve r is then closed, and also the valve in the pipe O. The valve M is next opened, and condensing water is turned upon the exterior of P by the cock Y, leading water from the cistern X. As the steam contained in P is condensed, forming a vacuum, a fresh charge of water is driven by atmospheric pressure up the pipe T.
Meantime, steam from the boiler has been let into the right-hand vessel P, the cock W having been first closed and R opened. The charge of water is driven out through the lower pipe and the cock R, and up the pipe S as before, while the other vessel is refilling preparatory to acting in its turn.
The two vessels thus are alternately charged and discharged as long as is necessary. Savery's method of supplying his boiler with water was at once simple and ingenious.
The small boiler D is filled with water from any convenient source, as from the stand-pipe S. A fire is then built under it, and, when the pressure of steam in D becomes greater than in the main boiler L, a communication is opened between their lower ends and the water
Fig. 8.—Savery's Engine, a. d. 1699.
passes under pressure from the smaller to the larger boiler which is thus "fed" without interrupting the work. G and N are gauge-cocks by which the height of water in the boilers is determined, and these attachments were first adopted by Savery.
19. Here we find, therefore, the first really practicable and commercially valuable steam-engine. Thomas Savery is entitled to the credit of having been the first to introduce into general use a machine in which the power of heat, acting through the medium of steam, was rendered useful.
It will be noticed that Savery, like the marquis of Worcester, and like Porta, used a boiler separate from the water-reservoir.
He added to the "water-commanding engine" of the marquis the system of surface condensation, by which he was enabled to change his vessels when it became necessary to refill them; and the secondary boiler, which enabled him to supply the working boiler with water without interrupting its action.
The machine was capable of working uninterruptedly for a period of time only limited by its own endurance.
Savery never fitted his boilers with the safety-valve, although it was subsequently used on Savery engines by Desaguliers; and in deep mines he was compelled to make use of higher pressures than his rudely-constructed boilers could safely bear.
The introduction of his machines was, therefore, greatly retarded by the fear, among miners, of the explosion of his boilers; in fact, such explosion did occur on more than one occasion.
20. The Savery engine was improved, about 1716 or 1718, by Dr. Desaguliers, who attached to it Papin's safety-valve, and substituted a jet injection from the stand-pipe into the "forcing-vessels" for the surface condensation of Savery's original arrangement.
21. The Savery engine, however, after all improvement in design and construction, though a working and a useful machine, was still a very wasteful one. The steam from the boiler, passing into the cold, wet water-reservoir or forcing-vessel, was condensed in large quantity, and also to a very serious extent, by coming into actual contact with the water itself.
Papin, who has already been referred to, in 1707 proposed to avoid this loss, to some extent at least, by the use of his piston, which
Fig. 9.—Papin's Steam-Engine, a. d. 1707.
e interposed between the steam and the water, as in Fig. 9, which is copied from a sketch given by Papin himself.
This engine is, in principle, a Marquis of Worcester engine, in which the piston E is introduced to separate the steam from the water which it impels, and thus to reduce the amount of loss by condensation.
This engine was never constructed, except experimentally, however, and is principally of interest in a history of the steam-engine from the fact that it was a useful suggestion to succeeding inventors.
Papin had, as early as 1698, abandoned his earlier but more advanced project of a piston, driven by steam-pressure on one side, assisted by a vacuum produced on the other; and he can only be regarded, therefore, as an ingenious and intelligent though unfortunate projector, and not as a successful inventor, notwithstanding his acknowledged ability and learning.