A History of the Growth of the Steam-Engine Part 3

He received his appointment and a baronetcy in 1660, and immediately commenced making experiments, partly at his own expense and partly at the cost of the royal exchequer, which were usually not at all remunerative. He built hand fire-engines of various kinds, taking patents on them, which brought him as small profits as did his work for the king, and invented the speaking-trumpet, calculating machines, and a capstan. His house at Vauxhall was full of curious devices, the products of his own ingenuity.

He devoted much attention to apparatus for raising water. His devices seem to have usually been modifications of the now familiar force-pump. They attracted much attention, and exhibitions were made of them before the king and queen and the court. He was sent to France on business relating to water-works erected for King Charles, and while in Paris he constructed pumps and pumping apparatus for the satisfaction of Louis XIV. In his book,[18] published in Paris in 1683, and presented to the king, and an earlier ma.n.u.script,[19] still preserved in the British Museum, Morland shows a perfect familiarity with the power of steam. He says, in the latter: "Water being evaporated by fire, the vapors require a greater s.p.a.ce (about two thousand times) than that occupied by the water; and, rather than submit to imprisonment, it will burst a piece of ordnance. But, being controlled according to the laws of statics, and, by science, reduced to the measure of weight and balance, it bears its burden peaceably (like good horses), and thus may be of great use to mankind, especially for the raising of water, according to the following table, which indicates the number of pounds which may be raised six inches, 1,800 times an hour, by cylinders half-filled with water, and of the several diameters and depths of said cylinders."

[18] "Elevation des Eaux par toute sorte de Machines reduite a la Mesure au Poids et a la Balance, presentee a Sa Majeste Tres Chretienne, par le Chevalier Morland, Gentilhomme Ordinaire de la Chambre Privee et Maistre de Mechaniques du Roy de la Grande Bretagne, 1683."

[19] "Les Principes de la Nouvelle Force de Feu, inventee par le Chevalier Morland, l'an 1682, et presentee a Sa Majeste Tres Chretienne, 1683."

He then gives the following table, a comparison of which with modern tables proves Morland to have acquired a very considerable and tolerably accurate knowledge of the volume and pressure of saturated steam:

-------------------------+------------------------ CYLINDERS. | POUNDS.

-----------+-------------+---------------------- Diameter | Depth | Weight in Feet. | in Feet. | to be Raised.

-----------+-------------+---------------------- 1 | 2 | 15 2 | 4 | 120 3 | 6 | 405 4 | 8 | 960 5 | 10 | 1,876 6 | 10 | 3,240 -----------+-------------+---------------------- Number of cylinders having a diameter of 6 feet and a depth of 12 feet.

| | 1 | 12 | 3,240 2 | 12 | 6,480 3 | 12 | 9,720 4 | 12 | 12,960 5 | 12 | 16,200 6 | 12 | 19,440 7 | 12 | 22,680 8 | 12 | 25,920 9 | 12 | 29,190 10 | 12 | 32,400 20 | 12 | 64,800 30 | 12 | 97,200 40 | 12 | 129,600 50 | 12 | 162,000 60 | 12 | 194,400 70 | 12 | 226,800 80 | 12 | 259,200 90 | 12 | 291,600 -----------+-------------+----------------------

The rate of enlargement of volume in the conversion of water into steam, as given in Morland's book, appears remarkably accurate when compared with statements made by other early experimenters.

Desaguliers gave the ratio of volumes at 14,000, and this was accepted as correct for many years, and until Watt's experiments, which were quoted by Dr. Robison as giving the ratio at between 1,800 and 1,900.

Morland also states the "duty" of his engines in the same manner in which it is stated by engineers to-day.

Morland must undoubtedly have been acquainted with the work of his distinguished contemporary, Lord Worcester, and his apparatus seems most likely to have been a modification--perhaps improvement--of Worcester's engine. His house was at Vauxhall, and the establishment set up for the king was in the neighborhood. It may be that Morland is to be credited with greater success in the introduction of his predecessor's apparatus than the inventor himself.

Dr. Hutton considered this book to have been the earliest account of the steam-engine, and accepts the date--1682--as that of the invention, and adds, that "the project seems to have remained obscure in both countries till 1699, when Savery, who probably knew more of Morland's invention than he owned, obtained a patent," etc. We have, however, scarcely more complete or accurate knowledge of the extent of Morland's work, and of its real value, than of that of Worcester.

Morland died in 1696, at Hammersmith, not far from London, and his body lies in Fulham church.

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 been 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 quant.i.ties 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.

The experiments of Papin, and the practical application of known principles by Savery, placed the needed apparatus in their hands.

[Ill.u.s.tration: Thomas Savery.]

THOMAS SAVERY was a member of a well-known family of Devonshire, England, and was born at Shilston, about 1650. He was well educated, and became a military engineer. He exhibited great fondness for mechanics, and for mathematics and natural philosophy, and gave much time to experimenting, to the contriving of various kinds of apparatus, and to invention. He constructed a clock, which still remains in the family, and is considered an ingenious piece of mechanism, and is said to be of excellent workmanship.

He invented and patented an arrangement of paddle-wheels, driven by a capstan[20] for propelling vessels in calm weather, and spent some time endeavoring to secure its adoption by the British Admiralty and the Navy Board, but met with no success. The princ.i.p.al objector was the Surveyor of the Navy, who dismissed Savery, with a remark which ill.u.s.trates a spirit which, although not yet extinct, is less frequently met with in the public service now than then: "What have interloping people, that have no concern with us, to do to pretend to contrive or invent things for us?"[21] Savery then fitted his apparatus into a small vessel, and exhibited its operation on the Thames. The invention was never introduced into the navy, however.

[20] Harris, "Lexicon Technic.u.m," London, 1710.

[21] "Navigation Improved; or, The Art of Rowing Ships of all rates in Calms, with a more Easy, Swift, and Steady Motion, than Oars can," etc., etc. By Thomas Savery, Gent. London, 1698.

It was after this time that Savery became the inventor of a steam-engine. It is not known whether he was familiar with the work of Worcester, and of earlier inventors. Desaguliers[22] states that he had read the book of Worcester, and that he subsequently endeavored to destroy all evidence of the antic.i.p.ation of his own invention by the marquis by buying up all copies of the century that he could find, and burning them. The story is scarcely credible. A comparison of the drawings given of the two engines exhibits, nevertheless, a striking resemblance; and, a.s.suming that of the marquis's engine to be correct, Savery is to be given credit for the finally successful introduction of the "semi-omnipotent" "water-commanding" engine of Worcester.

[22] "Experimental Philosophy," vol. ii., p. 465.

The most important advance in actual construction, therefore, was made by Thomas Savery. The constant and embarra.s.sing 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 was ever 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. Savery spent a considerable time in planning his engine and in perfecting it, and states that he expended large sums of money upon it.

Having finally succeeded in satisfying himself with its operation, he exhibited a model "Fire-Engine," as it was called in those days, before King William III. and his court, at Hampton Court, in 1698, and obtained his patent without delay. The t.i.tle of the patent reads: "A grant to Thomas Savery, Gentl., of the sole exercise of a new invention by him invented, for raising of water, and occasioning motion to all sorts of mill-works, by the impellant force of fire, which will be of great use for draining mines, serving towns with water, and for the working of all sorts of mills, when they have not the benefit of water nor constant winds; to hold for 14 years; with usual clauses."

Savery now went about the work of introducing his invention in a way which is in marked contrast with that usually adopted by the inventors of that time. He commenced a systematic and successful system of advertis.e.m.e.nt, and lost no opportunity of making his plans not merely known, but well understood, even in matters of detail. The Royal Society was then fully organized, and at one of its meetings he obtained permission to appear with his model "fire-engine" and to explain its operation; and, as the minutes read, "Mr. Savery entertained the Society with showing his engine to raise water by the force of fire. He was thanked for showing the experiment, which succeeded, according to expectation, and was approved of." He presented to the Society a drawing and specifications of his machine, and "The Transactions"[23] contain a copperplate engraving and the description of his model. It consisted of a furnace, _A_, heating a boiler, _B_, which was connected by pipes, _C C_, with two copper receivers, _D D_. There were led from the bottom of these receivers branch pipes, _F F_, which turned upward, and were united to form a rising main, or "forcing-pipe," _G_. From the top of each receiver was led a pipe, which was turned downward, and these pipes united to form a suction-pipe, which was led down to the bottom of the well or reservoir from which the water was to be drawn. The maximum lift allowable was stated at 24 feet.

[23] "Philosophical Transactions, No. 252." Weld's "Royal Society,"

vol. i., p. 357. Lowthorp's "Abridgment," vol. i.

[Ill.u.s.tration: FIG. 11.--Savery's Model, 1698.]

The engine was worked as follows: Steam is raised in the boiler, _B_, and a c.o.c.k, _C_, being opened, a receiver, _D_, is filled with steam.

Closing the c.o.c.k, _C_, the steam condensing in the receiver, a vacuum is created, and the pressure of the atmosphere forces the water up, through the supply-pipe, from the well into the receiver. Opening the c.o.c.k, _C_, again, the check-valve in the suction-pipe at _E_ closes, the steam drives the water out through the forcing-pipe, _G_, the clack-valve, _E_, on that pipe opening before it, and the liquid is expelled from the top of the pipe. The valve, _C_, is again closed; the steam again condenses, and the engine is worked as before. While one of the two receivers is discharging, the other is filling, as in the machine of the Marquis of Worcester, and thus the steam is drawn from the boiler with tolerable regularity, and the expulsion of water takes place with similar uniformity, the two systems of receivers and pipes being worked alternately by the single boiler.

In another and still simpler little machine,[24] which he erected at Kensington (Fig. 12), the same general plan was adopted, combining a suction-pipe, _A_, 16 feet long and 3 inches in diameter; a single receiver, _B_, capable of containing 13 gallons; a boiler, _C_, of about 40 gallons capacity; a forcing-pipe, _D_, 42 feet high, with the connecting pipe and c.o.c.ks, _E F G_; and the method of operation was as already described, except that _surface-condensation_ was employed, the c.o.c.k, _F_, being arranged to shower water from the rising main over the receiver, as shown. Of the first engine Switzer says: "I have heard him say myself, that the very first time he played, it was in a potter's house at Lambeth, where, though it was a small engine, yet it (the water) forced its way through the roof, and struck off the tiles in a manner that surprised all the spectators."

[24] Bradley, "New Improvements of Planting and Gardening." Switzer, "Hydrostatics," 1729.

[Ill.u.s.tration: FIG. 12.--Savery's Engine, 1698.]

The Kensington engine cost 50, and raised 3,000 gallons per hour, filling the receiver four times a minute, and required a bushel of coal per day. Switzer remarks: "It must be noted that this engine is but a small one in comparison with many others that are made for coal-works; but this is sufficient for any reasonable family, and other uses required of it in watering all middling gardens." He cautions the operator: "When you have raised water enough, and you design to leave off working the engine, take away all the fire from under the boiler, and open the c.o.c.k (connected to the funnel) to let out the steam, which would otherwise, were it to remain confined, perhaps burst the engine."

With the intention of making his invention more generally known, and hoping to introduce it as a pumping-engine in the mining districts of Cornwall, Savery wrote a prospectus for general circulation, which contains the earliest account of the later and more effective form of engine. He ent.i.tled his pamphlet "The Miner's Friend; or, A Description of an Engine to raise Water by Fire described, and the Manner of fixing it in Mines, with an Account of the several Uses it is applicable to, and an Answer to the Objections against it." It was printed in London in 1702, for S. Crouch, and was distributed among the proprietors and managers of mines, who were then finding the flow of water at depths so great as, in some cases, to bar further progress. In many cases, the cost of drainage left no satisfactory margin of profit. In one mine, 500 horses were employed raising water, by the then usual method of using horse-gins and buckets.

The approval of the King and of the Royal Society, and the countenance of the mine-adventurers of England, were acknowledged by the author, who addressed his pamphlet to them.

The engraving of the engine was reproduced, with the description, in Harris's "Lexicon Technic.u.m," 1704; in Switzer's "Hydrostatics," 1729; and in Desaguliers's "Experimental Philosophy," 1744.

The sketch which here follows is a neater engraving of the same machine. Savery's engine is shown in Fig. 13, as described by Savery himself, in 1702, in "The Miner's Friend."

_L_ is the boiler in which steam is raised, and through the pipes _O O_ it is alternately let into the vessels _P P_.

[Ill.u.s.tration: FIG. 13.--Savery's Engine, A. D. 1702.]

Suppose it to pa.s.s 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 the valve in the pipe _O_; the valve _M_ is next opened, and condensing water is turned upon the exterior of _P_ by the c.o.c.k _Y_, leading water from the cistern _X_. As the steam contained in _P_ is condensed, forming a vacuum there, 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 c.o.c.k _W_ having been first closed, and _R_ opened.

The charge of water is driven out through the lower pipe and the c.o.c.k _R_, and up the pipe _S_ as before, while the other vessel is refilling preparatory to acting in its turn.

The two vessels are thus 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 pa.s.ses, under pressure, from the smaller to the larger boiler, which is thus "fed" without interrupting the work. _G_ and _N_ are _gauge-c.o.c.ks_, by which the height of water in the boilers is determined; they were first adopted by Savery.

Here we find, therefore, the first really practicable and commercially valuable steam-engine. Thomas Savery is ent.i.tled to the credit of having been the first to introduce a machine in which the power of heat, acting through the medium of steam, was rendered generally useful.

It will be noticed that Savery, like the Marquis of Worcester, 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 charge his vessels when it became necessary to refill them; and added, also, the secondary boiler, which enabled him to supply the working-boiler with water without interrupting its work.