The next prominent experimenter on the powers of steam was Dr. Dionysius Papin. He was born at Blois about the middle of the seventeenth century, and educated to the profession of medicine. After taking his degree at Paris, he turned his attention more particularly to the study of physics, which soon occupied his whole attention; and under the celebrated Huyghens, then resident in that city, he made rapid progress. He would, doubtless, have risen to great distinction in his own country, but for the circumstance of his being a Protestant. To escape the persecutions to which all members of that persuasion were then subject, Papin fled from France in 1681, together with thousands of his countrymen, a few years before the Revocation of the Edict of Nantes. He took refuge in London, where he was welcomed by men of science, and more especially by the celebrated Boyle, under whose auspices he was introduced to the Royal Society, of which he was appointed Curator at an annual salary.

It formed part of Papin’s duty, in connection with his new office, to produce an experiment at each meeting of the Society. He was thus induced to prosecute the study of physical science; and in order to stimulate the interest of the members, he sought to introduce new subjects from time to time to their notice. One of the greatest novelties of his “entertainments” was the production of his well-known Digester, which excited a considerable degree of interest; and on one occasion a philosophical supper, cooked by the Digester, was served up to the Fellows, of which Evelyn gives an amusing account in his Diary.

He was led to the invention of the Digester by certain experiments which he made for Boyle. He discovered that if the vapour of boiling water could be prevented escaping, the temperature of the water would be raised much above the boiling point; and it occurred to him to employ this increased heat in more effectually extracting nutritious matter from the bones of animals, until then thrown away as useless. The great strength required for his Digester, and the means he was obliged to adopt for the purpose of securely confining the cover, must have early shown him what a powerful agent he was experimenting on. To prevent the bursting of the vessel from the internal pressure, he was led to the invention of the safety-valve, which consisted of a small moveable plate, or cylinder, fitted into an opening in the cover of the boiler, and kept shut by a lever loaded with a weight, capable of sliding along it in the manner of a steel yard. The pressure of the weight upon the valve could thus be regulated at pleasure. When the pressure became so great as to endanger the safety of the boiler, the valve was forced up, and so permitted the steam to escape. Although Papin was thus the inventor of the safety-valve, it is a curious fact that he did not apply it to the steam-machine which he subsequently invented, but adopted another expedient.

The reputation of Papin having extended to Germany, he was, in 1687, invited to fill the office of Professor of Mathematics in the University of Marburg, and accepted the appointment. He continued, however, to maintain a friendly correspondence with his scientific friends in England, and communicated to the Royal Society the results of the experiments in physics which he continued to pursue. In the same year in which he settled at Marburg, he submitted to the Society an important paper, which indicated the direction in which his thoughts were then running. It had occurred to him, as it had before done to Hautefeuille, that the explosion of gunpowder presented a ready means of producing a power to elevate a piston in a tube or cylinder, and that, when so raised, a vacuum could be formed under the piston by condensing the vapour, and so ensuring its return by the pressure of the atmosphere. He thought that he might thus be enabled to secure an efficient moving force. But it was found in practice, that the proposed power was too violent as well as uncertain, and it was shortly given up as impracticable.

Papin next inquired whether his proposed elastic force and subsequent vacuum might not better be produced by means of steam. He accordingly entered upon a series of experiments, which gradually led him to the important conclusions published in his celebrated paper on “A New Method of Obtaining very Great Moving Powers at Small Cost,” which appeared in the ‘Acta Eruditorum’ of Leipsic, in 1690. “I felt confident,” he there observes, “that machines might be constructed wherein water, by means of no very intense heat, and at small cost, might produce that perfect vacuum which had failed to be obtained by means of gunpowder.” He accordingly contrived a machine to illustrate this idea, but it was very imperfect and slow in its action, as may well be imagined from the circumstance that to produce the condensation he did not apply cold, but merely took away the fire! Still he was successfully working out, step by step, the important problem of steam power. He clearly perceived that a piston might be raised in a cylinder by the elastic force of steam, and that on the production of a vacuum by its condensation, the piston might be driven home again by the pressure of the atmosphere. The question was, how was this idea to be realised in a practicable working machine? After many experiments, Papin had the courage to make the attempt to pump water by atmospheric pressure on a large scale. He was employed to erect machines after his principle, for the purpose of draining mines in Auvergne and Westphalia; but from the difficulty he experienced in procuring and preserving a vacuum, and the tediousness of the process, his enterprise proved abortive.

The truth is, that fertile though Papin was in conception, he laboured under the greatest possible disadvantage in not being a mechanic. The eyes and hands of others are not to be relied on in the execution of new and untried machines. Unless eyes and hands be disciplined by experience in skilled work, and inspired by intelligence, they are comparatively useless. The chances of success are vastly greater when mind, eyes, and hands, are combined in one person. Hence the unquestionable fact that though the motive power of steam had long been the subject of ingenious speculation and elaborate experiment amongst scientific men, it failed to be adopted as a practicable working power until it was taken in hand by mechanics—by such men as Newcomen, the blacksmith; Potter, the engine-driver; Brindley, the millwright; and, above all, by James Watt, the mathematical instrument maker.

The sagacious foresight of Papin as to the extensive applicability of steam-power as a motive agent, is strikingly shown by the following passage in the paper above referred to:—“If any one,” says he, “will consider the magnitude of the forces to be obtained in this way (i. e., by the atmospheric high-pressure engine he was suggesting), and the trifling expense at which a sufficient quantity of fuel can be procured, he will certainly admit that this very method is far preferable to the use of gunpowder above spoken of, especially as in this way a perfect vacuum is obtained, and so the inconveniences above recounted are avoided. In what manner that power can be applied to draw water or ore from mines, to discharge iron bullets to a great distance, to propel ships against the wind, and to a multitude of other similar purposes, it would be too long here to detail; but each individual, according to the particular occasion, must select the construction of machinery appropriate to his purpose.” This last was, however, the real difficulty to be overcome. Steam, doubtless, contained a power to do all these things; but as for the machine that would work quietly, docilely, and effectively, in pumping water, discharging bullets, or propelling ships, the mechanic had not yet appeared that was able to make one.

Papin was, however, a man of great perseverance; and, strong in his faith as to the power of steam to propel ships, he gradually worked his way to the contrivance of a model steamboat. When in London, he had seen an experiment tried by the Prince Palatine Rupert on the Thames, in which a boat fitted with revolving paddles attached to the two ends of an axle which received its motion from a trundle working on a wheel turned round by horses, went with such rapidity as to leave the king’s barge, manned by sixteen rowers, far behind in the race. The idea which occurred to Papin was, to apply a steam machine to drive the paddles, and thus ensure a ship’s motion independent of wind or tide. For this purpose, it was necessary to convert the alternate motion of the piston-rod into a continuous rotary one; and this he proposed to effect “by having the rods of the pistons fitted with teeth, which would force round small wheels, toothed in like manner, fastened to the axis of the paddles.”

The use of paddle-wheels in propelling boats had long been known. The Harleian MSS. contain an Italian book of sketches, attributed to the fifteenth century, in which there appears the annexed sketch of a paddle-boat. This boat was evidently intended to be worked by two men turning the crank by which the paddles were made to revolve. There were many other early schemes of paddle-boats, some of which were proposed to be worked by horse-power. The name of Blasco Garay has often been mentioned as the first who applied the power of steam to the driving of paddle-boats; but for this there is not the slightest foundation. M. Bergenroth informs us that he has carefully examined all the documents relating to the trials of Blasco Garay in the archives at Simancas, but has found no reference whatever to steam as the power employed in causing the paddles to revolve.[20] The experiments were made at Malaga and Barcelona respectively, in the years 1540 and 1543: in one the vessel was propelled by a paddle-wheel on each side worked by twenty-five men, and in the other by a paddle-wheel worked by forty men.

It appears probable that although others before Papin had speculated as to the possibility of constructing a boat to be driven by the power of steam, he was the first to test the theory by actual experiment; the first to construct a model steamboat. His first experiments were doubtless failures. The engine contrived by himself was found inapplicable to the driving of ships, as it had been to the pumping of mines; and it was not until he saw the model of Savery’s engine exhibited to the Royal Society of London, in 1698, and witnessed the trial of the same inventor s paddle-wheel boat on the Thames in the course of the same year that it occurred to him to combine the two contrivances in one, and apply Savery’s engine to drive Savery’s paddle-wheels. Returning to Marburg, he proceeded with his experiments, and informed Liebnitz that he had employed both suction and pressure by steam; that he had made a model of a carriage propelled by this force, which succeeded; and he hoped that the same power would answer for boats. Papin prosecuted his idea with great zeal, trying many expedients, encountering many difficulties, and meeting with many disappointments. At length, after about fifteen years’ labour, he succeeded in constructing a model engine, fitted in a boat—“une petite machine d’un vaisseau à roues”—which worked to his satisfaction. His next object was to get his model transported to London, to exhibit it on the Thames. “It is important,” he writes to Liebnitz (7th July, 1707), “that my new construction of vessel should be put to the proof in a seaport like London, where there is depth enough to apply the new invention, which, by means of fire, will render one or two men capable of producing more effect than some hundreds of rowers.” Papin had considerable difficulty in obtaining the requisite permission from the authorities to enable his model to pass from the Fulda to the Weser; but at length he succeeded, and the little vessel reached Münden, when, to Papin’s great grief, it was seized by the boatmen of the river, and barbarously destroyed.

The year after this calamity befell Papin’s machine he wrote an urgent letter to his old friends of the Royal Society at London, asking them to advance him sufficient money to construct another engine “and to fit it so that it might be applied for the rowing of ships.” The Society, however, did not see their way to assisting Papin in the manner proposed, most likely because of the expense as well as uncertainty of the experiment. Two years later, worn out by work and anxiety, the illustrious exile died; and it was left for other labourers to realise the great ideas he had formed as to locomotion by steam-power.

The apparently resultless labours of these men will serve to show what a long, anxious, and toilsome process the invention of the steam-engine has been. The early inventors had not the gratification of seeing their toils rewarded by even the faintest glimmering of practical success. One after another, they took up the subject, spent days and nights of study over it, and, laying down their lives, there left it. To many the study brought nothing but anxiety, toil, distress, and sometimes ruin; while some fairly broke their hearts over it. But it was never abandoned. Disregarding the fate of their predecessors, one labourer after another resumed the investigation, advancing it by further stages, until at length the practicable working steam-engine was invented, presenting, perhaps, the most remarkable illustration of the power of human skill and perseverance to be found in the whole history of civilisation.

CHAPTER III.
Captain Savery—His Fire-engine.

The attempts hitherto made to invent a working steam-engine, it will be observed, had not been attended with much success. The most that could be said of them was, that, by demonstrating the impracticable, they were gradually leading other experimenters in the direction of the practicable. Although the progress made seemed but slow, the amount of net result was by no means inconsiderable. Men were becoming better acquainted with the elastic force of steam. The vacuum produced by its condensation in a closed vessel, and the consequent atmospheric pressure, had been illustrated by repeated experiments; and many separate and minor inventions, which afterwards proved of great value, had been made, such as the four-way cock, the safety-valve, and the piston moving in a cylinder. The principle of a true steam-engine had not only been demonstrated, but most of the separate parts of such an engine had been contrived by various inventors. It seemed as if all that was now wanting was a genius of more than ordinary power to combine them in a complete and effective whole.

To Thomas Savery is usually accorded the merit of having constructed the first actual working steam-engine. Little is known of his early history; and various surmises have been formed as to his origin and calling. Some writers have described him as the captain of a tin-mine; others as a naval captain; while a third says he was an immigrant Frenchman.[21] We are, however, enabled to state, from information communicated by his descendants, that he was the scion of a well-known Devonshire family. John Savery, of Halberton, or Harberton, afterwards of Great Totness, was a gentleman of considerable property in the reign of Henry VIII. In the sixteenth century the Saverys became connected by marriage with the Servingtons of Tavistock, another old county family, one of whom served as sheriff in the reign of Edward III. In 1588, Christopher Savery, the head of the family, resided in Totness Castle, of which he was the owner; and for a period of nearly forty years the town was represented in Parliament by members of the Savery family. Sir Charles served as Sheriff of Devon in 1619. Though the Saverys took the side of the Parliament, in resisting the despotic power assumed by Charles I., they nevertheless held a moderate course; for we find Colonel Savery, in 1643, attaching his name to the famous “round robin” presented to Parliament. Richard Savery, the youngest son of the Colonel, was father of Thomas Savery, the inventor of the “fire-engine.” Other members of the Savery family, besides Thomas, were distinguished for their prosecution of physical science. Thus we find from the family MSS., Servington Savery corresponding with Dr. Jurin, Secretary to the Royal Society, respecting an improvement which he had made in the barometer, and communicating the results of some magnetic experiments of a novel kind, which he had recently performed.[22]

Thomas Savery was born at Shilston, near Modbury, in Devon, about the year 1650. Nothing is known of his early life, beyond that he was educated to the profession of a military engineer, and in course of time duly reached the rank of Trench-master. The corps of engineers was not, however, regarded as an essential part of the military force until the year 1787, when the officers ranked with those of the Royal Artillery. The pursuit of his profession, as well as his natural disposition, led Savery to the study of mechanics, and he became well accomplished in the physical knowledge of his time. He occupied much of his spare time in mechanical experiments, and in projecting and executing contrivances of various sorts. One of his early works was a clock, still preserved in the family,[23] which until lately kept very good time; and when last repaired by a watchmaker of Modbury was pronounced to be a piece of very good work, of a peculiar construction, displaying much ingenuity.

Another of Savery’s early contrivances was a machine for polishing plate-glass, for which he obtained a patent. He was occupied about the same time with an invention for rowing ships in calms by the mechanical apparatus subsequently described in his treatise, entitled ‘Navigation Improved.’ He there relates how it troubled his thoughts and racked his brains to find out this invention, which he accomplished after many experiments, conducted “with great charge.” He naturally set much value on the product of so much study and labour; and he was proportionately vexed on finding that others regarded it with indifference. He professed to have had “promises of a great reward from the Court, if the thing would answer the end for which he proposed it;” but instead of a reward, Savery received only contumely and scorn. He attributed his want of success to the ill-humour of the then Surveyor of the Navy, who reported against his engine, because, said he, “it’s the nature of some men to decry all inventions that are not the product of their own brains.” He only asked for a fair trial of his paddle-boat, believing in its efficiency and utility; declaring, that it was not his “fondness for his own bratt that made him think so,” but the favourable opinions of several very judicious persons in town, that encouraged him to urge his invention for public adoption.

The invention in question consisted of a boat mounted with two paddle-wheels, one on each side, worked by a capstan placed in the centre of the vessel. The annexed cut will show the nature of the arrangement, which probably did not differ much from the scheme of Blasco Garay, above referred to.

Savery says he was led to make the invention through the difficulty which had been experienced in getting ships in motion so as to place them alongside of the enemy in sea-fights, especially during calm weather. He thought that if our fighting-ships could be made to move independent of the winds, we should thereby possess an advantage of essential consequence to the public service. “The gentlemen,” said he, “that were on the Brest expedition with my Lord Caermarthen must know how useful this engine would have been; for had they had them there on board each ship, they might have moved themselves where they had pleased.” He also urged the usefulness of the engine for packet-boats, bomb-vessels, and sloops, and especially for use in sea-fights, in bringing off disabled ships. When he had completed his invention, he took steps to bring it under the notice of Mr. Secretary Trenchard. The plan was shown to the King, who thought highly of it, and referred Savery to the Admiralty. When he went there he was told that he should have gone to the Navy Board. At the Navy Board he was told that certain objections to the adoption of his scheme had already been sent to the Admiralty.

Savery having ascertained that the Surveyor was himself the author of the objections, proceeded to discuss the matter with him. But the Surveyor was not a man to be argued out of his views by an inventor; and he shut up Savery with the remark: “What have interloping people, that have no concern with us, to do to pretend to contrive or invent things for us?” Savery was highly indignant at the official snub, and published the conversation in his Treatise. “Though one has found out,” said he, “an improvement as great to shipping as turning to windward or the Compass, unless you can sit round the Green Table in Crutched Friars, your invention is damned, of course;” and the testy inventor concluded: “All I have now to add is, that whoever is angry with the Truth for appearing in mean language may as well be angry with an honest man for his plain habit; for, indeed, it is as common for Lyes and Nonsense to be disguised by a jingle of words as for a Blockhead to be hid by abundance of Peruke.”[24]

Notwithstanding his rebuff by the Navy Surveyor, Savery proceeded to fit up a small yacht with his engine, and tried an experiment with it on the Thames, in sight of many thousands of spectators. The experiment was, in his opinion, entirely successful. The yacht, manned by eight sailors working the capstan, passed a ketch with all its sails spread, as well as other vessels. “All people,” said Savery, “seemed to like the demonstration of the use of my engine, the public newspapers speaking very largely of it, yet all to no purpose.” Savery had already expended 200l. in his experiments on the paddle-wheel boat, and was not disposed to go any further, now that Government had decided not to take up the invention. Indeed, its practical utility was doubtful. The power of the wind was, after all, better than hand-labour for working large ships; and it continued to maintain its superiority until the steam-engine was brought to perfection.

It is curious that it should not have occurred to Savery, who invented both a paddle-wheel boat and a steam-engine, to combine the two in one machine; but he was probably sick of the former invention, which had given him so much vexation and annoyance, and gave it up in disgust, leaving it to Papin, who saw both his inventions at work, to hit upon the grand idea of combining the two in a steam-vessel,—the only machine capable of effectually and satisfactorily rowing ships in a calm, or against wind and tide.

It is probable that Savery was led to enter upon his next and most important invention by the circumstance of his having been brought up in the neighbourhood of the mining districts, and being well aware of the great difficulty experienced by the miners in keeping their pits clear of water, to enable them to proceed with their underground operations. The early tin-mining of Cornwall was for the most part what was called “stream-work,” being confined mainly to washing and collecting the diluvial deposits of the ore. Mines usually grew out of these stream-works; the ground was laid open at the back of the lodes, and the ore was dug out as from a quarry. Some of these old openings, called “coffins,” are still to be met with in different parts of Cornwall. The miners did not venture much below the surface, for fear of the water, by which they were constantly liable to be drowned out. But as the upper strata became exhausted, they were tempted to go deeper in search of the richer ores. Shafts were sunk to the lodes, and they were followed underground. Then it was that the difficulty of water had to be encountered and overcome; for unless it could be got rid of, the deeper ores of Cornwall were as so much buried treasure. When the mines were of no great depth, it was possible to bale out the water by hand-buckets. But this expedient was soon exhausted; and the power of horses was then employed to draw the buckets. Where the lodes ran along a hill-side, it was possible, by driving an adit from a lower point, to let off the water by natural drainage. But this was not often found practicable, and in most cases it had to be raised directly from the shafts by artificial methods. As the quantity increased, a whim or gin moving on a perpendicular axis was employed to draw the water.[25] An improvement on this was the rack and chain pump, consisting of an endless iron chain mounted with knobs of cloth stiffened with leather, inclosed in a wooden pump of from six to eight inches bore, the lower part of which rested in the well of the mine. The chain was turned round by a wheel two or three feet in diameter, usually worked by men, and the knobs with which it was mounted brought up a stream of water according to the dimensions of the pump. Another method, considered the most effectual of all, was known as “the water-wheel and bobs,” consisting of a powerful pump, or series of pumps, worked by a water-wheel. But although there is no want of water underground in Cornwall, and no want of rain above ground, there are few or no great water-courses capable of driving machinery; besides, as the mines are for the most part situated on high ground, it will be obvious that water-power was available to only a very limited extent for this purpose.

It is also worthy of notice that the early mining of Cornwall was carried on by men of small capital, principally by working men, who were unable to expend any large amount of money in forming artificial reservoirs, or in erecting the powerful pumping machinery necessary for keeping the deeper mines clear of water. The Cornish miners, like the Whitstable oyster-dredgers, worked upon the principle of co-operation. This doctrine, now taught as a modern one, was practised by them almost time out of mind. The owner of the land gave the use of his land, the adventurers gave their money, and the miners their labour; all sharing in the proceeds according to ancient custom. For the use of his land, and for the ore taken from the mine, the lord usually took a sixth part; but in consideration of draining the mine, and in order to encourage the adventure, he was often content with an eighth, or it might be only a tenth part of the produce. The miners, on their part, agreed to divide in the proportions in which they took part in the work. Their shares of the ore raised were measured by barrows, and parcelled into heaps; “and it is surprising,” says Borlase, “to see how ready and exact the reckoners are in dividing, though oftentimes they can neither write nor read. The parcels being laid forth, lots are cast, and then every parcel has a distinct mark laid on it with one, two, or three stones, and sometimes a bit of stick or turf stuck up in the middle or side of the pile; and when these marks are laid on, the parcels may continue there half a year or more unmolested.”[26]

These were, however, the early and primitive days of mining, when the operations were carried on comparatively near the surface, and the capital invested in pumping-machinery was comparatively small in amount. As the miners went deeper and deeper into the ground, and the richer lodes were struck and followed, the character of mining became considerably changed. Larger capitals were required to sink the shafts and keep them clear of water until the ore was reached; and a new class of men, outside the mining districts, was induced to venture their money in the mines as a speculation. Yet the system above described, though greatly modified by altered circumstances, continues to this day; and the mining of Cornwall continues to be carried on mainly upon the co-operative or joint-stock system.

When the surface lodes became exhausted, the necessity of employing some more efficient method of pumping the water became more and more urgent. In one pit after another the miners were being drowned out, and the operations of an important branch of national industry were in danger of being brought to a complete standstill. It was under these circumstances that Captain Savery turned his attention to the contrivance of a more powerful engine for the raising of water; and after various experiments, he became persuaded that the most effective agency for the purpose was the power of steam. It is very probable that he was aware of the attempts that had been previously made in the same direction, and he may have gathered many useful and suggestive hints from the Marquis of Worcester’s ‘Century;’ but as that book contained no plans nor precise definitions of the methods by which the Marquis had accomplished his objects, it could have helped him but little towards the contrivance of a practicable working engine.[27]

How Savery was led to the study of the power of steam has been differently stated. Desaguliers says his own account was this,—that having drunk a flask of Florence at a tavern, and thrown the empty flask on the fire, he called for a basin of water to wash his hands, and perceiving that the little wine left in the flask had changed to steam, he took the vessel by the neck and plunged its mouth into the water in the basin, when, the steam being condensed, the water was immediately driven up into the flask by the pressure of the atmosphere. Desaguliers disbelieved this account, but admits that Savery made many experiments upon the powers of steam, and eventually succeeded in making several engines “which raised water very well.” Switzer, who was on intimate terms with Savery, gives another account. He says the first hint from which he took the engine was from a tobacco-pipe, which he immersed in water to wash or cool it; when he discovered by the rarefaction of the air in the tube by the heat or steam, and the gravitation or pressure of the exterior air on the condensation of the latter, that the water was made to spring through the tube of the pipe in a most surprising manner;[28] and that this phenomenon induced him to search for the rationale, and to prosecute a series of experiments which issued in the invention of his fire-engine.

However Savery may have obtained his first idea of the expansion and condensation of steam, and of atmospheric pressure, it is certain that the subject occupied his attention for many years. He had the usual difficulties to encounter in dealing with a wholly new and untried power, in contriving the novel mechanism through which it was to work, and of getting his contrivances executed by the hands of mechanics necessarily unaccustomed to such kind of work. “Though I was obliged,” he says, “to encounter the oddest and almost insuperable difficulties, I spared neither time, pains, nor money, till I had absolutely conquered them.”

Having sufficiently matured his design, he had a model of his new “Fire Engine,” as he termed it, made for exhibition before the King at Hampton Court in 1698. William III., who was himself of a mechanical turn, was highly pleased with the ingenuity displayed in Savery’s engine, as well as with its efficient action, and he permitted the inventor to dedicate to him ‘The Miner’s Friend,’ containing the first published description of his invention. The King also promoted Savery’s application for a Patent, which was secured in July, 1698,[29] and an Act confirming it was passed in the following year.

Savery’s next step was to bring his invention under the notice of the Royal Society, whose opinion on all matters of science was listened to with profound respect. He accordingly exhibited his model at a meeting held on the 14th of June, 1699, and it is recorded in the minutes of that date, that “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.” The inventor presented the Society with a drawing of his engine, accompanied by a description, which was printed in the ‘Transactions.’[30]

Savery next endeavoured to bring his invention into practical use, but this was a matter of much greater difficulty. So many schemes with a like object had been brought out and failed, that the mining interest came to regard new projects with increasing suspicion. To persuade them that he was no mere projector, but the inventor of a practicable working engine, Savery wrote and published his ‘Miner’s Friend.’ “I am not very fond,” he there said, “of lying under the scandal of a bare projector, and therefore present you here with a draught of my machine, and lay before you the uses of it, and leave it to your consideration whether it be worth your while to make use of it or no.”

Inventors before Savery’s time were wont to make a great mystery of their inventions; but he proclaimed that there was no mystery whatever about his machine, and he believed that the more clearly it was understood, the better it would be appreciated. He acknowledged that there had been many pretenders to new inventions of the same sort, who had excited hopes which had never been fulfilled; but this invention which he had made was a thing the uses of which were capable of actual demonstration. He urged that the old methods of raising water could not be carried further; and that an entirely new power was needed to enable the miner to prosecute his underground labours. “I fear,” said he, “that whoever by the old causes of motion pretends to improvements within the last century does betray his knowledge and judgment. For more than a hundred years since, men and horses would raise by engines then made as much water as they have ever done since, or I believe ever will, or, according to the law of nature, ever can do. And, though my thoughts have been long employed about water-works, I should never have pretended to any invention of that kind, had I not happily found out this new, but yet a much stronger and cheaper force or cause of motion than any before made use of.” He proceeded to show how easy it was to work his engine,—boys of thirteen or fourteen years being able to attend and work it to perfection after a few days’ teaching,—and how he had at length, after great difficulty, instructed handicraft artificers to construct the engine according to his design, so that, after much experience, said he, “they are become such masters of the thing that they oblige themselves to deliver what engines they make exactly tight and fit for service, and as such I dare warrant them to anybody that has occasion for them.”[31]

Savery’s engine, as described by himself, consisted of a series of boilers, condensing vessels, and tubes, the action of which will be readily understood with the help of the annexed drawing.[32]

Its principal features were two large cylindrical vessels, which were alternately filled with steam from an adjoining boiler and with cold water from the well or mine out of which the water had to be raised. When either of the hollow vessels was filled with steam, and then suddenly cooled by a dash of cold water, a vacuum was thereby created, and, the vessel being closed at the top and open at the bottom, the water was at once forced up into it from the well by the pressure of the atmosphere. The steam, being then let into the vessel from the top, pressed upon the surface of the water, and forced it out at the bottom by another pipe (its return into the well being prevented by a clack), and so up the perpendicular pipe which opened into the outer air. The second vessel being treated in the same manner, the same result followed; and thus, by alternate filling and forcing, a continuous stream of water was poured out from the upper opening. The whole of the labour required to work the engine was capable of being performed by a single man, or even by a boy, after very little teaching.

Although Savery’s plans and descriptions of the arrangement and working of his engines are clear and explicit, he does not give any information as to their proportions, beyond stating that an engine employed in raising a column of water 3½ inches in diameter 60 feet high, requires a fireplace 20 inches deep. Speaking of their performances, he says, “I have known, in Cornwall, a work with three lifts of about 18 feet each, lift and carry a 3½-inch bore, that cost 42s. a day (reckoning 24 a day) for labour, besides the wear and tear of engines, each pump having four men working eight hours, at 14d. a man, and the men obliged to rest at least a third part of that time.” He pointed out that at least one-third part of the then cost of raising water might be saved by the adoption of his invention, which on many mines would amount to “a brave estate” in the course of a year. In estimating the power of his engine, Savery was accustomed to compare it with the quantity of work that horses could perform, and hence he introduced the term “horse power,” which is still in use.

Although, in the treatise referred to, Savery describes an engine with two furnaces, the drawing which he presented to the Royal Society showed only one; and it appears that in another of his designs he showed only one cylindrical vessel instead of two. In order to exhibit the working of his engine on a larger scale than in the model, he proceeded to erect one in a potter’s house at Lambeth, where, Switzer says, though it was a small engine, the water struck up the tiles and forced its way through the roof in a manner that surprised all the spectators. Switzer mentions other engines erected after Savery’s designs for the raising of water at Camden House and Sion House, which proved quite successful. The former, he says, was the plainest and best proportioned engine he had seen: it had only a single condensing vessel; and “though but a small one in comparison with many others of the kind that are made for coal-works, it is sufficient for any reasonable family, and other uses required for it in watering middling gardens.”[33] Four receivers full of water, or equal to 52 gallons, were raised every minute, or 3110 gallons in the hour; whilst, in the case of the larger engines with double receivers, 6240 gallons an hour might easily be raised. The cost of the smaller engine was about fifty pounds, and the consumption of coal about a bushel in the twenty-four hours, supposing it was kept constantly at work during that time.

The uses to which Savery proposed to apply his engine were various. One was to pump water into a reservoir, from which, by falling on a water-wheel, it might produce a continuous rotary motion. Another was to raise water into cisterns for the supply of gentlemen’s houses, and for use in fountains and as an extinguisher in case of fire. A third was to raise water for the supply of towns, and a fourth to drain fens and marsh lands. But the most important, in the inventor’s estimation, was its employment in clearing drowned mines and coal-pits of water. He showed how water might be raised from deep mines by using several engines, placed at different depths, one over the other. Thus by three lifts, each of 80 feet, water might be raised from a mine about 240 feet—then considered a very great depth. From Savery’s own account, it is evident that several of his engines were erected in Cornwall; and it is said that the first was tried at Huel Vor, or “The Great Work in Breage,” a few miles from Helstone, then considered the richest tin mine in the county. The engine was found to be an improvement on the methods formerly employed for draining the mine, and sent the miners to considerably greater depths. But the great pressure of steam required to force up a high column of water was such as to strain to the utmost the imperfect boilers and receivers of those early days; and the frequent explosions which attended its use eventually led to its discontinuance in favour of the superior engine of Newcomen, which was shortly after invented.

Savery also endeavoured to introduce his engine in the coal-mining districts, but without success, and for the same reason. The demand for coal in connection with the iron manufacture having greatly increased in the county of Stafford, and the coal which lay nearest the surface having been for the most part “won,” the mining interest became very desirous of obtaining some more efficient means of clearing the pits of water, in order to send the miners deeper into the ground. Windlass and buckets, wind-mills, horse-gins, rack-and-chain pumps, adits, and all sorts of contrivances had been tried, and the limit of their powers had been reached. The pits were fast becoming drowned out, and the ironmasters began to fear lest their manufacture should become lost through want of fuel. Under these circumstances they were ready to hail the invention of Captain Savery, which promised to relieve them of their difficulty. He was accordingly invited to erect one of his engines over a coal-mine at the Broadwaters, near Wednesbury. The influx of water, however, proved too much for the engine; the springs were so many and so strong, that all the means which Savery could employ failed to clear the mine of water. To increase the forcing power he increased the pressure of steam; but neither boiler nor receiver could endure it, and the steam “tore the engine to pieces; so that, after much time, labour, and expense, Mr. Savery gave up the undertaking, and the engine was laid aside as useless.”[34]

He was no more successful with the engine which he erected at York-buildings to pump water from the Thames for the supply of the western parts of London. Bradley says that to increase its power he doubled every part, but “it was liable to so many disorders, if a single mistake happened in the working of it, that at length it was looked upon as a useless piece of work, and rejected.”[35] Savery’s later engines thus lost him much of the credit which he had gained by those of an earlier and simpler construction. It became clear that their application was very limited. They involved much waste of fuel through the condensation of the hot steam pressing upon the surface of the cold water, previous to the expulsion of the latter from the vessel; and eventually their use was confined to the pumping of water for fountains and the supply of gentlemen’s houses, and in some cases to the raising of water for the purpose of working an overshot water-wheel. Various attempts were made to improve the engine by Bradley, by Papin, by Desaguliers, and others; but no great advance was made in its construction and method of working until it was taken in hand by Newcomen and Calley, whose conjoint invention marks an important epoch in the history of the steam-engine.

Not much is known of the later years of Savery’s life. We find him a Captain of Military Engineers in 1702;[36] and in 1705, with the view of advancing knowledge in his special branch of military science, he gave to the world a translation, in folio, of Cohorn’s celebrated work on fortification. The book was dedicated to Prince George of Denmark, to whom he was indebted, in the same year, for his appointment to the office of Treasurer of the Hospital for Sick and Wounded Seamen. Various letters and documents are still to be found in the Transport Office, Somerset House, addressed to him in that capacity.[37] In 1714 he was further indebted to Prince George for the appointment of Surveyor to the Waterworks at Hampton Court; but he did not live to enjoy it, as he died in the course of the following year. He is said to have accumulated considerable property, which he bequeathed to his wife, together with all interest in his inventions. His will was executed on the day of his death, the 15th of May, 1715, and was proved four days after in the Prerogative Court of Canterbury. He there described himself as “of the parish of Saint Margaret, at Westminster, Esquire.” His widow herself died before all his effects were administered. There was a considerable amount of unclaimed stock, which the Savery family were prevented from claiming, as it had passed to the widow; and it has since been transferred to the credit of the National Debt.

CHAPTER IV.
Thomas Newcomen—The Atmospheric Engine.

The invention of the steam-engine had advanced thus far with halting steps. A new power had been discovered, but it was so dangerous and unmanageable that it was still doubtful whether it could be applied to any useful purpose. What was still wanting was an engine strong enough to resist the internal pressure of highly-heated steam, and so constructed as to work safely, continuously, and economically. Many attempts had been made to contrive such a machine; but, as we have shown, the results were comparatively barren. Savery’s small engine could raise water in moderate quantities to limited heights; but the pumping of deep mines was beyond its power. It could force water to a height of about sixteen fathoms; but as the depth of mines at that time was from fifty to a hundred yards, it was obviously incompetent for their drainage. It is true, Savery proposed to overcome the difficulty by erecting a series of engines, placed one over another in the shaft of the mine; but the expense of their attendants, the great consumption of fuel, the cost of wear and tear, the constant danger of explosion, and the risk of the works being stopped by any one of the engines becoming temporarily deranged, rendered it clear that the use of his engine for ordinary mining purposes was altogether impracticable.

Such was the state of affairs when Thomas Newcomen of Dartmouth took up the subject. Comparatively little is known of the personal history of this ingenious man. Mechanical inventors excited little notice in those days; they were looked upon as schemers, and oftener regarded as objects of suspicion than of respect. Thomas Newcomen was by trade an ironmonger and a blacksmith. The house in which he lived and worked stood, until quite recently, in Lower Street, Dartmouth. Like many of the ancient timber houses of that quaint old town, it was a building of singularly picturesque appearance. Lower Street is very narrow; the houses in it are tall and irregular, with overhanging peaked gable-ends. A few years since, Newcomen’s house began to show indications of decay; the timber supports were fast failing; and for safety’s sake it was determined to pull it to the ground.