Lives of Boulton and Watt by Samuel Smiles: Chapter 4
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 till 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.
The Newcomen family have long since become extinct in Dartmouth. They are said to have left the place long ago, and gone northward but we have been unable to trace them. The Newcomens appear to have occupied a respectable position in Dartmouth down to about the middle of the last century. Their burying place was in the north-side chapel of the fine old parish church of the town, where several tablets are erected to their memory. Amongst others, there is one to William Newcomin, Attorney-at-Law, who died the 24th of August, 1745, aged 57, supposed to have been a brother, and another of the same name, who died in 1787, aged 65, supposed to have been a son of the ironmonger.
Thomas Newcomen was a man of strong religious feelings, and from an early period of his life occupied his leisure in voluntary religious teaching. He belonged to the sect of Baptists; and the place was standing until recently in which he regularly preached. When he afterwards went into distant parts of the country on engine business, he continued to devote his Sundays to the same work. How he first came to study the subject of steam is not known. Mr. Holdsworth says a story was current in Dartmouth in his younger days, and generally believed, that Newcomen conceived the idea of the motive power to be obtained from steam by watching the tea-kettle, the lid of which would frequently rise and fall when boiling and, reasoning upon this fact, he contrived, by filling a cylinder with steam, to raise the piston, and by immediately injecting some cold water, to create a vacuum, which allowed the weight of the atmosphere to press the piston down, and so give motion to a pump by means of a beam and rods. [1]
It is probable that Newcomen was well aware of the experiments of Savery on steam while the latter was living at Modbury, about fifteen miles distant. It will be remembered that Savery was greatly hampered in his earlier contrivances by the want of skilled workmen; and as Newcomen had the reputation of being one of the cleverest blacksmiths in the county, it is supposed that he was employed to make some of the more intricate parts of Savery's engine. At all events, he could scarcely fail to hear from the men of his trade in the neighbourhood, what his speculative neighbour at Modbury was trying to compass in the invention of an engine for the purpose of raising water by fire. He was certainly occupied in studying the subject about the same time as Savery; and Switzer says he was well informed that "Mr. Newcomen was as early in his invention as Mr. Savery was in his, only the latter being nearer the Court, had obtained the patent before the other knew it on which account Mr. Newcomen was glad to come in as a partner to it." [2]
Another account [3] states that a draft of Savery's engine having come under Newcomen's notice, he proceeded to make a model of it, which he fixed in his garden, and soon found out its imperfections. He entered into a correspondence on the subject with the learned and ingenious Dr. Hooke, then Secretary to the Royal Society, a man of remarkable ingenuity, and of great mechanical sagacity and insight. Newcomen had heard or read of Papin's proposed method of transmitting motive power to a distance by creating a vacuum under a piston in a cylinder, and transmitting the power through pipes to a second cylinder near the mine. Dr. Hooke dissuaded Newcomen from erecting a machine on this principle, as a waste of time and labour, but he added the pregnant suggestion, "could he (meaning Pain) make a speedy vacuum under your piston, your work were done."
The capital idea thus cursorily thrown out - of introducing a moveable diaphragm between the active power and the vacuum — set Newcomen at once upon the right track. Though the suggestion was merely that of a thoughtful bystander, it was a most important step in the history of the invention, for it contained the very principle of the atmospheric engine. Savery created his vacuum by the condensation of steam in a closed vessel, and Papin created his by exhausting the air in a cylinder fitted with a piston, by means of an air-pump. It remained for Newcomen to combine the two expedients — to secure a sudden vacuum by the condensation of steam; but, instead of employing Savery's closed vessel, he made use of Papin's cylinder fitted with a piston. After long scheming and many failures, he at length succeeded, in the year 1705, [4] in contriving a model that worked with tolerable precision; after which ho sought for an opportunity of exhibiting its powers in a full-sized working engine. It ought to be mentioned, that in the long course of experiments conducted by Newcomen with the object of finding out the new motive power, he was zealously assisted throughout by one John Galley, a glazier of Dartmouth, of whom nothing further is known than that he was Newcomen's intimate friend, of the same religious persuasion, and afterwards his partner in the steam-engine enterprise.
Newcomen's engine may be thus briefly described:— The steam was generated in a separate boiler, as in Savery's engine, from which it was conveyed into a vertical cylinder underneath a piston fitting it closely, but moveable upwards and downwards through its whole length. The piston was fixed to a rod, which was attached by a joint or a chain to the end of a lever vibrating upon an axis, the other end being attached to a rod working a pump. When the piston in the cylinder was raised, steam was let into the vacated space through a tube fitted into the top of the boiler, and mounted with a stopcock. The pump-rod at the further end of the lever being thus depressed, cold water was applied to the sides of the cylinder, on which the steam within it was condensed, a vacuum was produced, and the external air, pressing upon the top of the piston, forced it down into the empty cylinder. The pump-rod was thereby raised; and the operation of depressing and raising it being repeated, a power was thus produced which kept the pump continuously at work. Such, in a few words, was the construction and action of Newcomen's first engine.
It will thus be observed that this engine was essentially different in principle from that of Savery. While the latter raised water partly by the force of steam and partly by the pressure of the atmosphere, that of Newcomen worked entirely by the pressure of the atmosphere, steam being only used as the most expeditious method of producing a vacuum. The engine was, however, found to be very imperfect. It was exceedingly slow in its motions; much time was occupied in condensing the contained steam by throwing cold water on the outside of the cylinder and as the boiler was placed immediately under the cylinder, it was not easy to prevent the cold water from splashing it, and thus leading to a further loss of heat. To remedy these imperfections, Newcomen and Calley altered the arrangement; and, instead of throwing cold water on the outside of the cylinder, they surrounded it with cold water. But this expedient was also found inconvenient, as the surrounding water shortly became warm, and ceased to condense until replaced by colder water; but the colder it was the greater was the loss of heat by condensation, before the steam was enabled to fill the cylinder again on each ascent of the piston.
Clumsy and comparatively ineffective though the engine was in this form, it was, nevertheless, found of some use in pumping water from mines. In 1711 Newcomen and Calley made proposals to the owners of a colliery at Griff, in Warwickshire, to drain the water from their pits, which until then had been drained by the labour of horses but, the owners not believing in the practicability of the scheme, their offer was declined. In the following year, however, they succeeded in obtaining a contract with Mr. Back, for drawing the water from a mine belonging to him near Wolverhampton. The place where the engine was to be erected being near to Birmingham, the ironwork, the pump-valves, clacks, and buckets, were for the most part made there, and removed to the mine, where they were fitted together. Newcomen had great difficulty at first in making the engine go but after many laborious attempts he at last partially succeeded. It was found, however, that the new method of cooling the cylinder by surrounding it with cold water did not work so well in practice as had been expected. The vacuum produced was very imperfect, and the action of the engine was both very slow and very irregular.
While the engine was still in its trial state, a curious accident occurred which led to another change in the mode of condensation, and proved of essential importance in establishing Newcomen's engine as a practicable working power. The accident was this: in order to keep the cylinder as free from air as possible, great pains were taken to prevent it passing down by the side of the piston, which was carefully wrapped with cloth or leather and, still further to keep the cylinder air-tight, a quantity of water was kept constantly laying on the upper side of the piston. At one of the early trials the inventors were surprised to see the engine make several strokes in unusually quick succession and on searching for the cause, they found it to consist in a hole in the piston, which had let the cold water in a jet into the inside of the cylinder, and thereby produced a rapid vacuum by the condensation of the contained steam. A new light suddenly broke upon Newcomen. The idea of condensing by injection of cold water directly into the cylinder, instead of applying it on the outside, at once occurred to him and he proceeded to embody the expedient which had thus been accidentally suggested, as part of his machine. The result was the addition of the injection-pipe, through which, when the piston was raised and the cylinder was full of steam, a jet of cold water was thrown in, and the steam being suddenly condensed, the piston was at once driven down by the pressure of the atmosphere.
An accident of a different kind shortly after led to the improvement of Newcomen's engine in another respect. To keep it at work, one man was required to attend the fire, and another to turn alternately the two cocks, one admitting the steam into the cylinder, the other admitting the jet of cold water to condense it. The turning of these cocks was easy work, usually performed by a boy. It was, however, a very monotonous duty, though requiring constant attention. To escape the drudgery and obtain an interval for rest, or perhaps for play, a boy named Humphrey Potter, who turned the cocks, set himself to discover some method of evading his task. He must have been an ingenious boy, as is clear from the arrangement he contrived with this object. Observing the alternate ascent and descent of the beam above his head, be bethought him of applying the movement to the alternate raising and lowering of the levers which governed the cocks. The result was the contrivance of what he called the scoggan, [5] consisting of a catch worked by strings from the beam of the engine. This arrangement, when tried, was found to answer the purpose intended. The action of the engine was thus made automatic; and the arrangement, though rude, not only enabled Potter to enjoy his play, but it had the effect of improving the working power of the engine itself; the number of strokes which it made being increased from six or eight to fifteen or sixteen in the minute. This invention was afterwards greatly improved by Mr. Henry Beighton, of Newcastle-on-Tyne, who added the plug-rod and hand-gear. He did away with the catches and strings of the boy Potter's rude apparatus, and substituted a rod suspended from the beam, which alternately opened and shut the tappets attached to the steam and injection cocks.
Thus, step by step, Newcomen's engine grew in power and efficiency, and became more and more complete as a self-acting machine. It will be observed that, like all other inventions, it was not the product of any one man’s ingenuity, but of many. One contributed one improvement, and another another. The essential features of the atmospheric engine were not new. The piston and cylinder had been known as long ago as the time of Hero. The expansive force of steam and the creation of a vacuum by its condensation had been known to the Marquis of Worcester, Savery, Papin, and many more. Newcomen merely combined in his machine the result of their varied experience, and, assisted by the persons who worked with him, down to the engine-boy Potter, he advanced the invention several important stages; so that the steam-engine was no longer a toy or a scientific curiosity but became a, powerful machine capable of doing useful work.
The comparative success which attended the working of Newcomen's first engine at the colliery near Wolverhampton, shortly induced other miners of coal-mines to adopt it. There were great complaints in the north, of the deeper mines having become unworkable. All the ordinary means of pumping them clear of water had failed. In their emergency, the colliery-owners called Newcomen and Calley to their aid. They were invited down to Newcastle-upon-Tyne in the neighbourhood of which town they erected their second and third engines. They were next summoned to Leeds and erected their fourth engine at Austhorpe, in 1714. It was the sight of this engine at work which first induced Smeaton, when a boy, to turn his attention to mechanics, and eventually led him to study the atmospheric-engine, with a view to its improvement. The cylinder of the engine erected at Austhorpe, like those winch had preceded it, was about 23 inches in diameter, and made about fifteen strokes a minute. The pumps, which were in two lifts, and of 9 inches bore, drew the water from a depth of 37 yards. The patentees had £250 a year for working and keeping the engine in order. Calley superintended its erection, and afterwards its working but he did not long survive its completion, as he died at Austhorpe in 1717.
The next engines were erected by Newcomen in Cornwall, where there was as great a demand for increased pumping-power as in any of the collieries of the north. The first of Newcomen's construction in Cornwall was erected in 1720, at the Wheal Fortune tin mine, in the parish of Ludgvan, a few miles north-east of Penzance. The mine was conducted by Mr. William Lemon, the founder of the fortunes of the well-known Cornish family. He was born in a humble station in life, from which he honourably raised himself by his great industry, ability, and energy. He began his career as a mining-boy; was at an early age appointed one of the managers of a tin-smelting house at Chiandower, near Penzance; and after the experience gained by him in that capacity he engaged in the working of the Wheal Fortune mine. With the help of Newcomen's engine, the enterprise proved completely successful and after realising a considerable sum he removed to Truro, and began working the great Gwennap mines on such a scale as had never before been known in Cornwall. [6]
The Wheal Fortune engine was on a larger scale than any that had yet been erected, the cylinder being 47 inches in diameter, making about fifteen strokes a minute. It drew about a hogshead of water at each stroke, from a pump 30 fathoms deep, through pit-barrels 15 inches in diameter, and its performances were on the whole regarded as very extraordinary. The principal objection to its use consisted in the very large quantity of coal that it consumed and the heavy cost of maintaining it in working order. There was a great waste, especially in boilers, the making of which was then ill understood. Smeaton relates that in the course of four years' working of the first Austhorpe engine, not fewer than four boilers were burnt out. The Wheal Fortune engine, however, answered its purpose. It kept down the water sufficiently to enable Mr. Lemon to draw up his tin, and on leaving the mine, he took with him to Truro a clear sum of ten thousand pounds. The engine-house is now in ruins, and presents a highly picturesque appearance, as seen from the heights of Trewal, reminding one of a Border Peel rather than of a mining engine-house.
Another of Newcomen's engines was erected about the same time at the Wheal Rose mine, a few miles north of Redruth. The engineer appointed to superintend its erection was Joseph Hornblower, who came front Staffordshire for the purpose about the year 1725. Mr. Cyrus Redding, one of Hornblower's descendants, says, "how he became in any way connected with Newcomen must have arisen from the latter being at Bromsgrove, when he visited Mr. Potter, who got him to build one of his newly-invented engines at Wolverhampton in 1712. [7] Another engine was afterwards erected by Hornblower at Wheal Busy, or Chacewater, and a third at Polgooth — all rich and well-known mines in Cornwall.
Though the use of Newcomen's engine rapidly extended, nothing is known of the man himself during this time. All over the mining districts his name was identified with the means employed for pumping the mines clear of water, and thereby enabling an important branch of the national industry to be carried on but of Newcomen's personal history, beyond what has been stated above, we can gather nothing. It is not known when or where he died, whether rich or poor. The probability is that being a person of a modest and retiring disposition, without business energy, and having secured no protection for his invention, it was appropriated and made use of brothers, without any profit to him, whilst he quietly subsided into private life. It is supposed that he died at Dartmouth about the middle of last century but no stone marks the place where he was laid. The only memorial of Newcomen to be found at his native place is the little steam-boat called by his name, which plies between Totness and Dartmouth.
During Newcomen's lifetime the proposal was revived of applying the steam-engine to the propelling of ships. Since Papin's time nothing had been accomplished in this direction. Now that the steam-engine was actively employed in pumping mines, it was natural enough that the idea should be revived of applying it to navigation. The most enthusiastic advocate of the new power was Jonathan Hulls, a native of Campden, in Gloucestershire, where he was born in 1699. He married a wife in 1719, before he was out of his teens; an act of indiscretion in which, however, he had the example of one no less distinguished than Shakspeare. Living as he did in an inland country place, it seems remarkable that he should have directed his attention to the subject of steam-navigation. We find him making experiments with models of boats on the river Avon, at Evesham, and in course or time he duly matured his ideas and embodied them in his patent of 1736. [8] He proposed to place a Newcomen engine on board a tow-boat, and by its means to work a paddle-wheel placed at the stern. His method of converting the rectilinear motion of his piston into a rotary one was ingenious, but, like Savery, he missed the crank on the paddle-shaft, and many years passed before this simple expedient was adopted. [9] "The work to be done by this machine," said he, "will be upon particular occasions, when all other means yet found out are wholly insufficient. How often does a merchant wish that his ship were on the ocean, when, if she were there, the wind would serve tolerably well to carry him on his intended voyage, but does not serve at the same time to carry him out of the river he happens to be in, which a few hours' work of the machine would do. Besides, I know engines that are driven by the same power as this is, where materials for the purpose are dearer than in any navigable river in England; therefore experience demonstrates that the expense will be but a trifle to the value of the work performed by those sort of machines, which any person that knows the nature of those things may easily calculate." His treatise was illustrated by a drawing, of which the following is a copy on a reduced scale.
The inventor, aware of the novelty of his proposal and of the readiness of the public to ridicule novelties, deprecated rash censure of his project, and only claimed for it a fair and unprejudiced trial. In order to exhibit the powers of his steam-boat, he constructed an engine in 1737, and had it fixed on board a little vessel for trial in the river Avon at Evesham. The trial was not satisfactory, and the engine was taken on shore again. "A failure! A failure!" cried the spectators, who stigmatised the projector as an ass. The prophet had, indeed, no honour whatever in his own country. Long after his steam-boat experiment had been forgotten, these lines about him were remembered:—
Jonathan Hull,
With his paper skull,
Tried hard to make a machine
That should go against wind and tide:
But he, like an ass,
Couldn't bring it to pass,
So at last was ashamed to be seen. [10]
Not much more is known of Jonathan Hulls's history. In 1754 he published, in conjunction with two others, a treatise on "The Art of Measuring made Easy, by the help of a new Sliding-rule’ and shortly after ‘The Malt-maker's Instructor’; but nothing more was heard of Jonathan Hulls's steam-boat.
We return to the Newcomen engine, which became increasingly employed as a pumping power in all the mining districts. Borlase, writing in 1758, says that "fire-engines" were then in regular use at North Downs near Redruth, Pitt-louarn, Polgooth, Wheal-rith, Pool, Dolcoath, Herland, and many other Places. [11] Indeed there was scarcely a tin or copper mine of any importance in Cornwall that had not one or more of Newcomen's engines at work. They were also in general use in Staffordshire, Yorkshire, Lancashire, and Northumberland. In the latter counties, where they were principally used for pumping water out of the coal mines, fuel was ready at hand, cheap and abundant. But in Cornwall it was otherwise. The coal had to be brought thither from a great distance, partly by sea and partly by land, and the cost of carriage was very heavy. It, therefore, became an object of much importance to reduce the consumption of fuel, to prevent the profits of the mines being absorbed by the heavy cost, of working the pumps. This, indeed, was the great objection to Newcomen's engine, especially in Cornwall. The consumption of fuel at some mines was so enormous, that it was doubtful whether the cost of steam did not exceed that of an equal amount of horse power, and it became more and more difficult to realise even a bare margin of profit. The two engines at Wheal Rose and Wheal Busy, near Chacewater, of 66 and 72 inches diameter, consumed each about thirteen tons of coal daily. To relieve the mining interest, in some measure, from this charge, government allowed a drawback of five shillings a chaldron on coal but in some cases this was found insufficient, and it began to be complained that the consumption of coal was so great, that the mines were barely paying.
Invention, however, was constantly at work, and new improvements were from time to time introduced, with the object of economising fuel and increasing the efficiency of the engine. Among the ingenious men who devoted themselves to this work, were ? Payne, Brindley, and Smeaton. Of these, the last especially distinguished himself by his improvements of the Newcomen engine, which he may be said to have carried to the highest perfection of which it was capable. His famous Chacewater engine was the finest and most powerful work of the kind which had until then been constructed, and it remained unrivalled until superseded by the invention of Watt, to whose life and labours we now proceed to direct the attention of the reader.
See Also
- Lives of Boulton and Watt by Samuel Smiles
- Lives of Boulton and Watt by Samuel Smiles: Chapter 3
- Lives of Boulton and Watt by Samuel Smiles: Chapter 5
Foot Notes
- ↑ Pamphlet on ‘Dartmouth: the advantages of its Harbour as a Station for Foreign Mail Packets, and a Short Notice of its Ancient and Present, Condition.' By A. H. Holdsworth. London,
- ↑ Switzer, ‘Introduction to a System of Hydrostatics and Hydraulics,' p. 349.
- ↑ Harris, ‘Lexicon Technicum.'
- ↑ It has been stated that Newcomen took out a patent for his invention in 1705; but this is a mistake, as no patent was ever taken out by Newcomen. It is supposed that Savery, having heard of his invention, gave him notice that he would regard his method of producing a speedy vacuum by condensation, as an infringement of his patent, and that Newcomen accordingly agreed to give him an interest in the new engine during the term of Savery's patent. It will, however, be observed that the principle on which Newcomen's engine worked was entirely different from that of Savery.
- ↑ Scogging is a north country word, meaning skulking one's work, from which probably the boy gave the contrivance its name. Potter, however, grew up to be a highly-skilled workman. He went abroad about the year 1720, and erected an engine at a mine in Hungary, described by Leupold in his "Theatrum Machinarum,' with many encomiums upon Potter, who was considered the inventor.
- ↑ Mr. Lemon eventually became the principal merchant and tin-smelter of Cornwall. Mr. Davies Gilbert says:— "The energies of his mind were not limited to these undertakings, great though they were. He cultivated a taste for literature, and, which is extremely unusual, acquired, amidst business, and at a middle age, the power of reading the classic authors in their original language. . . . He was distinguished in his district as "the great Mr. Lemon," but such were the impressions of his abilities, his exertions, and general merit, that a progress so rapid and unexampled does not appear to have excited envy, or any of those bad passions which usually alloy the enjoyment of prosperity."— ‘History of Cornwall,' ii. 84.
- ↑ It may be interesting to know that it required three hands to work Newcomen's first engines. I have heard it said that when the engine was stopped, and again set at work, the words were passed "Snift Benjy!" "Blow the fire, Pomery!" "Work away, Joe!" The last let in the condensing water. Lifting the condensing clack was called "sniffing," because on opening the valve, the air rushing through it made a noise like it man snifting. The fire was increased through artificial means by another hand, and all being ready, the machine was set in motion by a third."— Cyrus Redding, 'Yesterday and Today.' London, 1863. The "snifting clack" was a valve in the cylinder opening outwards, which permitted the escape of air or permanently elastic fluid, which could not be condensed by cold and run off through the eduction-pipe.
- ↑ In 1737 he published a Treatise on the subject entitled, ‘A description and Draught of a new-invented Machine for carrying Vessels or Ships out of or into any Harbour, Port, or River, against Wind or Tide, and in a Calm,' by Jonathan Hulls.
- ↑ In describing his mode of obtaining rotary motion by ratchet wheels, a weight, and ropes, Hulls states that he uses two axes, one behind the other, each of which is essential to the object; and he then adds, that when his tow-boat is to be used in shallow rivers, the machine works by two cranks fixed to the hindermost axis; to which cranks arc fixed two shafts (or poles) of proper length to reach the bottom of the river, and which move alternately forward from the motion of the wheels by which the vessel is carried on: so that the cranks, as described by Hulls, receive rotary motion from the axis on which they are placed, and do not, as has been erroneously stated, impart that motion to it. Bennet Woodcroft, ‘Sketch of the Origin and Progress of Steam Navigation.' London, 1848.
- ↑ There are several versions of the same satire current to this day in the villages of Campden and Hanging Aston.
- ↑ Borlase, 'Natural History of Cornwall,' p. 175.
Key to newcomen's Engine (see image above)
The illustration shows the several parts of Newcomen's atmospheric engine.
- a is the boiler;
- b, the piston moving up and down;
- c, the cylinder;
- d, a pipe proceeding from the top of the boiler, and inserted into the bottom of the cylinder, having a cock,
- e, to interrupt the flow of steam at pleasure;
- f, cold-water cistern, from which the cold water is conveyed by the pipe y, called the injection-pipe, and thrown in a jet into the cylinder, b, on turning the injection-cock, h; the sniffing-valve, i, enables the air to escape from the cylinder, while the siphon-pipe, j, enables the condensed steam to flow from the same cavity in the form of water; k, the main lever beam;
- l, the counterpoise or weight hung on the balance-beam, or on ?n, the pump-rod which works the pump, n.