Lives of Boulton and Watt by Samuel Smiles: Chapter 7

Papin's Digester

The Newcomen Model

Watt's House, Delftfield Lane

Watt's Apparatus

Dr. Joseph Black

CHAPTER VII. WATT'S EXPERIMENTS ON STEAM - INVENTS THE SEPARATE CONDENSER.

It was in the year 1759 that Robison first called the attention of his friend Watt to the subject of the steam-engine. Robison was then only in his twentieth, and Watt in his twenty-third year. Robison's idea was that the power of steam might be advantageously applied to the driving of wheel-carriages, and he suggested that it would be the most convenient for the purpose to place the cylinder with its open end downwards to avoid the necessity of using a working beam. Watt admits that he was very ignorant of the steam-engine at the time nevertheless, he began making a model with two cylinders of tinplate, intending that the pistons and their connecting-rods should act alternately on two pinions attached to the axles of the carriage-wheels. But the model, being slightly and inaccurately made, did not answer his expectations. Other difficulties presented themselves, and the scheme was laid aside on Robison leaving Glasgow to go to sea. Indeed, mechanical science was not yet ripe for the locomotive. Robison's idea had, however, dropped silently into the mind of his friend, where it grew from day to day, slowly and at length fruitfully.

At his intervals of leisure and in the quiet of his evenings, Watt continued to prosecute his various studies. He was shortly attracted by the science of chemistry, then in its infancy. Dr. Black was at that time occupied with the investigations which led to his discovery of the theory of latent heat, and it is probable that his familiar conversations with Watt on the subject induced the latter to enter upon a series of experiments with the view of giving the theory some practical direction. His attention again and again reverted to the steam-engine, though he had not yet seen even a model of one. Steam was as yet almost unknown in Scotland as a working power. The first engine was erected at Elphinstone Colliery, in Stirlingshire, about the year 1750; and the second more than ten years later, at Govan Colliery, near Glasgow, where it was known by the startling name of "The Firework." This had not, however, been set up at the time Watt began to inquire into the subject. But he found that the College possessed the model of a Newcomen engine for the use of the Natural Philosophy class, which had been sent to London for repair. On hearing of its existence, he suggested to his friend Dr. Anderson, Professor of Natural Philosophy, the propriety of getting back the model and a sum of money was placed by the Senatus at the Professor's disposal "to recover the steam-engine from Mr. Sisson, instrument maker, in London."

In the mean time Watt sought to learn all that had been written on the subject of the steam-engine. He ascertained from Desaguliers, from Switzer, and other writers, what had been accomplished by Savery, Newcomen, Beighton, and others: and he went on with his own independent experiments. His first apparatus was of the simplest possible kind. He used common apothecaries phials for his steam reservoirs, and canes hollowed out for his steam pipes. In 1761 he proceeded to experiment on the force of steam by means of a small Papin's digester and a syringe. The syringe was only the third of an inch in diameter, fitted with a solid piston; and it was connected with the digester by a pipe furnished with a stopcock, by which the steam was admitted or shut off at will. It was also itself provided with a stopcock, enabling a communication to be opened between the syringe and the outer air to permit the steam in the syringe to escape. The apparatus, though rude, enabled the experimenter to ascertain some important facts. When the steam in the digester was raised and the cock turned, enabling it to rush against the lower side of the piston, he found that the expansive force of the steam raised a weight of fifteen pounds with which the piston was loaded. Then, on turning the cock and shutting off the connexion with the digester at the same time that a passage was opened to the air, the steam was allowed to escape, when the weight upon the piston, being no longer counteracted, immediately forced it to descend.

Watt saw that it would be easy to contrive that the cocks should be turned by the machinery itself instead of by the hand, and the whole be made to work by itself with perfect regularity. But there was an objection to this method. Water is converted into vapour as soon as its elasticity is sufficient to overcome the weight of the air which keeps it down. Under the ordinary pressure of the atmosphere water acquires this necessary elasticity at 212°; but as the steam in the digester was prevented from escaping, it acquired increased heat, and by consequence increased elasticity. Hence it was that the steam which issued from the digester was not only able to support the piston and the air which pressed upon its upper surface, but the additional load with which the piston was weighted. With the imperfect mechanical construction, however, of those days, there was a risk lest the boiler should be burst by the steam, which was apt to force its way through the ill-made joints of the machine. This, conjoined with the great expenditure of steam on the high-pressure system, led Watt to abandon the plan; and the exigencies of his business for a time prevented him pursuing his experiments. Watt's own account of his early experiments will be found appended as notes to Brewster's edition of the articles ‘Steam and Steam-engines,’ written by Dr. Robison for the Encyclopaedia Britannica, and afterwards published in a separate form.

At length the Newcomen model arrived from London; and, in 1763, the little engine, which was destined to become so famous, was put into the hands of Watt. The boiler was somewhat smaller than an ordinary tea-kettle. The cylinder of the engine was only of two inches diameter and six inches stroke. Watt at first regarded it as merely "a fine plaything." It was, however, enough to set him upon a track of thinking which led to the most important results. When he had repaired the model and set it to work, he found that the boiler, though apparently large enough, could not supply steam in sufficient quantity, and only a few strokes of the piston could be obtained, when the engine stopped. The fire was urged by blowing, and more steam was produced, but still it would not work properly. Exactly at the point at which another man would have abandoned the task in despair, the mind of Watt became thoroughly roused. "Everything," says Professor Robison, "was to him the beginning of a new and serious study and I knew that he would not quit it till he had either discovered its insignificance, or had made something of it." Thus it happened with the phenomena presented by the model of the steam-engine. Watt referred to his books, and endeavoured to ascertain from them by what means he might remedy the defects which he found in the model but they could tell him nothing. He then proceeded with an independent course of experiments, resolved to work out the problem for himself. In the course of his inquiries he came upon a fact which, more than any other, led his mind into the train of thought which at last conducted him to the invention of which the results were destined to prove so stupendous. This fact was the existence of Latent Heat.

In order to follow the track of investigation pursued by Watt, it is necessary for a moment to revert to the action of the Newcomen pumping-engine. A beam, moving upon a centre, had affixed to one end of it a chain attached to the piston of the pump, and at the other a chain attached to a piston that fitted into the steam cylinder. It was by driving this latter piston up and down the cylinder that the pump was worked. To communicate the necessary movement to the piston, the steam generated in a boiler was admitted to the bottom of the cylinder, forcing out the air through a valve, when its pressure on the under side of the piston counterbalanced the pressure of the atmosphere on its upper side. The piston, thus placed between two equal forces, was drawn up to the top of the cylinder by the greater weight of the pump-gear at the opposite extremity of the beam. The steam, so far, only discharged the office which was performed by the air it displaced but, if the air had been allowed to remain, the piston once at the top of the cylinder could not have returned, being pressed as much by the atmosphere underneath as by the atmosphere above it. The steam, on the contrary, which was admitted by the exclusion of the air, could be condensed, and a vacuum created, by injecting cold water through the bottom of the cylinder. The piston being now unsupported, was forced down by the pressure of the atmosphere on its upper surface. When the piston reached the bottom, the steam was again let in, and the process was repeated. Such was the engine in ordinary use for pumping water at the time that Watt begun his investigations.

Among his other experiments, he constructed a boiler which showed by inspection the quantity of water evaporated in any given time, and the quantity of steam used in every stroke of the engine. He was astonished to discover that a small quantity of water in the form of steam, heated a large quantity of cold water injected into the cylinder for the purpose of cooling it; and upon further examination he ascertained that steam heated six times its weight of cold water to 212°, which was the temperature of the steam itself. "Being struck with this remarkable fact," says Watt, "and not understanding the reason of it, I mentioned it to my friend Dr. Black, who then explained to me his doctrine of latent heat, which he had taught for some time before this period (the summer of 1764); but having myself been occupied by the pursuits of business, if I had heard of it I had not attended to it, when I thus stumbled upon one of the material facts by which that beautiful theory is supported."

When Watt found that water, in its conversion into vapour, became such a reservoir of heat, he vas more than ever bent on economising it for the great waste of heat involving so heavy a consumption of fuel, was felt to be the principal obstacle to the extended employment of steam as a motive power. He accordingly endeavoured, with the same quantity of fuel, at once to increase the production of steam, and to diminish its waste. He increased the heating surface of the boiler, by making flues through it; he even made his boiler of wood, as being a worse conductor of heat than the brick-work which surrounds common furnaces; and be cased the cylinders and all the conducting-pipes in materials which conducted heat very slowly. But none of these contrivances were effectual; for it turned out that the chief expenditure of steam, and consequently of fuel, in the Newcomen engine, was occasioned by the reheating of the cylinder after the steam had been condensed, and the cylinder was consequently cooled by the injection into it of the cold water. Nearly four-fifths of the whole steam employed was condensed on its first admission, before the surplus could act upon the piston. Watt therefore came to the conclusion, that to make a perfect steam-engine, it was necessary that the cylinder should he always as hot as the steam that entered it; but it was equally necessary that the steam should be condensed when the piston descended, - nay, that it should be cooled down below 100°, or a considerable amount of vapour would be given off, which would resist the descent of the piston, and diminish the power of the engine. Thus the cylinder was never to be at a less temperature than 212°, and yet at each descent of the piston it was to he less than 100°: conditions which, on the very face of them, seemed to be wholly incompatible.

We revert for a moment to the progress of Watt's instrument-making business. The shop in the College was not found to answer, being too far from the principal thoroughfares. if he wanted business he must go nearer to the public, for it was evident that they would not come to him. But to remove to a larger shop, in a more central quarter, involved an expenditure of capital for which he was himself unequal. His father had helped him with money as long as he could, but could do so no longer. Though he was as much respected by his neighbours as ever, he had grown poor by his losses; and, instead of giving help, himself needed it. Watt therefore looked about him for a partner with means, and succeeded in finding one in a Mr. John Craig, in conjunction with whom he opened a retail shop in the Salt-market, nearly opposite St. Andrew's Street., about the year 1760; removing from thence to Buchanan's Land, on the north side of the Trongate, a few years later. Watt's partner was not a mechanic, but he supplied the requisite capital, and attended to the books. The partnership was on the whole successful, as we infer from the increased number of hands employed. At first Watt could execute all his orders himself, and afterwards by the help of a man and a boy; but by the end of 1764, the number of hands employed by the firm had increased to sixteen.

His improving business brought with it an improving income, and Watt — always a frugal and thrifty man — began to save a little money. He was encouraged to economise by another circumstance — his intended marriage with his cousin, Margaret Miller. In anticipation of this event, he had removed from his rooms in the College to a house in Delftfield Lane — a narrow passage then parallel with York Street, but now converted into the spacious thoroughfare of Watt Street.

Having furnished his house in a plain yet comfortable style, he brought home his young wife, and installed her there in July, 1764. The step was one of much importance to his personal wellbeing. Mrs. Watt was of a lively, cheerful temperament; and as Watt himself was of a meditative disposition, prone to melancholy, and a frequent sufferer from nervous headache, her presence at his fireside could not fail to have a beneficial influence upon his health and comfort.

Watt continued to pursue his studies as before. Though still occupied with his inquiries and experiments as to steam, he did not neglect his proper business, but was constantly on the look-out for improvements in instrument making. A machine which he invented for drawing in perspective proved a success; and he made a considerable number of them to order, for customers in London as well as abroad. He was also an indefatigable reader, and continued to extend his knowledge of chemistry and mechanics by perusal of the best books on these sciences.

Above all other subjects, however, the improvement of the steam-engine continued to keep the fastest hold upon his mind. He still brooded over his experiments with the Newcomen model, but did not seem to make much way in introducing any practical improvement in its mode of working. His friend Robison says he struggled long to condense with sufficient rapidity without injection, trying one expedient after another, finding out what would do by what would not do, and exhibiting many beautiful specimens of ingenuity and fertility of resource. He continued, to use his own words, "to grope in the dark, misled by many an ignis latuus." It was a favourite saying of his, that "Nature has a weak side, if we can only find it out;" and he went on groping and feeling for it, but as yet in vain. At length light burst upon him, and all at once the problem over which he had been brooding was solved.

One Sunday afternoon, in the spring of 1765, he went to take an afternoon walk on the Green, then a quiet, grassy meadow, used as a bleaching and grazing- ground. On week-days the Glasgow lasses came thither with their largest kail-pots, to boil their clothes in; and sturdy queans might be seen, with coats kilted, tramping blankets in their tubs. On Sundays the place was comparatively deserted, and hence Watt, who lived close at hand, went there to take a quiet afternoon stroll. His thoughts were as usual running on the subject of his unsatisfactory experiments with the Newcomen engine, when the first idea of the separate condenser suddenly flashed upon his mind. But the notable discovery is best told in his own words, as related to Mr. Robert Hart, many years after:-

"I had gone to take a walk on a fine Sabbath afternoon. I had entered the Green by the gate at the foot of Charlotte Street, and had passed the old washing-house. I was thinking upon the engine at the time, and had gone as far as the herd's house, when the idea came into my mind that as steam was an elastic body it would rush into a vacuum, and if a communication were made between the cylinder and an exhausted vessel, it would rush into it, and might be there condensed without cooling the cylinder. I then saw that I must get rid of the condensed steam and injection-water if I used a jet, as in Newcomen's engine. Two ways of doing this occurred to me. First, the water might be run off by a descending pipe, if an off-let could be got at the depth of 35 or 36 feet, and any air might be extracted by a small pump. The second was to make the pump large enough to extract both water and air. He continued: I had not walked further than the Golf-house when the whole thing was arranged in my mind."

Great and prolific ideas are almost always simple. What seems impossible at the outset appears so obvious when it is effected that we are prone to marvel that it did not force itself at once upon the mind. Late in life Watt, with his accustomed modesty, declared his belief that “if he had excelled, it had been by chance and the neglect of others." To Professor Jardine he said "that when it was analysed the invention would not appear so great as it seemed to be. In the state," said he, "in which I found the steam-engine, it was no great effort of mind to observe that the quantity of fuel necessary to make it work would for ever prevent its extensive utility. The next step in my progress was equally easy - to inquire what was the cause of the great consumption of fuel: this, too, was readily suggested, viz., the waste of fuel which was necessary to bring the whole cylinder, piston, and adjacent parts from the coldness of water to the heat of steam, no fewer than from fifteen to twenty times in a minute." The question then occurred, how was this to be avoided or remedied? It was at this stage that the idea of carrying on the condensation in a separate vessel flashed upon his mind, and solved the difficulty.

Mankind has been more just to Watt than be was to himself. There was no accident in the discovery. It had been the result of close and continuous study and the idea of the separate condenser was merely the last step of a long journey - a step which could not have been taken unless the road which led to it had been traversed. Dr. Black says, "This capital improvement flashed upon his mind at once, and filled him with rapture" a statement which, spite of the unimpassioned nature of Watt, we can readily believe.

On the morning following his Sunday afternoon's walk on Glasgow Green, Watt was up betimes making arrangements for a speedy trial of his new plan. He borrowed from a college friend a large brass syringe, an inch and a third in diameter, and ten inches long, of the kind used by anatomists for injecting arteries with wax previous to dissection. The body of the syringe served for a cylinder, the piston rod passing through a collar of leather in its cover. A pipe connected with the boiler was inserted at both ends for the admission of steam, and at the upper end was another pipe to convey the steam to the condenser. The axis of the stem of the piston was drilled with a hole, fitted with a valve at its lower end, to permit the water produced by the condensed steam on first filling the cylinder to escape. The first condenser made use of was an improvised cistern of tinned plate, provided with a pump to get rid of the water formed by the condensation of the steam, both the condensing-pipes placed in a reservoir of cold and the air-pump being water.

"The steam-pipe," says Watt, "was adjusted to a small boiler. When steam was produced, it was admitted into the cylinder, and soon issued through the perforation of the rod, and at the valve of the condenser; when it was judged that the air was expelled, the steam-cock was shut, and the air-pump piston-rod was drawn up, which leaving the small pipes of the condenser in a state of vacuum, the steam entered them and was condensed. The piston of the cylinder immediately rose and lifted a weight of about 18 lbs., which was hung to the lower end of the piston-rod. The exhaustion-cock was shut, the steam was readmitted into the cylinder, and the operation was repeated. The quantity of steam consumed and the weights it could raise were observed, and, excepting the non-application of the steam-case and external covering, the invention was complete, in so far as regarded the savings of steam and fuel."

But, although the invention was complete in Watt's mind, it took him many long and laborious years to work out the details of the engine. His friend Robison, with whom his intimacy was maintained during these interesting experiments, has given a graphic account of the difficulties which he successively encountered and overcame. He relates that on his return from the country, after the College vacation in 1765, he went to have a chat with Watt and communicate to him some observations he had made on Desaguliers' and Belidor's account of the steam-engine. He went straight into the parlour, without ceremony, and found Watt sitting before the fire looking at a little tin cistern which he had on his knee. Robison immediately started the conversation about steam, his mind, like Watt's, being occupied with the means of avoiding the excessive waste of heat in the Newcomen engine. Watt, all the while, kept looking into the fire, and after a time laid down the cistern at the foot of his chair, saying nothing. It seems that Watt felt rather nettled at Robison having communicated to a mechanic of the town a contrivance which he had hit upon for turning the cocks of his engine. When Robison therefore pressed his inquiry, Watt at length looked at him and said briskly, "You need not fash yourself any more about that, man; I have now made an engine that shall not waste a particle of steam. It shall all be boiling hot, — ay, and hot water injected, if I please." He then pushed the little tin cistern with his foot under the table.

Robison could learn no more of the new contrivance from Watt at that time but on the same evening he accidentally met a mutual acquaintance, who, supposing he knew as usual the progress of Watt's experiments, observed to him, "Well, have you seen Jamie Watt? " "Yes." "He'll be in fine spirits now with his engine?" "Yes," said Robison, "very fine spirits." "Gad!" said the other, "the separate condenser's the thing: keep it but cold enough, and you may have a perfect vacuum, whatever be the heat of the cylinder." This was Watt's secret, and the nature of the contrivance was clear to Robison at once.

It will be observed that Watt had not made a secret of it to his other friends. Indeed Robison himself admitted that one of Watt's greatest delights was to communicate the results of his experiments to others, and set them upon the same road to knowledge with himself and that no one could display less of the small jealousy of the tradesman than he did. To his intimate friend, Dr. Black, he communicated the progress made by him at every stage; and the Doctor kindly encouraged him in his struggles, cheered him in his encounter with difficulty, and, what was of still more practical value at the time, he helped him with money to enable him to prosecute his invention. Communicative though Watt was disposed to be, he learnt reticence when he found himself exposed to the depredations of the smaller fry of inventors. Robison says that had he lived in Birmingham or London at the time, the probability is that some one or other of the numerous harpies who live by sucking other people's brains, would have secured patents for his more important inventions, and thereby deprived him of the benefits of his skill, science, and labour. As yet, however, there were but few mechanics in Glasgow capable of understanding or appreciating the steam-engine; and the intimate friends to whom he freely spoke of his discovery were too honourable-minded to take advantage of his confidence. Shortly after, Watt fully communicated to Robison the different stages of his invention, and the results at which he had arrived, much to the delight of his friend.

It will be remembered that in the Newcomers engine the steam was only employed for the purpose of producing a vacuum, and that its working power was in the down stroke, which was effected by the pressure of the air upon the piston hence it is now usual to call it the atmospheric engine. Watt perceived that the air which followed the piston down the cylinder would cool the latter, and that steam would be wasted in re-heating it. In order, therefore, to avoid this loss of heat, he resolved to put an air-tight cover upon the cylinder, with a hole and stuffing-box for the piston-rod to slide through, and to admit steam above the piston, to act upon it instead of the atmosphere. When the steam had done its duty in driving down the piston, a communication was opened between the upper and lower part of the cylinder, and the same steam, distributing itself equally in both compartments, sufficed to restore equilibrium. The piston was now drawn up by the weight of the pump-gear the steam beneath it was then condensed in the separate vessel so as to produce a vacuum, and a fresh jet of steam from the boiler was let in above the piston, which forced it again to the bottom of the cylinder. From an atmospheric it had thus become a true steam-engine, and with a much greater economy of steam than when the air did half the duty. But it was not only important to keep the air from flowing down the inside of the cylinder: the air which circulated within cooled the metal and condensed a portion of the steam within and this Watt proposed to remedy by a second cylinder, surrounding the first with an interval between the two which was to be kept full of steam.

One by one these various contrivances were struck out, modified, settled, and reduced to definite plans the separate condenser, the air and water pumps, the use of fat and oil (instead of water as in the Newcomen engine) to keep the piston working in the cylinder air-tight, and the enclosing of the cylinder itself within another to prevent the loss of heat. They were all but emanations from the first idea of inventing an engine working by a piston, in which the cylinder should be kept continually hot and perfectly dry. "When once," says Watt, "the idea of separate condensation was started, all these improvements followed as corollaries in quick succession so that in the course of one or two days the invention was thus far complete in my mind."

The next step was to construct a model engine for the purpose of embodying the invention in a working form. With this object Watt hired an old cellar, situated in the first wide entry to the north of the beef-market in King Street, and there proceeded with his model. He found it much easier, however, to prepare his plan than to execute it. Like most ingenious and inventive men, Watt was extremely fastidious and this occasioned considerable delay in the execution of the work. His very inventiveness to some extent proved a hinderance; for new expedients were perpetually occurring to him, which he thought would be improvements, and which he, by turns, endeavoured to introduce. Some of these expedients he admits proved fruitless, and all of them occasioned delay. Another of his chief difficulties was in finding competent workmen to execute his plans. He himself had been accustomed only to small metal work, with comparatively delicate tools, and had very little experience "in the practice of mechanics in great," as he termed it. He was therefore under the necessity of depending, in a great measure, upon the handiwork of others. But mechanics capable of working out Watt's designs in metal were then with difficulty to be found. The beautiful self-acting tools and workmanship which have since been called into being, principally by his own invention, did not then exist. The only available hands in Glasgow were the blacksmiths and tinners, little capable of constructing articles out of their ordinary walks; and even in these they were often found clumsy, blundering, and incompetent. The result was, that in consequence of the malconstruction of the larger parts, Watt's first model was only partially successful. The experiments made with it, however, served to verify the expectations he had formed, and to place the advantages of the invention beyond the reach of doubt. On the exhausting-cock being turned, the piston, when loaded with 18 lbs., ascended as quick as the blow of a hammer and the moment the steam-cock was opened, it descended with like rapidity, though the steam was weak, and the machine snifted at many openings.

Satisfied that he had laid hold of the right principle of a working steam-engine, Watt felt impelled to follow it to an issue. He could give his mind to no other business in peace until this was done. He wrote to a friend that he was quite barren on every other subject. "My whole thoughts," said he "are bent on this machine. I can think of nothing else." He proceeded to make another and bigger, and, he hoped, a more satisfactory engine, in the following August; and with that object he removed from the old cellar in King-street to a larger apartment in the then disused pottery or delftwork near the Broomielaw. There he shut himself up with his assistant, John Gardiner, for the purpose of erecting his engine. The cylinder was five or six inches in diameter, with a two-feet stroke. The inner cylinder was enclosed in a wooden steam-case, and placed inverted, the piston working through a hole in the bottom of the steam-case. After two months continuous application and labour it was finished and set to work; but it leaked in all directions, and the piston was far from air-tight. The condenser also was in a bad way, and needed many alterations. Nevertheless, the engine readily worked with 10.5 lbs. pressure on the inch, and the piston lifted a weight of 14 lbs. The improvement of the cylinder and piston continued Watt's chief difficulty, and taxed his ingenuity to the utmost. At so low an ebb was the art of making cylinders that the one he used was not bored but hammered, the collective mechanical skill of Glasgow being then unequal to the boring of a cylinder of the simplest kind nor, indeed, did the necessary appliances for the purpose then exist anywhere else. In the Newcomen engine a little water was poured upon the upper surface of the piston, and sufficiently filled up the interstices between the piston and the cylinder. But when Watt employed steam to drive down the piston, he was deprived of this resource, for the water and the steam could not coexist. Even if he had retained the agency of the air above, the drip of water from the crevices into the lower part of the cylinder would have been incompatible with keeping the surface hot and dry, and, by turning into vapour as it fell upon the heated metal, it would have impaired the vacuum during the descent of the piston.

While he was occupied with this difficulty and striving to overcome it by the adoption of new expedients, such as leather collars and improved workmanship, he wrote to a friend, "My old white-iron man is dead;" the old white-iron man, or tinner, being his leading mechanic. Unhappily, also, just as be seemed to have got the engine into working order, the beam broke, and having great difficulty in replacing the damaged part, the accident threatened, together with the loss of his best workman, to bring the experiment to an end. But though discouraged by these misadventures, he was far from defeated, but went on as before, battling down difficulty inch by inch, and holding good the ground he had won, becoming every day more strongly convinced that he was in the right track, and that the important uses of the invention, could he but find time and means to perfect it, were beyond the reach of doubt.

But how to find the means! Watt himself was a comparatively poor man having no money but what he earned by his business of mechanical instrument making, which he had for some time been neglecting through his devotion to the construction of his engine. What he wanted was capital, or the help of a capitalist willing to advance him the necessary funds to perfect his invention. To give a fair trial to the new apparatus would involve an expenditure of several thousand pounds; and who on the spot could be expected to invest so large a sum in trying a machine so entirely new, depending for its success on physical principles very imperfectly understood?

There was no such help to be found in Glasgow. The tobacco lords, though rich, took no interest in steam power, and the manufacturing class, though growing in importance, had full employment for their little capital in their own concerns.

See Also

• Lives of Boulton and Watt by Samuel Smiles
• Lives of Boulton and Watt by Samuel Smiles: Chapter 6
• Lives of Boulton and Watt by Samuel Smiles: Chapter 8