As to the lethargy from which Roebuck sought to raise Watt, it was merely the temporary reaction of a mind strained and wearied with long-continued application to a single subject, and from which it seemed to be occasionally on the point of breaking down altogether. To his intimate friends, Watt bemoaned his many failures, his low spirits, his bad health, and his sleepless nights. He wrote to his friend Dr. Small[83] in January, 1769, “I have many things I could talk to you about—much contrived, and little executed. How much would good health and spirits be worth to me!” A month later he wrote, “I am still plagued with headaches, and sometimes heart-aches.”
It is nevertheless a remarkable proof of Watt’s indefatigable perseverance in his favourite pursuit, that at this very time, when apparently sunk in the depths of gloom, he learnt German for the purpose of getting at the contents of a curious book, the Theatrum Machinarum of Leupold, which just then fell into his hands, and contained an account of the machines, furnaces, methods of working, profits, &c., of the mines in the Upper Hartz. His instructor in the language was a Swiss dyer,[84] settled in Glasgow. With the like object of gaining access to untranslated books in French and Italian—then the great depositories of mechanical and engineering knowledge—Watt had already mastered both those languages.
In preparing his specification, Watt viewed the subject in all its bearings. The production of power by steam is a very large one, but Watt grasped it thoroughly. The insight with which he searched, analysed, arranged, and even provided for future modifications, was the true insight of genius. He seems with an almost prophetic eye to have seen all that steam was capable of accomplishing. This is well illustrated by his early plan of working steam expansively by cutting it off at about half-stroke, thereby greatly economising its use;[85] as well as by his proposal to employ high-pressure steam where cold water could not be used for purposes of condensation.[86] The careful and elaborate manner in which he studied the specification, and the consideration which he gave to each of its various details, are clear from his correspondence with Dr. Small, which is peculiarly interesting, as showing Watt’s mind actively engaged in the very process of invention. At length the necessary specification and drawings were completed and lodged early in 1769,—a year also remarkable as that in which Arkwright took out the patent for his spinning-machine.
In order to master thoroughly the details of the ordinary Newcomen engine, and to ascertain the extent of its capabilities as well as of its imperfections, Watt undertook the erection of several engines of this construction; and during his residence at Kinneil took charge of the Schoolyard engine near Boroughstoness, in order that he might thereby acquire a full practical knowledge of its working. Mr. Hart, in his interesting ‘Reminiscences of James Watt,’ gives the following account: “My late brother had learned from an old man who had been a workman at Dr. Roebuck’s coal-works when Mr. Watt was there, that he had erected a small engine on a pit they called Taylor’s Pit. The workman could not remember what kind of engine it was, but it was the fastest-going one he ever saw. From its size, and from its being placed in a small timber-house, the colliers called it ‘the Box Bed.’ We thought it likely to have been the first of the patent engines made by Mr. Watt, and took the opportunity of mentioning this to him at our interview. He said he had erected that engine, but he did not wish at the time to venture on a patent one until he had a little more experience.”[87]
At length he proceeded to erect the trial engine after his new patent, and made arrangements to stay at Kinneil until the work was finished. It had been originally intended to erect it in the little town of Boroughstoness; but as prying eyes might have there watched his proceedings, and as he wished to avoid display, being determined, as he said, “not to puff,” he fixed upon an outhouse behind Kinneil, close by the burn-side in the glen, where there was abundance of water and secure privacy. The materials were brought to the place, partly from Watt’s small works at Glasgow, and partly from Carron, where the cylinder—of eighteen inches diameter and five feet stroke—had been cast; and a few workmen were placed at his disposal.
THE OUTHOUSE BEHIND KINNEIL.
The process of erection was very tedious, owing to the clumsiness of the mechanics employed on the job. Watt was occasionally compelled to be absent on other business, and on his return he usually found the men at a standstill, not knowing what to do next. As the engine neared completion, his “anxiety for his approaching doom” kept him from sleep; for his fears, as he said, were at least equal to his hopes. He was easily cast down by little obstructions, and especially discouraged by unforeseen expense. Roebuck, on the contrary, was hopeful and energetic, and often took occasion to rally the other on his despondency under difficulties, and his almost painful want of confidence in himself. Roebuck was, doubtless, of much service to Watt in encouraging him to proceed with his invention, and also in suggesting some important modifications in the construction of the engine. It is probable, indeed, that but for his help, Watt could not have gone on. Robison says, “I remember Mrs. Roebuck remarking one evening, ‘Jamie is a queer lad, and, without the Doctor, his invention would have been lost; but Dr. Roebuck won’t let it perish.’”
The new engine, on which Watt had expended so much labour, anxiety, and ingenuity, was completed in September, 1759, about six months from the date of its commencement. But its success was far from decided. Watt himself declared it to be “a clumsy job.” His new arrangement of the pipe-condenser did not work well; and the cylinder having been badly cast, was found almost useless. One of his greatest difficulties consisted in keeping the piston tight. He wrapped it round with cork, oiled rags, tow, old hat, paper, horse-dung, and other things, but still there were open spaces left, sufficient to let the air in and the steam out. Watt was grievously depressed by his want of success, and he had serious thoughts of giving up the thing altogether. Before abandoning it, however, the engine was again thoroughly overhauled, many improvements were introduced in it, and a new trial was made of its powers. But this proved not more successful than the earlier ones had been. “You cannot conceive,” he wrote to Small, “how mortified I am with this disappointment. It is a damned thing for a man to have his all hanging by a single string. If I had wherewithal to pay the loss, I don’t think I should so much fear a failure; but I cannot bear the thought of other people becoming losers by my schemes; and I have the happy disposition of always painting the worst.”
Watt was therefore bound to prosecute his project by honour not less than by interest; and summoning up his courage, he went on with it anew. He continued to have the same confidence as ever in the principles of his engine: where it broke down was in workmanship. Could mechanics but be found capable of accurately executing its several parts, he believed that its success was certain. But there were no such mechanics then at Carron.