The Life of James Watt

"inches long, exceedingly truly bored, has a solid piston accurately fitted to it, so as to slide easy by the help of some "oil; the stem of the piston is guided in the direction of the "axis of the cylinder, so that it may not be subject to jam,

or cause friction in any part of its motion. The bottom of "this cylinder has a cock and small pipe joined to it, which, having a conical end, may be inserted in a hole drilled in "the cylinder of the engine near one of the ends, so that, by opening the small cock, a communication may be effected "between the inside of the cylinder and the indicator.

"The cylinder of the indicator is fastened upon a wooden or “metal frame, more than twice its own length; one end of a spiral steel spring, like that of a spring steelyard, is attached "to the upper part of the frame, and the other end of the spring is attached to the upper end of the piston-rod of the "indicator. The spring is made of such a strength, that "when the cylinder of the indicator is perfectly exhausted, "the pressure of the atmosphere may force its piston down "within an inch of its bottom. An index being fixed to the top of its piston-rod, the point where it stands, when quite "exhausted, is marked from an observation of a barometer "communicating with the same exhausted vessel, and the "scale divided accordingly."

"The joints of the cylinder, and other parts of Newco"men's engines, were generally made tight by being screwed

together upon rings of lead covered with glazier's putty, "which method was sufficient, as the entry of small quan"tities of air did not materially affect the working of those engines where only a very imperfect exhaustion was required. But the contrary being the case in the improved "engines, this method would not answer Mr. Watt's purpose. "He at first made his joints very true, and screwed them together upon pasteboard, softened by soaking in water, "which answered tolerably well for a time, but was not sufficiently durable. He therefore endeavoured to find out "some more lasting substance; and, observing that at the "iron foundries they filled up flaws by iron borings or filings "moistened by an ammoniacal liquor, which in time became

"hard, he improved upon this by mixing the iron borings or filings with a small quantity of sulphur and a little sal"ammoniac, to which he afterwards added some fine sand "from the grindstone-troughs. This mixture being moistened "with water and spread upon the joint, heats soon after it is "screwed together, becomes hard, and remains good and "tight for years; which has contributed in no small degree "to the perfection of the engines. Mr. Murdock, much about "the same time, without communication with Mr. Watt, "made a cement of iron borings and sal-ammoniac, without "the sulphur. But the latter gives the valuable property of "making the cement set immediately."

To those who study the physiological development of the mind, every fact in the history of an intellect such as that of Mr. Watt, is of peculiar interest. For of all the mental powers, the faculty of mechanical inventiveness is perhaps the most rare; and Mr. Watt has long been, by the consent of the greatest men of science in the world, placed "at the "head of all inventors in all ages and nations." It thus becomes worth remarking, that the ten years subsequent to 1775, during which he took out his five last patents, and made those other improvements on the steam-engine of which we have now given some account, were the period during which he seems to have combined the greatest maturity with the greatest activity of intellect; and that the time of his life which they comprehended, was from his fortieth to his fiftieth year. The labour involved in devising and adapting to practice his new inventions, and in preparing the drawings and descriptions of them required for the specifications of his patents, was, indeed, only a small part of that which he then underwent; for he was, for a great portion of the time, as we have already mentioned, daily occupied in superintending the erection of new engines or the alteration of old ones,-in watching and defeating the continual attempts made to pirate his inventions and rob his partner and himself of their moderate gains,-in "giving," as his son has said, "the constant

* Sir James Mackintosh, Speech at the Meeting at Freemasons' Hall, 1824.

"attention necessary to the concerns of a nascent mannfactory, and himself writing volumes of other letters on "business, which alone would have furnished full employ"ment even to an industrious intellect." "His mind also," continues the same excellent authority, "had been greatly "affected by his unavoidable absence from the death-bed "of his aged father; and during the greater part of the 'time, I well remember seeing him suffer under most acute "sick headaches, sitting by the fireside for hours together, "with his head leaning on his elbow, and scarcely able to 'give utterance to his thoughts. It was unquestionably the "busiest as well as the most anxious period of his life, and fraught with the most important results."

Mr. Watt, senior, died at Greenock in August, 1782. On the 1st of September his son writes, on receiving the intelligence of that event, to Mr. Cochrane :-"Yesterday brought "me your letter of the 23rd, containing the afflicting news of "the death of my worthy and kind father. When we con"sider his death as a removal from a state of pain and disease to a state where we must hope that he will meet the "reward of a well-spent and laborious life, we cannot with reason bewail his loss; yet there is something so afflicting "in the thought of the final, solemn departure of a beloved "friend and revered parent, that though I have been, by his “long illness and declining state, prepared for the event, the "account of it has given me much pain. It behoves

"me now, however, to lay aside unavailing regret, and to "thank God that he has hitherto preserved me from signal "misfortunes. My wife and family are all well, and my "children are promising, which circumstances I have great "reason to be grateful for, however I may be otherwise "afflicted."

Often, in the course of the period of which we have been speaking, especially towards its close, we find Mr. Watt complaining of his bad health, of what he calls his own

stupidity," and "want of the inventive faculty;" complaints which, had they issued from less sincere lips, might have been almost deemed ironical, but were with him, like every

thing else that he uttered, the honest expression of the true feelings of his mind. Towards the close of 1785, he says, "my own health is so bad that I do not think I can hold out "much longer, at least as a man of business." "I cannot "help being dispirited, because I find my head fail me much ; "business an excessive burden to me, and little prospect of any speedy release from it. Were we both young and "healthy, I see no reason to despair, but very much the con"trary; however, we must do the best we can, and hope for quiet in Heaven, when our weary bones are laid to rest:""on the whole, I find it now full time to cease attempting to "invent new things, or to attempt anything which is attended "with any risk of not succeeding, or of creating trouble "in the execution. Let us go on executing the things "we understand, and leave the rest to younger men, who "have neither money nor character to lose." Early in 1786, also, he writes:-"in the anguish of my mind amid the ❝ vexations occasioned by new and unsuccessful schemes, like "Lovelace, I curse my inventions,' and almost wish, if we "could gather our money together, that somebody else should "succeed in getting our trade from us." And, in June of the same year, "I should have written to you long ago, but have

really been in a worse situation in some respects this spring "than I have ever been in my life. The illness I was "seized with in London in the spring greatly weakened me "both in body and mind; and, I believe, was brought on by "over-exertions, endeavouring to get home as soon as pos"sible. The bodily disease has in great measure subsided; "but an unusual quantity of business, which by Mr. Boulton's frequent and long absences has fallen wholly on me, and "several vexations, with the consequent anxious thoughts, "have hitherto prevented my mind from recovering its 66 energy. I have been quite effete and listless, neither daring to face business, nor capable of it; my head and memory failing me much; my stable of hobby-horses "pulled down, and the horses given to the dogs for carrion. "In such a situation it requires something very pressing, or very animating, to make one put pen to paper. I have

"had serious thoughts of throwing down the burden I find myself unable to carry, and perhaps, if other sentiments "had not been stronger, should have thought of throwing off "the mortal coil; but, if matters do not grow worse, I may

perhaps stagger on. Solomon said that in the increase of "knowledge there is increase of sorrow: if he had substituted "business for knowledge, it would have been perfectly true."

The history of one other patent will exhaust the series of those taken out by Mr. Watt. On the 25th of March, 1785, he wrote to Mr. Boulton, "I think we are in the way of "getting quit of smoke in the engines;" and on the 10th of September in the same year, to Mr. De Luc, "I have some hopes of being able to get quit of the abominable smoke "which attends fire-engines. Some experiments which I "have made promise success. It is not on Mr. Argand's "principle, but on an old one of my own, which is exceedingly different." On the 9th of October, "We had a first "trial yesterday of a large furnace to burn without smoke "under the big boiler, at Soho, that used to poison Mr. B.'s garden so much, and it answered very well, as far as we "could judge from a wet furnace, and without the engines being at work."

Of the date of this invention being devised or completed by Mr. Watt, we have no more exact information; but in September of the same year in which he obtained his patent for it, he mentioned that the principle on which it proceeded was an old one of his own." Until that time he does not appear ever to have tried it on a large scale; but, both then and since, it has, we believe, been always found to answer well in practice. "It is astonishing," writes his son Mr. James Watt to him from Manchester in 1790, "what an

impression the smoke-consuming power of the engine has "made upon the minds of everybody hereabouts; nobody "would believe it until the engine was set a-going, and even "then they scarcely trusted to the evidence of their senses. "You would be diverted to hear the strange hypotheses "which have been started to account for it. However, it has "answered one extremely good end, it has made your

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The Life of James Watt: With Selections from His Correspondence