Mathieu's learned note on Delambre, ('Histoire de l'Astro'nomie au dix-huitième Siècle,' pp. 645-652, ed. 1827). There the priority is attributed to Rochon, who presented the Academy of Sciences with a description and a specimen of that sort of instrument in January and February, 1777, and in April following reported to the same learned body the measurements of Mars, of Jupiter, and of Saturn with his ring, which he had obtained by its aid.

Maskelyne, who, in December, 1777, presented his prismatic micrometer to the Royal Society, produced an attestation by Dollond that he had constructed it for him in the previous year, and taken it to the Observatory at Greenwich in August, 1776.*

To both of those dates Mr. Watt's invention appears to have been antecedent by several years; although of it we may say, as M. Mathieu has done of that of Rochon, "That "ingenious instrument did not receive, at the time, all the "attention which it deserved."

"The Abbés Boscovich, Fontana, Rochon, Maskelyne," wrote Dr. Patrick Wilson † to Mr. Watt, in 1778, "are a very

See the 'Philosophical Transac'tions' for 1777, vol. lxvii., pp. 799813, &c. See also Boscovich's 'Ac'count of a new Micrometer and Megameter,' ibidem, pp. 789-798.

+ Dr. Patrick Wilson was the sccond son of Dr. Alexander Wilson, celebrated not only for his accurate and ingenious observations on the solar spots, but also for having introduced a new era in the art of typefounding in this country: (see Humboldt's Cosmos,' vol. iii. pp. 273 and xevi; 'Phil. Trans.' for 1774, vol. lxiv. pp. 6-13; Preface to the Foulis Homer, vol. i. p. viii; and the interesting biographical memoir published in Brewster's Edinburgh Journal * of Science' for Jan. 1829, pp. 1-17.) The son shared largely in all his father's pursuits, and in 1786 became his successor in the astronomical professorship at Glasgow. His aptness for philosophical experiments was made favourably known by his various papers in the Philosophical Transactions. Having in 1799 resigned

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the chair of Practical Astronomy in order to reside near London, in the society of the Herschels and other friends distinguished in pursuits congenial to his own, he on that occasion, as a mark of his high regard" for the learned body so long and so "intimately known to him, and in "testimony also of his desire for the "future prosperity of the office of "Professor of Practical Astronomy "in the said College, which was first "filled by his ever-honoured father," endowed the University of Glasgow with a fund of considerable amount, for the purpose of purchasing astronomical books and apparatus, as well as of bestowing occasionally a gold prize medal on meritorious students of his favourite science. Dr. Patrick Wilson died at Kensington, 31st December, 1811. (See Deeds instituting Bursaries, Scholarships, and other Foundations in the College and University of Glasgow.' Privately printed for the University, 1850. pp. 253-258.)

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"creditable junto of philosophers, who are at present drawing "some attention as inventors of a prismatic micrometer. My "father and I feel a wish of seeing your name added to that "band of improvers. Your invention, though very little "known, was several years prior to any of theirs. If you "choose to assert this priority by any publication, it will "give us great pleasure to contribute our evidence in your "favour;"—and, to the same effect, and at the same time, Dr. W. Irvine :-"Pray have you seen the last volume of the "Transactions? You must surely know that it contains the description of a certain micrometer, that shall be nameless, "made by one J. Watt six or eight years ago, and which has "been in Macfarlane's Observatory in Glasgow for several years past. Would you not think it proper that the said "J. Watt should claim this discovery? And as the authors "of these papers in the Transactions have brought witnesses, "he might bring Dr. Reid, Dr. Wilson, Pat. Wilson, G. "Hamilton, &c., who are ready and willing to attest the same, and who are surely as respectable as Pat. Dollond "and Aubert; and to make the whole still stronger, I "should imagine you could have no objection to join in the "attestation. You may perhaps despise such unprofitable "inventions; but to others they will procure fame, and perhaps fortune."

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One other "gimcrack," and we have done with the long list of useful and ingenious contrivances with which it had been the pleasure of the great engineer, up to this period, to occupy his few hours of leisure ;-" I have invented a draw"ing-machine," he says, "the board horizontal, the index "almost as long as you please, and consequently the size of "the picture large; a telescopic sight; no specula; the "whole being performed by a most simple joint. When the "index does not exceed two feet long, the instrument and apparatus consist of a box 14 inches long, 14 deep, and 41⁄2 "inches broad, which opened is the drawing-board, and con"tains the apparatus, except a light wooden tripod head for

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*To Dr. Small, 11 December, 1773.

"the pocket, and a staff for the hand, of the ordinary size. "By help of this machine I can draw from an eminence a

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draught of level grounds that shall be a true projection of them, and shall measure by a scale of equal parts. It also " draws all kinds of perspective draughts, reduces maps, &c., "the board being always horizontal, whether the objects be "vertical or not."

Within a fortnight, however, came this reversal of the verdict thus pronounced:-"I caused to be made a part of "the machine I mentioned in my last; it has only one fault, "which is, that it will not do, because it describes conic "sections instead of right lines;"* and although there can be no doubt that by a little further labour on the part of the inventor this difficulty would have been overcome, yet events of more importance soon occurred, which seem to have put a stop to the career of "gimcracks," in which he and his friend Small had so long and cheerfully been running a race together, and which led the latter to remark to his friend,-"You might live by inventing only an hour in a "week for mathematical-instrument-makers."

The termination of Mr. Watt's labours as a civil engineer was an abrupt one, accompanied-and indeed in some measure caused by a melancholy event. Having been suddenly recalled from his survey of the Caledonian Canal in the autumn of 1773 by the intelligence of the dangerous illness of his wife, he had the deep grief of finding on his return home that she had died, after having given birth to a still-born child. Mrs. Watt is described as having been a very amiable person, whose gentle counsels and uniform good temper had often sustained her husband's hopes and animated his exertions, under the depressing circumstances of indifferent health, narrow means, and variable and often desponding spirits; from all of which he then suffered in no ordinary degree. By relieving his mind as far as possible of other care, and thus affording it the undisturbed leisure required

* 24 December, 1773.

for study and exertion in his various pursuits, she might even be said to have been of material, though, of course, subsidiary service to him in the progress of his great invention. She earnestly encouraged the hopes which he founded upon it; and even when these seemed for a time to be quite overthrown, her buoyant spirits did not sink, nor did her cheerful faith fail; but she wrote to him with truly feminine fortitude, -"I beg you would not make yourself uneasy, though things "should not succeed to your wish. If it" [the new steamengine] "will not do, something else will. Never despair.” *

"The few years," says Miss Campbell, "of his union with "Miss Miller passed in uninterrupted domestic happiness. "Of her untimely death, and the beautiful composure of "mind, and affecting tenderness for her husband and children, "that she displayed in her last moments, my mother never "could speak without tears."

The agony of grief which he suffered on losing so judicious, so beloved, and so faithful a friend, sufficiently appears from those of his letters of that date which have been preserved; although some others, it is to be regretted, appear to have been lost or destroyed, probably in consequence of containing no allusion to anything but his private sorrow. Of one, which survives only in the form of an undated fragment, addressed to Dr. Small, but evidently belonging to the period in question, the expressions are gloomy indeed;-more so, happily, than the habitual resignation of its writer to the will of the Supreme Disposer of all events seems ever to have permitted him to repeat. "Let us," he writes, "rejoice in our youth, " for age is dark and unlovely, and in the silent grave there is no joy, at least that we know of;-vive, et vale." And again :-"You are happy, Small, that have no such con"nection. Yet this misfortune might have fallen upon me "when I had less ability to bear it, and my poor children might have been left suppliants to the mercy of the wide "world. I know that grief has its period; but I have much "to suffer first. I grieve for myself, not for my friend; for

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* August 9, 1768.

"if probity, charity, and duty to her family can entitle her "to a better state, she enjoys it. I am left to mourn. "Let me leave this tale of woe."

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"Would that I might here transcribe," said Arago, “in all "their simple beauty, some lines of the journal in which he daily recorded his inmost thoughts, his fears, his hopes! "Would that you could see him, after this heavy affliction, pausing on the threshold of that home, where 'HIS KIND "WELCOMER' awaited him no more; unable to summon courage to enter those rooms, where he was never more to "meet 'THE COMFORT OF HIS LIFE!'"

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Of the four children who were the issue of Mr. Watt's marriage with Miss Miller, two died in infancy; one daughter married a Mr. Miller of Glasgow, but died early, leaving issue a son and two daughters, (now all dead, the daughters having left issue); and the only son of that family who attained manhood was the late Mr. James Watt, of Aston Hall, who long survived his father as his respected representative, and died, unmarried, in 1848.