534 COLIN MACLAURIN.
pounds per annum, besides the fees he received from the students attending the class, upon condition of performing all the duties of the office. On the 3d November, 1725, he was introduced to the university, as was at the same time his learned colleague and intimate friend, Dr Alexander Monro, professor of anatomy. The subjects which Mr Maclaurin introduced into the different courses of lectures on mathematics were very miscellaneous, and the classes soon became unusually numerous, there being upwards of a hundred young gen- tlemen attending his lectures, who being of different standings and proficiency, he was obliged to divide them into four or five classes, in each of which he em- ployed a full hour every day, from the 1st of November to the 1st of June. In the first or lowest class, (sometimes divided into two,) he taught the first six books of Euclid's Elements, plain trigonometry, practical geometi-y, the elements of fortification, and an introduction to Algebra. The second class repeated the Algebra again from its principles, and advanced farther in it, then proceeded to the theory of mensuration of solids, spherical trigonometry, the doctrine of the Sphere, dialling, and other practical parts. After this he gave the doctrine of the conic sections, with the theory of gunnery, and concluded with the elements of astronomy and optics. In the third class he went on in astronomy and per- spective, prelected on Sir Isaac Newton's Principia, and explained the di- rect and inverse method of fluxions. At a separate hour he began a class of experimental philosophy about the middle of December, which continued thrice every week till the beginning of April, and at proper hours of the night de- scribed the constellations and showed the planets by telescopes of various kinds. All Mr Maclaurin's lectures on these different subjects were given with such perspicuity of method and language, that his demonstrations seldom stood in need of being repeated. Such, however, was his anxiety for the improve- ment of his scholars, that if at any time he found they could not comprehend his meaning, or if upon examining them he found they could not readily de- monstrate the propositions which he had proved, he was apt rather to suspect that his own expressions had been obscure than their want of genius or atten- tion. He, therefore, would resume the demonstration in some other method, in order to try, if, by presenting it in a different light, he could give them a better view of it. Besides the labours of his public profession, lie had frequently many other employments and avocations. If an uncommon experi- ment was said to have been made any where, the curious were desirous of having it repeated by Mr Maclaurin. On all momentous occasions he was the first to be applied to ; and if an eclipse or comet was to be observed, his telescopes were always in readiness. Such was the elegance and amenity of his manners, that the ladies took the liveliest interest in his experiments and observations, and were delighted and surprised at finding how easily and familiarly he would re- solve the questions they put to him ; and to those gentlemen who had been his pupils his advice and assistance were never wanting ; nor was admittance refused to any except in his teaching hours, which were devoted to that purpose alone. The ingenious of all ranks courted his acquaintance and friendship, and so anxious and pressing were they to enjoy the pleasure of his company and con- versation after his usual avocations were over, that he was obliged to take from the ordinary hours of repose what he bestowed on his scholars and friends, and by persevering in deep and severe study, he exhausted his strength and greatly impaired his health. About this time, at the beginning of the year 1728, Sir Isaac Newton died, and his nephew, Mr Conduitt, proposed to publish an ac- count of his life, for which purpose he applied to Mr Maclaurin for his assist- ance, who out of gratitude to his great benefactor readily undertook the task, and finished the history of the progress which philosophy had made before Sir