SIMSON (Da. Ransil-0, in biography, professor of mathematics in the Universi ty of Glasgow, was born in the year 1687, of a respectable family, which had held a small estate in the county of Lanark for some generations. He was, we think, the second son of the family. A younger brother was professor of medicine in the University of St. Andrews, and is known by some works of reputation, particularly "A Dissertation on the Nervous System." occasioned by the dissection of a brain completely ossified.
Dr. Simson was educated in the Univer sity of Glasgow, under the eye of some of his relations who were professors. Eager after knowledge, he made great progress in all his studies : and as his mind did not, at the very first openings of science, strike into that path which afterwards so strongly attracted him, and in which he proceeded so far almost without a com panion, lie acquired in every walk of science a stock of information which, though it had never been much augment ed afterwards, would have done credit to a professional man in any of his studies. He became, at a very early period, an adept in the philosophy and theology of the schools, was able to supply the place of a sick relation in the class of oriental lan guages, was noted for historical know ledge, and one of the most knowing bota nists of his time. As a relief to other stu dies, he turned his attention to mathe matics. Perspicuity and elegance he thought were more attainable, and more discernible in pure geometry, than in any other branch of the science. To this therefore he chiefly devoted himself; for the same reason he preferred the ancient method of studying pure geometry. He considered algebraic analysis as little bet ter than a kind of mechanical knack, in which we proceed without ideas, and ob tain a result without meaning, and with out being conscious of any process of rea soning, and therefore without any convic tion of its truth. Such was the ground of the strong bias of Dr. Simson's mind to the analysis of the ancient geometers. It increased as he advanced, and his vene ration for the ancient geometry was carri ed to a degree of idolatry. His chief la bours were exerted in efforts to restore the works of the ancient geometers. The inventions of fluxions and logarithms at tracted the notice of Dr. Simson, but he has contented himself with demonstrat ing their truth on the genuine principles of ancient geometry.
About the age of twenty-five, Dr. Sim son was chosen Regius Professor of Ma thematics in the university of Glasgow. He went to London immediately after his appointment, and there formed an ac quaintance with the most eminent men of that bright era of British science. Among these he always mentioned Captain Hal ley (the celebrated Dr. Edmund Halley) with particular respect ; saying, that he had the most acute penetrstiou, and the most just taste in that science, of any man he had ever known. And, indeed, Dr. Hal
ley has strongly exemplified both of these in his divination of the work of " Appol toning de Sectione Spatii," and the eighth book of his " Conics," and in some of the most beautiful theorems of Sir Isaac New ton's "Principia." Dr. Simson also admir ed the wide and masterly steps which Newton was accustomed to take in his in vestigations, and his manner of substitut ing geometrical figures for the quantities which are observed in the phenomena of nature. It was from Dr. Simson that his biographer, to whom we are indebted for this article, learnt, "That the thirty-ninth proposition of the first book of the Prin cipia was the most important proposition that had ever been exhibited to the phy. sico-mathematical philosopher; and he used always to illustrate to his more ad.
vaned scholars the superiority of the ge ometrical over the algebraic analysis, by comparing the solution given by Newton of the inverse problem of centripetal forces, in the 42d proposition of that book, with the one given by John Bernoulli in the Memoirs of the Academy of Sciences at Paris for 1713. He had heard him say, that to his own knowledge Newton fre quently investigated his propositions in the symbolical way, and that it was owing chiefly to Dr. Halley that they did not finally appear in that dress. But if Dr. Simson was well informed, we think it a great argument in favour of the symbolic analysis, when this most successful prac tical artist (for so we must call Newton when engaged in a task of discovery) found it conducive either to dispatch, or perhaps to his very progress Returning to his academical chair, Dr. Simson dis charged the duties of a professor for more than fifty years, with great honour to the university and to himself. It is almost needless to say, that in his prelections he followed strictly the Euclidian method in elementary geometry. He made use of Theodosius as an introduction to apheri. cal trigonometry. In the higher geome try, he lectured from his own Conics ; and he gave a small specimen of the li near problems of the ancients, by ex plaining the properties, sometimes of the conchoid, sometimes of the cissoid, with their application to the solution of such problems. In the more advanced class, he was accustomed to give Napier's mode of conceiving logarithms, i. e. quantities as generated by motion; and Mr. Cotes's view of them, as the sums of ratiunculm ; and to demonstrate Newton's lemmas concerning the limits of ratios; and then to give the elements of the fluctionary calculus ; and to finish his course with a select set of propositions in optics, gnomonics, and central forces. His me thod of teaching was simple and perspi. cuous, his elocution clear, and his man ner easy and impressive. He had the respect, and still more, the affection, of his scholars.