Most Eminent Persons IN EVERY NATION; . :: WPE e RIN ARE ACCURATELY DISFLAYED. A NEW EDITION, IN FIFTEEN VOLUMES, GREATLY ENLARGED AND IMPROVED. VOL. VI. LONDON: G. NICOL, E, NEWBERY, HOOKHAM and CARPENTER, and HURST, and J. WHITE. 1798. NEW AND GENERAL BIOGRAPHICAL DICTIONARY. TULER (LEONARD) was born at Bafil, on the 14th of L April 1707 [A]; he was the fon of Paul Éuler, and of Margaret Brucker (of i family illuit-ious in literature); and spent the first year of his life at the village of Richen, of which place his father was Protestart ministet. Being intended for the church, his father, who had himself ftudied 'under James Bernouilli, taught hini matheniarits, tvith a view to their proving the ground-work of his other tudies, and in hopes that they would turn out a noble and ufeful secondary occupation. But they were destined to become a principal one, and Euler, assisted and per. haps secretly encouraged by John Bernouilli, who cafily dif, covered that he would be the greatest scholar he should ever edus cate, soon declared his intention of devoting his life to that pura Tuit. This intention the wise father did not thwart, but the son did not so blindly adhere to it, as not to connect with it a more than common improvement in every other kind of useful learning, insomuch that in his latter days men often wondered how with such a superiority in one branch; he could have been so near to eminence in all the rest. Upon the foundation of the Academy of Sciences at St. Petersburg, in 1723; by Cathetine I, the two younger Bernouillis, Nicholas and Daniel, had gone thither, promising, when they set out; to endeavour to procure Euler a place in it: they accordingly wrote to him soon after, to apply his mathematics to physiology; he did so, and studied under the best naturalists at Bafil; but at the same time, i. e. in 1727, published a differtation on the nature and propagation of sound ; and an answer to the question on the mafting of ships, which the Academy of Sciences at Paris judged. * [A] Eloge, by N, Fuss ; from Maty's Review, March Vol. VI. . В 1784. worthy fary to go from there were difficultithem, had been worthy of the acceffit. Soon after this, he was called to St. Petersburgh, and declared adjatant to the mathematical clafs in the academy, a class, in which, from the circumstances of the times (Newton, Leibnitz, and so many other immortals having just ceased to live), no easy laurels were to be gathered. Nature, however, who had organized so many mathematical heads at one time, was not yet tired of her miracles; and Me added Euler to the number. He indeed was much wanted; the science of the calculus integralis, hardly come out of the hands of its creators, was still too near the stage of its infancy not to want to be made inore perfect. Mechanics, dynamics, and especially hydrodynamics, and the science of the motion of the heavenly bodies, felt the imperfection. The application of the differential calculus, to them, had been sufficiently successful; but there were difficoltics whenever it was necef. sary to go from the fluxional quantity to the fluent. With regard to the nature and properties of numbers, the writings of Fermat (who had been fo successful in them), and together with thefe all his profours, cesearches, were lgs. Engineering and navigation were reducedite.vague principles, and were founded on a heap of often contradictory: observations, rather than a regular theory. The irregularitijës: is the motions of the celestial bodies, and especially the complication of forces which influence that of the moon, veče till the disgrace of geometers. Practical astronomy had yet to wrestle with the imperfection of telefcopes, insomuch, that it could hardly be faid that any rule for making them existed.--Euler turned his eyes to all these objects; he perfected the calculus integralis; he was the inventor of a new kind of calculus, that of fines; he fimplified analytical operations; and, aided by thefe powerful helpmates, and the astonishing facility with which he knew how to subdue expreffions the most intractable, he threw a new light on all the branches of the mathematics. But at Catherine's death the academy was threatened with extinction, by men who knew not the connection which arts and sciences have with the happiness of a people. Euler was offered and accepted a lieutenancy on board one of the empress's thips, with the promise of speedy advancement. Luckily things changed, and the learned captain again found his own element, and was named Professor of Natural Philosophy in 1733, in the room of his friend John Bernouilli. The number of inemoirs which Euler produced, prior to this period, is astonishing [B], but what he ath the acbranches of mobile intractabileh which hele werful (b) On the theory of the more remark. famous solution of the isoperimetrical proable curves the nature of numbers and blemasand an infinity of other objects, fries the calculus integralis-the move the hundredth part of which would have ment of the celestial bodiegothe attrac. made an ordinary man illustrious. tion of Spheroidico-elliptical bodiestike did |