Leonard Euler, Supreme Geometer (1707-1783)

Abstract

Leonard Euler, Supreme Geometer (1707-1783)' C. Truesdell On AUGUST 23, 1774, within a month of his appointment as Ministre de la Marine and the day before he was made Comptrolleur General of France, Turgot wrote as follows to Louis XVI: The famous Leonard Euler, one of the greatest mathemati­ cians of Europe, has written two works which could be very use­ ful to the schools of the Navy and the Artillery. One is a Treatise on the Construction and Manoeuvering of Vessels; the other is a commentary on the principles of artillery of Robins ... I propose that Your Majesty order these to be printed; . . . It is to be noted that an edition made thus without the consent of the author injures somewhat the kind of ownership he has of his work. But it is easy to recompense him in a manner very flat­ tering for him and glorious to Your Majesty. The means would be that Your Majesty would vouchsafe to authorize me to write on Your Majesty’s part to the lord Euler and to cause him to re­ ceive a gratification equivalent to what he could gain from the edition of his book, which would be about 5,000 francs. This sum will be paid from the secret accounts of the Navy. ’’The famous Leonard Euler,” then sixty-nine years old and blind, was the principal light of Catherine H’s Academy of Sciences in Petersburg. His name had figured before in the correspondence be­ tween Turgot, the economist and politician, and Condorcet, the * Acknowledgment. I am grateful to Dr. Marta Rezler for correction of some details regarding Voltaire. The research reported here was supported in part by a grant of the U.S. National Science Foundation to The Johns Hopkins University. 51 Irrationalism in the Eighteenth Century prolific if rather superficial mathematician and litterateur soon to become Perpetual Secretary of the Paris Academy of Sciences, and later first an architect and then a victim of the Revolution. Just twenty years afterward Condorcet was to die because his hands had been found to be uncalloused and his pocket to contain a volume of Horace, but in 1774 equality, while already advocated and projected by Turgot, had not progressed so far. In a France threatened by bankruptcy a minister of state could still find time to write in letters to a friend his opinions and doubts and conjec­ tures about everything from literature to manufacture, and by the way the solution of algebraic equations. It was such a minister who asked whether "this Euler, who lets nothing slip by unno­ ticed, might have treated in his mechanics or elsewhere’’ the most advantageous height for wagon wheels.1 In a time when intelligence was the highest virtue, when even men and women then thought to be lazy and stupid (and today proved by their words and deeds to have been lazy and stupid) were portrayed with little wrinkles of alertness around their sparkling, understanding eyes, the name of Leonard Euler, the greatest mathematician of the century in which mathematics was almost unexceptionally regarded as the summit of knowledge, was better known than those of the literary and musical geniuses, for example Swift and Bach. In the firmament of letters only Vol­ taire outshone Euler. True, in all the world there were but seven or eight men who could enter into discourse with him, Voltaire certainly not being one of them, and most of what he wrote could be understood in detail by only two or three hundred, Voltaire not being one of these either, but pinnacles could then still be ad­ mired from below. In the volume for 1754 of The Gentleman’s Magazine, a British periodical of general interest the contents of which ranged from heraldry to midwifery, we find an article en­ titled "Of the general and fundamental principles of all mechan­ ics, wherein all other principles relative to the motion of solids or fluids should be established, by M. Euler, extracted from the last Berlin Memoirs." The anonymous extractor concludes that Euler’s principle "comprises in itself all the principles which can contrib­ ute to the knowledge of the motion of all bodies, of what nature...