=958.= The general knowledge of our author [Leonhard Euler] was more extensive than could well be expected, in one who had pursued, with such unremitting ardor, mathematics and astronomy as his favorite studies. He had made a very considerable progress in medical, botanical, and chemical science. What was still more extraordinary, he was an excellent scholar, and possessed in a high degree what is generally called erudition. He had attentively read the most eminent writers of ancient Rome; the civil and literary history of all ages and all nations was familiar to him; and foreigners, who were only acquainted with his works, were astonished to find in the conversation of a man, whose long life seemed solely occupied in mathematical and physical researches and discoveries, such an extensive acquaintance with the most interesting branches of literature. In this respect, no doubt, he was much indebted to an uncommon memory, which seemed to retain every idea that was conveyed to it, either from reading or from meditation.--HUTTON, CHARLES. _Philosophical and Mathematical Dictionary (London, 1815), pp. 493-494._ =959.= Euler could repeat the Aeneid from the beginning to the end, and he could even tell the first and last lines in every page of the edition which he used. In one of his works there is a learned memoir on a question in mechanics, of which, as he himself informs us, a verse of Aeneid[6] gave him the first idea. --BREWSTER, DAVID. _Letters of Euler (New York, 1872), Vol. 1, p. 24._ [6] The line referred to is: “The anchor drops, the rushing keel is staid.” =960.= Most of his [Euler’s] memoirs are contained in the transactions of the Academy of Sciences at St. Petersburg, and in those of the Academy at Berlin. From 1728 to 1783 a large portion of the Petropolitan transactions were filled by his writings. He had engaged to furnish the Petersburg Academy with memoirs in sufficient number to enrich its acts for twenty years--a promise more than fulfilled, for down to 1818 [Euler died in 1793] the volumes usually contained one or more papers of his. It has been said that an edition of Euler’s complete works would fill 16,000 quarto pages.--CAJORI, F. _History of Mathematics (New York, 1897), pp. 253-254._ =961.= Euler who could have been called almost without metaphor, and certainly without hyperbole, analysis incarnate.--ARAGO. _Oeuvres, t. 2 (1854), p. 433._ =962.= Euler calculated without any apparent effort, just as men breathe, as eagles sustain themselves in the air.--ARAGO. _Oeuvres, t. 2 (1854), p. 133._