=1026.= Newton took no exercise, indulged in no amusements, and worked incessantly, often spending eighteen or nineteen hours out of the twenty-four in writing.--BALL, W. W. R. _History of Mathematics (London, 1901), p. 358._ =1027.= Foreshadowings of the principles and even of the language of [the infinitesimal] calculus can be found in the writings of Napier, Kepler, Cavalieri, Pascal, Fermat, Wallis, and Barrow. It was Newton’s good luck to come at a time when everything was ripe for the discovery, and his ability enabled him to construct almost at once a complete calculus.--BALL, W. W. R. _History of Mathematics (London, 1901), p. 356._ =1028.= Kepler’s suggestion of gravitation with the inverse distance, and Bouillaud’s proposed substitution of the inverse square of the distance, are things which Newton knew better than his modern readers. I have discovered two anagrams on his name, which are quite conclusive: the notion of gravitation was _not new_; but Newton _went on_.--DE MORGAN, A. _Budget of Paradoxes (London, 1872), p. 82._ =1029.= For other great mathematicians or philosophers, he [Gauss] used the epithets magnus, or clarus, or clarissimus; for Newton alone he kept the prefix summus.--BALL, W. W. R. _History of Mathematics (London, 1901), p. 362._ =1030.= To know him [Sylvester] was to know one of the historic figures of all time, one of the immortals; and when he was really moved to speak, his eloquence equalled his genius.--HALSTED, G. B. _F. Cajori’s Teaching and History of Mathematics in the U. S. (Washington, 1890), p. 265._ =1031.= Professor Sylvester’s first high class at the new university Johns Hopkins consisted of only one student, G. B. Halsted, who had persisted in urging Sylvester to lecture on the modern algebra. The attempt to lecture on this subject led him into new investigations in quantics.--CAJORI, F. _Teaching and History of Mathematics in the U. S. (Washington, 1890), p. 264._