1 66 THE POPULAR SCIENCE MONTHLY 



Clairaut and Eeaumer were leaders in the academy from 1700 to 1750, 

 but Clairaut can not be put by the side of Newton in mathematics, or 

 even of Leibniz, nor, eminent as he was, had he the creative mind of 

 Bernouilli. Yet he was not without honor in other countries as well as 

 in his own. In 1750 his Lunar Tables were crowned by the Academy 

 of St. Petersburg. Eeaumer, a many-sided man, carried physics to the 

 heights where Buffon and Cuvier found them. Yet during the first 

 half of the century the academy was unable to point to many men of 

 the first rank among its members. Nearly all of them were men of 

 ability, eager in the pursuit of knowledge, but wanting in those peculiar 

 gifts which belong to men like Newton, or Descartes, or Leibniz. Yet 

 the academy did a vast deal of excellent work. Problems relating to the 

 sun, the moon and the earth were carefully and patiently studied. New- 

 ton's theories were shown by D'Alembert to be true, Bradley's discovery 

 of aberration of the stars was made more valuable by measuring that of 

 the planets and of the sun, and by estimating the amount of attraction 

 on the earth. Thury discussed the figure of the earth. Thus, as M. 

 Maury says, " a sort of propylea was formed for the Mecanique celeste 

 of La Place." If Clairaut lacked somewhat in intellectual domination 

 on account of the gruffness of his manners and his love of solitude, in 

 all these respects Eeaumer was his opposite. At his reception into the 

 academy he read a paper on gravity, but he devoted his life to the study 

 of the problems of physics. Dissatisfied with the Florence thermometer 

 then in general use, he invented one which met the needs of the time. 

 He made important discoveries in zoology, and wrote a fine history of 

 insects. In practical affairs he was useful in improving the methods 

 employed in the manufacture of pottery, and to his suggestions the 

 iron industry owes a great deal. It is not surprising that with his 

 attractive manners, his genial disposition, he should rule the academy 

 for a score of years, and that he and Clairaut should be universally 

 regarded as its two greatest men, whose fame was eclipsed in later years 

 only by D'Alembert and Buffon. 



New sciences like embryology gradually appear, and the sphere of 

 those already studied is largely widened. De Lagny, who died in 1733, 

 made important contributions to geometry and trigonometry, Nicole 

 to the calculus of infinite distances. Joseph Saurin, 24 years older than 

 Nicole, a Cartesian in physics but a Newtonian in mathematics, was 

 also eminent for his knowledge of geometry. Carre published tlie 

 differential calculus of Marquis de I'Hopital, and Varignon, Fontaine 

 and Clairaut improved and rendered more valuable the discoveries of 

 Leibniz and Newton. The differential calculus we owe, so it is asserted, 

 to the two Bernouillis, Joseph and Jean. During the period from 1699 

 to 1750 the academy was an important aid to mechanics, and it made 

 large contributions to the knowledge of astronomy and geometry. In 

 the first quarter of the century Dominique Cassini by his published 



