Babbage, Peacock, Whewell 119 



Whewell (1794-1866), whose name will chiefly be remem- 

 bered by his " History of the Inductive Sciences," a book 

 in three volumes published in 1837, and containing a large 

 quantity of useful information. Whewell ultimately became 

 Master of Trinity College, and gained great influence in the 

 University, but his attitude in later life became strongly 

 conservative and antagonistic to all proposed reforms. 



A new branch of science " Physical Optics " emerged 

 from the work of Fresnel and Young, and when Arago and 

 Brewster had discovered the beautiful colour effects shown 

 by polarized light transmitted through plates cut out of 

 crystals, mathematicians had a good opportunity of applying 

 their talents to test the powers of the wave-theory. When, 

 as in Arago's experiments, the light sent through the plate 

 is confined to a parallel beam, the difficulties are compara- 

 tively slight, and were dealt with satisfactorily by the 

 French physicists. But a number of parallel beams sent 

 through the plate in all directions, and properly locussed, 

 show more complicated and very beautiful effects, coloured 

 bands being crossed by light or dark brushes of various shapes. 

 The mathematical analysis then becomes more formidable, 

 especially when the crystals have as in the case of quartz 

 the peculiar property of turning the direction of the light 

 vibration. Among those who successfully attacked these 

 problems Airy held a distinguished place. 



George BiddeU Airy (1801-1892) had a brilliant Univer- 

 sity career. He entered the University at the age of eighteen, 

 and four years later graduated as Senior Wrangler, and 

 obtained the first Smith's prize. In 1826 he was elected to 

 the Lucasian Professorship, a position which Newton's name 

 has always invested with a certain glamour. 



Though keenly interested in many branches of Physics, 

 Airy was more particularly attracted by astronomical pro- 

 blems, and when a vacancy in the Plumian Professorship 

 occurred in 1828, he became a candidate, and after election 

 took charge of the Cambridge Observatory, which had just 

 been established, mainly through the efforts of George 

 Peacock. The wide range "of subjects enriched by Airy's 

 investigations may be illustrated by noting the titles^of his 

 first six contributions to science. These were : "On the 



