444 CAVENDISH. 



of physical and of practical astronomy of the theory of 

 mathematical and astronomical instruments of me- 

 chanical and dynamical sciences, both theoretical and 

 practical of pure mathematics in all its branches, geo- 

 metry, the integral and differential calculus, the doctrine 

 of chances and annuities. He seems in his application 

 of mathematics to physics to have disregarded elegance, 

 and even simplicity, and to have chosen always the 

 shortest and most certain path to his object. Accordingly 

 this somewhat surprises the mathematical reader ; as 



when we find him using ^7 (or rather ~r> for he 



always employs the Newtonian notation) for the sub- 

 normal, having taken x for some other quantity than 

 the abscissa, and using three letters, as a, 2, and a% to 

 denote segments of the same line, when perhaps a is 

 the whole line, and a x is equal to z. But that 

 he had the most familiar and masterly knowledge of 

 the calculus is plain throughout all his investigations, 

 as it is that his trust in its powers induced him to 

 throw himself willingly and habitually upon them. 

 In this respect he stands not only at the head of 

 chemical philosophers, but alone among them, with 

 perhaps one or two exceptions in the French school. 



In giving the history of his labours, and the cha- 

 racter of his intellectual capacity, we have written the 

 life of Cavendish. His personal history cannot be 

 expected to have any striking interest ; yet they who 

 have been dwelling on his scientific eminence will not 

 be displeased to know somewhat of his ordinary life. 

 He was of a most reserved disposition, and peculiarly 

 shy habits. This led to some singularity of manner, 



