Mathematics. 79 



I had solved some of the problems contained in 

 it and sent them to him, which led to a corres- 

 pondence, as Mr. Wallace sent me his own solutions 

 in return. Mine were sometimes right and some- 

 times wrong, and it occasionally happened that we 

 solved the same problem by different methods. At 

 last I succeeded in solving a prize problem ! It was 

 a diophantine problem, and I was awarded a silver 

 medal cast on purpose with my name, which pleased 

 me exceedingly. 



Mr. Wallace was elected Professor of Mathematics 

 in the University of Edinburgh, and was very kind 

 to me. When I told him that I earnestly desired 

 to go through a regular course of mathematical and 

 astronomical science, even including the highest 

 branches, he gave me a list of the requisite books, 

 which were in French, and consisted of Francceur's 

 pure "Mathematics," and his "Elements of Me- 

 chanics," La Croix's " Algebra," and his large work 

 on the " Differential and Integral Calculus," together 

 with his work on " Finite Differences and Series," 

 Biot's "Analytical Geometry and Astronomy," 

 Poisson's "Treatise on Mechanics," La Grange's 

 "Theory of Analytical Functions," Euler's "Algebra," 

 Euler's " Isoperimetrical Problems" (in Latin), Clair- 

 ault's " Figure of the Earth," Monge's " Application 

 of Analysis to Geometry," Callet's "Logarithms," 



