356 Mary Somerville. 



but I have no doubt that it will be decided in the 

 affirmative, and that even the cause of gravitation 

 will be known eventually. 



At this time I had the pleasure of a visit from 

 Mr. Peirce, Professor of Mathematics and Astronomy, 

 in the Harvard University, U.S., and Superintendent 

 of the U.S. Coast Survey, who had come to Europe 

 to observe the eclipse. On returning to America 

 he kindly sent me a beautiful lithographed copy of 

 a very profound memoir in linear and associative 

 algebra. Although in writing my popular books I 

 had somewhat neglected the higher algebra, I have 

 read a great part of the work ; but as I met with 

 some difficulties I wrote to Mr. Spottiswoode, asking 

 his advice as to the books that would be of use, and 

 he sent me Serret's " Cours d'Algebre Supe'rieure," 

 Salmon's " Higher Algebra," and Tait on " Quater- 

 nions ; " so now I got exactly what I wanted, and I 

 am very busy for a few hours every morning ; de- 

 lighted to have an occupation so entirely to my 

 mind. I thank God that my intellect is still 

 unimpaired. I am grateful to Professor Peirce 

 for giving me an opportunity of exercising it so 

 agreeably. During the rest of the day I have 

 recourse to Shakespeare, Dante, and more modern 

 light reading, besides the newspapers, which always 

 interested me much. I have resumed my habit 



