78 Mary Somerville. 



I did not go into society, I rose early, and, 

 having plenty of time, I resumed my mathe- 

 matical studies. By this time I had studied 

 plane and spherical trigonometry, conic sections, and 

 Fergusson's "Astronomy." I think it was imme- 

 diately after my return to Scotland that I attempted 

 to read Newton's " Principia." I found it extremely 

 difficult, and certainly did not understand it till 

 I returned to it some time after, when I studied 

 that wonderful work with great assiduity, and wrote 

 numerous notes and observations on it. I obtained 

 a loan of what I believe was called the Jesuit's 

 edition, which helped me. At this period mathe- 

 matical science was at a low ebb in Britain; reverence 

 for Newton had prevented men from adopting the 

 "Calculus," which had enabled foreign mathema- 

 ticians to carry astronomical and mechanical science 

 to the highest perfection. Professors Ivory and 

 de Morgan had adopted the " Calculus"; but several 

 years elapsed before Mr. Herschel and Mr. Babbage 

 were joint-editors with Professor Peacock in pub- 

 lishing an abridged translation of La Croix's 

 "Treatise on the Differential and Integral Cal- 

 culus." I became acquainted with Mr. Wallace, 

 who was, if I am not mistaken, mathematical 

 teacher of the Military College at Marlow, and 

 editor of a mathematical journal published there, 



