88 JAMES CLERK MAXWELL. [CHAP. IV. 



The following letters to his father still belong to 

 his schoolboy life : 



[April] 1847. 



I have identified Descartes' ovals with mine. His 

 first oval is an oval with one of its foci outside ; the second 

 is a meloid with a focus outside. It also comprehends the 

 circle and apioid. The third is a meloid with both foci 

 inside ; and the fourth is an oval with both foci inside." 







He says with regard to the last that rays from A are re- 

 flected to B, which I can disprove. . . . 



[This is interesting as a proof of the complete independ- 

 ence and originality of the communication made to the Eoyal 

 Society on April 6th, 1846. It is also important as an 

 example of that love of comparing his own results with 

 great authorities, which made Maxwell the most learned as 

 well as the most original of scientific men. See above, p. 

 74, where Forbes promises to consult books on the subject, 

 and the references to Descartes in the Proceedings. Forbes 

 cannot, however, have made any very careful scrutiny into 

 the history of the matter, else he would have mentioned 

 that Descartes actually figures the cord by which his ovals 

 are described, and his process is precisely that of Maxwell.] 



