Conic Sections. 



265 



X 



+ 

 X 



'■a 



u 



H- 



SI- 

 + 



+ 



CI 



+ 



1-0 





CN 



HN 



»* 





o 



3 



re 

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-H I 



(N 



o 

 o 



+ 



>» i-1j 



Vol. XXXL— No. 2. 



