437J 
115 
437. 
DÉMONSTRATION NOUVELLE DU THÉORÈME DE M. CASEY 
PAR RAPPORT AUX CERCLES QUI TOUCHENT À TROIS 
CERCLES DONNÉS. 
[From the Annali di Matematica pura ed applicata, tom. I. (1867), pp. 132—134.] 
This is in fact the investigation contained in the paper 414, “ On Polyzomal Curves otherwise the curves 
\/t7+vF-f &c. = 0,” Annex ii. pp. 568—573, “On Casey’s theorem for the circle which touches three given 
circles,” viz. it is based on the identity of the two problems 1° to find a circle touching three given circles, 
2° to find a cone-sphere (sphere of radius zero) passing through three given points in space. 
15—2