1 6 1 Mijcellanea Curiofa. 



leaft Refiftance. Draw BM, GP, perpendi- 

 cular to ACL, alfo BL, GN, parallel to ACL, 

 and ON, parallel to BM. 



cx BM * GL 3 

 Now — — — , is the Refiftance up- 



r x GB 2 



on the Surface generated by the Rotation of 



cxGPxON* 



the Lineola GB about ACL, and — . — , 



r x GO* 



h the ReiTftancfc upon the. Surface generated 

 OG, in like manner ( by Cor. * 3, ) And 

 the Sum of both thefe Refinances muft be 

 a Minimum, viz. 



c x BM x GL 5 c x GP x ON 3 



_ — \ — c= a Mini- 



rxGB 2 rxOG* 

 mum. 



And confequently in the Line RS (fo pa- 

 rallel to ACL that ON = GL) the point G 

 is to be fought, fuch, that this may happen } 

 which, fuppofing the points O and B to be 

 flrd, will be eafily found by the common 

 Method, de Maximis & Minimis. And pro- 

 fecuting the Calculus, we [hall come at laft 



BM x BL GP x NG 



to this Equation, := — — ; 



BG + OG 4 



BM x BL 



whence 'tis plain that- — =:' a con- 



BG 4 



ftant Quantity. . So that if the AbfcilTe 

 AM Xj and the Ordinate BM then 

 will BL dx, LG dy (which I have ftp- 



pos'd 



