Mifcellanea Curioja. 361 



Menifci the fame difference becomes 



— L L. — . 0 f wn i c h I need give no 



g r — J f + r & 

 other Demonftration,but that by a due Reduction 

 it will fo follow from what is premifed, as will 

 the Theorems for all forts of Problems relating to 

 the Foci of Optick-Glaffes 



a 4 AP- 



