formed by Contact of a Liquid with a Cylinder. 839 

 OY, and at any point P (w s y) the equation to the surface is 



JL 1 _ i 



(i.) 



__ T 



where a 2 — — , and a is therefore of the dimensions of a 

 99 



o" ■* |° * ° / 



/ 



I 



length. R x and R 2 , the principal radii of curvature at P, 

 are given by 



(l+3/i 2 ) S/2 



Ri= — - 



#2 



and 



_ x x^/l+yi 2 



R 2 = PN=-^- A = 



remembering that 



sin 6 -y x 



tan 0= — tan (f)=—y 1 . 



Hence, substituting in (i.) and clearing of fractions we have 

 for the differential equation of the meridional curve 



or 





(ii.) 



