264, Prof. G. F. FitzGerald <m the 



H — 9 • , 2 *° 



r\_oe y V s l J r 



-fL #2 ^ cos/?* — or 

 E=g 2 .-2".6 1 - 



r La z r 2 ( J r 



In this form it is evident at once that the highest terms 

 vanish in the longitudinal component 



r t r 



r # 



+ y«(« + ^ + 27-^ + ^) 



In order to get this we have to observe that when applied 

 to the circular part only 



Hf)-(f)-(9 v - 



Any particular typical term of this order vanishes over the 

 quartic cone the coefficient of h - — - — • 



This is the cone of intersections of the systems of spheres 

 x 2 + y* + z* = 20.x 

 with the cubics 



+ , 2 {(a + 2£ + 7-f^ + 7~1. 



In the particular case of a series of end-on vibrators for 

 which /3=7 = 0, this cubic breaks up into the plane x=0 

 and the quadric cone 



