﻿Manchester Memoirs, Vol. xlix. (1905), No. 4- 3 



the same shape as the upper surface AOB. Through O, 

 the centre of AOB, draw two lines, OY, OX, the former 

 coinciding with the axis of the cylinder and the latter 

 being at right angles to it. 



Let / = pressure per unit area on the surface AB. 

 /= length of cylinder. 

 R = radius of cylinder. 

 rj = coefficient of rigidity of the jelly. 

 Considering the equilibrium of a mass contained within a 

 cylinder of radius x, we obtain for the differential equation 

 of the section of the surface AOB, 



whence 



27r.Tr// -r =p x 7rX 



y — — ix A 



The surface AOB is thus a paraboloid of revolution 

 and it can easily be shown algebraically that the volume 



between AB and AOB equals 



tt/R 4 

 8r// " 



It may be inci 



dentally mentioned that the result is analogous to the flow 

 of a viscous fluid along a tube of circular bore, 



The apparatus used in the actual experiments is shown 

 diagrammatically in Fig. 2. 



The glass tube EF is closed at its extremities with 



