C44 
PROFESSORS A. W. REINOLD AND A. W. RUCKER 
If a sphere and cylinder are in communication, the radius of the sphere must be 
twice that of the cylinder if.the films are to be in equilibrium when they have the 
same surface tension. The following results apply to a case in which the radii of the 
rings which support the sphere are 1*6 times greater than that of those to which the 
cylinder is attached. The symbols with dashes affixed refer to the sphere. 
Y=l, X=l-25, <^=0*625 = 35° 48', 
a=/3=l, E = F = A 1 =l, 
Y'=1'6, X'=1‘25, a'—2, (3' = 0, 
Sec 0 1 , =a , /Y / =l‘25, <^'=36° 52', 
E=; sin <f>i= 0'59995, F = log<, tan^+^ ^ = 0-69307, 
A i = COS (f) x \ 
Since dV = — dV', we get from equation (10) 
da{1 — (cot (f) l — tan </q)} /tan (f> l 
— 2da 11 — (sin </>/+ cosec </>/)log,tan^ +J/log, tan 
or 
da— — 2 , 0343<r/a / . 
In like manner, from equation (8) 
da-\-d/3= — 0'922Sda, 
c?a'+c/yS'= — l’dOScZa'. 
If, as before, dY—0, we get from (12) 
dT=-~,X 3-2812 da = ——- 0 X IT 129 da, 
a + (3 a + /3 
or, since a-\-/3=2, 
2(da — da')T/dT= — 3*699,.(U) 
which gives the sensitiveness in this case. 
The general result of this investigation is to prove that our apparatus was capable 
of being used so as to be far more sensitive than .Plateau's, and probably than 
Ludtge’s, as used by him. The latter does not mention the diameter of the tube he 
employed; but if we assume that Plateau’s bubble had a radius of 0'5 cm. (which 
seems to have been the smallest he used), and that Ludtge’s tube had a radius of 
1 cm., and that the sagittse of the spherical segments were half the radius, we find 
