602 PROF. J. J. THOMSON AND MR. G. F. C. SEARLE ON THE RATIO OF THE 
The following are the results of the weighings on two separate days ;— 
[1.] Temp. 17. 
[2.] Temp. 15-3.: 
Weio-lit of water put into funnel. 
4403-15 
4403-53 
Weight of water left in tan and tube. 
1-33 
1-35 
Volume of a piece of wax underneath the glass top 
-70 
0 
Weight of water in space between the cylindei-s is tlierefore 
4402-5-2 
4402-18 
Correction to vacuum. 
4-66 
4-06 
Correction for temperature. 
5-10 
3-91 
Correction for error in 500-grm. weight. 
•50 
•50 i 
Correction for inequality of arms .. 
•09 
•04 
Volume between the cylinders is. 
4412-87 
4411-29 
The mean of these is 
4412-08 c.c. 
which we take as the value of the volume between the cylinders. 
If d is the mean distance between the cylinders, I the length of the inner cylinder, 
a and h the radii of the outer and inner cylinders respectively 
so that 
4412-08 _ 
TT (« h) I ’ 
d = -94128 cm. 
^ 1 + z= 1-0800262 ; 
0 0 
2 log ^ = -1.5397063. 
The thicknesses of the pieces of ebonite between the guard rings and the cylinder 
at the top and bottom were respectively -2934 and -288. Correcting for the air space 
the effective length of the C 3 dinder is 
60-9784 + -2907 = 61-2691 cm. 
Hence the electrostatic measure of the capacity 
61-2091 
— -15397063 ’ 
= 397*927 cm. 
No correction is required for want of coincidence between the axes of the c^dinders, 
for if c he the distance between the axes the correction is proportional to c"/(a^ — d^)- 
In our experiments c was less than -01, so that the correction only amounts to one 
part in more than 30,000. 
