PROF. J. J. THOMSON AND MR. G. P. C. SEARLE ON THE RATIO OF THE 
The means of the observations at different speeds are given in the following table. 
Speed. 
Electromagnetic 
measut-e of 
capacity x 10“-i. 
i 80 
443-327 
: G4 
443'434 
i t)5 
443-701 
' 48 
443-478 
42 
443-418 
‘ 32 
443-460 
10 
443-675 
The means for the different speeds thus agree very well together, the greatest 
difference from the mean being about one part in 2000. There does not seem any 
indication of an effect depending on the number of times the condenser is charged per 
second, such as was very marked in Professor Rowland’s experiments (‘ Phil. Mag.,’ 
vol. 28, 1889). 
Since the electrostatic measure of the capacity is 397'927, and the electromagnetic 
measure 443'454 X 10~~^ 
= 2*9955 X 10 ^° cm. sec~'. 
The value of the B.A. unit is taken to be •9807 X 10'^ in absolute measure. 
This value of “ v ” agrees very nearly indeed wuth tlie value obtained by the most 
recent experiments for the velocity of light in air, these are 
Cornu (1878) 
Michelson (1879) 
Michelson (1882) 
Newcomb (1885) 
• 7 
In conclusion we desire to express our thanks to Mr. 11. S. Cole, of Emmanuel 
College, vdro lias given us valuable assi.stance on several occasions. 
3'003 X 10^'^ cm. sec b 
2-9982 X lOR 
2-9970 X 10^0. 
2-99015 n 
2-99(582 y X fU^b 
2-99700 J 
