Effect of Electrical Convection. 



29 



The symbols have the following meanings : — E is the elec- 

 trometer reading, from which is deduced V, the potential of 

 the disks in volts, by means of the calibration curve of the 

 electrometer, 1\ the number of seconds required by the east 

 disk to make 1990 revolutions, T 2 the same for the disk on 

 the west side, N the mean number of revolutions of the two 

 disks per second deduced therefrom, i the test-current 

 measured in amperes, cl and D as described above. The 

 ratio of the two systems of units is calculated from these data 

 in the manner described below. 



March 25, 1902. 



Table I. 



1 . . 



Direction of rotation: east disk + , west disk — . 



2d. 2D. E. 



T r T 2 . 



i. 



73 78 | 59-7 

 75 81 61-0 



72 j 80 59-5- 



73 82 60-5 

 72 85 61 



37-8 

 38-8 

 38-6 

 38-8 

 38-2 



424 

 42-2 

 42-4 

 42-0 

 41-8 



■389x10-41 



73-0 81-2 60-3 



38-4 



422 



•389x10-4 



V = 6310 volts. N=.49-3. Hence w = 3'00x 10 10 . 



Direction of rotation: east disk — , west disk-f . 



72 



72 

 73 



72 



75 



83 

 79 



85 



80 

 81 



60-5 38-6 42-2 

 610 390 42-6 



59-8 38-6 42-8 

 58-0 38-0 42-4 

 59 5 384 42-2 



•389x10-4 



72-8 



81-6 



59-8 38-5 42 5 



•389X10-4 



Y = 6260 volts. N=49*l. Hence i? = 2"95xl0 10 . 



Mean value of v : 2-98 x 10 10 . 



To compare the observed values of 2D with those which 

 should be expected on the assumption that the magnetic 

 effect of a moving charged body is similar to that produced 

 by a conduction current, the ratio v of the two systems of 

 electric units was calculated in the same manner as described 

 in the previous paper. No attempt was made at an accurate 

 comparison until all the observations had been completed. 



Referring to my previous paper w r e have 



where the symbols have the meanings there given. (I take 



