OF ELECTROSTATIC UNITS IN THE ELECTROMAGNETIC UNIT. 
427 
turns in each of the coils, and that the estimate of their electromagnetic effect derived 
from this was as nearly as possible accurate. 
The mean value of v given by all the series of observations of 1870, which include, 
however, considerable variations, is 294’5xl0 8 centims. per second. The mean result 
of the later comparisons, excluding those which have been mentioned as less trustworthy, 
is 292 - 4xl0 8 centims. per second. 
These later observations were made under much more favourable circumstances ; still, 
as the causes of the variations in the earlier comparisons are not known, it has been 
thought right to include them also in the record of the observations. 
The last measurement, that of 1872, furnishes the most probable value of v, 293 x 10 s 
centims. per second. 
