Prof. Thomson on the Measurement of Electromotive Force. 321 



differences between those shown in Table II. and those shown in 

 Tables IV. and V., which agreeing on the whole closely with one 

 another fall considerably short of the former. 



* Distance between discs of absolute electrometer =■£■$ foot=£ inch. 



Area of each =•187 square foot. 



Force of gravity at Glasgow on unit mass =32*2 dynamical units of force; 

 that is to say, generates in one second a velocity of 32*2 feet per second. 



f This is most directly obtained by finding the force between the discs of the 

 absolute electrometer per square foot, and reducing, according to the inverse 

 proportion of squares of distances, to what it would have been if the distance 

 between them had been equal to the length of the spark. 



