EuTHERFOKD. — Oil Magnetic Viscobitij. 



199 



20 



30 



40 



It will be observed that the curreut rises rapidly to a 

 maximum, and then slowly decreases in value through a long 

 interval of time. 



When more than two-thirds of the quantity of electricity 

 had already passed through the secondary, the slightest varia- 

 tion of the screw often caused large alterations in the deflec- 

 tion. 



This irregularity in the deflections was evidently due to the 

 fact that the current in the secondary was oscillating very 

 rapidly. 



It was not thought necessary to investigate the oscillations 

 further, as the subject has been treated experimentally by 

 Helmholtz, Schiller, and others. 



