708 



the strength of the current in the variable resistance. Besides we 

 used a resonance frequency meter of Hahtmann and Brai'n, with 

 wliich we could accurately determine definite frequencies (45 ; 45,5; 

 46 up to 55). The intermediate frequencies were interpolated by 

 means of the ampèremeter. The amplitude of the vibrations of the 

 cylinder was measured in the same way as in the former experi- 

 ments. However, in order to increase the precision we now took a 

 scale distance of 145 cm. 



In fig. 2 the results have been plotted graphically. The numbers 



