PEIRCE. — BEHAVIOR OF THE CORE OF AN ELECTROMAGNET. 153 



belonging to Q. The curves M> N were taken with a secondary coil 

 of 16 turns and comparatively high resistance closed ; the boundaries 



SECONDS. 



Figure 46. 



Direct and reverse current curves for a coil of 1394 turns belonging to the 

 magnet Q when a secondary circuit of 1394 turns was closed and open. 



of the shaded areas m, n show the forms of the currents induced in 

 this secondary as obtained from an oscillograph in the circuit. Since 



SECONDS. 



Figure 47. 



Direct and reverse curves representing currents in a primary coil of 823 turns 

 belonging to the magnet Q, for open and closed secondary circuit. The second- 

 ary coil had 2788 turns. For the curves which start at the voltage was about 

 20.6 ; for the curves which begin at X the voltage was about 82 and the maximum 

 current 7.55 amperes. 



