PEIRCE. — ESTABLISHMENT OF CURRENT IN COIL. 



159 



Figure 8. The value of di/dt for a reverse current in the coil of the magnet 

 J when i? = 19.5 and r = 15. 



Figure 7. The full curve, OP, shows the rate of increase of the flux of 

 magnetic induction through the core of the magnet J while a reverse current 

 of 1.3 amperes is being established in the exciting coil of 1394 turns. The 

 current curve is shown on an arbitrary scale by the dotted line. 



