10 INDUCTION SHOCKS 
ascending limb of the curve of Fig. 3 steeper, but will 
also carry it higher; that is, the current induced in the 
secondary will not only reach its maximum intensity 
more quickly, but that maximum will be greater; this 
result being due to the fact that the intensity is greater 
the more rapid is the alteration in the field of force 
cutting the coil. 
While a current is flowing steadily through the pri- 
mary coil no induction is manifest; but when the current 
is broken there is produced in the secondary coil a 
break induced current. The agency generating this cur- 
rent is the sudden withdrawal of the field of force from 
the secondary coil. 
With the breaking of the primary circuit it would 
seem at first thought that the lines of force should dis- 
appear instantly and that there should be an instan- 
taneous leap of the break induced current from zero to 
maximum. As a matter of fact the growth of the break 
current, although very rapid, is not instantaneous, for the 
reason that with the breaking of the primary circuit 
the energy absorbed from the current at its make by 
the inductance within the coil is released and manifests 
itself as the " extra current," jumping across the points 
of broken contact as a spark and prolonging slightly 
the decay of the primary current. 
The chief difference between Fig. 10, p. 33, which rep- 
resents the course of a break induced current, and Fig. 3, 
