The Theory of Automatic Regulators. 287 
It will now be interesting to see how ^ alters when load rushes occur. 
We shall again assume a fluctuation from one quarter to full load. For 
550 volts and no load the excitation is 8'2 amperes, or 100000 ampere turns. 
If this voltage is to be kept constant, the excitation for one quarter load 
must be 8*75, for full load, 10*5 amperes (taken from the no-load charac- 
teristic, not given). The ratio ^1 must thus increase from 4-65 at no-load 
to about 6'0 at quarter load and ll'O at full load. This alteration is caused 
by the generator solenoid So, the position of whose core indirectly influences 
the tension of spring and thus the above ratio. 
