244 
DR. J, HOPKINSON AND MR. E. WILSON ON 
generator with 7 '2 amperes. In this case the motor is working at higher E.M.F. on 
open circuit than the generator. Curves corresponding to those in the Experiment 1 
were obtained and are marked in a similar manner. 
The potential curves in fig. 15 have been integrated, and the integral curves so 
obtained are given in fig. 16. These give therefore the inductions in terms of the 
time. 
3. In fig. 17 the frequency is 70, the generator is excited with 18‘6 and the motor 
with 11'5 amperes. The generator is working with a higher E.M.F. on open circuit 
Fig. 17. 
than the motor. The potential curves have been integrated, and the integral curves 
are given in fig, 18. 
It was observed that when the exciting current of the motor was decreased, that 
o 
of the generator being kept fairly constant (the two machines being equally excited 
with about 18 amperes each to begin with), the current between the machines 
