1287 
(If the figure refers to the whole magnetic moment, the horizontal 
one, on which the residual field acts may be derived from it by 
multiplication by a certain constant factor). ; 
The magnetization passes through ABC or DEF in a certain 
HEEE ie 
Seemee Ae 
Eee ee eae 
EAA HA 
EH 
EERS 
eee 
HEZE 
Deegan 
CELE EEE 
time z’.') Now it is evident that, in the case of a perfect compen- 
} 
sation 77, the forces exerted by the residual field would be wholly 
neutralized, if the magnetization followed the line OC. For then it 
would inerease proportionally to 7 and so the action of the residual 
field on the magnetic moment of the cylinder and that of the current 
in the compensating coil on the transverse magnet would also 
change proportionally to each other. They would neutralize each 
‘) We may imagine the breaking of the current and therefore the change re- 
presented by FGA or CHD to take place in an extremely short time, so that 
the forces acting ou the iron during this time cannot have an appreciable in- 
fluence on its motion. The interval in question may be neglected with respect to 
the time +’ necessary for the changes ABC or DEF, which take place after the 
above considered interval + during which the remanent magnetization OA or OD 
has existed. On account of the self-induction it lasts an observable time 7’ after 
the closing of the circuit before the current has reached its full intensity 7, (OK 
or OL) and the magnetic moment the corresponding value M, (KC or LF). 
