SIEMEN'S GALVANOMETER. 229 



oscillations are about the axis of revolution, the magnet is always in 

 the same position in respect of the sphere ; it follows from this that, 

 different to what is the case in other arrangements, the induced 



Fig. 163. 



currents are strictly proportional to the velocity, whatever be the 

 amplitude of the oscillations. 



As these induced currents are very strong, and the oscillating 

 system has a very small moment of inertia, so great a damping 

 is easily obtained that the motion becomes aperiodic. 



