450

INVENTIONS OF NTKOIA TESLA.

This machine possesses several advantages. For example, if wemagnetize the cores alternately, as indicated by the characters ns, it will be seen that the magnetic circuit between the poles ofeach part of a casting is completed through the solid iron sidebars. The bearings for the shaft are located at the neutral pointsof the held, so that the armature core is not affected bv the mag-netic condition of the held.

The improvement is not restricted to the use of four pole pieces,as it is evident that each pole piece could be divided or more thanfour formed by the shape of the casting.