CH. IV SHUNT-WOUND MOTOKS 93 



An electric steering gear has been made on this prin- 

 ciple by the Union Electricitats Gesellschaft, a descrip- 

 tion of which may be found in the ' Elektrotechnische 

 Zeitschrifb,' 1897, No. 5. Two multipolar motors are 

 connected by a differential driving gear to the main shaft 

 operating the rudder, in such a way that when rotating 

 at equal speeds in opposite directions they communicate 

 no motion to the main shaft. The two armatures are 

 connected in parallel, and the magnets in series with one 

 another : a rheostat is placed in parallel with each magnet 

 circuit. When the main shaft has to be moved, the 

 induction factor of one motor is increased, and of the other 

 is decreased, by altering the resistance in the rheostats 

 in parallel with the magnets. 



