DIAMAGNETIC ELECTRIC ENGINE. 137 



a straight bar, a semi-circular bar of iron, adapted 

 to pass through two semi-circular helix coils. 



This machine, operated by a voltaic battery, de- 

 veloped considerable effective power in moving 

 a locomotive engine on a railroad in Washington ; 

 but failed to produce mechanical action as cheaply 

 as by the combustion of coal. 



