350 



Electro Magnetism. 



Art. XVIII. — Electro Magnetis^n; by Charles G. Page, M. D., 

 WashingtoDj D. C. 



In YoL XXXV, No, 2, of this Journal, I described a revolving 

 armature and mentioned that the plan admitted of enlargement 

 only with the alteration of the mode of revolution. I must pre- 

 mise here, (as I have heretofore expressed myself.) that I do not 

 suppose this power susceptible of infinite increase, and in giving 

 these descriptions to the public, I am only selecting from the mul- 

 titude of machines I have constructed, such forms as obviously 

 economize a given galvanic power. A number of machines 

 wherein the poles of the magnets were changed, and others where 

 the poles were not changed, but both systems, the stationary and 

 revolving, were rendered magnetic and non magnetic at intervals, 

 have been laid aside as not worth describing. Another form 

 wherein the magnets were made to revolve and attracted by sta- 

 tionary armatures is obviously defective, as will be readily seen by 

 referring to figure 3d, and supposing the systems reversed. If the 

 armatures were stationary, and the charged magnets revolving, 

 the magnets would always be attracted by the nearest armature ; 

 consequently the magnets would be charged only during one half 

 of a revolution. Figures 1, 2, and 3, are modifications on a large 

 scale of the revolving armature described in No. 2, of the last vol- 

 ume of this Journal. In figure 1, h b, are two Electro Magnets 



Fig. 1. 



disposed at right angles to each other, and firmly secured to 

 wooden pillars. Where it is practicable, the magnets should be 



