is only converted into these forces as 

 the current encounters and overcomes- 

 resistance. 



The operations of these two forms 

 are characteristically different. The for- 

 mer are feeble in power and are trans 

 m-issible to but short distances. They 

 act by continuity, and speedily diminish 

 in intensity as- the square of the distance 

 increases. The latter are transmissible 

 in any direction, and by any pathway, 

 and have scarcely any terestrial limits, 

 They are transported by wires over con- 

 tinents and beneath oceans, and many 

 miles of space have been traversed by 

 them without visible means of conduc- 

 tion. But, unlike the former, they do 

 not pass as sensible light and heat. 



Their functions differ. The magnetic 

 form of light may be employed in photo- 

 graphy, and by it the various shades of 

 color may be discerned in the night sea- 

 son. In strength and brilliancy the 

 magnetic light alone resembles that of 

 the sun. 



In our studies of these forces we have 

 been greatly impressed with :he similar 

 ity between the operations of the mag- 

 netic class and the productions of the 

 sun. This similarity naturally suggests 

 the question whether there is not good 

 reason to suppose that sunlight and sun 

 heat, as to their production, follow the 

 analogy of the superior process, rather 

 than the inferior, that its action is 

 magnetic, rather than combustive. 



Thip suggestion affords immense re- 

 lief. . If light and heat are regarded as 

 magnetic, we are apparently eased of 

 the^ great burden of finding adequate 

 supplies of material to keep up, and to 

 keep uniform, the vast conflagration sup- 



