28 New Theories of the Great Forces. 



between these great bodies, may be found A 

 Grand Magnetic Circuit. In this grand 

 magnetic circuit is found the key to the whole 

 subject of the correlation and identity of all 

 the forces. 



And now, as preparatory to using this key 

 that we may enter in and consider the inti- 

 mate nature of the physical forces, we would 

 be impressed with the clear and full idea of 

 this mighty current, which bears upon its 

 tide, as one, all manner of forces with which 

 we have to do. 



It remains for us to tell what this great 

 current is, and what it does. To the child, to 

 the savage, and to the civilized man alike, it 

 comes first and pre-eminently as light. 



