630 HENRY A. KOWLAND 



neither are we so ignoble as to seek knowledge because " Knowledge is 

 power " two sayings which are certainly true, but low and sordid in 

 their tone. 



We have, then, the beautiful fabric of mathematical electricity given 

 to the world by Poisson, Green, Helmholtz, Thomson, Maxwell, and 

 others whose names are immortal. No hypothesis as to the nature of 

 electricity rests at its base. Starting from the most simple laws of 

 electricity and magnetism, it rises from a stable foundation and rears 

 its form high in the air, never to be overturned, whatever the fate of 

 the so-called electric fluid or the ultimate theory of magnetism. On the 

 simple fact that there is no electric force inside a closed conductor, it is 

 proved that the electric attraction and repulsion varies inversely as the 

 square of the distance. The fact is sufficient to give us the whole theory 

 of electrostatic distribution on conductors. 



From the simple fact that we can break a magnet up into parts which 

 are similar to each other, and that these parts attract and repel each 

 other in a certain manner, we derive many important facts with regard 

 to magnetism. 



From the magnetic action of the current we find, by an application of 

 the great law of conservation of energy, all the laws of induced cur- 

 rents, either from magnets or other currents. By an almost superhu- 

 man effort of the intellect we detach our electric currents from matter, 

 and suppose them to take place in the ether of space, and we have the 

 grand electro-magnetic theory of light given to us by Maxwell. 



But the subject is too vast to be treated in a moment. Suffice it to 

 say that no person at the present day has the right to express an opin- 

 ion on any theoretical question connected with electricity without a 

 knowledge of its mathematics. 



This study has led us to alter our ideas on many questions. What 

 is the mechanism of electri'c or magnetic attraction? Faraday has 

 given us his idea of lines of force, and has made them play an important 

 part in the theory of magnetic induction. When treated mathemati- 

 cally, Maxwell has shown that all electric and magnetic attractions can 

 be explained by a tension along the lines of force and pressure at right 

 angles to them an idea due to Faraday. 



The mathematical theory of these lines shows that all electrostatic 

 forces between either conductors or non-conductors can be explained in 

 this manner. As the laws of magnetic attraction are the same in every 

 way as electrostatic attraction, if we should do away with electric con- 

 duction, it follows that magnetic attraction is to be explained in exactly 



