980 Transactions of the A3ierican Institute. 



degrees west, thus keeping pace with the North magnetic pole on 

 this continent. 



It is evident, I think, from what has been shown, that the north 

 and south are the superior poharities, to which all others are second- 

 ary, because all others are in their influence purely local, while the 

 influence of the north and south is paramount and universal. 



We must, therefore, look to a yet higher source for the origin 

 of that magnetic attraction which shall cause the revolution of the 

 magnetic poles in the period of time in which we have seen that 

 they do revolve.* 



We have already seen that magnetism is a universal principle, 

 and one of the forces which nature employs in the government of 

 the universe; we have seen, too, that the force which it exerts is 

 centripetal, and identifies itself with the force which controls the 

 motion of gravitating bodies; we have seen that the dine of attrac- 

 tion from any center around which the earth may revolve, must be 

 at an angle to her axis on which she daily turns, and that the polar 

 attraction is at such an angle; we have seen that if the attraction 

 of the needle to the pole be governed and controlled by the attrac- 

 tion of magnetism from a center around which the earth revolves, 

 and such attraction is at an angle to the earth's axis, then that point 

 on the earth's surface to which the needle is directed, and whicli we 

 have called the magnetic pole, shall revolve about the North pole 

 in the same time in which the earth revolves about the governino- 

 center of attraction; and we have seen that the magnetic pole does 

 revolve about the North pole once in about six hundred and forty 

 years, taking the period of one hundred and sixty years to be accu- 

 rate, in which it has been seen that ninety degrees of the revolution 

 has been performed. 



All these conditions are necessary to the truth of our theory 

 (and more might be both cited and proved), and they are condi- 

 tions, all of which we have seen to exist; and one of these 

 conditions, viz: the revolution of that subtle influence and imma- 

 terial point which we have called the "magnetic pole," could not 

 exist or be performed by any other means than the magnetic 

 attraction to the center around which the earth revolves. 



Our limited astronomy has given us the data of no higher revo- 

 lution of the earth than that around the sun, although it is inferred 

 from the order of things that she may revolve in company around 



•The North and South poles revolve together, each being always opposite to tho other, 

 find at an angle to the earth's axis. 



