Location of the Isogonic Lines 



different degrees and kinds of motion, communicated from molecule to 

 molecule, shows its energy in light, heat, electricity or magnetism. 



The cause of magnetism, therefore, is a condition of vibration of 

 matter, occasioned by cosmical forces. 



The observations of Schwabe and Oarrington show that this force 

 originates in the sun, and that the time and degree of vibration, of 

 the sympathetic material of our earth, corresponds with occasions of 

 great disturbance of the solar surface. 



To produce the evidences of a magnetic or electrical condition in 

 either iron or steel, no extensive paraphernalia of apparatus is necessary. 

 We are surrounded at all times by a diffused vibratory force greater in 

 its total quantity than the combined power of all the artificial apparatus 

 in the world. The earth and the atmosphere are full of it, and I can- 

 not but believe that each instant every molecule of matter of inorganic 

 or organic nature, the upper air and the firm ground beneath our feet 

 is more or less under the influence of the little apparent forces that 

 create what we call terrestrial magnetism. 



Asa proof of this I have purposely chosen an article familiar to 

 every one, an article which cannot be made a permanent magnet, 

 which is not in itself magnetic in the sense of polarized force and 1 

 which few would believe could be made to exhibit all the phenomena 

 of a magnetic needle without battery or magnetized steel to affect 

 it or induce in it, by contact, the form of power whose laws we are 

 engaged in studying. 



This is nothing more than a bar of soft iron. That it has no per- 

 manent magnetism is shown by the magnetic needle which I now 

 approach to it, having either pole equally attracted at either of its 

 ends, and in no case repelled, as it would be if any portion of this bar 

 were possessed of permanent magnetism. 



Some other implements that I have are equally simple and as easily 

 understood. They are bits of soft iron; common nails, likewise with- 

 out permanent magnetism, and without the power of retaining mag- 

 netism, except as long as it may be induced in them by contact with 

 permanent steel magnets, or by inclosure within a wire helix in the 

 circuit of a battery affording electric or electro-magnetic force. 



Simple as the present apparatus is, and without either battery power 

 or steel magnet, or wire conveying electricity, I am able to show you 

 some of the important facts in terrestrial magnetism, so as to explain 

 to some extent the cause of the declination and the variation of the 

 magnetic needle. 



To make a theory intelligible, it is best to demonstrate the funda- 



