248 Mr. Sturgeon on Electro-Magnetism. 



grand natural magnet, possessing a capacity for conducting 

 the electric fluid. The former of those properties is admitted 

 by almost every writer on magnetics ; and the latter it is pre- 

 sumed will be as readily conceded. 



From the second experiment we see the magnet rotate on 

 its axis by the influence of electric currents from its equator 

 to its poles. Had the magnet been a sphere instead of a bar, 

 it might have represented the earth or planet more perfectly ; 

 but its figure, it is presumed, can make no difference in the 

 result of the experiment. 



It is now well known that electricity can be excited by heat, 

 and the success of thermo rotations in the manner that I ob- 

 tain them would, if formed into a sphere, depend upon the 

 difference of temperature between the equator and poles. This 

 property is obviously analogous to the natural state of the 

 earth ; for the sun exerting his greatest influence a few de- 

 grees only on each side of the equator, the polar regions are 

 constantly kept at a very low temperature ; so much so, that 

 every attempt yet made to explore them has been rendered 

 abortive in consequence of a prevailing intensity of cold; 

 whilst the equatorial parts, it is well known, are as constantly 

 kept in the other extreme. That thunder and lightning are 

 by far more prevalent in the torrid than in the frigid zones, is 

 a fact that cannot be denied; and that this difference of elec- 

 trical phamomena is principally caused by the superior action 

 of the sun in those parts, appears more than probable. Hence 

 it may be fairly concluded, that the action of the sun either 

 partly or wholly governs the general electrical phamomena of 

 nature ; and, either by producing or exciting this wonderful 

 agency in the equatorial regions, dispenses its influence from 

 thence to the poles of the earth. 



Another circumstance that would be something in favour 

 of the hypothesis is, that a magnetic body free to move in any 

 direction, (a sphere suspended in space, for instance,) and 

 having currents of electricity passing over its surface to its 

 poles, would not only rotate, but would likewise maintain its 

 parallelism. This may be easily demonstrated upon the prin- 

 ciples shown in Professor Barlow's " Magnetic Attractions," 

 second edition, p. 249, under the head Electro-magnetism. 



Let NZC'Z', fig. 4, represent the magnetic sphere. NS 

 its poles. Likewise suppose ZC and Z'C to proceed from 

 the zinc and copper sides of two batteries of equal power. 

 Then the electric force in that part of the magnet between 

 Z and C, or in the northern hemisphere, will tend to carry 

 the pole N towards n. And the electric force in the southern 

 hemisphere between Z' and C will at the same time have a 



like 



