Mr. Stufgeon on Electro-Magnetism. 243 



when the poles of the magnet or the direction of the force in 

 the . wire is changed, the results of the experiments in every 

 case appear to be reversed. And in explanation, these, as 

 well as every electro-magnetic phenomenon, are generally con- 

 sidered to proceed from a reciprocal disposition of the wire 

 and magnet to place themselves at right angles to each other, 

 for, when so situated, and at or near the centre of the latter, 

 nothing further can be obtained ; for both wire and magnet, 

 when free to move, will in this position remain at rest. 



Convinced as it were that the rotations are in different di- 

 rections on the opposite poles when employed singly ; it would 

 seem as if experimenters had been fully persuaded of the im- 

 possibility of obtaining rotations, by bringing into action at 

 the same time both poles of the above-named magnet; or, 

 whatever else may have prevented them, we have never yet 

 heard of any thing of the kind being attempted. 



By referring the reader to a Postscript in my last paper on 

 thermo-rotations, and which appeared in your Journal for 

 April last, it will be there seen that a rotation had been ob- 

 tained under the above circumstances ; and that I had at that 

 time rotated the wire or system of wires in the form of a sphere 

 around and by the influence of both poles of an internal mag- 

 net. 



This experiment, it was observed, first suggested itself on 

 reading Dr. Halley's theory of terrestrial magnetism, and was 

 instituted with a view not only to be somewhat imitative of 

 that philosopher's hypothesis, but likewise to serve in part to 

 exhibit the earth's rotative motion on its axis. 



It is by no means intended from this experiment to assert, 

 that the rotatory motion of the earth and planets is really 

 the effect of electro-magnetism, or that the variation of the 

 compass-needle depends upon the theory alluded to; but merely 

 to detail an experimental fact as exhibited by the apparatus 

 in its present imperfect state, the mechanism of which con- 

 fines the experiment greatly within the limits it might have 

 been extended to. However, it already proves that a galva- 

 nized sphere, when free to move and containing within it a 

 magnetic nucleus or kernel, laill rotate by the influence of that 

 central magnet; and that also, were the magnet free to move, 

 a probability is manifested that it would rotate at the same 

 time, i. c. they would both rotate at the same time by the reci- 

 procal action of each other. 



I hiving dining my leisure hours been busily employed in 

 fitting up an apparatus for other new experiments, I have not, 

 till now, had an opportunity to describe that by which this 

 is made. The experiment, however, has been witnessed du- 

 ll h 2 ring 



