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the present case, either from actual observation or natural consider- 

 ations, that such a force should be looked to for explanation. 



1st, Of actual observation. The poles of any force should bear a 

 certain known relation to the equator thereof ; and if we find the 

 magnetic equator coincident with that of the atmosphere, which may- 

 be considered as marked out by the line of equatorial calms, we 

 might reasonably suppose a connection between their poles. But 

 we do not. The mean positions of these equators are very different 

 from each other, and are subject to such totally different movements 

 through the year, that we cannot legitimately expect any nearer 

 coincidence in their polar points. 



2d, Of natural considerations. Mechanical force may always bo 

 taken as the cause, and not as the consequence, of the magnetic or 

 electric currents by which it is accompanied. Certainly in the case 

 of an electrical machine, the electric spark may be made to produce 

 mechanical energy, as shewn in knocking small light pith balls about ; 

 but how incomparably less is this force to that employed to turn the 

 machine round in the first instance to produce the electricity. 



Now, the atmosphere enveloping and rubbing over the world, may 

 be taken as a large electrical machine, and does produce electric and 

 magnetic forces ; but these, although startling enough when wit- 

 nessed by us, little pigmies of men, are of infinitely small moment 

 compared to the force required to keep the whole atmosphere in 

 motion, and to overcome its friction and inertia. 



Again, with regard to the intensity of terrestrial magnetism, it is 

 found with one of Gauss's large bars for determining the horizontal 

 force, by being suspended by two wires separated in the direction of 

 its axis, that the whole magnetic force amounts to less than 100,000th 

 part of the weight of the bar, that is, the force or attraction of 

 gravity. 



Similar experiments might be adduced, to shew that when a body 

 is heated, though electrical currents may be produced, and may have 

 a certain mechanical power, that yet the quantity of this is almost 

 infinitely small compared to what might be produced by employing 

 the heat directly. 



Hence, there can be no reasonable doubt, that the principal move- 

 ments of the atmosphere must be owing to mechanical and thermotic 

 causes, and only the smaller features to electric and magnetic currents. 



A parallel case of the proneness of men to run for an explanation 



