NATURAL PHILOSOPHY. 191 



the earth is not affected by the occurrence of the tides ; nor do his formulae 

 reveal any permanent alteration in die motion of the lunar orb which dis- 

 turbs the repose of our oceans. These results, announced by so high an 

 authority, might be received without a careful examination if the fundamen- 

 tal principles of natural philosophy did not discountenance the idea of an 

 actual creation of power by lunar attraction. The tides constitute an im- 

 portant mechanical agent ; and, could their whole force be rendered availa- 

 ble, it would be found adequate to several hundred times the labor of the 

 human population. So great an amount of motive power, whether appro- 

 priated to the great purposes of nature and art, or wasted in overcoming 

 fVkiion, cannot be produced without some expense ; and my present object 

 is to trace the change which it involves in the motions of the earth and the 

 moon. As the extreme disproportion between the momentum of the oceanic 

 waters and that of the planetary bodies is the chief source of error in these 

 investigations, I shall commence by showing how the tidal action should 

 operate, if the moon moved around the earth in an exact circle, situated in 

 the plane of the equator, and not more than 34,000 miles in diameter. Her 

 periodical revolution, in this case, would occupy nearly twelve hours, and 

 the lumar day would be about twenty -four hours in length. The tidal action 

 on the seas nearest to the moon would be almost twice as great as on those 

 most distant ; the former being about 5,000 times, and the latter over 2,500 

 times, the disturbing action now exerted by the moon on the watery domain. 

 The aqueous appendage of our planet would, in this case, form two great 

 movable oceans, sustained on its opposite sides by the attraction of our satel- 

 lite, and keeping pace with her movements. Without taking into considera- 

 tion oscillations of the solid part of the earth which might possibly occur in 

 these circumstances, it is evident that there should be a general flow of the 

 waters from west to east ; and though the current may be alternately re- 

 versed in deep channels, the force propelling it in an eastern direction should 

 always maintain the ascendency. A vast body of water, circulating around 

 the earth from west to east, could not fail to accelerate its rotary motion ; 

 although the result would not be exhibited by the formulae of Laplace. The 

 moon, in this case, would sustain a loss of momentum to a more considera- 

 ble extent. It is well known that the attraction of mountains modifies the 

 direction of terrestrial gravity in their vicinity ; and that a plumb-line on 

 that part of the equator immediately west of the Andes would be slightly 

 deflected to the east. In the case we have supposed, the direction of terres- 

 trial gravity would experience a similar deflexion at places in conjunction 

 with the moon from the attraction of the excess of waters which swelled be- 

 hind her. Accordingly, the lunar orb would be drawn, not directly to the 

 earth's centre, but always to a point a little westward of it, and a constant 

 loss of motion would be an inevitable consequence. It would be different 

 if the earth could preserve an invariable form, for in that case its attraction 

 on a satellite being always directed to the centre, or alternately deflected east 

 and west of that point, the loss and gain of motion should be evenly balanced 

 'after one or many revolutions. Other investigations lead to the same con- 

 clusion. A satellite revolving just beyond the confines of -our atmosphere, 



