ebb and flow in its channel after the manner of the Sea. If the attraction of the body S were taken away; the water would acquire no motion of flux and reflux by revolving round the quieſcent centre of the globe. The caſe is the ſame of a globe moving uniformly forwards in a right line, and in the mean time revolving about its centre. (by cor. 5. of the laws of motion) and of a globe uniformly attracted from its rectilinear courſe (by cor. 6. of the ſame laws.) But let the body S come to act upon it, and by its unequable attraction the water will receive this new motion. For there will be a ſtronger attraction upon that part of the water that is neareſt to the body, and a weaker upon that part which is more remote. And the force LM will attract the water downwards at the quadratures, and depreſs it as far as the ſyzygies; and the force KL will attract it upwards in the ſyzygies, and withhold its deſcent, and make it riſe as far as the quadratures; except only in ſo far as the motion of flux and reflux may be directed by the channel of the water. and be a little retarded by friction.
Cor. 20. If now the annulus becomes hard, and the globe is diminiſhed, the motion of flux and reflux will ceaſe; but the oſcillating motion of the inclination and the præceſſion of the nodes will remain. Let the globe have the ſame axis with the annulus and perform its revolutions in the ſame times, and at its ſurface touch the annulus within, and adhere to it; then, the globe partaking of the motion of the annulus, this whole compages will oſcillate, and the nodes will go backward. For the globe, as we ſhall ſhew preſently, is perfectly indifferent to the receiving of all impreſſions. The
