170 Mechanicl Powerc. Book VIII.

Tbirdly, the foreſaid Globe may be underſtood to move bythe motion of the Centre towards C, and in like manner bythe motion of the orb towards A, to wit, ſo that the point Btends to E and D,&c. and in each caſe the motion of theCentre may be equal to the motion of the orb, or greater, orleſſer.

Fourthiy, Note, that if Copernicus his opinion be true, tliatthe earth is moved with this mixt motion, to wit, by the mo-tion of Centre through à. circle of the greater orb about theSun, and by the motion of the orb about the proper Centre 5.and the motion of the Centre ſhould be greater than the motionof the orb, according to the common opinion concernipg theDiameter of the great orb, which the earth runs through in oneWhole year: Where alſo obſerve, that every point of the ſameparallel Circle are moved with unequal velocity; for whe-ther we ſuppoſe the motion of the orb and the motion of theCentre to be towards the ſame part, ſuppaſe towards C, whenthe point E comes to FP, and the Centre H in G, the point Bwill be in E, and the point D will be in L, wherefore the pointof Contact B is moved ſloweſt of all, but the oppoſite point Dſwifteſt of all; that anſwers to the Nocturnal meridian, this to-the Diurnal meridian. Or whether we ſuppoſe the earth to-be moved by the motion of the Centre towards C, and themotion of the orb from B in E, D, Cc. in this caſe the con-trary happens, to wit, the point of Contact B is moved ſwifteſtof all, for it comes to L, and the point D ſloweſt, for it comesto E; and theſe kinds of motion of divers points of the ſamecirele will be flower, or ſwifter, according to the divers propor-tions of velocity of the motion of the Centre, and the motion.of the orb, nevertheleſs all will be by crooked lines, as appearsby what has been ſaid.

Fiſibly, after this laſt manner, ſome Epicicles are ſaid to.move by Aſtronomers, to wit, by the motion of the Centreto the Faſt, according to the Series of the Signs, or, as they ſay,in the Confequent; ſuppoſe the Centre. C towards A, and theSupream point, or the Flanets Apgæum D, moved in the op-poſite part fiom D in E towards the, weſt, and, as they ſay, in.the Antecedent. N

But ſince the foreſaid motion may be divers according torhe divers magnitudes, and proportions of the Circles, it ap-pears neverthelets from the doctrine deliver'd before, tbaf theines