For (in the same second figure) let any body, as K L M N, be understood to be moved with simple circular motion; and let the circle, which every point thereof describes, have any determined quantity, suppose that of the same K L M N. Wherefore the centre A and every other point, and consequently the moved body itself, will be carried sometimes towards the side where is K, and sometimes towards the other side where is M. When therefore it is carried to K, the parts of the fluid medium on that side will go back; and, supposing all space to be full, others on the other side will succeed. And so it will be when the body is carried to the side M, and to N, and every way. Now when the nearest parts of the fluid medium go back, it is necessary that the parts next to those nearest parts go back also; and supposing still all space to be full, other parts will come into their places with succession perpetual and infinite. Wherefore all, even the least parts of the fluid medium, change their places, &c. Which was to be proved. It is evident from hence, that simple motion, whether circular or not circular, of bodies which make perpetual returns to their former places, hath greater or less force to dissipate the parts of resisting bodies, as it is more or less swift, and as the lines described have greater or less magnitude. Now the greatest velocity that can be, may be understood to be in the least circuit, and the least in the greatest; and may be so supposed, when there is need. [Sidenote: If a fluid be moved with simple circular motion, all the points taken in it will describe their circles in times proportional to the distances from the centre.]