the Rotatory Motion of Bodies . 2.87 
equator will always touch and roll along the faid im- 
moveable circle (dl), the velocity of the point of con- 
2 c 
tact (along that circle) being = pr— 7, whilft the fpheroid 
turns about its proper axis (oq.) with the primitive an- 
gular velocity c , and the poles o and q_ (by the faid 
rolling of the equator) defcribe circles (whofe radii are* 
each = 
dl, with the angular velocity d (or their proper velocity 
--) which we fuppofed given to them by the impulfe^.. 
Thus the motion of the fpheroid confequent to the im- - 
pulfe appears to be remarkably regular. 
And in the very fame manner may be explained the 
motion of a cylinder, whofe primitive motion about its . 
proper axis may be difturbed by fome pereuffive force in 
like manner as we fuppofed the fpheroid difturbed ; only 
(inftead of the former fubftitution for f) fubftituting for 
the accelerative force arifing from the centrifugal force . 
of the particles of the revolving cylinder its proper value . 
— x (computed in our Appendix) and afterwards : 
proceeding as we have done with regard to the fpheroid, 
(d) Other ways of folving the problem are alfo fiaggelled by the preceding 
articles e 
bd 
7 x 
r*'+b’ 
V 
4 r'+S+W x 
i) 
parallel to the faid circle 
b de- - 
