I 2 I

Chap. 3. PHILOSOPHY.

the center, as the progreftive motion would carry it off, thebody will defcribe a circle about the center A, this center oftlie force being alfo the center of the circle.

4. I f the body, inftead of fetting out in the line B C per-pendicular to A B, had fet out in another line B G more in-clined towards the line A B, moving in the curve line B H ;then as the body, if it were to continue its motion in the lineB G, would for fome time approach the center A; the centri-petal force would caufe it to make greater advances towardthat center. But if the body were to fet out in the line BI re-clined the other way from the perpendicular B C, and were tobe drawn by the centripetal force into the curve line B K; thebody, notwithftanding any centripetal force, would for fometime recede from the center; fmce fome part at leaft of thecurve line B K lies between the line BI and the perpendicular BC.

y. Thus far we have explained fuch effects, as attendevery centripetal force. But as thefe forces may be very diffe-rent in regard to the different degrees of ftrength, where-with they aft upon bodies in different places; I fhall now pro-ceed to make mention in general of iome of the differencesattending thefe centripetal motions.

d. To reaffume the confideration of the la ft mentionedcafe. Suppofe a centripetal power direfted toward the pointA (in fig. 74.) to aft on a body in B, which is / moving inthe direction of the ftraight line B C, the line B C reclining°ff from AB. If from A the ftraight lines AD, AE, AF are

R drawn