QUESTION IJLBy Peter Dclamar, now c.f the ITni~vexTitv or Ten 11IV1 va;.i.i.4 **Suppofe a ball, let fall from a ftate of reft into the curve of a given cycloid, whole axis is perpendicular to the plane of the horizon : It is required to find (geometrically) in what oflaid curve, the motion will be the fwifteft, towards the horizon ?