AOP be the ellipſis pQ And becauſe the magnitude of that little circle Tt, and TN or PO its diſtance from the axis CO is alſo given, the ellipſis pQ will be given both in kind and magnitude, as alſo its poſition to the right line PO. And ſince the area POp is proportional to the time, and therefore given becauſe the time is given the angle POp will be given. And thence will be given p the common interſection of the ellipſis and the right line Op, together with the angle OPp in which the projection APp of the trajectory cuts the line OP. But from thence (by conferring prop. 41. with its 2d cor.) the manner of determining the curve APp eaſily appears. Then from the ſeveral points P of that projection erecting to the plane AOP the perpendicular PT meeting the curve ſuperficies in T, there will be given the ſeveral points T of the trajectory. Q. E. I.
