Page:Philosophical Transactions - Volume 004.djvu/200



His Excellent Mathematician, having composed a Learned Treatise concerning the Doctrine of Motion, and what thereon depends, managing it in a manner altogether Geometrical, was pleased, upon the importunity of his Friends, to permit the First Part thereof to come abroad, whilest the others are still in the Printers hands; which is about One third part of what he did, near two years since, impart to the R. Society, and was by them desired to make it publick. In this First Part he delivers,

1. The General Rules of Motion, promising thereto, as becomes a strict Reasoner and good Geometrician, the Definitions belonging to that Subject; and then comprising the Rules themselves in Thirty Propositions: In which he takes occasion, among many other weighty particulars, to intimate, That it is principally the business of a Mechanician, to excogitate and make practicable such Engins, to be interposed between the Strength and the Weight, as may so moderate the Celerity of Motion, as to compensate the Greatness of the Weight, by the Slowness of the