PREFACE.
begins with the Laws of Motion. Not that this previous Step is abſolutely neceſſaryj it being eaſie to have ſhewn the Properties of the Mechanical Powers without it. But the Importance of thoſe Principles being ſo great, and the Underſtanding of them being a convenient tho' not a neceſſary Introduction to the remaining part, I am Perſuaded the Reader will not be diſpleaſed to meet them there. Their extenſive uſe as being the Foundation of all Natural Philoſophy, inclined me to treat of them more diffuſely than has hitherto been done; partly for an Introduction to higher Speculations, and partly becauſe it has been my fortune to meet ſome times with ingenious perſons, but not converſant in theſe matters, who have not ſo readily underſtood and aſſented to ſome things relating to them, as one would have expected.
From thoſe Principles the Properties of the Mechanical Towers are demonſtrated; in the doing of which, Mathematical Terms have been avoided as
