PREFACE.

H AVING read and considered the De-sign of the several Books hitherto pub-lished for the Explanation of the Newto-nian Philosophy, under the Titles ofCommentaries, Courses, Essays, Elements, Sys-tems, &c. I observed not one of them allcould be justly esteemed a True System,or Compleat Body of this Science.

I would not here be understood to haveany Design of depreciating the Labours ofthose Gentlemen who have gone before meon this Subject; I only would intimate thattheir Views and Designs were very dif-ferent from mine, which is to present theWorld with a Physigo-MathematicalTreasury of Natural Knowledge,upon the Principles of the Newtonian Philo-sophy ; which I have been chiefly enabled toeffect from the Abundance of Materials sup-plied by the Authors of the Treatises in thefollowing Catalogue, each of which is excel-lently good in his Way.

So that if the Cafe be truly stated, myBook may be looked upon as a General Com-pendium or Abridgment of all theirs. For asA 2 they