AN

INTRODUCTION

то

Natural Philofophy:

OR,

Philofophical Lectures

Read in the

University of Oxford,

Anno Dom. 1700.

To which are Added,

The DEMONSTRATIONS of Mon-
fieur HUYGENS's Theorems, concerning
the Centrifugal Force and Circular Motion.

By JOHN KEILL M. D.
Savilian Profeffor of Aftronomy. F. R. S.

Tranflated from the laft Edition of the Latin.

THE FOURTH EDITION.

LONDON:

Printed for M. SENEX, W. INNYS, T. LONGMAN and
T. SHEWELL. MDCCXLV.

1860. e. 2