BY JOHN PLAYFAIR, F. R. S. EDIN. EDINBURGH: PRINTED FOR BELL & BRADFUTE, AND G. G. & J. ROBINSON, LONDON. M,DCC, CV, lib. comm. Hodgson 7-5.39 38677 PREFACE. T is a remarkable fact in the history of science, that the oldest book of Elementary Geometry is still considered as the best, and that the writings of EUCLID, at the distance of two thousand years, continue to form the most approved introduction to the mathematical sciences. This peculiar distinction the Greek geometer owes to the elegance and correctness of his demonstrations, added to an arrangement most happily contrived for the purposes of instruction; advantages which, when they reach a certain eminence, secure the works of an author from being forgotten, more effectually than even originality of invention. In passing, however, through the hands of the ancient editors, during the decline of science, the excellence of his writings had been considerably obscured, and much skill and learning have been employed by the modern mathematicians to deli. ver them from blemishes, with which, it is certain, that they were not originally marked. Of these mathematicians, A 2 |