1

1

0

ELEMENTS

OF

GEOMETRY;

1

CONTAINING

THE FIRST SIX BOOKS OF EUCLID,

WITH A

SUPPLEMENT

ON THE

QUADRATURE OF THE CIRCLE

AND

THE GEOMETRY OF SOLIDS;

TO WHICH ARE ADDED,

ELEMENTS OF PLANE AND SPHERICAL

TRIGONOMETRY.

SECOND EDITION, ENLARGED,

BY

JOHN PLAYFAIR, F. R. S. EDIN.
PROFESSOR OF MATHEMATICS IN THE UNIVERSITY

OF EDINBURGH,

CEDINBURGH:

PRINTED FOR BELL & BRADFUTE; AND

G. & J. ROBINSON, LONDON.

Edine T20 148.04,700

1857. april. 25.

hers N. A.

Gifts Gift of
Haven jr, s

of Portsmouth N. Ib.

ENTERED IN STATIONERS HALL.

Edinburgh,
Printed by A. NEILL & Co.

}

30-329

48

PREFACE.

Tis

a remarkable fact in the history of science, that the oldest book of Elementary Geometry is still confidered 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 remarkable distinction the Greek geometer owes 'not only to the elegance and correctness of his demonstrations, but to an arrangement most happily contrived for the purposes of inftruction; advantages which, when they reach a certain eminence, secure the works of an author against the injuries of time, more effectually than even originality of invention. The Elements of EUCLID, however, in paffing through the hands of the ancient editors, during the decline of science, had fuffered fome diminution of their excellence, and much skill and learning have been employed by the modern mathematicians to deliver them from blemishes, which certainly did not enter into their original compofition.

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