THE

ELEMENTS

OF

EUCLID.

VIZ.

THE FIRST SIX BOOKS,

TOGETHER WITH THE

ELEVENTH AND TWELFTH.

The Errors, by which THEON, or others, have long ago
vitiated these Books, are corrected,

And fome of EUCLID's Demonstrations are restored.

ROBERT SIMSON, M. D.

Emeritus Professor of Mathematics in the University of Glasgow.

To this FIFTH EDITION are also annexed,

ELEMENTS of PLAIN and SPHERICAL TRIGONOMETRY.

EDINBURGH

Printed for J. NOURSE, London, and J. BALFOUR, Edinburgh,

M,DCC,LXXV.

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