THE

E L EM EN TS

OF

EU CLI D,

V I Z.

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 some of EUCLID's Demonstrations are Restored.

ALSO,
THE BOOK OF

EUCLID'S DATA,

In like manner Corrected.

BY.

ROBERT SIMSON, M. D.
Emeritus Professor of Mathematics in the University of Glasgow.

TO THIS EDITION ARE ALSO ANNEXED,
ELEMENTS OF PLANE and SPHERICALTRIGONOMETRY.

PRINTED AND SOLD BY ANDREW FOULIS, PRINTER TO THE UNIVERSITY;
SULD ALSO BY KOLENT CROSS, NEAR THE COLLEGE ; ;AMES
LUNCAN, DUNLOP AND WILSON, AND BY J. AND

W. SHAWS, BOOKSELLERS.

M.DCC.LXXXI.

3

For Grad 3 n.rr. Bernant

at
31-1923