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.

ALSO,

THE BOOK OF

EUCLID'S DAТА,

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.

GLASGOW:

PRINTED AND SOLD BY ANDREW FOULIS, PRINTER TO THE UNIVERSITY;
SOLD ALSO BY ROBERT CROSS, NEAR THE COLLEGE; JAMES

DUNCAN, DUNLOP AND WILSON, AND BY J. AND

W. SHAWS, BOOKSELLERS.

M.DCC.LXXXI.

For Grad. 3
W. W. Bemaul

5-31-19213.