Lill.

THE

ELEMENTS OF EUCLID,

VIZ.

THE FIRST SIX BOOKS,

TOGETHER WITH

THE ELEVENTH AND TWELFTH.

THE ERRORS,

BY WHICH THEOX, OR OTHERS, HAVE LONG AGO VITIATED TAESE 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 SPHERICAL TRIGONOMETRY.

PHILADELPHIA:

PUBLISHED BY

THOMAS DESILVER JR., No. 247, MARKET STREET,

AND

ROBERT DESILVER, No. 110, WALNUT STREET.

LYDIA R. BAILEY, PRINTER.