ESSENTIALS

LATE PROFESSOR OF MATHEMATICS IN BUCHTEL COLLEGE, AUTHOR OF

DEVELOPMENT OF ENGLISH LITERATURE

AND LANGUAGE

If a man's wit be wandering, let him study the mathematiks; for in demonstra-
tions if his thought be called ever so little away, he must begin again.-Lord Bacon

CHICAGO
S. C. GRIGGS AND COMPANY

TO

MY FRIEND AND BENEFACTOR,

GOVERNOR CHARLES FOSTER.

NIHIL EST TAM POPULARE QUAM BONITAS.—Cicero.