PROFESSOR OF NATURAL PHILOSOPHY AND ASTRONOMY IN YALE COLLEGE

Revised Edition.

INCLUDING THE LATEST DISCOVERIES.

NEW YORK:

HARPER & BROTHERS, PUBLISHERS,

329 & 331 PEARL STREET,

FRANKLIN SQUARE.

1855.

Entered according to Act of Congress, in the year 1840, by

Marsh, Capen, Lyon, and Webb,

in the Clerk's Office of the District Court of Massachusetts.