PATH OF BIELA'S COMET.

LETTERS
ON
ASTRONOMY,
IN WHICH THE
ELEMENTS OF THE SCIENCE
ARE

FAMILIARLYEXPLAINED IN CONNECTION WITH BIOGRAPHICAL

SKETCHES OF THE MOST EMINENT ASTRONOMERS.

WITH NUMEROUS ENGRAVINGS.

By DENISON OLMSTED, LL.D.,

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.

ADVERTISEMENT

TO THE

REVISED EDITION.

Since the first publication of these Letters, in 1840,the work has passed through numerous editions, andreceived many tokens of public favor, both as a class-bookfor schools and as a reading-book for the familycircle. The valuable discoveries made in the sciencewithin a few years have suggested an additional Letter,which is accordingly annexed to the series in thepresent revised form, giving a brief but comprehensivenotice of all the leading contributions with which Astronomyhas of late been enriched.

The form of Letters was chosen on account of thegreater freedom it admits, both of matter and of style,than a dress more purely scientific. Thus the technicalportion of the work, it was hoped, might be relieved,and the whole rendered attractive to the youthfulreader of either sex by interspersing sketches ofthe master-builders who, in successive ages, havereared the great temple of Astronomy, composing, asthey do, some of the most remarkable and interesting[iv]specimens of the human race.

The work was addressed to a female friend (nowno more), who was a distinguished ornament of hersex, and whose superior intellect and refined taste requiredthat the work should be free from every thingsuperficial in matter or negligent in style; and it wasdeemed by the writer no ordinary privilege that, in thecomposition of the work, an image at once so exaltedand so pure was continually present to his mental vision.

Yale College, January, 1853.
[5]

CONTENTS.