Part 1

E-text prepared by Colin Bell, Brenda Lewis, David King, and the Online Distributed Proofreading Team (http://www.pgdp.net) from page images generously made available by Internet Archive (https://archive.org)

Images of the original pages are available through Internet Archive. See https://archive.org/details/heavensabovepopu00gillrich

Transcriber's note:

Text enclosed by underscores is in italics (italics).

Superscripts, such as P to the second power, are shown by the caret character "^" before the superscript, such as P^2.

Subscripts are similarly shown by an underscore before the subscript which is wrapped in curly braces, such as M_{2}.

The Heavens Above: A Popular Handbook of Astronomy

THE HEAVENS ABOVE:

A Popular Handbook of Astronomy.

J. A. GILLET,

Professor of Physics in the Normal College of the City of New York,

and

W. J. ROLFE,

Formerly Head Master of the High School, Cambridge, Mass.

With Six Lithographic Plates and Four Hundred and Sixty Wood Engravings.

Potter, Ainsworth, & Co., New York and Chicago. 1882.

Copyright by J. A. Gillet and W. J. Rolfe, 1882.

Franklin Press: Rand, Avery, and Company, Boston.

PREFACE.

It has been the aim of the authors to give in this little book a brief, simple, and accurate account of the heavens as they are known to astronomers of the present day. It is believed that there is nothing in the book beyond the comprehension of readers of ordinary intelligence, and that it contains all the information on the subject of astronomy that is needful to a person of ordinary culture. The authors have carefully avoided dry and abstruse mathematical calculations, yet they have sought to make clear the methods by which astronomers have gained their knowledge of the heavens. The various kinds of telescopes and spectroscopes have been described, and their use in the study of the heavens has been fully explained.

The cuts with which the book is illustrated have been drawn from all available sources; and it is believed that they excel in number, freshness, beauty, and accuracy those to be found in any similar work. The lithographic plates are, with a single exception, reductions of the plates prepared at the Observatory at Cambridge, Mass. The remaining lithographic plate is a reduced copy of Professor Langley's celebrated sun-spot engraving. Many of the views of the moon are from drawings made from the photographs in Carpenter and Nasmyth's work on the moon. The majority of the cuts illustrating the solar system are copied from the French edition of Guillemin's "Heavens." Most of the remainder are from Lockyer's "Solar Physics," Young's "Sun," and other recent authorities. The cuts illustrating comets, meteors, and nebulæ, are nearly all taken from the French editions of Guillemin's "Comets" and Guillemin's "Heavens."

CONTENTS.

I. THE CELESTIAL SPHERE 3

II. THE SOLAR SYSTEM 41

I. THEORY OF THE SOLAR SYSTEM 41

The Ptolemaic System 41

The Copernican System 44

Tycho Brahe's System 44