ADVERTISEMENT

TO THE SEVENTH EDITION.

THE favourable reception which the various editions of this performance have met with from the public has induced the author to undertake an entire revision of every part of the work, and to make such alterations, amendments and additions, as, upon a careful re-consideration of the subject, appeared to be wanting.

Since the time of its first publication, four additional planets, belonging to our system, have been discovered, and many important improvements have been made in several branches of the science; which it became necessary to notice. This has accordingly been done, in a manner which it is hoped will render the work as satisfactory and complete, as the popular plan that was first adopted, will admit.

ROYAL MILITARY ACADEMY, WOOLWICH,

June 24, 1816.

CONTENT S.

LETTER

I. On the Use and Advantage of Astronomy
II. Of the Figure and Motion of the Earth
III. Of the Solar System, and Firmament of the

IV. Of the Systems of Ptolemy, Tycho Brahe, and

Copernicus

V. Of the System of Descartes

VI. Of the Discoveries of Kepler and Galileo

VII. Of the Newtonian System and Discoveries
VIII. Of the Nature of the Tides

IX. Of the Latitude and Longitude, and the

Methods of discovering them

X. The same subject continued

XI. Of the different Lengths of Days and Nights,

129

148

167

181

and the Vicissitudes of the Seasons
XII. Of the Natural and Artificial Divisions of Time
XIII. Of the Equation of Time, or the Difference
between Mean Time and Apparent

192

XVII. Of the Distances and Magnitudes of the Sun,

Moon, and Planets

253

XVIII. The same subject continued .

268

LETTER

PAGE

XIX. Of the Motion, Refraction, and Aberration of

XX. Of the Constellations, and the Phænomena of
the fixed Stars

312

XXII. On Comets, Aeroliths, and Meteors
XXIII. Of the Eclipses of the Sun and Moon
XXIV. Of the new Planet, and other Discoveries

353

371

391

AN EXPLANATION of the principal Terms made
use of in Astronomy

407