PREFACE.

THE author has no other apology to present for offering to the public the following work on "Popular Astronomy" than the marked favour with which his "Orbs of Heaven " has been received, both in this country and in Europe.

The science of Astronomy is so rapidly progressive, that to keep the public advised of its advances new works are required almost every year. This may be offered as an additional reason for the present publication.

In the preparation of the work I have availed myself of so many sources of information that it would be quite impossible for me to specify the authors or the volumes to which I am indebted. The plan and the cast is all my own. I have endeavoured to follow the path of real discovery, and in every instance to present the facts and phenomena, so as to afford to the reader and student an opportunity to exercise his own genius in their discussion and resolution, before offering the explanation reached by ancient or modern science. It is hoped that this method of treating the subject, which is new (so far as I know), may avail in exciting a greater interest in the examination of those great problems of the universe, whose successful solution constitutes the chief honour of human genius.

In a few instances I have ventured to present the results of my own observations, and have occupied a short space in exhibiting a sketch of new methods and new instruments, which have been introduced into the observatories at Cincinnati and at Albany.

DUDLEY OBSERVATORY, January, 1860.