Astronomy

Автор: Simon Newcomb, LL.D.
Издательство: NewYork, Henry Holt And Company
Страниц: 400
Год: 1892
Размер: 13,4 МБ

PREFACE

The present treatise is a condensed edition of the Astronomy of the American Science Series. The book has riot been shortened by leaving out anything that was essential, but by omitting some of the details of practical astronomy, thus giving to the descriptive portions a greater relative extension.

The most marked feature of this condensation is, perhaps, the omission of most of the mathematical formulae of the larger treatise. The present work requires for i f s understanding only a fair acquaintance with the principles of algebra and geometry and a slight knowledge of elementary physics. The space which has been gained by these omissions has been utilized in giving a fuller discussion of the more elementary parts of the subject, and in treating the fundamental principles from various points of view.

A familiar and secure knowledge of these is essential to the students' real progress. The full index makes the work of value as a reference-book to a student who has studied it and put it aside.

As in the larger work, the matter is given in two sizes of type. It will be found that the larger type contains a course practically complete in itself, and that the matter of the smaller type is chiefly explanatory of the former. It is highly desirable, however, that the book should be read as a whole, while the actual class -work may be confined to the subjects treated in the larger type, if the class is pressed for time. A celestial globe, and a set of star-maps (PROCTOR'S "Half -Hours with the Stars" is as good as any), will be found to be of use in connection with the study ; and if the class has access to a small telescope, even, much can be learned in this way. A mere opera-glass will suffice to give a correct notion of the general features of the moon's surface, and a very small telescope, if properly used, will do the same for the larger planets.