У книзі описано основні поняття, які характеризують параметри поля дифузно відбитого планетами випромінювання та газово-аерозольного середовища планетних атмосфер. Розглянуто особливості розсіяння світла на частинках різної природи і форм; формування молекулярних смуг поглинання в планетних атмосферах; вплив земної атмосфери на характеристики параметрів світлових потоків в умовах їх проходження крізь атмосферу; методи спектрофотометричних і спектрополяриметричних спостережень та їх редукції, у тім числі й за вплив земної атмосфери; методи визначення фізичних характеристик планетних атмосфер. Наведено основні результати вивчення оптичних характеристик поля дифузно відбитого випромінювання та фізичних характеристик, насамперед аерозольної складової, атмосфер Венери, Марса, Юпітера, Сатурна, Урана, Нептуна, супутників Титана і Тритона. Обговорено деякі проблеми глобальних змін клімату та озоносфери Землі.

THE following work is designed as a text-book for universities and technical schools, and as a manual for the field astronomer. The author has not sought after originality, but has attempted to present in a systematic form the most approved methods in actual use at the present time.

Each subject is developed as fully as the necessities of the case are likely to require; but as the work is designed to be a practical one, those methods and developments which have merely a theoretical or historic interest have been excluded.

THE design of the following treatise is to furnish a text-book for the instruction of college classes in the first principles of Astronomy. My aim has accordingly been to limit the book to such dimensions that it might be read entire without omissions, and to make such a selection of-topics as should embrace every thing most important to the student. I have aimed to express every truth in concise and simple language ; and when it was necessary to introduce mathematical discussions, I have limited myself to the elementary principles of the science. The entire book is divided into short articles, and each article is preceded by a caption, which is designed to suggest the subject of the article. Whenever it could be done to advantage, I have introduced simple mathematical problems, designed to test the student's familiarity with the preceding principles. At the close of the book will be found a collection of miscellaneous problems, many of them extremely simple, which are to be used according to the discretion of the teacher.

Let me begin with a confession and some explanations. Before beginning this project, I knew nothing about planetary radar astronomy. I quickly realized that I was not alone. I discovered, too, that most people confuse radar astronomy and radio astronomy. The usual distinction made between the two is that radar astronomy is an "active" and radio astronomy a "passive" form of investigation. The differentiation goes much deeper, however; they represent two disparate forms of scientific research.

THE object of this little book is to give in simple language a comprehensive idea of the Universe. It is intended to supply a felt want, and does not aspire to be an exhaustive text-book of the science of astronomy ; neither does it aspire to deal with the mathematical and instrumental sides of the science. The use of technical phrases has been as far as possible avoided, so that the beginner may have no difficulty in thoroughly mastering the book and in proceeding to the more advanced works on the subject.

THIS work is designed to meet the special requirements of officers of the Merchant Service, and to be a complete Text-; Book on Navigation, etc., for the general student.

THE present work is not a compendium of astronomy or an outline course of popular reading in that science. It has been prepared as a text-book, and the author has purposely omitted from it much matter interesting as well as important to a complete view of the science, and has endeavored to concentrate attention upon those parts of the subject that possess special educational value. From this point of view matter which permits of experimental treatment with simple apparatus is of peculiar value and is given a prominence in the text beyond its just due in a well-balanced exposition of the elements of astronomy, while topics, such as the results of spectrum analysis, which depend upon elaborate apparatus, are in the experimental part of the work accorded much less space than their intrinsic importance would justify.

THE author has embraced the opportunity afforded by a second edition of this work to introduce into it certain changes which, without modifying the general plan and scope, will, it is hoped, increase its usefulness. For the most part these changes are made in the direction of increased simplicity or of increased precision, and are most conspicuously shown in 19, 23, 3,2, 37 and 38. The tables at the end of the book have been considerably increased, both in extent and precision, and now suffice for approximate as well as rough determinations of time, latitude and azimuth without the use of an almanac.

THE following treatise was undertaken at the suggestion of some friends, and in a persuasion, that a classic of the kind was necessary in our institutions of learning. The larger works on astronomy seemed too unwieldly for common use. Much of Mr. Ferguson's original work had become obsolete ; and it may now be considered as defective, for want of the great improvements of Herschel and his cotemporaries. Though Dr.Brewster may have supplied the deficiency, he has retained much of the obsolete part, and his work is too expensive for admission into most of our seminaries. The latter objection applies with equal force to Enfield, and some others. Most of the smaller works on astronomy had not been published, or were not known to the author of this, when it was commenced. Though the public are now favored with several compends on astronomy, none of them seem calculated for that class of students, for which this was intended.