A Treatise on Spherical Astronomy

Spherical Astronomy I mean that part of Mathematical Astronomy which lies between the vast domain of Dynamical Astronomy on the one hand arid the multitudinous details of Practical Astronomy on the other. I have aimed at providing for the student a book onS pherical Astronomy which is generally within the limits thus indicated, but I have not hesitated to transgress those limits now and then when there seemed to be good reason for doing so. For example I have just crossed the border of Dynamical Astronomy inC hapter VII., and in two concluding chapters I have so far entered on Practical Astronomy as to give some account of the fundamental geometrical principles of astronomical instruments. It has been assumed that the reader of this book is already acquainted with the main facts of Descriptive A stronomy. The reader is also expected to be familiar with the ordinary processes of Plane andS pherical Trigonometry and he should have at least an elementary knowledge of Analytic Geometry and Conic Sections as well as of theD ifferential and Integral Calculus. It need hardly be added that the student of any branch of Mathematical Astronomy should also know the principles of Statics and Dynamics. As a guide to the student who is making his first acquaintance withS pherical A stronomy, I have affixed an asterisk to the titles of those articles which he may omit on a first reading; the articles so indicated being rather more advanced than the articles which precede or follow. Such articles as relate to the more important subjects are generally illustrated by exercises. In making a selection from the large amount of available material I have endeavoured to choose exercises which not only bear directly on the text, but also have some special astronomical or mathematical interest. It will be seen that the Tripos examinations at Cambridge and many College examinations at (Typographical errors above are due to OCR software and don't occur in the book.)