Books with title A Treatise on Spherical Astronomy

Unlike some other reproductions of classic texts (1) We have not used OCR(Optical Character Recognition), as this leads to bad quality books with introduced typos. (2) In books where there are images such as portraits, maps, sketches etc We have endeavoured to keep the quality of these images, so they represent accurately the original artefact. Although occasionally there may be certain imperfections with these old texts, we feel they deserve to be made available for future generations to enjoy.

Spherical or positional astronomy is used primarily to map objects on the celestial sphere. In this technical work, first published in 1908 and intended for advanced students, Sir Robert Stawell Ball (1840-1913) breaks down the field into distinct areas of study. Assuming a good level of geometry and trigonometry, he begins with fundamental formulae before moving into the determination of coordinates, atmospheric refraction, the theory of cartography, and more. Each section contains exercises derived from a variety of sources, including contemporary Cambridge examinations. The coverage ranges from the calculation of stellar parallax to the geometrical principles behind the Mercator projection. Testifying to the knowledge expected of university students in the early twentieth century, Ball's book remains instructive to their modern counterparts. More accessible to the general reader, The Story of the Heavens (1885), Star-Land (1889) and A Popular Guide to the Heavens (1905) are also reissued in this series.

Unlike some other reproductions of classic texts (1) We have not used OCR(Optical Character Recognition), as this leads to bad quality books with introduced typos. (2) In books where there are images such as portraits, maps, sketches etc We have endeavoured to keep the quality of these images, so they represent accurately the original artefact. Although occasionally there may be certain imperfections with these old texts, we feel they deserve to be made available for future generations to enjoy.

Vi PREFACE The work on the subject to which I have most frequently turned while preparing this volume is Briinnow sS pherical A stronomy, a most excellent book which is available in English andF rench translations as well as in its original German. A mong recent authors I have consulted Valentiner sextensive Handworterbuch derA stronomie which no student of astronomy can afford to overlook, and I have learned much from the admirable writings of Professor Newcomb. I have to acknowledge with many thanks the assistance which friends have kindly rendered to me. Mr Arthur Berry has furnished me with many solutions of exercises, more especially ofT ripos questions. Dr J. L. E. Dreyer has read over the chapter on Aberration and made useful suggestions. Mr W. E. Hartley has helped in the correction of the proofs as well as in the revision of parts of the manuscript. Mr A. R. Hinks has given me help in the correction of the proofs and I am also indebted to him for assistance in the chapter on theS olar Parallax. Dr A. A. Rambaut has devoted much time to the reading of proofs and has assisted in many other ways. Mr F. J. M. Stratton has revised some of the pages, especially those on the rotation of the moon. Dr E. T. Whittaker has given me useful suggestions especially in the chapter on Refraction, and he has also helped in reading proofs, and my son, Mr R. S. Ball, has drawn many of the diagrams. Lastly, I must acknowledge my obligation to theS yndics of the University Press, who have metall my wishes in the kindest manner. The list of parallaxes of stars (p. 328) is based on more extensive lists given by Newcomb inT heS tars and Kapteyn in the Groniugen publications No. 8. The results stated for aC entauri, Sirius and aG ruis have been obtained byS ir D. Gill; those for Procyon, A ltair, A ldebaran, Capella, Vega, A rcturus, by Dr Elkin ;that for Cordoba Zone 5h 243(Typographical errors above are due to OCR software and don't occur in the book.)

This scarce antiquarian book is a facsimile reprint of the original. Due to its age, it may contain imperfections such as marks, notations, marginalia and flawed pages. Because we believe this work is culturally important, we have made it available as part of our commitment for protecting, preserving, and promoting the world's literature in affordable, high quality, modern editions that are true to the original work.

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.)

Astronomer and philosopher Sir John Herschel (1792-1871), the son of William and the nephew of Caroline, published his 1833 Treatise on Astronomy in the 'Cabinet Cyclopaedia' series of which the first volume had been his enormously successful Preliminary Discourse on the Study of Natural Philosophy. He is regarded as the founder of the philosophy of science, and made contributions in many fields including mathematics, the newly discovered process of photography, and the botany of southern Africa, which he studied while making astronomical observations of the southern hemisphere, and where he was visited by Darwin and Fitzroy on the Beagle voyage. It was however as the natural successor to his father's astronomical studies that he is best remembered, and this book, which is written for the interested lay person, places strong emphasis on the importance of accurate observation and on avoiding preconceptions or hypotheses not based on such observation.