It remains gratefully to acknowledge the help that I have received in my work. Mr. W. W. Rouse Ball, Tutor of Trinity College, whose great knowledge of the history of mathematics—a subject very closely connected with astronomy—has made his criticisms of special value, has been kind enough to read the proofs, and has thereby saved me from several errors; he has also given me valuable information with regard to portraits of astronomers. Miss H. M. Johnson has undertaken the laborious and tedious task of reading the whole book in manuscript as well as in proof, and of verifying the cross-references. Miss F. Hardcastle, of Girton College, has also read the proofs, and verified most of the numerical calculations, as well as the cross-references. To both I am indebted for the detection of a large number of obscurities in expression, as well as of clerical and other errors and of misprints. Miss Johnson has also saved me much time by making the Index of Names, and Miss Hardcastle has rendered me a further service of great value by drawing a considerable number of the diagrams. I am also indebted to Mr. C. E. Inglis, of this College, for fig. 81; and I have to thank Mr. W. H. Wesley, of the Royal Astronomical Society, for various references to the literature of the subject, and in particular for help in obtaining access to various illustrations. I am further indebted to the following bodies and individual astronomers for permission to reproduce photographs and drawings, and in some cases also for the gift of copies of the originals: the Council of the Royal Society, the Council of the Royal Astronomical Society, the Director of the Lick Observatory, the Director of the Instituto Geographico-Militare of Florence, Professor Barnard, Major Darwin, Dr. Gill, M. Janssen, M. Loewy, Mr. E. W. Maunder, Mr. H. Pain, Professor E. C. Pickering, Dr. Schuster, Dr. Max Wolf. ARTHUR BERRY. KING’S COLLEGE, CAMBRIDGE CONTENTS. PAGE PREFACE v CHAPTER I. PRIMITIVE ASTRONOMY, §§ 1-18 1-20 § 1. Scope of astronomy 1 §§ 2-5. First notions: the motion of the sun: the motion and _phases_ of the moon: daily motion of the stars 1 § 6. Progress due to early civilised peoples: Egyptians, Chinese, Indians, and Chaldaeans 3 § 7. The _celestial sphere_: its scientific value: _apparent distance_ between the stars: the measurement of _angles_ 4 §§ 8-9. The rotation of the celestial sphere: the _North_ and _South poles_: the _daily motion_: the _celestial equator_: _circumpolar stars_ 7