x Preface
and hope I have been fair and courteous to those whose views I cannot
accept. My own personal contributions to the subject represent the outcome
of twenty-five years of fairly continuous thought and work, and a considerable
number of my results are published for the first time in the present book.
I have to thank many friends for help and courtesies of various kinds,
and particularly Dr W. S. Adams, Director of Mount Wilson Observatory,
for permission to reproduce a large number of photographs. My thanks are
again due to the officials and staff of the Cambridge University Press for
extending to the present book the consummate skill and unremitting care by
which they transform a mass of muddled manuscript into a masterpiece
of typography.
J. H. Jeans
Dorking,
January 25, 1928.
PREFACE TO SECOND EDITION
AS the first edition had the good fortune to be rather speedily exhausted,
t\ the preparation of a second edition has been a pleasant and compara
tively light task.
I have expanded the book by references to various observational and
theoretical results which have appeared since the first edition was written,
and have allotted space more liberally to certain problems and investigations
which friendly critics thought I had dismissed too briefly in the original
book. Finally I have corrected a number of minor errors and misprints, and
have to thank many friends and correspondents for bringing these to my
notice.
J. H. Jeans
Dorking,
November 14, 1928.