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PREFACE TO THE NEW EDITION
I have revised this volume for the present edition. It was impossible not to notice in the chapter on the Fifth Satellite of Jupiter that still further discoveries in the same direction had been made since that chapter was originally written. The latter part of the chapter on the Boundaries of Astronomy is mainly an endeavour to weigh the arguments for and against the truth of the nebular theory of the origin of the Solar System. I may, therefore, here say that further consideration of the subject only tends to make me feel more confident that the nebular theory does really express the law of nature.
ROBERT S. BALL.
Cambridge,
21st February, 1906.
