[Illustration] [Illustration: Frontispiece] WONDERS OF PHYSICAL SCIENCE =Readable Books in Natural Knowledge= Globe 8vo. WONDERS OF PHYSICAL SCIENCE. By E. E. FOURNIER, B.Sc. TILLERS OF THE GROUND. By Marion I. NEWBIGIN, D.Sc. THREADS IN THE WEB OF LIFE. By Professor J. ARTHUR THOMSON, M.A., and MARGARET R. THOMSON. _And others to follow._ MACMILLAN AND CO., LTD., LONDON. =Readable Books in Natural Knowledge= WONDERS OF PHYSICAL SCIENCE [Illustration] MACMILLAN AND CO., Limited LONDON • BOMBAY • CALCUTTA MELBOURNE THE MACMILLAN COMPANY NEW YORK • BOSTON • CHICAGO ATLANTA • SAN FRANCISCO THE MACMILLAN CO. OF CANADA, Ltd. TORONTO [Illustration] WONDERS OF PHYSICAL SCIENCE BY E. E. FOURNIER, B.Sc. ASSOCIATE OF ROYAL COLLEGE OF SCIENCE, LONDON To try things oft, and never to give over, doth wonders.--BACON. MACMILLAN AND CO., LIMITED ST. MARTIN’S STREET, LONDON 1910 PUBLISHERS’ NOTE SO much attention is now given to the practical and systematic study of science in schools that the valuable influence of descriptive scientific literature is apt to be overlooked. An intimate knowledge of the simplest fact in Nature can be obtained only by personal observation or experiment in the open air or the laboratory, but broad views of scientific thought and progress are secured best from books in which the methods and results of investigation are stated in language which is simple without being childish. Books intended to promote interest in science must differ completely from laboratory guides, text-books, or works of reference. They should aim at exalting the scientific spirit which leads men to devote their lives to the advancement of natural knowledge, and at showing how the human race eventually reaps the benefit of such research. Inspiration rather than information should be the keynote; and the execution should awaken in the reader not only appreciation of the scientific method of study and spirit of self-sacrifice, but also a desire to emulate the lives of men whose labours have brought the knowledge of Nature to its present position.