Produced by Chris Curnow, Josephine Paolucci and the Online Distributed Proofreading Team at http://www.pgdp.net. (This file was produced from images generously made available by The Internet Archive.) SOAP-BUBBLES AND THE FORCES WHICH MOULD THEM. [Illustration: Experiment for showing by intermittent light the apparently stationary drops into which a fountain is broken up by the action of a musical sound. (_See_ page 109.)] SOAP-BUBBLES AND THE FORCES WHICH MOULD THEM. _BEING A COURSE OF THREE LECTURES_ DELIVERED IN THE THEATRE OF THE LONDON INSTITUTION ON THE AFTERNOONS OF DEC. 30, 1889, JAN. 1 AND 3, 1890, BEFORE A JUVENILE AUDIENCE. BY C. V. BOYS, A.R.S.M., F.R.S., ASSISTANT PROFESSOR OF PHYSICS AT THE ROYAL COLLEGE OF SCIENCE, SOUTH KENSINGTON. PUBLISHED UNDER THE DIRECTION OF THE GENERAL LITERATURE COMMITTEE. SOCIETY FOR PROMOTING CHRISTIAN KNOWLEDGE, LONDON: NORTHUMBERLAND AVENUE, W.C.; 43, QUEEN VICTORIA STREET, E.C. BRIGHTON: 129, NORTH STREET. New York: E. & J. B. YOUNG & CO. 1896. TO G. F. RODWELL, THE FIRST SCIENCE-MASTER APPOINTED AT MARLBOROUGH COLLEGE, _This Book is Dedicated_ BY THE AUTHOR AS A TOKEN OF ESTEEM AND GRATITUDE, AND IN THE HOPE THAT IT MAY EXCITE IN A FEW YOUNG PEOPLE SOME SMALL FRACTION OF THE INTEREST AND ENTHUSIASM WHICH HIS ADVENT AND HIS LECTURES AWAKENED IN THE AUTHOR, UPON WHOM THE LIGHT OF SCIENCE THEN SHONE FOR THE FIRST TIME. PREFACE. I would ask those readers who have grown up, and who may be disposed to find fault with this book, on the ground that in so many points it is incomplete, or that much is so elementary or well known, to remember that the lectures were meant for juveniles, and for juveniles only. These latter I would urge to do their best to repeat the experiments described. They will find that in many cases no apparatus beyond a few pieces of glass or india-rubber pipe, or other simple things easily obtained are required. If they will take this trouble they will find themselves well repaid, and if instead of being discouraged by a few failures they will persevere with the best means at their disposal, they will soon find more to interest them in experiments in which they only succeed after a little trouble than in those which go all right at once. Some are so simple that no help can be wanted, while some will probably be too difficult, even with assistance; but to encourage those who wish to see for themselves the experiments that I have described, I have given such hints at the end of the book as I thought would be most useful.