MOD JIV. CLE A TEXT-BOOK OF PHYSICS VOLUME I. FIFTH EDITION, Revised, Fully Illustrated. Price 10s. 6d. PROPERTIES OF MATTER VOLUME II. FIFTH EDITION, Revised, Fully Illustrated. 8s. 6d. SOUND CONTENTS.-The Nature of Sound and its chief Characteristics.-The Velocity of Sound in Air and other Media.-Reflection and Refraction of Sound.-Frequency and Pitch of Notes.Resonance and Forced Oscillations.-Analysis of Vibrations.-The Transverse Vibrations of Stretched Strings or Wires.-Pipes and other Air Cavities.-Rods.-Plates.-Membranes.Vibrations maintained by Heat.-Sensitive Flames and Jets.-Musical Sand.-The Superposition of Waves.-Index. VOLUME III. THIRD EDITION, Fully Illustrated. 15s. CONTENTS.-Temperature.- Expansion of Solids.-Liquids.-Gases.-Circulation and Con- THE EARTH'S ATMOSPHERE 44 By Dr. THOMAS LAMB PHIPSON. The book should prove of interest to general readers, and students of science."-Nature. In Crown 8vo, Cloth. Illustrated with Diagrams. THE FORCE OF THE WIND By HERBERT CHATLEY, B.Sc. Eng. (Lond.), In Large 8vo. Profusely Illustrated. 8s. 6d. net. WIRELESS TELEGRAPHY WIRELESS By GUSTAVE EICHHORN, Ph.D. "Well written . . . and combines with a good deal of description a careful investigation of the fundamental theoretical phenomena."-Nature. In Two Volumes, Large 8vo, Strongly Bound in Half-Morocco. PHYSICO-CHEMICAL TABLES FOR THE Use of ANALYSTS, PHYSICISTS, CHEMICAL MANU- VOLUME I.-CHEMICAL ENGINEERING, PHYSICAL CHEMISTRY. Price 24s. net. Superintendent of the Chemical Laboratories, and Lecturer on Inorganic Chemistry and London: CHARLES GRIFFIN & CO., LTD., EXETER STReet, Strand. A TEXT-BOOK OF PHYSICS BY J. H. POYNTING, Sc.D., F.R.S. HON. Sc.D. VICTORIA UNIVERSITY LATE FELLOW OF TRINITY COLLEGE, CAMBRIDGE; MASON PROFESSOR OF PHYSICS IN THE UNIVERSITY OF BIRMINGHAM AND SIR J. J. THOMSON, M.A., F.R.S., HON. Sc.D. DUBLIN HON. D.L. PRINCETON; HON. Sc.D. VICTORIA; HON. LL.D. GLASGOW FELLOW OF TRINITY COLLEGE, CAMBRIDGE; CAVENDISH PROFESSOR OF ROYAL INSTITUTION PROPERTIES OF MATTER WITH 168 ILLUSTRATIONS FIFTH EDITION, CAREFULLY REVISED LONDON CHARLES GRIFFIN AND COMPANY, LIMITED EXETER STREET, STRAND 1909 [All rights reserved] الى PREFACE. THE volume now presented must be regarded as the opening one of a series forming a Text-Book on Physics, which the authors are preparing. The second volume, that on Sound, has already been issued, and the remaining volumes dealing with Heat, Magnetism and Electricity, and Light will be published in succession. As already stated in the preface to the volume on Sound, 'The Text-Book is intended chiefly for the use of students who lay most stress on the study of the experimental part of Physics, and who have not yet reached the stage at which the reading of advanced treatises on special subjects is desirable. To bring the subject within the compass thus prescribed, an account is given only of phenomena which are of special importance, or which appear to throw light on other branches of Physics, and the mathematical methods adopted are very elementary. The student who possesses a knowledge of advanced mathematical methods, and who knows how to use them, will, no doubt, be able to work out and remember most easily a theory which uses such methods. But at present a large number of earnest students of Physics are not so equipped, and the authors aim at giving an account of the subject which will be useful to students of this class. Even for the reader who is mathematically trained, there is some advantage in the study of elementary methods, compensating for their cumbrous form. They bring before us more evidently |