A 



TEXT-BOOK OF PHYSICS. 



BY 



J. H. POYNTING, So.D., F.R.S. ; 



FOREIGN MEMBER OP THE ACCADEMIA DEI LINCEI, ROME ; HON. D.Sc., VICTORIA UNIVERSITT ; 



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. ; 



CORRESPONDING MEMBER OF THE INSTITUTE OF FRANCE ; FOREIGN MEMBER OF THE 

 BERLIN ACADEMY; HON. So.D., DUBLIN; HON. D.L., PRINCETOWN; HON. 



D.Sc., VICTORIA; HON. LL.D., GLASGOW; HON. PH.D., CRACOW; 



FELLOW OF TRINITY COLLEGE, CAMBRIDGE ; CAVENDISH PROFESSOR OF EXPERIMENTAL 



PHYSICS IN THE UNIVERSITY OF CAMBRIDGE ; PROFESSOR OF NATURAL 



PHILOSOPHY IN THE ROYAL INSTITUTION. 



HEAT. 



WITH 193 ILLUSTRATIONS. 

 FOURTH EDITION, REVISED. 



LONDON: 

 CHARLES GRIFFIN AND COMPANY, LIMITED; 



EXETER STREET, STRAND. 

 1911. 



[All rights reserved.] 



