MISCELLANEOUS PAPERS BY HEINRICH HERTZ LATE PROFESSOR OF PHYSICS IN THE UNIVERSITY OF BONN WITH AN INTRODUCTION BY PROF. PHILIPP LENARD AUTHORISED ENGLISH TRANSLATION BY D. E. JONES, B.Sc. LATELY PROFESSOR OF PHYSICS IN THE UNIVERSITY COLLEGE OF WALES, ABERYSTWYTH AND G. A. SCHOTT, B.A., B.Sc. DEMONSTRATOR AND ASSISTANT LECTURER IN THE UNIVERSITY COLLEGE OF WALES, ABERYSTWYTH London MACMILLAN AND CO., LTD. NEW YORK: MACMILLAN & CO. 1896 All rights reserved