(Jury, 1904.] 
THE 
SCIENTIFIC TRANSACTIONS 
OF THE 
MOV ws DUIS IEN SOCINTY. 
VOLUME VIIL—(SERIES IL.) 
VIII. 
THE PENETRATING RADIUM RAYS. 
BY 
J. A. McCLELLAND, M.A., 
Professor of Experimental Physics, University College, Dublin. 
DUBLIN: 
PUBLISHED BY THE ROYAL DUBLIN SOCIETY. 
WILLIAMS AND NORGATE, 
14, HENRIETTA STREET, COVENT GARDEN, LONDON ; 
20, SOUTH FREDERICK STREET, EDINBURGH: anp 7, BROAD STREET, OXFORD. 
PRINTED AT THE UNIVERSITY PRESS, BY PONSONBY AND GIBBS. 
1904. 
