[ November, 1899. ] 
THE 
SCIENTIFIC TRANSACTIONS 
OF THE 
Ip O VG IDUIBIGIDN TS Oxes hil 
VOLUME VII—(SERIES II.) 
stele 
AN ESTIMATE OF THE GEOLOGICAL AGE OF THE EARTH. 
By J. JOLY, M.A., D.Sc., F.R.S., 
Honorary Secretary of the Royal Dublin Society ; 
Professoor of Geology and Mineralogy in the University of 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 WELDRICK, 
1899. 
