[August, 1898.J 



THE 



SCIENTIFIC TRANSACTIONS l'^'^'^ ^^ 133, 



ROYAL DUBLIN SOCIETY. 



VOLUME VII.— (SERIES 11.) 



MUS. COMP. ZOOL 

 LIBRARY 



Ar-rt > 5 '^^ 



HARVARD 

 I. UNIVEBSITY 



A DETEEMINATION OF THE WAVE-LENGTHS OF THE PRINCIPAL LINES 

 IN THE SPECTRUM OF GALLIUM, SHOWING THEIE IDENTITY WITH 

 TWO LINES IN THE SOLAR SPECTRUM. By W. N. HARTLEY, F.R.S., 

 AND HUGH EAMAGE, A.R.C.Sc.I. 



(Plate I.) 



DUBLIN: 



PUBLISHED BY THE ROYAL DUBLIN SOCIETY. 

 WILLIAMS AND NORGATE, 



14, HENRIETTA STREET, COVENT GARDEN, LONDON ; 



20, SOUTH FREDERICK STREET, EDINBURGH; and 7, BROAD STREET, OXFORD. 



PKINTED AT THE TJNIVEESITY PEESS, BY PONSOKBT AND WELDKICK. 



1898. 



Price One Shilling. 



