[July, 1891.] 



THE 



SCIENTIFIC TEANSACTI0N8 



OF THE 



ROYAL DUBLIN SOCIETY. 



VOLUME IV. (SERIES II.) 



XI. 



ON THE CAUSE OF DOUBLE LINES AND OF EQUIDISTANT SATELLITES IN 

 THE SPECTEA OF GASES. By GEORGE JOHNSTONE STONEY, 

 M.A., D.Sc, F.E.S., Vice-President, Eoyal Dublin Society. 



DUBLIN: 



PUBLISHED BY THE EOYAL DUBLIN SOCIETY. 



LONDON: WILLIAMS AND NORGATE. 



PRINTED AT THE UNIVERSITY PRESS, BY PONSONBY AND WELDRICK, 



PBINTERS TO THE SOCIETT. 



1891. 



Price Two Shillings. 



