Proceedings of the American Academy of Arts and Sciences. 

 Vol. XXXIX. No. 2. —July, 1903. 



CONTRIBUTION'S FROM THE JEFFERSON PHYSICAL LABORATORY, 



HARVARD COLLEGE. 



ON THE PROLONGATION OF SPECTRAL LINES. 



By Thkodork Lyman. 



With a Plate. 



Investigations on Light and Hkat hade or publishkd, wholly or in part, with Appropriations 



from the rumford fcnd 



