Proceedings of the American Academy of Arts and Sciences. 

 Vol.. XXXIX. No. ;5. — Jii.Y, 1903. 



CONTRIBUTIONS FROM THE JEFFERSON PHYSICAL LABORATORY, 



HARVARD COLLEGE. 



AN EXPLANATION OF THE FALSE SPECTRA FROM 

 DIFFRACTION GRATINGS. 



By Theodork Lyman. 



With a Plate. 



Investigations on Light anb Heat made or published, wholly or in part, with Appropriations 



FROM the Romford Fond 



