The article is reprinted from the Journal of the Optical Society of America Vol. 31, No. 11, November 1941 and was presented at the Ninth Summer Conference on Spectroscopy and Its Applications, held at the Massachusetts Institute of Technology, July 21-23, 1941.
Beckman, Arnold O., and Cary, H. Howard (Henry Howard). “A Quartz Photoelectric Spectrophotometer,” November 1941. Beckman Historical Collection, Box 17, Folder 16. Science History Institute. Philadelphia. https://digital.sciencehistory.org/works/6395w7637.