Hawkins electrical guide ... : questions, answers & illustrations : a progressive course of study for engineers, electricians, students and those desiring to acquire a working knowledge of electricity and its applications ; a practical treatise (1914)
Hawkins, N. (Nehemiah), 1833-1928 · New York : T. Audel & Co. · leaf 45
which the red rays reflected by the doubleconvex lens would strike, and S, the line where the violet rays would be projected. Theaddition of the double concave lens brings the red and violet together again at G. A com-bination of two such lenses F H, placed the proper distance apart and the…
Electrical engineering
Internet Archive · Brigham Young University · Public Domain Mark 1.0. Free to use for anything.
