Physical description

Part of a series entitled “Optical Munitions - School of Natural Philosophy, 1942-1945”. Black and white photo of E.R.Johnson testing fused sandwiched plate glass in a polarimeter. N.B. As at time of writing it is not certain that the “man” pictured in nos. 147 and 149 is the same individual as pictured in no 140. (EGM. 11/11/99)

Inscriptions & markings

On back of photo in pencil: “No. 20 E.R. Johnson”