Arthur James Dalladay born December 1894 in West Ham, Essex. Died 1989 in Gravesend, Kent. Dalladay was the editor of the "British Journal Photographic Almanac & Photographer's Daily Companion" for 30 years from around 1937 to 1967.
He built the very first photographic spot meter in about 1935; he described it in the BJP Almanac of 1937 on pages 127-138. This meter still exists, in the possession of a subsequent editor of the Journal. Within a decade or so, there appeared two commercial meters based on the same principle.