© S M Jones
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Arthur James Dalladay (1894-1989) was the editor of the "British Journal Photographic Almanac and Photograper'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.