Quarter-plate `Cameo' camera used to take 'second phase' of Cottingley Fairies photographs, 1918-1920 Photographs 1915-1920
Hollerith 45 column horizontal electrical sorting machine, 1920-1930 Computing & Data Processing 1920-1930
Rexophone crystal set with two pairs of Telefunken headphones (out of three), 1923-1930 Radio Communication 1923-1930