4 0 c m
33cm
actual image size: 25cm x 32cm
Description
Engraving by Delzers after a photograph. Hughes (1831-1900) emigrated to America in 1837 where he patented the improved type-printing telegraph in 1855. In 1878 he invented the microphone almost simultaneously with Ludtge.
Image Details
Image Ref.
10301925
© Science Museum / Science & Society Picture Library