
4 0 c m
32cm
actual image size: 24cm x 32cm
Description
Photograph. Hughes (1831-1900) emigrated to America in 1837 where he patented the improved type-printing telegraph in 1855, and invented the microphone almost simultaneously with Ludtge in 1878.
Image Details
Image Ref.
10301915
© Science Museum / Science & Society Picture Library