'Mica Strip With Notched Edges Ready for Winding.' One of four examples of photosensitive (selenium) material in various stages of construction. Fixed to wooden mount. Part of apparatus for transmitting pictures by telegraph (phototelegraphy). Designed and constructed by Dr Shelford Bidwell in 1881. Mica Strip With Notched Edges Ready for Winding 1880-1900
'Mica Strip Wound With Wire.' One of four examples of photosensitive (selenium) material in various stages of construction. Fixed to wooden mount. Part of apparatus for transmitting pictures by telegraph (phototelegraphy). Designed and constructed by Dr Shelford Bidwell in 1881. Mica Strip Wound With Wire 1880-1900
