One of the most interesting examples of the attempts to see by radio was
made the subject of a patent by Nipkow in 1884. The proposed transmitter
consisted of a selenium cell and an objective lens, with a spirally
perforated disc rotating between the cell and lens “to dissect the
scene.”
The receiving device employed the polarizing light valve used by Major
George O. Squire, and Professor A. C. Crehore, to measure the flight of
gun shells at Fort Monroe, Virginia, in 1895.
The Nipkow scheme was preceded by Shelford Bidwell’s device for “the
telegraphic transmission of pictures of natural objects,” described in
_Telegraphic Journal_ 1881, Vol. 9, page 83; and later almost exactly
duplicated by M. Henri Sutton, and rather fully described in _Lumiere
Electrique_, Vol. 38, page 538, 1890.
[Illustration: [Machines]]