Bakewell, Frederick C.

SUBJECT AREA: Telecommunications

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fl. 1850s

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British inventor of the "copying telegraph", the basis of facsimile transmission.

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Although little appears to be known about his life, Bakewell deserves a place in this dictionary for a single invention that was to have a significant impact upon communication. The invention of photography early in the nineteenth century soon led to a desire to transmit images over a distance. Although telegraphy was still very much in its infancy, Bakewell realized that the key to a viable system of facsimile, as it came to be known, was to dissect the image to be transmitted sequentially by scanning it in a series of parallel lines with some sort of sensor and to synchronously reconstruct it at the receiving end—a process that anticipated the way in which modern television works. To this end the line image was drawn with varnish on a sheet of tin foil, which was then wrapped around a cylinder. As the cylinder was rotated, presumably by some kind of regulated clockwork mechanism similar to that used later in the early phonographs of Edison, an electrical contact driven by a screw thread caused the image to be scanned along a spiral path, giving a series of on-off signals. At the receiving end, instead of the tin foil, a sheet of paper wetted with a suitable chemical was darkened by the current pulses as they arrived.

A practicable system did not become possible until a dry form of receiving-paper that was insensitive to light became available in the 1930s; once established, however, the technique remained the basis of commercial machines into the 1980s.

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Bibliography

1853, Electric Science.

1857, A Manual of Electricity.

Further Reading

J.Malster \& M.J.Bowden, 1976, "Facsimile. A Review", Radio \& Electronic Engineer 46:55.

See also: Bain, Alexander

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