ABSTRACT

The concept of the transmission of visual images over greater-than-optical distances is very much older than that of transmitting signals via wireless waves, pre-dating it by almost a hundred years. By the beginning of the nineteenth century various proposals were being put forward, most of them of no practical value because of the multiplicity of wires demanded between transmitter and receiver, but by 1842 Alexander Bain had devised a chemical telegraph which foreshadowed a workable system. This was followed in 1847 by Bakewell’s model which recognized the need to dissect the picture into elements and reconstruct it at the receiver, a fundamental principle of television to this day. By 1867 the art of picture transmission had advanced to the point where a commercial service was put into operation in France, although with only qualified success.