Pantelegraph

The pantelegraph (Italian: pantelegrafo; French: pantélégraphe) was an early form of facsimile machine transmitting over normal telegraph lines developed by Giovanni Caselli, used commercially in the 1860s, that was the first such device to enter practical service.

[1] The receiving apparatus reproduced the transmitted image by means of paper impregnated with potassium ferricyanide, which darkened when an electric current passed through it from the synchronized stylus.

[3] By 1856, he had made sufficient progress for Leopold II, Grand Duke of Tuscany to take an interest in his work, and the following year he travelled to Paris where he was assisted by the engineer Paul-Gustave Froment, to whom he had been recommended by Léon Foucault, to construct the first pantelegraph.

In November 1860 a telegraph line between Paris and Amiens was allotted to Caselli which enabled a true long-distance experiment, which was a complete success, with the signature of the composer Gioacchino Rossini as the image sent and received, over a distance of 140 km (87 mi).

[1][4][5] In 1867 the Director of Telegraphs, de Vougy, had a second line set up from Lyon to Marseille; the transmission cost was 20 centimes per square centimetre of image, and the service was operated until 1870.