Giovanni Caselli Biography – Pantelegraph and Fax Inventor

Last Update: August 9th, 2021

Giovani Caselli (18151891) was an Italian physicist credited with being the inventor of the pantelegraph, which later evolved into the modern-day facsimile machine.

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As a student, Caselli studied religion, science, history, and literature. Along with his interest in science, he studied to become a Catholic priest, ordained in 1836.


The name pantelegraph was a combination of the words “telegraph” – a system for transmitting messages over long distance wires, and “pantograph,” a machine that was used to copy drawings and words.

While teaching physics at the University of Florence, he focused his research on the transmission of image and simple words. Working on similar projects at the time were Alexander Bain and Frederick Bakewell. Caselli’s largest challenge was working on synchronization between the transmitter and receiver of the machine.

Caselli’s system was different from that of Bain and Bakewell‘s was it used a regulating clock to help the sending and receiving mechanism working together – synchronization was the major problem experienced by other facsimile inventors at the time (ironically, Alexander Bain‘s experience was primarily as a clockmaker).

The pantelegraph worked by making an image with non-conductive ink onto a piece of tin foil. As a stylus passes over it the tin foil, it lightly touches it, passing with parallel scans slightly apart (similar to the technology of faxing today that scans line by line).

The pantelegraph then conducts electricity where there is ink and no ink on the page.  Telegraph lines (or similar system) are used to transmit the signal. The receiver on the opposite end then takes the signal and writes ink onto the paper.

Leopold II, the Grand Duke of Tuscany financed Caselli’s invention. He was so impressed with the capabilities of the machine that he financed more of his experiments.

Leopold II later introduced Caselli to Napoleon III, who was intrigued with the technology. He later further developed his pantelegraph with the help of French inventor Leon Foucault.

In 1860 Napoleon saw a demonstration of the pantelegraph and placed orders for the service to work within the French national telegraph network. With the help of Napoleon (both with access to the telegraph network as well as financial), the pantelegraph was successfully tested over 800km between Paris and Marseille. Through French law, it was enacted in 1864 that it would be officially accepted, with operations starting in 1865 between Paris and Lyon, extended to Marseille in 1867.

As a comparison, Alexander Graham Bell received his telephone patent, nine years later, in 1876.

Further Information on Giovanni Caselli:

Biography on Giovanni Caselli (English Translation)
Giovanni Caselli Biography from
Video of Pantelegraph in Operation

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