Biography of Giovanni Caselli


The pantelegraph developed by Giovanni Caselli was a system of sending and receiving images over long distances by means of telegraph. The images transmitted by telegraph were reproduced using electrochemistry. This system was actually the first prototype of a fax machine.

Abbe Caselli, an Italian physicist, has an interesting history. Giovanni Caselli was born in Siena in 1815. He studied literature and science. From 1841 to 1849 he lived in Modena as a tutor of the sons of Marquis of San Vitale, but as he took part in the riots for annexation of Duchy of Modena to Piedmont, he was expelled from the Duchy.

While teaching physics at the University of Florence, he devoted his research to making progress in the telegraphic transmission of images, an issue which had been proving a stumbling block for several researchers for quite a few years, including the Britons Bain and Bakewell, due to a failure to achieve a perfect synchronization between transmitting and receiving devices.

In 1856, the results were conclusive enough for the Grand Duke of Tuscany to take an interest in Caselli’s invention and, the following year, Caselli went to Paris where he was to be given decisive help by the famous inventor and mechanical engineer Paul Gustave Froment, to whom he had been recommended by Foucault, who had already entrusted Caselli with the task of making his pendulum. In 1862 Giovanni Caselli built a machine he called a “pantelegraph” (Pantèlègraphe) (the word is a combination of “pantograph”, a tool that copies drawing, and “telegraph”, a machine that sends messages over a wire.)

Caselli’s pantelegraph

At the end of the first half of the last century in the field of electrochemical telegraphs, Caselli’s pantelegraph solved a problem faced by the Englishmen Alexander Bain and Frederick Bakewell. In 1846 Bain was able to electrochemically reproduce conventional graphic signs using paper soaked in potassium ferrocyanide. Bain’s idea was taken up and even surpassed by Bakewell, who was able to send written script.

Nonetheless both Bain and Bakewell’s systems were unsuitable: reception obtained with Bakewell’s method was poor, lacking synchronism betweentransmitter and receiver. Caselli overtook both of them with his pantelegraph or Universal Telegraph, but also included a “synchronizing apparatus” to help two machines work together. This unique machine was a precursor of commonly known since the 1980s fax mashine. Once completed, the final device met with unequivocal enthusiasm from the Parisian scientific world and a Pantelegraph Society was created to prepare its exploitation.

Napoleon III and the pantelegraph

What is more, the Emperor Napoleon III himself, passionately interested in mechanics and modern inventions, visited Froment’s workshops on May 10th 1860 to watch a demonstration of the device. The enthusiastic Emperor gave Caselli access to the lines he needed in order to continue his experiments in Paris, from the Froment workshops to the Observatory. Then, in November of the same year, a telegraphic line was also allocated to Caselli between Paris and Amiens to enable a real intercity experiment, which was apparently a total success.

Caselli had in fact managed to eliminate the last remaining fault in his machine by making the synchronization timers independent of the current relayed by the telegraphic line itself, which was too sensitive to atmospheric disturbances. The pantelegraph, Caselli’s first invention, wasregistered in 1861.

The French press was brimming with laudatory articles on the pantelegraph, while the top brass from high society and the scientific and administrative worlds hurried along to Froment’s workshops to find out about the new process. In September 1861, King Victor-Emmanuel invited Caselli and his machines to a series of triumphant demonstrations at the Florence Exhibition.

A scheme of a telegraph line connecting the transmitter and receiver units of Caselli’s pantelegraph

Finally, in 1863, the French Legislature and Council of State adopted texts authorizing the official exploitation of an initial line between Paris and Marseille, while across the Channel, Caselli obtained authorization for the experimental use of a line between London and Liverpool over a four-month period. In 1865 the pantelegraph started his duty between Paris and Lyon, duty which ended in 1870 following the defeat of Sedan, having been planned new lines. The pantelegraph system transmited nearly 5,000 faxes in the first year.

Made of cast iron and standing more than 2 m high, this primitive, but effective machine worked as follows. The sender wrote a message on asheet of tin in non-conducting ink. The sheet was then fixed to a curvedmetal plate. The stylus of the transmitter scanning an original document by moving across its parallel lines (three lines per millimetre).

The signals were carried by telegraph to the marked out the message in Prussian blue ink, the colour produced by a chemical reaction, as the paper was soaked in potassium ferrocyanide. To ensure that both needles scanned at exactly the same rate, two extremely accurate clocks were used to trigger a pendulum which, in turn, was linked to gears and pulleys that controlled the needles.

Caselli’s facsimile telegraph (pantelegraph) receiver

L. Figuier “Les Merveilles de la Science”, Paris, 1866

A picture of a working pantelegraph model

First pictures sent and received over long distance using Casselli’s pantelegraph

At the time in which the Paris-Lyon Pantelegraph worked regularly, Napoleon, having in vain proposed to Caselli the French citizenship to allow him acceed to the rank of general inspector and co-ordinator of the the French telegraph, awarded him the Legion of Honor. The Pantelegraph worked also between London and Liverpool in order to build up a public service.

But the program was withheld because of the economical crisis which in 1864 stroke badly England and the Financial Society, with which Caselli had undertaken the final agreements. Even Russia was interested in his Pantelegraph, but instead of creating a public service, it was used to send messages between the two imperial residences of St. Petersburg and Moscow.

However, Caselli’s system seems to have suffered from a number of deficiencies, and although it continued in use for some years on the telegraph lines around Le Havre and Lyons, it did not realise the hopes of its promoters, as the transmissions were often illegible. Probably this was because of the continuing difficulty of keeping the transmitter and receiver in synchronization.

The Pantelegraph Society did not prove equal to the market which was apparently opening up and, failing to undertake any energetic promotion of the device, was content to wait passively for its capital to be remunerated via the flood of orders which were supposed to pour in from all over the world.

In Italy, after an initially euphoric reception, the sluggishness of the administration and haughtiness of ministers led Caselli to give up any further development of his invention. In France, he clashed with theTelegraphs administration which, fearing competition with its ordinary telegraphic network, refused to lower the tariff for handwritten dispatches – which were nevertheless prohibitive – and even advised taxing such dispatches at a higher rate than ordinary ones.

Sadly enough, Caselli’s invention was introduced at a time when the World had started to invest heavily in conventional telegraph services. When the pantelegraph appeared, France was in fact in the process of setting up a complete telegraphic network, using the Hugues, Morse and then Baudot systems, replacing the former Chappe optical telegraph, which had been experimented since 1792.

More than just a technical step forward, a qualitative transformation in the use of the telegraph system was underway. What had until then been an instrument of the governing powers and the stock exchange, was about to establish itself as a relatively commonplace means of communication, conveying a variety of urgent yet trivial pieces of news such as births, deaths, marriages or tourist hotel reservations. Because it had previously been limited to two powerful forces requiring extreme rapidity and perfect secrecy – the State and Finance – the Chappe telegraph had quickly become a myth within French society.

What is more, popular literature glorified the telegraph’s somewhat worrying and imperial vocation in this respect as, for example, in Alexander Dumas’ The Count of Monte Cristo, or in the chronicles of the would-be-poet Barthelemy. The myth of instantantaneousness at the exclusive service of the government or the banking sector was about to become outdated at the very time when Caselli thought he was reaching his goal. Designed to transmit images, the pantelegraph, like today’s fax, was perfectly able to transmit written texts correctly.

However, whether conscious or not, there was a general refusal to allow it any other other role than the transmission of a banking signature or a trademark, since this was the only system capable of doing so, and the administration went on to ensure it was gently stifled out of existence.

Any innovation strategy contains a great many traps, not the least of which is indeed to become fascinated to the extent of being hemmed in by the new technology contained within a given invention and which distinguishes it from all other existing processes, to the ultimate detriment of its flexibility of use and any real possibilities of development. In this respect, the pantelegraph adventure was all the more remarkable given that a tremendous short-cut was almost taken in the history of telecommunications at the time when its destiny was at stake in Paris.

Indeed, in 1863, two top civil servants from the Chinese Empire requested a demonstration at the Froment workshops and could not hide their amazement and admiration in the face of an invention which, in one swoop, solved the tricky problem of the telegraphic transmission of ideograms.

In 1884, fairly far-reaching negotiations appear to have taken place between China and Italy with the aim of carrying out experiments on the Caselli pantelegraph in Peking, but these were not followed up. However, this particular use of the telegraph, anticipated very early on by Caselli, was taken up much later by the Japanese, to whom we owe the massive diffusion of the fax.

Today, pantelegraphs lie dormant in a few rare museums. Those kept at the Musee National des Techniques were given another chance to prove their reliability in 1961, between Paris and Marseille, during the commemoration of the first tests, and in 1982, at the Postal Museum in Riquewihr, where they operated faultlessly, six hours a day, for several months.

Some of other Caselli’s inventions were: an electrical marine torpedo which came back to the launching point in the event of missing the mark, an hydraulic press and an instrument that measures the speed of the locomotives.

In the minds of the public, the pantelegraph was associated exclusively with the transmission of images. The advantages of also using it to send text were only dimly perceived in the 1860s.

The Pantelegraph company in Paris did little to improve the situation, making only feeble efforts to promote its services. Convinced of the superiority of its technology, it was content to wait for investors to appear. None did, however, and the Pantelegraph company was eventually squeezed out of the market – an early example of how a new and superior technology failed to gain a foothold because an earlier technology was already established.

Caselli’s invention subsequently fell into disuse and he died a disappointed man in Florence in 1891.


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