Giovanni Caselli Italian physicist Date of Birth: 25.04.1815 Country: Italy

1. Biography of Giovanni Caselli
2. Work in Parma and Political Involvement
3. Professorship and Research at the University of Florence
4. Invention of the Pantelgraph
5. Success and Recognition
6. Later Life and Legacy

Biography of Giovanni Caselli

Giovanni Caselli, the Italian physicist, was born on April 25, 1815, in Siena, Italy. In the early years of his career, Caselli studied literature, history, natural sciences, and religion. Despite his clear interest in physics, Caselli intended to become a priest and was ordained in 1836.

Work in Parma and Political Involvement

In 1841, Caselli moved to Parma in the province of Modena to become a tutor for the sons of a local aristocrat. He used the money earned from this position to build an experimental model of his pantograph telegraph, also known as the pantelgraph or universal telegraph. In 1849, Caselli participated in popular uprisings and called for the annexation of Modena by the Kingdom of Sardinia. As a result, he was forced to leave for Florence.

Professorship and Research at the University of Florence

In the same year, Caselli became a professor of physics at the University of Florence, where he studied physics, electrochemistry, electricity, electromagnetic interaction, and magnetism under the guidance of Leopoldo Nobili. In 1851, Caselli started publishing a journal called "The Recreation," in which he explained physics in a language understandable to ordinary people.

Invention of the Pantelgraph

The term "pantelgraph" is a combination of the words "pantograph," a device that copies written text and drawings, and "telegraph," a device capable of sending messages over long distances. While working at the University of Florence, Caselli devoted much of his time to developing a technology that could transmit both text and simple drawings. Other physicists, such as Alexander Bain from Scotland and Frederick Bakewell from England, conducted similar research during this time. The main challenge was achieving perfect synchronization between the transmitter and the receiver to ensure accurate message transmission. Caselli's developments in this field surpassed the work of his contemporaries. He built a prototype of his device in 1856 and demonstrated its capabilities in the presence of Leopold II, the Grand Duke of Tuscany. Impressed by Caselli's invention, the Grand Duke offered to finance his experiments. When the Grand Duke's enthusiasm waned, Caselli moved to Paris and showcased his apparatus to Napoleon III, who became an enthusiastic supporter of the new technology. From 1857 to 1861, Caselli worked on his pantelgraph in Paris with the assistance of French inventor and mechanical engineer Léon Foucault.

Success and Recognition

In 1858, an improved version of Caselli's device was demonstrated by French physicist Alexandre-Edmond Becquerel at the French Academy of Sciences. In 1860, Caselli had the opportunity to test his invention within the French national telegraph network. Thanks to the financial support from Napoleon, Caselli had access not only to French telegraph lines but also to significant amounts of money. The tests were successful, with the signature of composer Gioachino Rossini making a telegraphic journey from Paris to Amiens, covering a distance of 140 km. The next test took place between Paris and Marseille, covering a distance of 800 km, and it also succeeded. In 1865, a permanent pantelgraph communication was established between Paris and Lyon, followed by Paris and Marseille two years later. Grateful France awarded Caselli the Legion of Honour, and Parisian physicists and engineers founded the Pantelgraph Society to share ideas for improving the pantelgraph.

Later Life and Legacy

Alexander Graham Bell received his telephone patent (No. 174465) from the US Patent Office in 1876. Caselli had patented his invention (E.P. 2532) in France in 1861 and in the United States in 1863 (No. 37563). Soon, pantelgraph communication was introduced in other countries such as the United Kingdom and Russia. In the end, Caselli returned to Florence, where he passed away on June 8, 1891.