Pantelegraph
Encyclopedia
The pantelegraph was an early form of facsimile machine transmitting over normal telegraph lines developed by Giovanni Caselli
Giovanni Caselli
Giovanni Caselli was an Italian physicist. He is the inventor of the pantelegraph , the predecessor of the modern fax machine...

, used commercially in the 1860s, that was the first such device to enter practical service, It could transmit handwriting, signatures, or drawings within an area of up to 150 x 100mm.

Description

The Pantelegraph used a regulating clock with a pendulum which made and broke the current for magnetizing its regulators, and ensured that the transmitter's scanning stylus and the receiver's writing stylus remained in step. To provide a time base, a large pendulum was used weighing 8 kg (17.6 lb), mounted on a frame 2 m (6.6 ft) high. Two messages were written with insulating ink on two fixed metal plates; one plate was scanned as the pendulum moved to the right and the other as the pendulum moved to the left, so that two messages could be transmitted per cycle. The receiving apparatus reproduced the transmitted image by means of paper impregnated with potassium ferricyanide
Potassium ferricyanide
Potassium ferricyanide is the chemical compound with the formula K3[Fe6]. This bright red salt contains the octahedrally coordinated [Fe6]3− ion. It is soluble in water and its solution shows some green-yellow fluorescence.-Preparation:...

, which darkened when an electric current passed through it from the synchronized stylus. In operation the Pantelegraph was relatively slow; a sheet of paper 111mm x 27mm, with about 25 handwritten words, took 108 seconds to transmit.

The most common use of the Pantelegraph was for signature verification in banking transactions.

History

While employed teaching physics at the University of Florence, Giovanni Caselli devoted much time to researches into the telegraphic transmission of images. The major problem of the time was to get perfect synchronization between the transmitting and receiving parts so they would work together correctly. Caselli developed an electrochemical technology with a "synchronizing apparatus" (regulating clock) to make the sending and receiving mechanisms work together that was far superior to any technology Bain
Alexander Bain (inventor)
Alexander Bain was a Scottish inventor and engineer who was first to invent and patent the electric clock. Bain installed the railway telegraph lines between Edinburgh and Glasgow.-Early life:...

 or Bakewell
Frederick Bakewell
Frederick Collier Bakewell was an English physicist who improved on the concept of the facsimile machine introduced by Alexander Bain in 1842 and demonstrated a working laboratory version at the 1851 World's Fair in London.-Biography:Born in Wakefield, West Yorkshire, he eventually moved to...

 had.

By 1856, he had made sufficient progress for Leopold II, Grand Duke of Tuscany
Leopold II, Grand Duke of Tuscany
Leopold II of Tuscany was the last reigning 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
Léon Foucault
Jean Bernard Léon Foucault was a French physicist best known for the invention of the Foucault pendulum, a device demonstrating the effect of the Earth's rotation...

, to construct the first Pantelegraph. In 1858, Caselli's improved version was demonstrated by French physicist Alexandre-Edmond Becquerel at the French Academy of Sciences
French Academy of Sciences
The French Academy of Sciences is a learned society, founded in 1666 by Louis XIV at the suggestion of Jean-Baptiste Colbert, to encourage and protect the spirit of French scientific research...

 in Paris.

On 10 May 1860 Napoleon III visited Froment's workshop to observe a demonstration of the device, and was so enthused by the device that he secured access for Caselli to the telegraph lines he needed to further his work, from Froment's workshops to the Paris Observatory
Paris Observatory
The Paris Observatory is the foremost astronomical observatory of France, and one of the largest astronomical centres in the world...

. 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
Gioacchino Rossini
Gioachino Antonio Rossini was an Italian composer who wrote 39 operas as well as sacred music, chamber music, songs, and some instrumental and piano pieces...

 as the image sent and received, over a distance of 140 km (87 mi).

The first "pantelegram" was sent from Lyons to Paris on 10 February 1862. The Corps législatif later ordered the installation of the pantelegraph on the railway line between the two cities, and from February 1863 the public was able to use it. French law was enacted in 1864 for the pantelegraph facsimile system to be officially accepted. The next year in 1865 the operations started with the Paris to Lyon line and extended to Marseille
Marseille
Marseille , known in antiquity as Massalia , is the second largest city in France, after Paris, with a population of 852,395 within its administrative limits on a land area of . The urban area of Marseille extends beyond the city limits with a population of over 1,420,000 on an area of...

 in 1867.

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

Russian Tsar Nicolas I installed an experimental service between his palaces in Saint Petersburg
Saint Petersburg
Saint Petersburg is a city and a federal subject of Russia located on the Neva River at the head of the Gulf of Finland on the Baltic Sea...

 and Moscow
Moscow
Moscow is the capital, the most populous city, and the most populous federal subject of Russia. The city is a major political, economic, cultural, scientific, religious, financial, educational, and transportation centre of Russia and the continent...

 between 1851 and 1855. In the first year of operation of the pantelegraph the system transmitted almost 5,000 faxes, with a peak of faxes being sent at the rate of 110 per hour. In spite of all this, the technology developed too slowly to make it fully reliable; allowing to fall into obsolescense. Following the Franco-Prussian War
Franco-Prussian War
The Franco-Prussian War or Franco-German War, often referred to in France as the 1870 War was a conflict between the Second French Empire and the Kingdom of Prussia. Prussia was aided by the North German Confederation, of which it was a member, and the South German states of Baden, Württemberg and...

, the Pantelegraph was superseded by Bernhard Meyer's autographic telegraph which used a drum with a helical edge and allowed transmission speeds twice as fast as those of the Pantelegraph.

Surviving machines

There are few remaining examples of the original pantelegraph. A formidable display of the pantelegraph was mounted in 1961 at the Musée National des Techniques
Musée des Arts et Métiers
The Musée des Arts et Métiers is a museum in Paris that houses the collection of the Conservatoire National des Arts et Métiers , which was founded in 1794 as a repository for the preservation of scientific instruments and inventions.-History:Since its foundation, the museum has been housed in the...

, when a centennial celebration of the device was performed between Paris
Paris
Paris is the capital and largest city in France, situated on the river Seine, in northern France, at the heart of the Île-de-France region...

 and Marseille
Marseille
Marseille , known in antiquity as Massalia , is the second largest city in France, after Paris, with a population of 852,395 within its administrative limits on a land area of . The urban area of Marseille extends beyond the city limits with a population of over 1,420,000 on an area of...

. Again in 1982 their reliability was displayed; two pantelegraphs were used for six hours a day, for several months, performing without error.

External links

  • Giovanni Caselli, by Eugenii Katz. Internet Archive
    Internet Archive
    The Internet Archive is a non-profit digital library with the stated mission of "universal access to all knowledge". It offers permanent storage and access to collections of digitized materials, including websites, music, moving images, and nearly 3 million public domain books. The Internet Archive...

     version.
  • Facsimile & SSTV Historythis site has lots of images
  • Secret Life of The Fax Machine - Illustrated History by Cartoonist Tim Hunkin
    Tim Hunkin
    Tim Hunkin is an English engineer, cartoonist, writer, and artist living in Suffolk, England. He is best known for creating the Channel Four television series The Secret Life of Machines, in which he explains the workings and history of various household devices...

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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