Relay history: range finder


We continue our history of the origin of the digital switch, examining in detail the occurrence of the first telegraph. After all, it is with this device that the electric telegraph should be compared. Well, then, it's just an interesting thing.

Brothers chapp

In 1789, Claude Chappe lived without worries. He was listed as a priest, and received income from the church benefit , located in the countryside of France. But instead of spending days saving peasant souls, he went to Paris, joined a group of philosophers, and began to write works on experimental physics.

With the advent of the revolution, his life became more complicated. The new government abolished the benefits, and Chapp needed a new source of revenue. His brothers Ignatius, Claude and Abraham were also unemployed. The brothers returned to their hometown in Brittany and developed a new scheme of earnings. They decided to create a long-distance messaging system and sell it to a new revolutionary government.

The first attempt, made in the winter of 1790 - 1791, was based on a system of synchronized clocks. They placed two pendulum clocks with special symbols on the dials behind the house of their parents. The person who wanted to send a message struck the gong, and the sender and receiver started their watches on this signal. Then the sender once again gave a sound signal at the moment when the arrow hit the symbol it needs. The receiver of the signal checked his dial and recorded the received symbol. According to a special directory of these characters could make words.

Shupps knew that sound could not be used as a practical method of synchronization over long distances. Claude tried many other methods for transmitting the “start the clock” and “write the character” signals, including electricity - but to no avail. As a result, he stopped on a board with one dark and one bright sides. Turning the board with the light side replaced the gong beat. With the help of a telescope, the recipient could distinguish the dark and bright side for many kilometers.

By the summer of 1792, Claude realized that he could even get rid of the clock with the dial, simply by adding more boards. Their positions can directly encode the desired character. By this time, he and his brothers had already gained enough confidence and began to seek support in the Legislative Assembly, of which Ignatius was a member. They called their device "telegraph", or "long-distance recorder."

As a result, the panels were replaced with a signal semaphore consisting of three movable metal arms on a pole. Each position encoded its own character. The ingenious system of pulleys allowed the operator to control the semaphore with the help of levers, which needed to be located exactly in the same position as the semaphore had to be brought.

Enlisting the support of like-minded people from the new National Convention , Shuppa received funding to create a trial line in northern France in April 1793. Satisfied with the operation of the device, the government ordered the construction of a full-size line from Paris to Lille, 225 miles from the north-west border. By the summer of 1794, she was loudly recognized because she was able to transmit information about the French victory in the Austrian Netherlands (in the territory of modern Belgium) just a few hours after the event itself. Excluding signal lights and other old technologies of the same low bandwidth, no other message has traveled such a long distance faster than a horse rider.

Telegraph era

In 1796, Abraham Nicklas Edelcrantz wrote in his treatise on the telegraph:

With new inventions it often happens that a part of the public finds them useless, and another part considers them impossible. When it becomes clear that the opportunity and benefit cannot be denied in any way, the majority agrees that this device was fairly easy to invent, and that they had known about it for a long time.

Indeed, after proving the success of the invention, the society considered the Shapp system in France to be a great blessing of the Republic, after which imitators appeared all over Europe - making the necessary corrections to the design to calm national pride. The first and best among them was Edelcrantz himself, a Swedish librarian, teacher and poet, who, hearing about the telegraph Shappov in September 1794, immediately began experimenting with his own versions of the project. Britain, Prussia, Spain, the Netherlands, and others built telegraph systems of one kind or another in the next decade.

Telegraph station at the top of the medieval church in Montmartre (then - outside the borders of Paris)

The telegraph was especially loved by Napoleon, who used it as an instrument of political control and military power. Immediately after the coup d'état of 1799, which made him the First Consul, he signaled the received power with the help of a telegraphic message: "Paris est tranquille et les bons citoyens sont contents" ["In Paris is quiet, and good citizens are happy"]. As emperor, he led the further expansion of the system, which stretched across the Padan lowland in northern Italy (the scene of his early victories) all the way to Venice.

European rulers like Napoleon saw in the telegraph primarily a tool of state power, especially in wartime. Many European systems were built as early warning systems against invasions during the long series of wars provoked by the French Revolution, which lasted until the final defeat of Napoleon in 1815. Ignatius Chappe complained in his History of the Telegraph that the higher forces did not consider it possible to adapt the telegraph for commercial use. He believed that the invention, if given a chance, was able to create new trans-European markets, and turn Paris into the financial capital.

Instead, the French closed most of the network during the annual Amiens peace in 1802-1803, the British allowed their system to become unusable at the end of the Napoleonic wars in 1815, and the Swedish telegraph system fell into disrepair at the end of hostilities with Russia in 1809.

Entrepreneurs set up private commercial lines in Germany, Britain and France, usually for early warning of approaching ships. For example, Johann Schimdt ruled the line from Cuxhaven on the North Sea to the port of Hamburg on the Elbe from 1837 to 1848. But these were only exceptions. In the United States, for example, all telegraphs were only small private enterprises — they were mainly built in Boston, Philadelphia and New York.

Why, I wonder, did the telegraph take so long to appear? Its physical elements - metal and wooden parts, pulleys and ropes, have been known since ancient times. The only new component that increased its practicality was the telescope, which allowed building stations 5 miles apart. But even to this instrument, by the beginning of the experiments, Shapp was almost 200 years old. During this time, several methods of transmitting messages over long distances using telescopes and visual signals have been proposed - one of the most famous belongs to Robert Hooke . And nothing came of it.

Hence, the explanation of the phenomenon must be sought not in the lack of technical resources. Surely this is the perseverance, energy and political training of the Chapp brothers. I also think that the special situation generated by the revolutionary French also played a role. Others, though imitated their telegraph, never built networks of the same scale and size.

All the governments of France in the 1790s felt (not without reason) that they were in a state of constant siege and emergency. A new tool that can warn them about the activity of their many enemies should have liked them. It is enough for the National Convention to push through the idea of ​​Shapps, allowing them to charge a high price for their device and cut down trees and other obstacles when building their line.

Part of the ideology of the Revolution was to unite the entire French nation, and sweep aside the fragments of the localist habits of the feudal era. Therefore, projects such as the metric system, designed to replace many local systems of weights and distances with one, supposedly more rational, system were supported. The telegraph, with its towers stretching from one corner of France to another, fit well with ideology. Bertrand Barer, a prominent delegate to the National Convention, put the telegraph on a par with typography, gunpowder and compass in the gallery of inventions that "made the greatest obstacles to human civilization disappear and made possible the unification of people into great republics."

Optical and electric

The existence of the telegraph has affected all attempts to transmit messages using electricity. Now the electric spotlights had a clear example to follow. They built a new type of telegraph - at various times it was called electric, electromagnetic, voltaic, galvanic, etc. - depending on the place, time and temperament.

It is worthwhile to dwell on two historical examples, when the paths of development of the optical and electric telegraphs intersected.

Optical inspires electric

On April 10, 1809, the Austrian army crossed the River Inn and invaded the kingdom of Bavaria , an ally of France. Napoleon was quickly informed via the nearest telegraph station in Strasbourg. He arrived at the front from Paris on the 16th, drove the Austrians from Bavaria and defeated their forces near Vienna three months later in the Battle of Wagram . This was the last of the great successes of Napoleon.

The ministers of the Bavarian government were amazed at the speed of Napoleon’s arrival. In less than a week, the message and the man made a circular journey more than 1600 km long, that is, 150 miles a day. They sought the advice of an eminent member of the Academy of Sciences, Samuel Sömmering , and asked him for a technical proposal for building their own telegraph.

To their surprise, Sömmering returned at the end of the same summer with a proposal in which it was not the Chapp telegraph that was described, but its electrical version. It was based on the principle of electrolysis - the separation of water into hydrogen and oxygen using electricity. It consisted of 35 wires, each of which ended in a separate container with water. The ends of the wires were supplied with a letter of the alphabet and a number from 0 to 9. The application of electricity to the wires made the bubbles rise in front of the desired letter or number.

Sömmering sent a copy of the device to Paris, hoping that Napoleon would also be interested in her, but the emperor never saw her. His device would become another historical wonder, like many other electric telegraphs, invented around 1800 - but it suddenly launched a chain of events that led to the appearance of the first commercial telegraph in almost thirty years and 800 km from that place. And Napoleon still had to play one of the roles in this chain. In due time we will return to this story.

Optical eliminates electrical?

Another story relates to Francis Ronalds, the British electrician experimenter, inventor and remarkable engineer. In the summer of 1816 he decided to prove the practicality of the electric telegraph. In the simplest form, his system repeated the first experiments of Chappe - it consisted of synchronized clocks with dials at each end of the line. The difference was that the sync signal was electric.

When he connected his car with a wire, a pair of balls of porous wood material at the far end of the wire acquired a charge and began to repel each other, which was a signal that the recipient needed to either start his watch or read the character from the dial and write the right letter . In his lawn, he stretched 13 km of iron wire on two large wooden frames to demonstrate how the system works at decent distances from a practical point of view.

Ronalds wrote to the British Admiralty about his new method of “telegraphic transmission” and requested an audience to demonstrate his “adaptation”. Admiralty Secretary John Barrow unceremoniously replied to him that "telegraphs of any type are now completely useless, and that no other telegraph other than the already existing one will be accepted for service."

This story is often told, gloatingly pointing to Barrow's myopia, but there are several subtle points in it:

1. The Ronalds system was not like the successful electric telegraphs of the 1840s. There is no reason to believe that if Barrow had responded enthusiastically to Ronalds' letter, the electric telegraph would have appeared successfully several decades before the deadline.

2. European states considered the telegraph a military instrument, and after the fall of Napoleon, the need for such a system really passed (or sharply decreased).

3. Finally, the admiralty has become accustomed to the constant stream of proposals for improving the telegraph, most of which were sent to them by deceivers and madmen. Ronalds himself admitted that "everyone knows that the telegraph has long bored everyone in the admiralty."

However, the potential benefits of the electric telegraph were clear. The optical telegraph had a mass of natural enemies: rain, smoke, fog, snow, short winter days — in bad conditions, it could take days to send messages. The station in the British Admiralty in London, for example, did not work 100 days a year because of the “London fog” (that is, coal smoke). Electric telegraph with well-insulated wires is not dependent on the weather. His messages would always come instantly. Moreover, it would cost less to maintain, since people were only needed where the messages were sent from and where they were received - and not at intervals of every ten kilometers in rural areas.

But for the time being it remained unclear whether the potential of information transfer is realized by means of electricity.

What to read:

• John J. Fahie, A Year of Electricity 1837 (1884) [1974 reprint]
• Daniel R. Headrick, When Information Came of Age (2000)
• Gerard J. Holzmann and Björn Pehrson, The Early History of Data Networks (1995)


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