Up until the middle of the XIX century the only means of communication between the European continent and England, between America and Europe, between Europe and the colonies remained steamship mail. About incidents and events in other countries, people learned too late for weeks and sometimes months. For example, the news from Europe to America were delivered in two weeks, and it was still not the long term. Therefore, the creation of the telegraph to meet the most urgent needs of humanity. After this technical novelty appeared in all parts of the world and the globe girded telegraph lines, needed only hours and sometimes minutes to ensure that the news over electrical wiring rushed from one hemisphere to another. Political and stock quotes, personal and business messages on the same day may be delivered to interested parties. Thus, the Telegraph should be attributed to one of the most important inventions in the history of civilization, because with it the human mind won a great victory over the distance.
But apart from the fact that the Telegraph has opened a new milestone in the history of communication, it is important to the invention by the fact that here for the first time, and, moreover, in a fairly large scale, electric power was used. That the creators of the telegraph was first demonstrated that an electric current can be made to work for the needs of the person and, in particular, to transmit messages. Studying the history of the telegraph, you can see how in a few decades, the young science of electric current and telegraphy went hand in hand, so that each new discovery in electricity inventors used immediately for various methods of communication.
As is known, electrical phenomena met people in ancient times. Even Thales, rubbing a piece of amber hair, then watched as Goth attracts small bodies. The reason for this was that by rubbing amber communicated an electric charge. In the XVII century learned to charge the body with the help of an electrostatic machine. Soon it was found that there are two kinds of electric charges: they were called negative and positive, and noticed that the body having the same sign charge, repel each other, and different signs - attract. For a long time, exploring the properties of electric charges and charged bodies, had no idea of the electric current. It was opened, it can be said casually Bologna Galvani professor in 1786. Galvani in experimenting with electrostatic machine for many years, studying its effect on the muscles of animals - especially frogs (Galvani cut foot frog with a portion of the spinal column, one electrode of the machine let the spine, and the other - to any muscle, by passing discharge muscles contract and foot twitching). Once Galvani hung frog legs with a copper hook to the iron lattice balconies, and to his great astonishment I saw that the foot jerked as if she missed through electrical discharge. This reduction occurred every time the hook was connected to the grid. Galvani thought that in this experiment the source of electricity is very foot of the frog. Not everyone agreed with this explanation. Pisa Professor Volta first realized that electricity is caused by the connection of two different metals in the presence of water, but not clean, and is a solution of any salt, acid or alkali (such electrically conductive environment became known as the electrolyte). For example, if zinc and copper plates soldered together and immersed in an electrolyte, in electrical circuit phenomena occur, resulting in the electrolyte flowing chemical reaction. A very important factor here was the following - if before scientists were able to obtain only a momentary electrical discharges, but now they had to deal with a fundamentally new phenomenon - a constant electric current. Current, unlike the discharge can be observed over extended periods of time (until the electrolyte does not take place until the end of the chemical reaction), it was possible to experiment with it, finally, it can be used. However, the current generated between a pair of plates, resulting in a slightly, but Volta learned to enhance it. In 1800, combining several of these pairs together, he received the first-ever electric battery called voltaic pile. This battery consisted of laid one on another plate of copper and zinc, among which are pieces of felt soaked in brine. In the study of the electrical state of the post Volta discovered that medium pairs voltage almost completely unnoticed, but it is growing at a remote plates. Consequently, the voltage of the battery was the greater, the greater the number of pairs. While this column poles were connected to each other, it does not exhibit any action, but by closing the end by a metal wire in the battery begun chemical reaction, and appeared in the wire an electric current. Creation of the first electrical battery was an event of the greatest importance. Since that time, an electric current is the subject of the most careful study of many scientists. After that, there were also the inventors who have tried to use the newly discovered phenomenon of human needs.
It is known that an electric current is an ordered motion of charged particles. For example, in the metal - the movement of electrons in the electrolytes - positive and negative ions, etc. Passage of current through the conductive medium is accompanied by a number of phenomena, which are called the actions of the current. The most important of them - is thermal, chemical and magnetic. Talking about the use of electricity, we usually mean that the application is one or another of the current action (for example, an incandescent bulb - heat in the motor - the magnetic, in electrolysis - chemical). Since the electric current is initially opened as a result of a chemical reaction, the chemical effect of the current first of all drew attention to themselves. Noticed was that when current passes through the electrolyte excretion observed substances in solution or gas bubbles. When a current is passed through water may be, for example, decompose it into its constituent parts - the hydrogen and oxygen (this reaction is called electrolysis of water). It is this current action and formed the basis of the first electric telegraph, which are therefore called electrochemical.
In 1809, the first project of the telegraph was introduced in the Bavarian Academy. His Zemering inventor proposed to use for the communication means of gas bubbles produced by passing current through the acidified water. Telegraph Zemeringa consisted of: 1) voltaic column A; 2) alphabet B, wherein the letters correspond to the individual wiring 24 connects through a column volt wire stick pins into the holes (B2 on this compound is shown in an enlarged view, and a plan view B3); 3) the rope E of 24 wires twisted together; 4) alphabet C1, quite an appropriate set of B and is placed on the station receiving telegrams (here the individual wiring passed through the bottom of the glass vessel with water (the C3 is a plan of the vessel); 5) the D alarm, consisting of a lever with a spoon (as he enlarged presented at C2).
When Zemering like wire, he first filed another station sign with the help of an alarm clock, and it stuck to the two poles of the conductor loops in the letters B and C. The current passes through a conductor and the water in a glass vessel C1 by expanding it. The bubbles accumulated in the stomach and lifted her so that she took the position indicated by a dotted line. In this position, the movable lead ball under its own gravity was rolled into the funnel and it went down into the cup, causing the alarm action. Once at the receiving station was all prepared to receive dispatches, I gave it to put together a pole wire in such a way that the electric current passed through all of the letters that make up the transmitted message, and the bubbles are separated from the corresponding letters of the other station. Subsequently, the telegraph Schweiger significantly simplified by reducing the number of wires to just two. Schweiger has introduced different combinations of passing current. For example, various current duration of action and thus different lengths of decomposition of water. But the telegraph was still too difficult: to observe the effervescence was very tiring. The work went slowly. Therefore, the electrochemical telegraph never received practical application.
Next step in the development of telegraphy associated with the opening action of the magnetic current. In 1820 the Danish physicist Oersted during one of the lectures accidentally discovered that a conductor with electric current affects the magnetic needle, that is, behaves like a magnet. Intrigued by this, Oe was soon discovered that a magnet with a certain force interacts with the conductor through which electric current flows - attracts or repels it. In the same year, a French scientist Argo made another important discovery. Wire on which he missed the electric current was accidentally shipped in a box with iron filings. Sawdust stuck to the wire as if it were a magnet. When the current is turned off, chips have fallen. Having studied this phenomenon, Argo has created the first magnet - one of the most important electrical devices, which is used in a variety of electrical appliances. The simplest electromagnet easy to prepare each. To do this, take the iron bar (best nonhardened "soft" iron) and tightly wound on his insulated copper wire (this wire is called a solenoid coil). If we now connect the ends of the winding to the battery, a bar magnetized and will behave as well-known to all the permanent magnet, that is, attract and retain small metal objects. With the disappearance of the current in the coil block immediately demagnetized by opening the circuit. Usually, the electromagnet is a coil inside which an iron core is inserted.
Observing the interaction of electricity and magnetism, Schweiger in the same 1820 invented galvanoskop. This device consisted of a single coil of wire inside which was placed in a horizontal state of the magnetic needle. When passed through the wire an electric current, the needle deflected to one side. In 1833 Nervandar invented a galvanometer in which the current is measured directly on the corner of the magnetic needle deflection. Passing current known forces could get known deflection galvanometer. This effect and the electromagnetic telegraph system was built.
The first such telegraph invented by Baron Schilling Russian citizen. In 1835, he demonstrated his pointer telegraph to the congress of scientists in Bonn. The transfer device Schilling consisted of keyboard keys 16 serving for the current circuit. Receiving instrument consisted of 6 galvanometers with the magnetic needle, suspended on silk threads to the copper pillars; above arrows on strings were reinforced two-color paper flags one side of them was painted white, the other - black. Both stations were connected by telegraph Schilling eight wires; six of them were connected with a galvanometer, one was used for reverse current and one - for the call-up apparatus (electric bell). When the starting station, press the keys and let the current at the receiving station was deflected corresponding arrow. Various provisions of the black and white flags on different disks gave the conditional combination, consistent with the letter of the alphabet or numbers. Later Schilling improved his apparatus, with 36 different variations of the magnetic needle it only corresponded to 36 arbitrary signal.
When the demonstration experiments Schilling attended the Englishman William Cook. In 1837, he was somewhat improved apparatus Schilling (in Cook arrow at each point to the rejection of this or that letter, shown on the board of these characters evolved words and phrases) and tried to arrange a telegraphic message in England. Generally, telegraphs, working on the principle of a galvanometer, got some distribution, but very limited. The main disadvantage was the difficulty of operation (telegrapher had to quickly and accurately capture the fluctuations of arrows eye that was enough exhausting), and the fact that they did not record the messages on paper. Therefore, the main way of telegraph went the other way. However, the device of the first telegraph lines helped to solve some important problems related to the transmission of electrical signals over long distances.
Since the wire is very difficult to hold the spread of the telegraph, the German inventor Steingel tried to limit ourselves to a single wire, and keep the current back on railroad tracks. To this end, he conducted experiments between Nuremberg and Fürth and found that the reverse wire in general there is no need, as for the transmission of messages is enough to ground the other end of the wire. Then began one station to ground the positive pole of the battery, on the other - a negative, thus getting rid of the need to carry out a second wire, as it did before. In 1838 Steinheil in Munich built a telegraph line about 5 km in length, using the earth as a conductor for the return current.
But in order to telegraph became a reliable communication device, it was necessary to create a machine that could record the transmitted information. The first such device with recording instruments was invented in 1837 by American Morse.
Morse was a painter by profession. In 1832, during the long voyage from Europe to America, he became acquainted with the electromagnet device. Then he had the idea to use it for signal transmission. By the end of the journey he had already come up with a device with all necessary accessories electromagnet moving strip of paper, as well as his famous alphabet, consisting of a system of points and dashes. But it took many years of hard work before Morse managed to create a workable model of the telegraph. This was compounded by the fact that at that time in America, it was very difficult to get any electrical appliances. Virtually all Morse had to do by yourself or with the help of his friends from the New York University (where he was invited in 1835 by a professor of literature and fine arts). Morse took to forge a piece of soft iron and cocked it in the form of a horseshoe. Insulated copper wire was not yet known Morse bought a few meters of wire and insulated with paper. The first big disappointment befell him when found insufficient magnetization of the electromagnet. This was due to a small number of turns of wire around the core only reading the book by Professor Henry, Morse was able to correct the mistakes and put together the first working model of your device. On a wooden frame attached to the table, he installed an electromagnet and clockwork drives the paper tape. By the pendulum of a clock, he attached an anchor (spring) magnet and a pencil. Produced using a special device, the telegraph key, and the closure of the current opening forcing the pendulum to swing back and forth, and pencil sketching on paper tape moving dashes that corresponded filed by current conventional signs.
It was a major success, but there were new difficulties. When transmitting a signal over a long distance due to the resistance of the wire the signal strength is weakened to such an extent that he could no longer control the magnet. To overcome this difficulty, Morse invented a special electromagnetic contactor, a so-called relay. The relay is an extremely sensitive electromagnet that spoke even the weakest currents coming from the line. Each attraction anchors relay closes the current local battery by passing it through an electromagnet writing instrument.
Thus, Morse invented all the basic parts of his telegraph. He completed the work in 1837. Another six years were spent in his futile attempts to interest the US government as their invention. Only in 1843 the US Congress decided to allocate 30 thousand dollars to build the first telegraph line length of 64 km between Washington and Baltimore. First, it laid underground, but later discovered that the insulation can not withstand moisture. I had to quickly correct the situation and pull the wire from the ground. May 24, 1844 the first telegram was sent officially. Four years later, telegraph lines were already in most states.
Morse telegraph was extremely practical and easy to handle. Soon he received the widest dissemination throughout the world and brought to its creator deserved fame and fortune. The design is very simple. The main parts of the apparatus were transmitting device - key, and the receiver - the writing instrument.
Morse key consisted of a metal arm that rotates around a horizontal axis. Both the front and the small metal cones touch each lying beneath the plates, whereby the current circuit occurred posterior axis located. To imagine the work key, denoted all his contact numbers. Let the front cone is 1, and the rear - 3. Lying underneath the plate, respectively, will be considered as the 2nd and 4th contacts. The key position when the handle is not lowered, the contacts 3 and 4 are closed, and 1 and 2 - are open. Plate 2 is connected to a battery wire. With the body of the lever is connected to wire wire to a remote station, while the plate 4 has a connection with the writing instrument. On the receiving station receives the wire goes to the receiving magnet.
When the telegram came, the electric current is passed through the key levers in such a way that the wire he did in the plate 4 and then - in the writing instrument (terminals 1 and 2 at the time were disconnected) When sending telegrams terminals 3 and 4 is disconnected. Then, the current from the battery when circuit pins 1 and 2 went to the reception station. If telegraph circuit is closed for a short time - I took a short signal when holding the key at the bottom for longer - Receive longer.
The writing instrument on the receiving stations convert these signals into a system of dots and dashes. He worked as follows. From the station transmit current fed to M and M1 spiral. Held by the iron pieces are magnetized and attracted iron plate B. As a result, the pin About, who was on the other shoulder A, pressed against the paper web P, which curtailed by a circle R rolls V and W in the direction of the arrow. At the same time the pin end, which was a pencil, writing on the tape dots or dashes, depending on whether - it is pressed for a short or longer time. Once the effect of the current was stopped (this happened every time the telegraph operator at the transmitting station opens key chain), the spring f delayed the pin down, so that the plate B moved away from the electromagnet. The movement of rollers V, and W going by clockwork, which is driven by lowering the weights G. The degree of deflection of the lever can be adjusted by means of m and n screws.
The disadvantage of the Morse apparatus lay in the fact that messages are sent to them were clear only to professionals who are familiar with Morse code. In the future, many inventors worked on the creation of direct-printing apparatus, recording is not conditional combination, and the words themselves telegram. Widespread was invented in 1855 by direct-printing machine Hughes. Its main parts are: 1) keypad with rotary contactor and a board with a hole (this transmitter accessory); 2) letter a wheel with a device for printing (this receiver). The keyboard was placed 28 keys, with which you can transmit 52 characters. Each key levers of the system was connected to a copper rod. In normal position, all the rods are in the sockets, and each slot arranged on the board along the circumference. Above these sockets rotated at 2 revolutions per second contactor, so-called truck. She is driven to rotate the descending weights of 60 kg and a system of gears on the receiving station with exactly the same speed of the rotating wheel lettering. On its rim were teeth with signs. Rotating the bogie and the wheels occurred synchronously, ie at the moment when the truck passed over the slot corresponding to a particular letter or symbol, the same character found himself in the bottom of the wheel over the paper tape. When you press one of the copper rod raised himself and spoke of his nest. When the truck touched him, the circuit is closed. The electric current instantly reaches receiving station and passing through the electromagnet coil made paper tape (which was moving at a constant rate) to rise and touch the lower teeth of the printing wheels. Thus the desired letter was printed on the tape. Despite the apparent complexity, telegraph Hughes worked pretty fast and experienced telegrapher handed it to 40 words per minute.
Born in the 40s of XIX century, the telegraph in the following decades developed rapidly. telegraph wires crossed continents and oceans. In 1850, an underwater cable, Britain and France were connected. The success of the first submarine line has caused a number of others: between England and Ireland, England and Holland, Italy and Sardinia, etc. In 1858, after several unsuccessful attempts failed to lay a transatlantic cable between Europe and America. However, it only worked for three weeks, after which the connection was broken. Only in 1866 constant telegraph was finally established between the Old and New Worlds. Now events in America, on the same day became known in Europe, and vice versa. In subsequent years, the rapid construction of telegraph lines went around the globe. Their total length is only in Europe amounted to 700 thousand. Km.