In 1833 John Herschel, a British astronomer, went to South Africa to study the southern skies. He took with him a powerful telescope and many other instruments. He wanted to make charts and maps of the sky which people in the northern half of the world never saw. John Herschel planned to stay at the Cape of Good Hope for three or four years to complete his work.
Then Richard Locke, a reporter on the staff of the New York Sun, had a bright idea. Whatever he wrote about John Herschel’s discoveries would be believed as there was no means of verifying it. No one would find out the truth unless he sent a man or message by ship to South Africa, and even then it would take months to receive a reply from the astronomer. In the meanwhile, Locke decided to have all the fun he could.
In his first article he reported that Herschel had invented a new kind of telescope. Every detail of this telescope was so cleverly thought out that even scientists were taken in. Then the fun started. Locke wrote that with the help of this wonderful telescope, Herschel had seen that the hills and mountains on the moon were made of precious stone. Several forms of life were also reported to have been discovered. Monsters, shaped like huge round balls, rolled about at dizzy speeds over the sands of the lunar sea-shore.
Readers were thrilled and believed the tall tales told by Locke. Locke did the job so well that even scientists were deceived.
Months later, the news came that the whole story was a big hoax, the greatest in the history of science!
No one would dream of playing such a trick nowadays. Thanks to the discovery of the telegraph, we can get news across continent and oceans within minutes.
Ever since Oersted discovered that an electric current could move a magnet, people began trying to put electricity to work.
An Australian scientist tried a system as early as 1809. He set apart one wire for each letter of the alphabet. These wires were placed in a vessel full of water. When electricity passed through any of the wires, a tiny bubble appeared at its base. Though this invention made quite a stir, it did not prove very useful.
Later, around 1825, another inventor, Baron Schilling, made a magnetic telegraph. The electric current passing through the wire turned a magnetic needle which moved over black and white spaces marked on a card. Schilling used a code in which ‘black-white’ meant one letter, ‘black-black-white’ meant another, and so on.
An English professor, Charles Wheatstone, made a small change in this instrument in 1837. He made the needle move over a dial the rim of which was marked with figures and letters. Messages could be read by watching the needle move from letter to letter. It was slow work, but the Railways found it useful and the instrument was in use for years. Wheatstone made a fortune.
Then came Samuel F.B. Morse, the real inventor of the telegraph in its modern form.
One would hardly have expected Morse to make this invention. He was born in America, and although he studied science at school, he chose to be an artist and became quite famous as a portrait painter. Then he went on a tour of Europe to see famous works of art.
He heard about the telegraph when he was returning from Europe on board a ship. A fellow traveller who was a scientist, spoke to him of the work being done on electricity in France. He also showed Morse a small electromagnet he was taking with him to America.
This set Morse thinking. If an electric current could flow any distance through a wire, why shouldn’t it be made to carry messages?
It was an intriguing thought. He had to paint, however, and so he continued to paint, but the idea stuck in his head. His friend, Dr. Gale, at New York University, was pleased at his enthusiasm and encouraged him to work in the college laboratory.
Gale knew of Joseph Henry, a pure scientist, who had done some work in this field. Joseph Henry always helped anyone who came to him with scientific problems. He helped Morse too and showed him a telegraph line about five kilometres long which he had laid in 1832. It created an electromagnet which swung and struck a gong. A code was used for sending and reading messages from the sound of the gong.
Morse decided to use this device, but had still two problems to solve. The device had only been operated over a distance of five kilometres, and Morse wanted his telegraph to operate over hundreds of kilometres. Besides, Morse did not like the code Henry had used. He wanted to find a better code.
Joseph Henry helped to solve the first problem. A device known as a ‘relay’ was fitted at various points along a line. It was just a coil of wire with a battery placed at the end of each section to boost up the fading signals.
To solve the next problem, Morse invented the famous ‘Morse Code’ which is used even nowadays for all types of signaling, especially in the army and the navy. It consists of dots and dashes and each group of these stands for a letter of the alphabet.
Morse took out a patent for his invention in 1837, and tried to persuade the Government to use it on a large scale. But there were delays and for five years Morse led a life of poverty and neglect. At last, the Government gave him $30,000 for a test to show the value of his invention. Morse laid a line of wire from Washington to Baltimore- a distance of about 65 kilometres. The wires were carried overhead, supported by poles, and a battery of 100 cells was used to supply the current. On May 24, 1844, the first message was sent and received. It read “What hath God wrought?” Indeed, God had wrought a miracle that was fated to the change the world.
A . – J . – – – S . . .
B -. . . K – . – T –
C – . – . L . – . . U . . –
D – . . M – – V . . . –
E . N – . W . – –
F . . – . O – – – X – . . –
G – – . P . – – . Y – . – –
H . . . . Q – – . – Z – – . .
I . . R . – .
The test was a complete success. The American Government took a long time making up its mind about going, in for the telegraph in a big way. But private businessmen came forward and soon telegraph wires began to hum over the whole country.
Scientists and inventors were quick to see that anyone who could find a way of sending more than one message over the same wire would make a fortune. A young man, Alexander Graham Bell, was one of those who became interested. He had, moreover, the good fortune to make an even greater invention-the telephone. Bell, who used to teach the deaf, had studied the construction of the human ear to see how it responded to sound. He had the idea of making speech visible so that the deaf could see it by means of a vibrating needle.
Any sound sets up waves of pressure in the air which spread out all around, like ripples when a stone is thrown into a pond. A sound is heard when the pressure waves reach the ear and made the eardrum and the small bone behind it vibrate or start moving forward and back. Similarly when you speak into a telephone the pressure waves strike a flexible iron diaphragm (a thin disc) which moves forward and backward, with the sound waves produced by the voice. In other words, the diaphragm is made to vibrate.
One day, Bell was working with his partner, Watson, in a laboratory. They were carrying out an experiment with a strip of metal which was being made to vibrate. The strip got struck. Watson plucked it, and the sound it made travelled along the wire to Bell, who was working in the next room. He rushed to see what the matter was. He was thrilled when he saw what had happened. God had wrought another miracle!
Bell had to work for another year before he succeeded in perfecting his invention. His apparatus consisted of a horn-shaped speaking tube, at the narrow end of which was a flat disc. This vibrated to the sound waves made by the voice speaking into the tube. The vibration set up variations of electric current in an electromagnetic coil. And then these variations travelled along the connecting wire to a receiving apparatus where the vibrations of a second diaphragm made the same sound waves in the air as those originally made by the speaker at the other end.
Bell’s invention received the first prize at the exposition that was held at Philadelphia in 1876. The device was improved and began to be widely used.
Telegraphs and telephones began to span the length and breadth of continents. But they had yet to span oceans. Some way of carrying the wires across the sea had to be found. Many efforts were made. Several men failed and lost fortunes. But others succeeded.
It was not an easy job. Electric cables had to be laid along the sea-bed which was several kilometres deep at places. Perhaps the first underwater signals were sent in India. Dr. O’Shaughnessy, Director of the East India Company’s Telegraphs, sent them by a cable laid across the Hoogly river in 1839. His cable was made of wire covered with rubber and then enclosed in a lead pipe.
The first efforts to link up England with France were made by John Watkins Brett. His brother, who was an engineer, worked with him. Their contract was due to end on September 1, 1850. By the time they got the cable ready, they had only three days left for laying it. They just got through a message and thus fulfilled their contract.
The next morning the line went completely dead. The cable had got caught in the anchor of fishing boat and the fisherman had cut off a piece to show to his friends.
The task of laying a cable across the Atlantic was a gigantic one. Americans and Englishmen worked together and the navies of the two nations helped. After many setbacks and failures the work was completed in 1866. The cable ran from Valentia Bay near the south-west tip of Ireland to Newfoundland and then on to Canada. Europe thus joined hands with America across the Atlantic!
After 1866, many other under-sea cables were laid. In 1870 Britain and India were linked. Formerly it took a telegram one week to reach Bombay from England. Usually messages were transmitted in relays by one station receiving and passing a message onto the next station. This resulted in many mistakes and it often became difficult to make out the original message. After under-sea cables were laid, messages could be sent within minutes.
As time passed many new inventions were made. We have already seen how the telephone carried the human voice across thousands of kilometres. Then came the radio and the television.
Nowadays a man can read what is happening all over the world in his morning newspaper. News from the farthest corners of the earth is flashed, received and printed overnight.
Today we are on the threshold of a new era in telecommunications. Very soon we are going to have new global telegraph, telephone and television services via communication satellites. One of the greatest achievements of mankind is the present-day fast communication system.
First published by National Book Trust, India.