Marconi, Guglielmo (1874-1937)
Marconi, Guglielmo (1874-1937)
MARCONI, GUGLIELMO (1874-1937)
Guglielmo Marconi, the originator of wireless telegraph signals, created the means of overcoming many of the hurdles to the commercialization of wireless. In particular, he was the first person to transmit radio signals across the Atlantic Ocean without the use of cables.
Marconi was born in the Italian countryside in somewhat modest circumstances. While he had little formal education (although his mother did tutor him), he loved to read about experiments with electricity that were described in the books in his father's library. Marconi audited courses at the University of Bologna, because he could not gain admittance to the university for credit, and studied under Augusto Righi, a scientist who had worked with electromagnetic waves. Since Righi was also a neighbor, Marconi would often visit him with questions and ideas. Righi rarely encouraged Marconi's ideas about a practical system of transmitting information using these electromagnetic waves. Still, Marconi showed a dogged persistence in trying out method after method in his experiments.
In 1895, after following the experiments of Heinrich Hertz, Marconi (at twenty-one years of age) devised a system that allowed him to ring a bell that was two rooms away in his attic workshop. He was able to do this purely by striking a telegraph key that created electromagnetic waves. Marconi began producing this effect at longer and longer distances, eventually moving outside and sending the signals over a distance of several hundred yards. Initially, distances were overcome simply by using more powerful electrical charges, a condition that would never allow practical wireless communication to travel very far. Marconi eventually found that if he placed part of the transmitter on the ground, resistance was cut dramatically and the signal would travel much farther. Thus, Marconi invented the grounded antenna and began sending telegraph signals over distances of up to two miles (regardless of hills or other obstacles).
After the Italian Ministry of Post and Telegraph rejected his initial presentation of the invention, Marconi took it to England. After applying for a patent to protect his idea, he began working to gain British support. Since his mother was Irish, he had several family connections in England and was able to arrange a presentation of the invention to William Preece of the British postal system in 1896. Preece became an avid supporter and provided postal system personnel to help Marconi continue to develop his system. By 1899, Marconi had established a wireless link across thirty-two miles of the English Channel.
The wireless system as it then existed allowed for only one person at a time to transmit in a given geographical area. If multiple transmissions were sent simultaneously, they were incomprehensible or canceled each other out. Marconi looked for a way to tune the signal to specific wavelengths. By 1900, he had succeeded in developing a system of tuned multiplex telegraphy, which allowed multiple messages to be sent from the same transmitter simultaneously with each message being received accurately by different receivers in different locations.
Another obstacle to be overcome by Marconi was a belief by many scientists that electromagnetic waves would not be able to follow the curve of the earth and could, therefore, never transmit signals across the vastness of an ocean. In 1899, Marconi had transmitted signals from ship to shore over a span of sixty-six nautical miles, far more than enough to ensure that the waves were somehow bending around or traveling through the ocean to reach the shoreline. Marconi was convinced that the wireless could span the ocean, and he set out to prove it. He had a powerful transmitting station built in Poldhu, on the coast of England, and set sail for St. John's, Newfoundland. Once there, Marconi attached a receiving wire to a kite and flew the kite at a height of four hundred feet. To anyone who expressed interest in what he was doing, Marconi pretended that he was working on contacting passing ships on their transatlantic voyages. On December 12, 1901, he received the letter "S" several times and had an assistant verify the reception. He then announced to the world that he had received a message from England, which was more than twenty-one hundred miles away across the Atlantic.
Still, many people doubted Marconi's claim because of the bias of his only witness and the simplicity of the message. Therefore, Marconi outfitted the ship Philadelphia with sophisticated wireless equipment, a telegraph recorder that would mark the signals on paper tape, and a public listening-room so passengers and crew could serve as witnesses to the receptions. The experiment, which took place during a 1902 voyage where the ship sailed from Cherbourg to New York, was a success. Marconi recorded receiving signals from over a distance of more than two thousand miles. As a by-product of his experiment, Marconi also found that the signals traveled best at night, but this was a phenomenon that he was at a loss to explain.
In 1907, Marconi finally perfected the system of transatlantic wireless and began commercial service between Glace Bay, Nova Scotia, and Clifden, Ireland. His work on wireless brought him the Nobel Prize for physics in 1909.
The early 1910s were full of lawsuits in which Marconi was forced to defend his patent rights. He emerged victorious, however, and the results were financially profitable for his British, American, and international companies. In 1916, during World War I, America wanted to avoid foreign control in wireless properties that were being used by the military. As a result, the American Marconi Company was forced by the U.S. government to merge with General Electric. Thus, Marconi lost the influence he had established in wireless communication in America. In his home base of Britain, however, Marconi and his companies were influential in the startup of public radio broadcasting and helped to establish the British Broadcasting Company, which later became the British Broadcasting Corporation (BBC).
Marconi continued to experiment on improving radio broadcasting. He eventually was able to send messages in specific directions and around the globe. He also performed experiments with radar and with microwave, proving that microwaves could also travel beyond the horizon of the earth. In 1924, he set up a system of wireless stations that linked England to the British colonies around the world. He also set up a radio service for the Vatican in Rome in 1931 and created the first microwave link so that the Pope's messages could instantly be sent several miles away to the short-wave transmitter that could then broadcast the message live to the world. Failing health restricted Marconi's activity for much of the last ten years of his life. He died of heart failure in 1937.
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Stephen D. Perry