The first Morse Code message sent across the Atlantic Ocean by radio, as opposed to cable, was received by Guglielmo Marconi (1874-1937) on 12th December 1901. He was stationed at Signal Hill, near St John’s, Newfoundland, and the signal was received from a transmitting station at Poldhu, near Lizard Point in Cornwall, England.
Marconi first started experimenting with wireless telegraphy in 1895 in his native Italy, but moved to England in 1896 because he hoped to attract more interest and support, which was indeed the case. He developed gradually more sophisticated transmitting and receiving equipment and achieved progressively greater distances over which signals could be transmitted.
He was particularly interested in establishing ship-to-shore radio communications, and many of his early experiments were from ships and yachts to receiving stations that he had built onshore. There was clearly a business opportunity here because ships could not be connected by undersea cables in the way that fixed stations could. During the course of these experiments it became clear that radio signals could be picked up even when the transmitter and receiver were not within line of sight of each other, as would be the case when a ship was below the horizon as far as the shore station was concerned. If radio signals could “bend”, what limit could there be to how far they could travel?
Marconi became convinced that it should be possible to send a radio signal for thousands of miles, provided that the transmitting equipment was powerful enough. However, up to this point the best distance achieved had been no greater than about 90 miles (from near Boulogne on the French coast to Chelmsford in Essex, where Marconi had established his business headquarters). Nevertheless, he pressed on with his project to leap the Atlantic.
Work on the transmitting station at Poldhu Cove began in October 1900, the plan being to build a similar station at Cape Cod, Massachusetts, and the work on this station began in March 1901. Each station was to comprise 20 masts, each being 200 high, set in a circle that was 200 feet in diameter. In terms of transmitting equipment, Marconi calculated that the energy needed to send a signal the required distance would be around 20,000 volts, and this was to be provided by a Hornsby-Ackroyd oil-driven engine that would drive a 25 kilowatt alternator and a pair of transformers that would boost the alternator’s 2,000 volts to the necessary 20,000 volts. The final output of the plant, in terms of signal energy, would be 100 times greater than that of any previously built transmitter.
All seemed to be going well until 17th September 1901. By this time the aerials at both Poldhu and Cape Cod were nearly complete and Marconi was carrying out tests on the parts of the system that were serviceable, getting very satisfactory results. However, on that day a storm blew up and wrecked the circle of masts. This was clearly a massive setback, but it proved possible to create a temporary aerial, based on only two masts, that was operational only seven days later. Experiments using this aerial showed that strong signals could reach Marconi’s station at Crookhaven in County Cork, Ireland, 225 miles away, so Marconi decided that there was no need to rebuild the station before trying the ultimate test.
He therefore abandoned the original plan to set up two-way communications between Poldhu and Cape Cod and on 26th November 1901 he set sail, with two colleagues, for St John’s, Newfoundland. He had begun to have doubts about whether the signals would reach as far as Cape Cod and decided to bridge a shorter distance, Newfoundland being the closest point of the North American continent to Cornwall. As it happened, just before setting sail he heard news that the Cape Cod station had also been wrecked in a gale.
The party arrived at St John’s with a quantity of balloons, hydrogen cylinders and large kites, apart from their portable receiving apparatus. They were received hospitably by the authorities at St John’s (Newfoundland was still a British colony at the time) and offered space in a disused fever hospital on a rocky promontory overlooking the town. The appropriately named Signal Hill had been used in past ages for sending semaphore communications, and was also close to the point at which the first transatlantic cable had reached shore in 1866.
The trio tried various methods for getting an aerial wire airborne using the balloons and kites. The winds were strong and at times threatened to be too strong, but, once in place, the kites were perfectly serviceable for what was needed.
(See Part 2 of this article for the conclusion of the story)
Picture credit: Photograph of Guglielmo Marconi taken in 1908; public domain, copyright expired.
This article was originally published be me, John Welford, on Helium.com on 21st March 2011 - http://www.helium.com/items/2122840-the-first-transatlantic-radio-signal-and-guglielmo-marconi
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