Expérience
12 December 1901
Salvan - Les Marécottes
The Transatlantic Revolution or The World at the Doorstep of Wireless
The first tests carried out at Villa Griffone (Italy) and at Salvan (Switzerland) in 1895 were still quite far from the goal. Even though Marconi’s wireless communication had already reached several kilometres at the beginning of the 20th century, a transatlantic communication still seemed as audacious as it was irresistible. How were radio waves going to clear the 3,200 kilometres? Many scientists at the time considered that the experiment was doomed to failure. As far as they were concerned, radio waves could only travel in a straight line. The curvature of the earth between Canada and England represented the equivalent of a 240 kilometre high mountain, leading to many smiles at the idea of wireless transatlantic communication.From one bank of the Atlantic to the other
Convinced that it would be possible, Marconi accepted the challenge and began to build a station at the Poldhu site in Cornwall. In spite of many bad surprises such as the storm of 1901 that reduced the impressive circular aerial at its pylons to a pile of rubble, the young scientist managed to construct a transmitter that was one hundred times more powerful than all the previous ones.It proved far more difficult to build a station across the Atlantic. Marconi’s first attempt was at Cape Cod, Massachusetts. However, as predicted by the natives, the circular aerial was soon wiped out by a gale. After another fruitless attempt, the researcher, helped notably by Mr. Kemp and Mr. Paget, decided to set up his equipment in an old hospital at Signal Hill near St. John’s, Newfoundland. This time, the reception aerials were supported in the air by a balloon or kite.
“Can you hear anything, Mr Kemp?”
The atrocious weather conditions of that early December 1901 made the tests on the Canadian coast particularly difficult. The Poldhu station (Cornwall) had been instructed to transmit the Morse code “S” (dot, dot, dot) continually from 11:30 a.m. to 2:30 p.m. After numerous attempts, numerous adjustments and many moments of despair following the loss of kites or balloons, the Signal Hill station appeared to be receiving some signals. Indeed, the telephone ear-piece linked to the Branléy wave detector began to crackle. On December 12th, 1901, shortly after 12:30 p.m., Marconi thought he heard the Morse “S”. He handed the telephone over to his collaborator saying: “Can you hear anything, Mr. Kemp?”. Kemp’s positive response and the much verification that followed, offered Marconi and the rest of the world a new revolutionary outlook.Therefore, the obstacles presented by the curvature of the earth and the distance of transmission were, thanks to the obstinacy and talent of Marconi, filed away as bad memories. From then on, the whole world was on the doorstep of wireless.
