Detector used in Marconi's original transatlantic radio tests, 1901.
© Science Museum / Science & Society Picture Library
On 12 December 1901 Guglielmo Marconi (1874-1937) succesfully transmitted a series of signals acros the Atlantic, from Poldhu in Cornwall to Signal Hill, Newfoundland, heralding the birth of transatlantic radio communication. The signals were picked up by a tiny device known as the 'Italian Navy' detector. This is one of the two in use on that famous day. The test proved that long-distance radio communication was a practical posibility.