On This Day…

25th April 1874 Marconi was born

Guglielmo Giovanni Maria Marconi was an Italian physicist and inventor of the successful wireless telegraph. In 1909 he received the Nobel Prize for Physics and worked on the development of shortwave wireless communication, which constitutes the basis of nearly all modern long-distance radio.


Aerial improves signal

In 1894 Marconi began experimenting at his father’s estate near Bologna, using comparatively crude apparatuses: an induction coil for increasing voltages, with a spark discharger controlled by a Morse key at the sending end and a simple coherer (a device designed to detect radio waves) at the receiver. Following preliminary experiments – over a short distance – he first improved the coherer then, by systematic tests, he showed that the range of signalling was increased by using a vertical aerial with a metal plate or cylinder at the top of a pole connected to a similar plate on the ground. The range of signalling was thus increased to about 2.4 km (1.5 miles), enough to convince Marconi of the potential of this new system of communication.


Wireless sets and the military

In 1896 Marconi demonstrated his wireless communications system to representatives of the Army, Navy and Post Office on Salisbury Plain. Three years later, the Army tested Marconi wireless sets unsuccessfully during the Second Boer War. The Royal Navy, however, had greater success using wireless as did some commercial shipping companies and by the outbreak of the War in 1914 the Army was using a small number of wireless sets.

There remained much scepticism about the usefulness of this means of communication and there was a lack of interest in its exploitation but Marconi’s great triumph was yet to come. In spite of the opinion expressed by some distinguished mathematicians that the curvature of the Earth would limit practical communication by means of electric waves to a distance of 161–322 km (100–200 miles), Marconi succeeded in December 1901 in receiving at St. John’s, Newfoundland, signals transmitted across the Atlantic Ocean from Poldhu in Cornwall, England. This achievement created an immense sensation and although much remained to be learned about the laws of propagation of radio waves around the Earth and through the atmosphere, it was the starting point of the vast development of radio communications, broadcasting, and navigation services that took place in the next 50 years, in which Marconi continued to play an important part.