Analogue communications

Abstract

BY ‘COMMUNICATIONS’ we really mean ‘electronic communications’, whose era began with the opening of a commercial telegraph by Cooke and Wheatstone on the Great Western Railway in London in 1839. In the USA Morse’s telegraph opened between Baltimore and Washington, a distance of 65 km, in 1844. Telegraphy grew so rapidly that by about 1860 Dickens could remark in a novel on the wires festooned about London. The practical and theoretical demands of the electric telegraph produced a remarkable number of inventions and discoveries, particularly when submarine cables of great length were laid¹. William Thomson, later Lord Kelvin, was knighted in 1866 for his substantial contributions to undersea telegraphy.