In 1890 the coherer was discovered by Branly, and simultaneously by Oliver Lodge.
Lodge’s coherer was a very delicate instrument, and by its means the electric waves could be detected at a much greater distance than was possible with the conductors used by Hertz.
In 1895, in Cambridge, Mr. Rutherford (now Professor of Physics in McGill University), first showed that the waves could be observed by a magnetic detector.
He discovered that a weakly magnetized steel wire becomes instantaneously demagnetized under the influence of electrical oscillations, such as electric waves. With his detector he succeeded in establishing communication at half a mile.
In 1896 Marconi came from Italy to England, and, with the help of a Government grant, obtained through the instigation of Sir William Preece, head of the British telegraph department, commenced a series of experiments in wireless telegraphy. Very rapid strides were made, and the distance to which signals could be sent was very much increased.
An important development soon followed in regard to the use of a vertical wire for transmitting the waves, instead of a horizontal one, which increased the distance still more.
Although Marconi has come to be chiefly associated with the development of wireless telegraphy, other systems have been established in various countries which involve slight modifications in the apparatus employed.
In Germany the Arco Slaby system is used with success, and in the United States the De Forest is being installed in many places.
Then there is the Armstrong, Orling and the Muirhead Lodge system. In England a wireless telegraph company was organized in 1902.
This company, having secured the Marconi patents, aimed to monopolize that business in Great Britain, but, as the Government there controls the telegraphs, this was not permitted.