This consists of a receiving antenna similar to the sending antenna, and in any wireless telegraph station it is usual to make the one and the same antenna do duty as a receiver or sender by switching it over from one apparatus to the other.
Braun showed that oscillations suitable for the purposes of electric wave creation in wireless telegraphy could be set up in a circuit consisting of a Leyden jar or jars, a spark gap and an inductive circuit, and communicated to an antenna either by inductive or direct coupling (Brit.
Highton in experiments described in 1872, also revived the same suggestion for wireless telegraphy.
In addition to U.S. government buildings (marine hospital and barracks, agricultural experiment station, wireless telegraph station and magnetic observatory), there are two public schools (one for whites and one for Thlinkets), the Sheldon Jackson (ethnological) Museum, which is connected with the Presbyterian Industrial Training School, a parochial school of the Orthodox Greek (Russian) Church, a Russian-Greek Church, built in 1816, and St Peter's-by-the-Sea, a Protestant Episcopal mission, built in 1899.
There are no roads in the province, and very little internal communication and trade; but a wireless telegraphic system has been installed in communication with Rhodes: and there is a landline from Bengazi to Tripoli.
When used as a receiver for wireless telegraphy Marconi inserted the oscillation coil of this detector in between the earth and a receiving antenna, and this produced one of the most sensitive receivers yet made for wireless telegraphy.
In practical wireless telegraphy the antenna is generally a collection of wires in fan shape upheld from one or more masts or wooden towers.
Such an oscillation valve was first used by Fleming as a receiver for wireless telegraph purposes in 1904 as follows: - In between the receiving antenna and the earth is placed the primary coil of an oscillation transformer; the secondary circuit of this transformer contains a galvanometer in series with it, and the two together are joined between the external negative terminal of the carbon filament of the above-described lamp and the insulated platinum plate.
Many other more or less imperfect devices - such as those of Mahlon Loomis, put forward in 1872 and 1877, and Kitsee in 1895 - for wireless telegraphy were not within the region of practically realizable schemes.
The inventions of Slaby, Braun and others were put into practice by a German wireless telegraph company, and very much work done in erecting land stations and equipping ships.