WIRELESS TELEGRAPHY.

Dominion, Volume 4, Issue 1196, 3 August 1911, Page 5

WIRELESS TELEGRAPHY.

AEROPLANE COMMUNICATED WITH. By Telegraph—Press AssneinMnii-Cnpyrleht Paris, August 1. Military officers'on board a Farman biplane transmitted wireless messages to tho Eiffel Tower from a distance of thirty miles by means of electricity generated in tho aeroplones's motor, the extar apparatus weighing thirty pound.s A STATION AT FEZ. . Paris, August 1. Fez, the capital of Morocco, is nowconnected by wireless -with Paris via Oran. An alternative service by another route will bo ready immediately.' WIRELESS IN THE AIR. An aeroplane equipped with telegraphic apparatus by. means of which it can communicate with the land is an auxiliary in warfare which far surpasses the aeroplano without it. Ascent and descent are not always an easy matter in uncertain or awkward country, and an airman reconnoitring for an army is at a great disadvantage if, having flown ten or twenty miles to ascertain the enemy's positions, ho must return that distance and descend in order to communicate his information. Wireless telegraphy from air to earth is a very different problem from ordinary wireless, though to the lay mind it would seem simple enough. In an ordinary wireless station there is a mast, from which depend one or more aerial wires; but thcro is also a very stroog connection with the earth (or the metal sides of a ship, or even the sea, in the case of a station afloat), which acts as an essential complement of tho aerial, and forms a vital part of the wireless system.

Now, when you are in the air (writes Mr. T. Thome Baker in the "Daily Mail") thcro is obviously neither earth nor water; ono has to deal with wireless in the strictest sense of the term, and signals sent from the aeroplane are liable to die out very quickly when it gets any distance from the receiving station. This absence of an "earth" is the stumbling-block to wireleis telegraphy from the air, but, like' most other electrical difficulties, it can bo overcome. In the apparatus used by me at the recent experiments on the War Office flying .ground, two s'eperafe aerial elements, or antennae, were employed; a wire of special construction, very large superficially, but very light, ran from each sido of the airman to the extreme side of the front planes of the machine, and thence backwards to the tail; in this way two equal aerial wires, some forty feet" long, were obtained, one ef whicli performed the same oifico as the "earth" would bo in an ordinary wireless station. A powerful, but small, sparking coil was fixed in a light wooden box to the passenger seat, behind the airman, and in this box also was the whole of the apparatus necessary to generate the electric w/ives. Some experiments were carried out last September in America from an aeroplane to n land station, when Mr. James M'Curdy sent a message to a wireless operator from Barren Island to Sheepshead Bay race track; in this instance, a long aerial wire trailed behind the machine, fifty feet in length, weighed down with a lead bob. Such a system, however successful it might be", would be very dangerous for serious work. Any loose wire might get caught in the propeller, which would instantly be smashed owing to its high speed.