WIRELESS TELEGRAPHY.

Dominion, Volume 3, Issue 871, 18 July 1910, Page 11

WIRELESS TELEGRAPHY.

$ AN INSTALLATION AT AUCKLAND. (By TeloßrttpS.—Special Correspondent.) ,' Auckland, July 15. The "Star" publishes an interesting account of tho installation'of a wireless telegraphy plant here. Monsieur Roussol, a middle-aged Frenchman, who is employed as carpenter and general handyman at the Sacred Heart College, Ponsonby, has developed a taste for tho mysteries of electricity that amounts almost to genius. In spare moments he has put his industry and talent to good purpose, and quite recently completed and installed a wireless telegraphic plant, practically making everything on the premises, and effecting an improvement on tho Marconi mechanism in ono important particular. Tho ingenious Frenchman has himself made tho battery and the Rhumkorff coil in which seven miles of delicately thin wire has been absorbed, tho spark gap, two condensers which are used to regulate, the strength of tho sparks, tho transformer for treating tho current in its passage from tho spark gap to tho aerial wire, tho receiving apparatus, and tho mast with aorial wires, which has yet to be erected. Tho battery that has been, made does not develop sufficient current to transmit messages to a greater distance than 40 or 50 miles. A 6 inch spark only can be obtained, and it requires a 4 or 5 feet spark 1 to allow tho wave travelling a distance of 500 or 600 miles, but the apparatus is admirably adapted for tho educational purposes for which it has been designed, with the exception of tho battery which effects tho transmission of messages in the manner stated. The plant can deal quite effectually with the reception of messages at almost any distance, and this fact has been demonstrated in an unexpected manner through legislation prohibiting tlio erection of tho poles necessary to carry aorial wires to receivo waves. Tho receiving apparatus at present is unconnected, but so sensitive is the magnetic coherer that warship's messages liuvu been intercepted, one especially (though in code) being distinctly recorded, and another, presumably from a much longer distance, being rather faintly recorded. It is in connection with the receiving apparatus that Monsienr lloussel has made an important departure from the Marconi instrument. With tho latter the coherer takes the form of a vacuum tube with tho air exhausted, and filled with nickel and silver filings.' Tho local production is a magnetic coherer, with an iron bar running through a glass tube, no air exhausted, and the fillings consisting of soft iron filings. Not only have the iron filings a better action, but the magnet adjusted to the sido can be shifted to any position to increase- or decrease the sensitiveness of the receiver. This appliance is so sensitive that it records the slightest electric spark in the same room, and sparks from a Wiinshurst influencing machine located in another room &ome distance awny were also plainly and separately recorded. It is also of interest to mention that tho Wimshnrst machine was made by Monsieur Roussol, and is valued at £20 at husk. Tho whole of the wireless plant is benutifully finished, the brass work being particularly well fitted. Legislation prescribes a penalty of £500 for erecting; apparatus for receiving or transmitting wireless messages, and tho college authorities cannot,- without permission, erect the mast for the necessary aerial wires. As the plant is intended only for educational purposes, tho authorities arc hopeful that it will not be long before the require;! permission p£ U"s Government will be aivea. .