WIRELESS TELEGRAPHY.

Poverty Bay Herald, Volume XXVI, Issue 8512, 9 May 1899, Page 4

WIRELESS TELEGRAPHY.

In a recent interview with a reporter of the New Zealand Herald, Professor F. D. Brown, of Auckland, who has recently returned from a trip to the Old Country, made the following reference to the subject of wireless telegraphy :— " I have just been unpacking these this afternoon," he remarked, pointing ti an array of shinintr instruments, and proceeded to explain the merits of the various nppliances. Most of them, it may be obBerved, are pieces of apparatus used in connection with the production of the Hertz wave, which is tho essential feature of wireless telegraphy, and are the newest and most up-to-date appliances that it was possible to obtain, Croolces tubes, Marconi wave generators, and so on. The professor then had a few words to say about the utility uf the so-called " wireless telegraphy." " Over short distances, or comparatively short distances, it is cheap enough, but I will say this, that wireless telegraphy will never supersede the old form of telegraphing with wires." "And why?"

"Simply because, although connection between two places is cheap over a small distance, as the distance increases the cost of providing suitable apparatus becomes so enormously greater that it) will never be worth while to utilise it over lone; distances, although it is theoretically possible." "What is the longest known distance over which telegraphy without wires has been successfully accomplished ?"

"About 18 miles is the longest distance, but three miles is usually about the limit. This method of Marconi's is not the only form of wireless telegraphy in use. There aro two other distinct methods. There is an 'electro-magnetic induction method. 1 I don't know whether that conveys much to you, but the apparatus is in use on the south coast of Wales, and has been in working order for some time, operating over a distance of three miles. There is also a Tiethod in which leakage of electricity into the ground is the chief principle, producing an effect like the ' bulge ' produced on pouring a stream of water into a lake, an effect which may be detected by sensitive instruments a long way off."