WIRELESS TELEGRAPHY.

Taranaki Daily News, Volume LV, Issue 302, 15 May 1913, Page 5

WIRELESS TELEGRAPHY.

"US A NEBULOUS STATE.'" REDUCTION IN ORDINARY CARLES ANTICIPATED. By Cable—Press Association—Copyright. Sydney, May 1.4. Mr. Milhvard, manager of the Pacific Board, commenting on Canada's recentlyannoiuiead contract with the Paulsen Wireless Company, foreshadowed a. reduction in the cost of coded cables to London from 3s to 2s Bd, a saving osf 4d a word. Though he had no information from the London office on .the matter, if the wireless system proved efficient and a benefit to the public, the Pacific Company would certainly make arrangements with the Poulsen Company to carry their messages to Australia, and whatever reduction in the rates could be obtained would be passed on to .the public. At the same time he looked upon wireless communication across the Atlantic as being in a somewhat nebulous state. Something would have to be done to make the system more reliable than at present before it could be generally used for cominencial and press purposes. THE HELIOGRAPH NOT SUPERSEDED BY "WIRELESS." How often lias one seen the sun's rays reflected by a window or skylight from a far-distant building; yet how few have ever realised that by a scientific adaptation of this principle communication can be established for considerable distances ? Pew people (outside the "Services") have any idea of the possibilities of the heliograph as a means of carrying information frbm point to point. This handy little instrument, packed securely in a strong leather case, which renders it practically immune from damage, can be carried quite easily .by any single person. Fixed on its tripod, which can also be carried quite easily as a walkingstick by the same person, it can- be erected and fixed in working order in a few moments.

When it is pointed out that, as far back as the Egyptian campaign of 1882, messages were sent over a distance of 80 miles, and that only recently in South Africa, a distance of 117 miles has been accomplished, it will be readily understood that the heliograph is of very great use to officers commanding troops operating in the field. Presenting no points of vulnerability to the enemy, its advantages over telegraphy, which necessitates, a laying of wires, either along the ground or on poles (which line can easily be cut at any one place along the line, thus rendering it useless) are readily perceived. Briefly speaking, the "helio" consists of a mirror mounted in a frame, capable of being depressed or elevated, trained right or left, from which a reflection of the sun's rays can be thrown on or off a distant station, the flashes being read just as one would read the flashes of a signal lamp. Primarily intended as a sun .instrument, good ,work has also been accomplished by the light of the moon, and also by a strong artificial light, but the range with artificial light is considerably smaller.

By the ingenious arrangement of another mirror, called the duplex, the position of the sun, with regard to the distant station, is rendered immaterial. Thus the instrument <-an be used when the sun and distant station are opposite to each other, or, in other words, messages can be sent when the sun is behind the sender's'back.

The mirror in general use is one of oin. diameter, but in India and tropical countries, where the sun is of much greater power than in more temperate zones, one of lOin. in diameter is supplied for use.

The advantages of the heliograph are its extreme portability, its great range (which depends on the strength of the sun, and the height above the level attainable by the sending and receiving stations), its secrecy, its rapidity (it can be worked almost as quickly as an ordinary telegraph key).

Its disadvantage is that men require a considerable amount of training and practice.