SCIENCE AND INVENTIONS

New Zealand Herald, Volume LI, Issue 15504, 10 January 1914, Page 4 (Supplement)

SCIENCE AND INVENTIONS

TELEGRAPHY FROM AEROPLANE. Long distance wireless telegraph experiments recently mado from a- Breguet aeroplane to a' ground station at Douai, France,' showed excellent results. The aeroplane- is a : three-seated flyer designed for the government of Siam. The aeroplane kept on its'flight from the aerodome and sent* messages every five minutes to a land station in the town of Douai. The musical wave method was employed, and it is claimed thai .message's could he heard with the aeroplane,as far. as-60'miles off, in spite of the small power used in the apparatus on board. . •■-.;. • THE ASSOUAN DAM., The Assouan 'dam on the Nile can be called upon to furnish a large amount of hydraulic power for operating an electric plant; it is estimated that it would-fur? nish- no less than 150,000 horse-power. During five months; in ; the autumn ' and winter tho water of the Nile accumulates in the dam. and when it overflows the height of the resulting fall and the great volume •of water would furnish some 150,000 • horse-power. Current could be used for the manufacture from the atmosphere of nitrogenous products for use as fertiliser, This would be of great value to the countrv, for it is stated that Egypt imported no less- -£700,000 worth of fertilisers during the last year. ■ < , NOISELESS ! CITY , STREETS.." There is coming into use in Germany a cheap and ready method- of: asphalting a 6tone-paVid street which is showing good results. The spaces between paving blocks arc cleaned out to the depth cf about an inch, and then a-layof,melted asphalt is flowed over the street surface, the depth of.the layer being,about one inch. Before, if is cooled, sand is sprinkled on and the surface is smoothed At Frankfort a section ,of this kind is now laid.- and it appears to stand the.wear remarkably well. Should the method -prove ; a success .in general practico, it will afford an excellent means for deadening .tho noise of city traffic at a small' expense. It is quickly carried out and it need not step the,, circulation on narrow streets for any length of time. Moreover;' repairs are easily made. , s • SMOKE HELMETS FOR FIREMEN. A new type of smoke helmet enables a fireman to remain in a smoke-filled room for an indefinite length of time without resorting to tho use of oxygen -tanks to sustain life. ' The' new devico consists of a canvas hood, somewhat similar in appearance to a diver's helmet, with mica , squares admitting light. ' This fits closely over the head and shoulders. From it i trails a hose which roaches down ..to the floor, through' which air is carried , to the wearer. As heated smoke, fumes, , etc., have a tendency to rise,'there is, ordinarily, more free oxygen in tho smoky room close to the floor. In walking . around in a smoke-filled room the wearer . of the helmet breathes the air taken from [ the floor by the trailing hose. Air valves i in tho tori of the helmet afford escape for , the' exhaled air, so that a fresh supply is always received from, the floor. To prevent the hose from collapsing a; spiral • spring runs its entire length, and a heavy end' keeps the hose always near the, floor, experiments have shown that'a person can remain in a smokd-laden room for 20 minutes after, the end of the hose is closed. The advantages of this helmet are that it dispenses with heavy oxygen tanks, and may be worn by man or woman of any size, to whom it may be adjusted in less than a minute's time.

NEUJMIN'S COMET.

Ncujmin's comet has aroused not a littb interest among astronomers. It was oiscovered on September 6 last, five days after Metcalfe comet. From private sources it has been learnt that the period of 25A years,' calculated by Einarsson and Nicholson, is probably correct and that the object is really a comet, although a very queer One. It was discovered, in the Crimea, where the Pulkowa Observatory maintains a station mainly for the .observation of asteroids. The object was fount' on one of their photographic plates,' and was at first supposed to be an asteroid, as there was no evidence of, nebulosity. When notice of the object an asteroid reached Bergersdorf, near Hamburg. Germany, it was observed visually, and it was decided to be a comet. Viewed in the great telescope of the Yerkes Observatory (United States), the object indeed appears like m asteroid, but it has a very faint nebulous appendage which, -to the practised eye, distinguishes it from an asteroid. Hence the object is nearly all nucleus. Were it not for the presence of the inconspicuous tail, the star-like appearance of the object might easily mislead oven a, practised astronomer into taking it for an asteroid The comet is barely visible in a five-inch telescope as a small faint haze. The comet by no chance can ever be seen with the naked eye. •

PROGNATHOUS JAWS. The projecting jaws and somewhat elongated form of ■■ the arch or horseshoe formed by the series of teeth in some races, which are therefore called "prognathous" seem to have a certain value of utility to their possessore. The projecting jaw of negroes and other prognathous races must give a more powerful grip than does the smaller jaw of orthonathous or "straight-faced" peoples. The formation of the chin absent in apes and in the | Neanderthal and Heidelberg extinct races 'of men— present in all living races of men— due, it appears, not to a forward growth of the ohm in the more recent races of man, but to a shrinking of the arch of the teeth, so that as it becomes reduced the line occupied by the front teeth recedes inwards, whilst tho bone below it remains unshrunken and projecting as chin. Why the dental arch should be reduced in size—that is to say, what is the advantage of such reduction— not easy to suggest. It is not improbable that there is a " correlation"—an inner necessary connection—between the growth in size and activity of the brain (as we pass from man-like ape to ape-like man) and the diminution in the size and power of the jaws—the latter having to dwindle as the former increases. But such guesses at correlation are dangerous, and must be regarded strictly as mere guesses, unless they are hacked by observations in other independent species, showing' reason •to suspect, there also, a correlation identical in its terms. TELEGRAPHY IN CHINA. The Chinese written language has several hundred thousand different characters. None of these can be spelled bo as to indicate accurately how they are pronounced. Besides there are hundreds of ways of pronouncing each character, as there are hundreds of spoken dialects in China, although the book language is the same throughout the country. How is it possible to send a telegram in such a country and in such a language? The difficulties have been overcome, and it is really less trouble, and less expensive to send a message in Chinese than in English. There is in every Chinese telegraph office a special dictionary, or catalogue, or code book, whatever you may choose to call it, in which the characters aro numbered from one on up. A total number of 9999 may be catalogued under the present system. A certain number of blank spaces have been reserved to add special characters from time to time. Tho sender of tho telegram simply writes his message in the usual way. The operator will probably know the numbers of most of the characters. If not ho can readily find them in the catalogue. For each character he sends fivo Morse signals, e.g., 5913, 0013, 0414, which represents the characters " Yuan Shi Kai." It will at once appear that only ten different signals aro needed for telegraphing 9999 different characters in Chinese. By splitting up an unusual character into its common parts it may be easily sent. Private codes aro readily prepared with this system. Already tho chief cities of tho country, and many small places, have telegraph offices. It is hoped that under tho republican form, of government the whole service will bo extended, improved, and made less expensive. In addition to the ordinary wire service, China now has several powerful wireless stations, and arrangements are being made to coyer the country with them.. . ■ ■• . ' • • ■