SCIENCE AND INVENTIONS.

New Zealand Herald, Volume XLVII, Issue 14453, 20 August 1910, Page 4 (Supplement)

SCIENCE AND INVENTIONS.

ELECTRICITY FOR PRINTER'S INK An* inventor has come forward who proposes to substitute in printing for ink «in electric current. By passing the cuirent into type made of metal, which is a good conductor, and thence through tho paper a clear black impression, he says, is made upon the paper, the tone of the impression being determined by the strength of the current. NEW SYSTEM OF ILLUMINATION. A new system of illumination which is coming into favour consists in castling the light of a lamp against a white surface, such as a. ceiling, the light thereby being reflected and diffused. When arc lamps are adopted to this system, u lamp is used in which the carbon-feeding machine is placed below the. arc. The result is practically an inverted arc lamp.

HEALING BY WIRELESS. Healing by wireless current is the Litest scientific idea. An apparatus lias been devised by a. Berlin firm of electricians, who claim tiiat by its agency the Hertzian waves may be passed through the human body with curative effect. Tho inventors say it will give relief to internal diseases when applied to the organ affected, and that 1 hero are> no detrimental effects otherwise. The current, will also produce sterilisation in the part through which it is directed, and thus prevent blood-poisoning. HELIUM FROM VESUVIUS. Helium, the " sun metal," thus named because it was found by spectroscopic observation in Ihe sun before it was known to exist on the earth, appears to exist in perceptible quantities in a number of minerals exuded from Vesuvius, and also in the air about Naples. Professor A. I'iutti has recently examined by a new method the gas emitted by several Vesuvian minerals, and finds that helium is often present. He has detected its presence in so small a quantity of ordinary air as three and ahalf cubic centimetres. BARCELONA'S TROLLEY SYSTEM. Ancient Barcelona in Spain has perhaps one of the best and most complete electric tram services' in Europe,' some 156 miles of lino being worked by the several companies within the boundaries of tho city and suburbs. The whole system is controlled by German and Belgian syndicates. In tho present year about 12i miles of new rails have been laid, mainly in completion of small branch lines in several of the more important streets. The overhead trolley system is the only one employed. SOME BIG CHAIN CABLES. Some of the biggest, if not the biggest, chain cables in the world are those made m South Wales for certain new quadruplescrew turbine Atlantic liners. The iron, bar used in making the links is 3;] in in diameter at the smallest part. Each link is about 22.jin long and weighs about 160 pounds. When tested for strength the breaking stress of 265.7 tons required by law, instead of fracturing these gigantic. links, simply elongated them about one inch. With the highest stress that tho testing machine could give, about 370 tons, the links showed no signs of cracks.

PEARL CULTURE. A pearl-making industry flourishes hi Japan in Die sheltered bay of Ago. Tho method of producing the jewels is simple and oxtre.inely successful, and is thus described : With groat care pearl oysters are developed until they are about three years old, when small pearls or round pieces of nacre, which are to serve as the nuclei of large pearls, are introduced into the shells. Tho oysters are then put back into the sea and left undisturbed for at least four years, at the end of which time they are gathered and opened, when it is found that the animal has invested tho inserted nucleus with many layers of nacre, producing a large and perfect pearl. All that is required is care and patience.

THE TELEWRITING MACHINE. The Lord Mayor of London recently inanimated the ~t.elewrit.ing exchange in Walbrook. the first cxchango of its kind in the world. There was a "largo gathering of city business men in the offices of the company, where several instruments had been fixed up for a display of the telewriter. It is oniv necessary to write with a pencil oil a roll of ordinary paper, and the message is instantaneously reproduced in facsimile at the other end. Sir William Treloar, chairman of the directors, said that it. was some thirty years since the first attempt was made to transmit handwriting by the aid of electricity over wires. The Lord Mayor remarked that among other merits the invention would have that of being a preventive against, crime, because the user would have his handwriting transmitted in facsimile form. Tho Lady Mayoress sent the first message over the wire, addressed to the General Post Otlice, the officials of which have given facilities for experimenting with the invention. The Lord Mayor also sent a message of felicitation to the Postmaster-General.

TO CONCEAL SUBMARINES. The picsence of the submarine boat is sometimes made known to the enemy by the train of bubbles that rise to the surface of the water from the gas-engine exhaust. These bubbles are readily discernible, and indicate the course which is being pursued, thus enabling the enemy to take measures for defence or a counter attack. In order to prevent a submarine boat from betraying its course in this way (says the Scientific American), an inventor has devised a method of retaining the exhaust pases, permitting them to escape only at irregular intervals in large quantities. Although tho single* large gas bubble thus produced would indicate the position of the submarine, it would not give, any information as to tho direction in which it was [ravelling or its rate of speed. The exhaust gases of the engine are led to a ga« purifier and cooler, and then enriched | with oxygen and passed through the enj gine again, so that the engine works in a. closed cycle. An automatic valve serves to carry out. the gases, when they reach too high a pressure, and conduct them to a receptacle, whence they may be released by a hand-operated valve whenever dei sired.

PHOTOGRAPHING THE COMET. The apparatus with which. Havard's photographs ha\e been made is simplo. For obtaining details of the head, the socalled Draper telescope has been. used. The instrument is so named for Professor Ilerry Draper, a pioneer at the Observatory in photographing heavenly bodies, who left, fund for its erection. The instrument, gives a. focal length—the distance, between the lens and tire photographic plate—of 153 inches. Over the lens is fitted a. ) holographic lens called a, corrector. With this apparatus, and a common plate-holder for a. live by eight plate, fixed 011 the lower end of the tube, the work is done. Kor obtaining a, negative to show the length of the. comet's I,ill, an even simpler apparatus is used. No telescope is employed. A plain box of iron, shaped like a common box camera, takes an eight by ten plate-holder. It is fitted with an ordinary view lens of high grade, such as newspaper photographers use in everyday work. Over the frcnt of the camera. is fitted an al omnium shield, to protect the lens from the dew. This is known as a "dew tap." The catn-i.'i is placed on a soapstone slab, which is fastened to a, corner of the balcony tailing on the second storey of the main Observatory. The instrument is at(ached to an apparatus that by means of a simple gear tips it, a given distance each second, so that the camera, once set, mechanically follows the course of the comet. The speed is regulated by a pendulum clock in the building, which has electrical connection with the camera, and ticks off the rate at which a* tooth on a wheel moving the camera moves forward one notch 011 a, corresponding disc. The usual c-> l osuro of a plate, with this apparatus is about 30 minutes. The size of the imago obtained 011 the plate, varies from a pin-iioad for the comet's head to the 5i.79 of appeta t