Science and Invention.

Alexandra Herald and Central Otago Gazette, Issue 451, 8 December 1904, Page 7

Science and Invention.

A LARGE PHOTOGRAPH. A PHOTOGRAPH covering 195 square feet of space has just been taken for the St. Louis World'*. Fair. In point of size alone this photograph breaks all previous records. Apart from that the photograph has been pronounced one of the most beautiful and perfect ever developed and printed. The scene selected embraces the Bay of Naples. The camera was mounted on the battlements of the Castle of San Martina, and miles away in the distance on the left Vesuvius looms up impressively. In the enormous width of the photograph the whole panorama of Vesuvius and the city of Naples is spread out with wonderful realistic effect before the spectator. OJ< HYPNOTISM. M. A. Jounet, a French scientist, says: * My advice is, that no human being should ever suffer himself to be hypnotised except by a person absolutely beyond moral suspicion. Science readily admits that suggestion hat a forceful action on the heart's functions; its influence on the subject's pulse was proved long ago. The proof remains to be adduced that a hypnotist can stop a human subject's heart from beating for good and all. At Marseilles I personally increased and diminished the number of a man's pulse beats at will, and as far as I could go in either direction within the limits of safety. So it is known that human circulation can be seriously affected by hypnosis, even if if is uncertain that the heart can be stopped.' RUSSIAN PUMICESTONE. The Russian Government has recently announced that pumicestone-has been found within less than 2£ft. of the surface in the village of Malaya Kutma, about four miles from Kars. The pumice lies in horizontal strata, which aro-g£fJuJihick. It is very porous and is found partly in lumps and partly in triturated, earthy heaps, which contain pieces of spongy

pumice of various sizes. Owing to its great fragility it is easily crumbled. Pumice is exported from Kars in two varieties—viz., pure, in lumpsj and triturated, combined with other foreign matter. The pure pumice, which is valued in proportion to the size of the lumps, is used for polishing metals, lumber, leather, ivory, etc., as well as for preparing a sort of soap known as ' pumice soap.' The scattered pumice is used for preparing hydraulic cement. There is stated to be a project on foot to export tbe pumioe by rail from Kars to the port of Poti, and thence ship it to Odessa.

AJi ARTIFICIAL HALO. A halo may bo produced artificially, and its appearance beautifully illustrated by crystallising some salt (such as alum) upon a glass plate, and then lookiog through the plate at the sun or a bright light, then the luminous circles above described will be observed. The formation of a circle of light around the sun or moon, and the production of the dark circle to which we have referred, may also be illustrated by an interesting imaginary experiment, which is thus described by the late Prof. Loomis ; an eminent authority of the subject of atmospheric phonomc na: 'lf we conceive a beam of light to be admitted through a small aperture into a dark room, and to fall upon a large number of ice-prisms having angles of sixty degrees and occupying every possible position, all the incident rays will be deviated from their first direction, but in no case will the deviation bo less than about twenty-two degrees. A largo number of spectra will be cast upon tho opposite wall, but opposite to the aperture through which the light is admitted there will be a circle of twenty-two degrees radius, bordered with the red end of each spectrum will be turned towards the centre of the circle. If the number of the spectra be sufficiently great, they will together form a circle of twenty-two degrees radius, bordered with the red upon the inside ; but beyond the red the different colours will be so superposed as to produce a light nearly white. . . The circle within the halo is much darker than the space without it, because from no part of this circle can a ray ot the sun, refracted by the ice-prisms, reach the eve of the observer.' A DEER-LIKE ANTELOPE; Hitherto there has been supposed to exist a sharp distinction between deer- and antelopes, according to the nature of their horns; but recent discoveries in North America tend to show that this distinction is only a feature of the present day. Deer, it is almost superfluous to mention, have deciduous bony antlers, while in antelopes the horns are covered with hollow sheaths, which are never shed and never branched.

JYIAGIC CLOCKS. Clocks that require no winding, have no works to get out of order, and are synchronised without the aid of batteries and contracts, are the latest inducement to John Bull to cultivate a more methodical time system, not only in the streets, but in commercial houses, banks, hotels, and at railway stations—every where, in fact, where uniformity ought to be encouraged. The invention is a Continental creation produced in Zurich, where the clocks come from. To illustrate how it works we shall assume that, it has been adopted on our railways for the whole of its system. First of all, there would be set up a master clock, which resembles very closely in style the familiar grandfather pattern. To outward appearance it would differ very little from any. other clock. At all the other stations along the line and in the offices secondary clocks would be installed, consisting simply of the ordinary round dial and minus springs and all the other complicated works that go to make an ordinary going clock. How do these hundred or more clocks go ? In the explanation is to be found the secret of the invention. The master clock is not an ordinary clock. It not only keeps perfect time itself, but its control over the others is such that it makes them do so also. The certainty of action which the generation of electric current by induction provides has been utilised by the inventor. In .the master clock there is a magnetic inductor of special form consisting of an iron core placed within a fixed coil. Alternately the core is magnetised and demagnetised. Once every minute the inductor is actuated, thus generating a momentary current, which is carried to all the secondary clocks by means of wires, and produces on'a small apparatus an effect which advance the minute, hands of the secondary clocks. This is repeated minute after minute and hour after hour, so that uniformity of time over the whole of the system is insured. All that is necessary is to wind the master clock in the usual way, and the rest works automatically. It is claimed by the inventor that, as there are no batteries to break down, and no contacts to wear out, his system is superior to anything that has been produced. Moreover, maintenance expenses and supervision are done away with, The system can be applied over as wide an area as desired. Although the invention is only now being introduced in England by the Magneta Company, it is largely adopted on the Continent. The Bhine port of Cologne and the towns of Baden and Lugano each has a complete installation, Cologne having recently extended the system to 200 clocks. It is also at work at the Federal Palace, Berne; the Law Courts, Dresden; the Ministry of the Interior, Dresden, and in many banks, hotels, theatres and factories.

SUBMARINE BOATS. * The first genuine submarine was. con-, structed by Van Drebel in IG2O, and his appears to be the first vessel of the kind possessing means of purifying the air from a self-contained source. Armand-Maiziere planned the first steam-driven submarine boat in 17-05. He was followed by Eobert Pulton, of steamship fame, who constructed the Nautillus in 1800. This vessel proved remarkably successful, the inventor having succeeded in carrying out various manoeuvres at Brest, and remaining submerged five hours. Tho first attempt to employ a submarine vessel in warfare seems to have been made during the War of Independence (177G), when David Bushnell made a futile effort to destroy the blockading frigate Eagle. Submarine navigation- -received unrelaxed attention during the whole of the last century, whichsuggests the slow but gradual realisation of early ideas and conceptions. The intrepid and energetic designer Wilhelm Bauer constructed his first vessel, Der Brautauscher, at Kiel in 1850. She was wrecked, and' never recovered. After undergoing many disappointments abroad and in England, Bauer built a boat for Russia—Le Diable Marin—in 1855, in which he narrowly escaped destruction. About 18G0, a Dutchman —Tetar van Elven—was the first to employ an optical tube. Alstitt, in ISG3, built a boat fitted with an alternative steam and electrical motive power—a forerunner of the mixed propulsion type, Bourgeois and Brun, in ISGO-3, constructed their Plongeur; and at the blockado of Chailestown, in 18G3-4, the Housatonic was sunk by a torpedo fixed to her hull by a ' David' submarine, which, however drowned its crew in the process. In ISG6 Saeber designed a vessel having a" movable propeller, afterwards a prominent feature in some designs. Progress continued, and a singular combined submarine .boat and railway Lacomme.