SCIENCE NOTES.

Otago Witness, Issue 2914, 19 January 1910, Page 84

SCIENCE NOTES.

—New American Naval Gun.— A New York telegram states that remarkable claims are made for a new Min gun which, it is understood, is being perfected prior to trials before experts of the Navy Department. It is described as a 63-ton weapon, with an extreme effective range of 25 miles, to which distance it can hurl a projectile weighing 14001 b. —A Useful Hat.— A leading Parisian milliner has invented a hat which may be adapted for various occasions at will. It can be laker to pieces. When its removable brim is packed away under the brow it becomes a close-fitting toque suitable for motoring, railway travelling, or for walks in rough weather. If its owner finds herself unexpectedly called upon to appear in evening dress she has simply to readjust her crown, and she is ready for any function demanding the greatest elegance. —New' Gas-making System at St. Helens. “We have seen a new system of carbonising which is proved to have a producing capacity 60 per cent, greater than any existing system working upon the same ground space. In view of that one fact alone we must admit that there is a very great future before the system of carbonisation in vertical retorts.” This opinion was expressed- by Mr Bel ten, of Cncster. a wellknown gas engineer, at. a mooting ot ihe Manchester District Institution of Das Engineers in St. Helen?.

—“ Lin-on” Made of Paper.—• Wo already have a-rlilicia 1 silk, made from wood fibre and now (says Popular fee fence Siftings! a German inventor has produced .» new kind of cloth, which ho weaves from threads which have a cotton centre covered with paper. Tiia?o threads can bo woven into a variety of fabrics, and the cloth is | strong enough to use for napkins, taole ■ linen, and even underwear. Cloth so made | bleaches well, and .clothing made from it i s warm, since the paper makes it an excel’■int non-conductor of heat and cold. More- ■ over, it is very cheap—a third of the cost of cotton and a tenth that of linen. —Wireless Messages for Aviators. — I Foreseeing an enormous development of -ir travel in the near future, Dr Freidrich | Lux has devised a system of wireless signal- | ing by which, airships may be kept con- j stoutly informed cf their exact whereabouts. \ He proposes establishing wireless stations I over the country at a distance of 40 or 50 \ miles apart. Each station he intends shall « rend out every five minutes a. signal of a law letters by which it may bo identified. | For receiving" these signals every airship | —ill need- sn*aihsaratus weicrbmg about 61b. 'One aviator will not only know the name t Die nearest station, but the varying strength of the electric impulses m.eived . vill tell him,whether he is approaching <* i receding from a particular station. —The . Heat of the Stars. — Some interesting questions were raised at , (he last meeting of the- Academy of Sciences, j 1. Baillaud, director of the Paris Observa- j lory, communicated to hie colleagues t.he^ refits of an investigation made by M. Nor>ann as to the heat of the stars. It apoars that the coldest star observed is in ho constellation of Perseus, with a temerature of 29S0deg, and the hottest is in ' "gurus, with a temperature of 60,C00deg. ho sun. contrary to the usual presumption, ■ one of the coldest stars, since its tempera* ■"o only reaches SOSOdeg ; the tempera- , ire of the Pole Star is given at SSOOdeg. -ofessor See developed the thesis that •igratory bird's find their way south or u-fch by following instinctively the electric currents which are formed in the atmo--6[ here, especially in autumn and spring. --Strength at Various Ages.— -\cocM'c.ing to excellent authority, the muscles, in .common with all organs of the human body, have their periods of development and decline, our physical strength increasing up to a certain age, and then, decreasing. Tests of the strength of several thousand individuals have been made, and the following figures are given as the averages derived from such tests. The lifting power of a youth of 17 is 2801 b: in his twentieth year this increases to 5201 b ; and n the thirtieth and thirty-first years respecively it reaches its height, 3651 b. At the -X pi rat ion of the thirty-first year the strength begins to decline, very gradually at first. By the fortieth year it has decreased 81b. and such diminution continues at a slightly-increasing rate until the fiftieth year is reached, when the figure is 3301 b. Subsequent to this nei icd strength fails more and more rap:dlv, until the weakness of old ago is reached. —Paper Money and Disease. — A correspondent calls attention in the Daily News to some interesting figures recently made public dealing with a bacteriological analysis of Amenican paper money. Tho investigation took place in the laboratory of Yale University, and two dozen of the dirtiest bills procurable were submitted to tho test, with the result that each bill on the average was found to harbour no fewer than 142,000 bacteria. The t.wo most imrortant discoveries made, however, were that all the bacilli proved lo bo non-virulcnt, and that the cleanest of the bills had,, with one exception, the biggest population of bacteria. But if one can credit the statement of another American expert who carried out a similar investigation some years previously, this Yale bundle of bills was comparatively free from pollution, for the expert in question, a Dr Graham, asserted that on one particular filthy note he counted over 900,000,000 bacteria !

-Under-water Signals at Holyhead.— j Trinity House has supplemented the exist- ' ing facilities for warning ships of peril in , time of fog by installing a submarine signal ■ station off the North Stack, near Holyhead * A‘bell, under'the water, has been placed | here. It will give five strokes in quick ■. succession, followed by a silent interval of | 10s*ec The isound, ifc has been ascertained, | will travel from 10 to 20 miles—the water j being a better conductor than air,—anal the j steel” hull of any ship within a radius > will act as a- sounding drum. By means I of a microphone —such as* many ships ha\o fitted in their hulls—the sound of the bell will be concentrated' and carried' to the bridge, and in thick weather the navi gat- | ing officer will thus be able to locate his nJdtion when, entering. Holyhead: Similar^,

coasts, and it is now annonaoed Jbat «ti has been installed on board the W aiidsina* Bank Light Vessel, outside the en»ra.tioa ti the Rivet Schelde. --Vepetation. Extraordinary by Electricity. — Ar%ong the believers in tire influence o; atmospheric electricity on vegetation is Professor Lemstroem, of the University of Helsingfors, Finland. He fixd/i, says Popular Science Siftings, that plants in the polar regions escaping night frosts have a much more rapid and luxuriant growth than those in warmer climates, and that despite primitive cultivation with wooded ploughs and harrows, great crops are yielded by rye, barley, and oats. The rapid growth is usually attributed to the continuous daylight of two or three summer months. This explanation is unsatisfactory, ancli it has been proved that, even in those months, the aggregate of heat and light, is loss than at 60deg of latitude, or furl hen south. Various facts have convinced Professor Lemst room that Arctic vegetation is stimulated l, v (,l U v electrical currents—eo often manifested in Iho aurora borealis —that flow between the- earth and the atmosphere in the north. In th( annua! rings of conifers he has found variations showing extra growth in yearn and latitudes of great electrical activity. and in experiments with a Holtz electrical machine he has hastened tho growth of barley, wheat, and rye by an artificially charged atmosphere. Tho theory sngests an explanation of the pointed loaves of .conifers and barbed ears of grain, which conduct the electric currents to these plants. —The Making of Deserts. — It is in cutting down and burning forests of large trees (says Sir Kay Lanfces-tcr in me Daily Telegraph) that man has done the most harm to himself and the other living occupants of many regions of the earths surface. Wo can trace these evil results from more recent examples back into thoremote past. The water supply of the town of Plymouth was assured by Draike, who brought water in a channel from Dartmoor. But ilie cutting down of the trees has now rendered the great wet sponge, from which tho water was drawn all the year, no longer a sponge. It no longer “holds” the water of the rainfall, but in consequence of the removal of the forest and the digging of ditches the water quickly runs off.t.hej moor, and the whole countryside suffers -from drought. This sort’ of thing has occurred wherever man has been sufficiently civilised -and enter prising to commit "the. folly of destroying forests. Forests have an immense effect on climate, causing humidity, and similarly causing moderate and- persistent instead of torrential streams. In fact, T'hether it is duo to man’s improvident actiost or to natural climatic changes, it appears, tfc*t the formation of “desert” is due in the first place to the destruction of fovert and V.he consequent formation of a barren, fcundy area. Sand-deserts are not, ca wted to be supposed, sea-bottoms from which the water has retreated, but areas of diestruction of veg-etation-T-often (though not always), both in Central Asia and in North Africa (Egypt, etc.), started by the deliberate destruction - of forest by man. —A Celestial Procession. — A most fascinating discovery has just been' made by Professor Boss regarding a moving cluster of 39 stars in the constellation Taurus (the Bull). These stars represent literally a “flight of suns,” all drifting in the same direction, with an average velocity of about 25 miles a second. There are stars “marching in widely extended ranks, by a plan, along a prescribed track, under orders sealed perhaps forever to human intelligence.” They are all urging their way onward through the star depths with a velocity compared, with which the swiftest motions known to us are a$ absolute rest. Each star in the celestial march is a glowing mass of gas, thousands of times larger than the globe on which we live. They may even rival our bright day star the sun in all its majesty and glory) es the sun exceeds the earth. Each star in the celestial procession may be pouring forth supplies of beat and light and swaying by its attraction the motions of attendant earths like our own. The fact that these stars are constantly urging their way through the heavens leads us to a consideration of what has been termed star drift. Every star is in motion; for tho eo-calkd “fixed stars” long ago broke away from their moorings and began to flit at Large through space. It is a slow star that moves at the rate or only a mile a second 1 , the average speed being ten miles. At this rate, a star traverses more than 315 million miles a year. Tho stars are travelling forever on a journey of which we know neither tho beginning nor the end. As the astronomer poet of Persia expresses- it: — There was the Door to which I found no key; There was the Veil through which I might not see.