Science Siftings

New Zealand Tablet, 18 May 1911, Page 931

Science Siftings

BY ‘VOLT’

An Interesting Discovery. Explorers have recently discovered a new stalactite cave in the Dachsteiu Mountains, Upper Austria, and estimate it to be the largest of its kind in Europe. The principal tunnel measures about one mile and a quarter, with numerous branchings of varying length. The cave has two levels. In the upper, two immense ice halls were found, having precipitous glaciers some 300 feet in length. Spread over the lower level were a series of halls, the largest 600 feet long and 100 feet high. Among the paleontological specimens found were brachiopods and cave bears. The Heating Value of Coal. Preparations are under way by the United States Government to extend the new method of coal purchasing which, partially operated a short while ago, has ployed its feasibility. The coal bills are paid on the basis of the actual heating value of the coal, deduced by tests of samples made by the Geological Survey. The analysis show the quality of the fuel in terms of carbon, sulphur, volatile matter, ash and moisture, and its heating capacity in calorics. This new basis has found favor with all parties concerned. 1 Through Giant Tubes Under River. 0 on^nJ. ig l' n ,i ic piece of engineering, costing more than o,UUU,UuO dollars is going on in the heart of Chicago so rapidly but quietly that the casual observer will not know it until he finds himself some morning plunged from the light of day into a world of electric light, with concrete floor, walls and ceiling all about him, and only a small circle of daylight ahead. With the time for completion of three under-the-river tunnels not far away, thousands 01. workers for the north and west sides who ride on surface cars to and from their places of business will, it is hoped forget the meaning of the word * blockade,’ for it is to help do away with congestion in Chicago’s ‘loop district’ that these tunnels are being built. 1 Wireless on a Submarine. , ni The largest submarine in the British Navy, known as 1 i i / ece , ntl y been . pipped with a wireless teleapli plant, which can be used when the vessel’s hull is entirely submerged, leaving above the water only a slender mast supporting the aerial wires or antennae of the wireless installation (says a writer in Englneerintj) Experiments have recently been successfully carried out with this vessel in Torbay, the cruiser Bonaventure establishing and maintaining coramuniactum with the D 1 when submerged. 3i? , Dl , r t eplled I l ’. 01 below . the surface. The installation was tested when the submarine was submerged to a depth just sufficient to keep above water, the periscope, which Is seen half-way up the mast. . . The possibilities of such a development are considerable, as not only could the actions of submarines be directed by these means from idp S ?]iJt SSeS bat a flotilla of submarines will be able to fhomci Systm or , tllC! Purpose of communicating among themselves when submerged, their value in Val warfare being thus considerably improved.’ "airaie As Others Hear Us. himself 6 la pL person 4- a man , becomes acquainted with is himself. He cannot see, himself as others see him nor can he even hear his own voice with the ears of the rest of the world. v In proof of this latter inability, Doctor Daley, rin La Mature, describes some of his experiments If a person records on a phonograph a few sentences oronouncod by. himself, together with others by his friends and causes the machine to reproduce these] it generally happens that he easily recognises his friends’ voices but not his own. On the other hand, the friends recognise his voice perfectly. This fact proves that everyone hours his own voice differently from others. The difference lies in the quality of the tone. One hears his own voice not only through the air, as do his auditors, but across' the solid parts situated between the organs of speech and those of f iear Ti S \ - The sound thus produced has a different timbre from that conducted to the ear by the air above Take the end of a wooden rod between the teeth and nro nounco a vowel continuously. Let the other end he X?.' » ake n between the teeth and released by another perr* , at , the same time, stops his e?,rs.‘ The latter will find that every time he seizes the rod in his teeth the sound S stronger than when it reaches the ear Through the air above, and has a different quality. The passage S ° hd body a,,K ™" tsVt3 i»ten,raS