Science Siftings

New Zealand Tablet, Volume XXXIV, Issue 7, 15 February 1906, Page 29

Science Siftings

By 'Volt'

Alpha Centauri, a bright star of the southern hemisphere, is the nearest star to the solar system. Yet it is 275,020 times as far from the earth as the sun (says the ' Chicago 'News '). That is, it is 25,000,000,000,000 miles away. The light of this star requires four and one-third years to travel to the earth. Yet other stars are so much further aw.ay from the earth that the distance to Alpha Centauri is a mere yard stick with which to measure their greater distances. The Atmosphere. The earth's sensible atmosphere is generally supposed to extend some 10 miles in height, probably farther, but becoming at only a few miles from the surface of too great a tenuity to support lite. The condition and motions of this aerial ocean play a most important part in the determination of climate, modifying by absorbing the otherwise intense heat of the sun, and when laden with clouds hindering the earth from radiating its acquired heat into space. The Points of the Compass. To tell the points of the compass by a watch: point the hour hand at the sun. Then south is half-way between the hour hand and the figure 12 of the dial To measure an angle by a watch : Lay two straight-edged pieces of paper on the angle, crossing at the apex Holding them wheie they overlap, lay them on the face of the watch with the apex in the centre. Read the angle by the minutes of the dial, each minute being six degrees of arc. It is easy to measure within two or three degrees in this way. Enamel ware and Appendicitis. A discovery that is likely to prove somewhat startling to householders has been made in connection with a local surgical case (writes the Albury correspondent of the Sydney ' Daily Telegraph.'). Dr. Kennedy lately had occasion to operate on a person in Albury for appendicitis, 'and he found that the trouble had bjeen caused apparently by the taking into the system of' a number of small pieces of enamel. The enamel was of a kind that is used extensively now for the lining of kitchen pots and pans. It is common experience that this enamel chips, and the presumption is that in the case under notice some of the pieces had passed into the patient's body with the food cooked in vessels lined in this way. The medical opinion is that the matter is of great public importance, in view of the general use of enamel ware in the kitchen. Bells Rung by Compressed Air. The chimes of St. Patrick's Cathedral, New York City, are rung by compressed air. Nineteen bells are in the spire. The heaviest weighs 60001 b, the lightest 300 ft. The keyboard of the chimes is in the sacristy. The operator presses a key corresponding to a bell in the spire. This establishes an electric connection, which opens a valve in the steeple, conducting compressed air to a piston with a clapper that strikes the bell. Electricity is the trigger and compressed air the motive power of playing the chimes. An Accidental Discovery. The art of etching on glass was accidentally discovered. A .jeweller of Nuremberg, by some mischance, allowed a drop of aqua regia to fall upon the glass of his spectacles. He noticed that the glass became corroded and softened where the acid had touched. That was hint enough for him. He drew figures upon glass with varnish, applied corroding fluid, . then cut away the glass around the drawing. When the varnish was removed the figures appeared raised upon a dark ground. New Use for the Shark. The shark, which is so abundant in the waters of Central America, is to be utilised in commercial products. A company has been formed which converts sharks' fins into jelly and tinned soup, makes fine machinery oil from their livers, handsome leather, equal to alligator's, from their skins, walking-sticks from their backbones, and numerous articles from their jawbones and teeth.