Science Siftings

New Zealand Tablet, 29 April 1915, Page 47

Science Siftings

By ‘ Volt.’

. . ' Rock ' Asphalt. V:’. _ - Strange as it may seem, the asphalt with which so many roads in London, Pans, and other great cities are paved was found by. accident. Many years ago, in Switzerland, natural rock asphalt was discovered, and for more than a century it was used for the purpose of extracting the rich stores of bitumen it contained. In time it was noticed that pieces of rock which fell from the waggons and were crushed by the wheels formed a: marvellously fine road surface when assisted by the heat of the sun. A proper road of asphalt rock was then made, following upon this discovery, and in 1854 an experimental roadway was laid in Paris. From that time the use of rock asphalt for the making of roads and pavements has increased by leaps and bounds* and has extended to many countries. ■ ■ . Effects of Shell Splash. An authority on naval matters says that when v firing at a range of five miles, which is about what some nations practise" now, the shot takes' twelve seconds - to get to its destination ; during that time the ship it is being sent to, if steaming at the rate of 20 knots, will have changed Tier position 120 yards. The gun must be pointed in a direction which allows for this.. Then there is the forward movement of the ship from which the firing takes place, and which will be imparted to the projectile, and must bo allowed for; and there are other corrections to be applied. The splash of a 12in shell rises higher than a battleship’s mast; it contains about 2000 tons ol water, and would drown a small ship. The 14001 b shell of a 13.5 in gun would make an even greater splash. Indeed, experience in this war has revealed a curious phenomenon: the fire caused by one successful- shot will sometimes be extinguished by the huge volume of water thrown over the ship by a subsequent shot which falls short. . Paper Clothes. Paper dishes of every kind and paper underclothing were very seriously proposed as the next advance step of sanitation among civilised peoples by a noted hygienist before the Congress of Sanitation. Substitute the fire for the wash-tub in every possible particular of life, was his demand; and, to show that such. substitution was possible now in a great many details, -he had obtained and he exhibited a great quantity of samples of paper goods. He quoted the results of an investigation which showed that cups, plates, bowls, and other tableware, taken as samples in hotels and homes, had been found to be infected with dangerous germs, even when they were supposed to have been thoroughly washed. And he told of hospitals that have adopted the precaution of giving all the dishes an extra bath in a strong antiseptic mixture. Accordingly he suggested that the doctors attending the congress should advocate the general use of paper tablecloths, paper napkins, paper plates, cups, saucers, and bowls, and paper servingdishes ; so that after each meal most of the table-ware could be burned, leaving only a small number of dishes and the silver-ware to be boiled before they were again used. Paper linings could be used in indispensable china dishes. The most novel of his sanitation ideas was that underclothing should be made of paper and destroyed after it has been used once. Paper underclothing is entirely practicable now, and woukLnot be much more expensive than ordinary cotton underwear at current laundry rates, and perhaps as cheap as linen clothing. - *. 5"