SCIENCE OF THE DAY.

New Zealand Herald, Volume LXV, Issue 20058, 22 September 1928, Page 5 (Supplement)

SCIENCE OF THE DAY.

THE FIRST PNEUMATIC TYRE. It is forty years ago sinco John Boyd Dunlop applied for the patent for the first pneumatic tyro. school in Dreghorn, Ayrshire, Dunlop had observed that a largo wooden roller was easier to pull than a smaller one, because, as it had a larger area of surface bearing on the ground, the pressure on each unit of area was less. It was a complaint from his small son Johnny, then aged nine, which actually materialised in tho first rubber tyres to be filled with air. Johnny had grumbled about tho difficulty of riding on thin solid tyres over the uneven stone setts of Belfast's streets. His father made two air tubes from sheet rubber one-thirty-second of an inch thick, which he fixed to a wooden disc with a thin strip of linen and blew up with a football pump. The tyres were then fitted to a tricycle made by Dunlop with specially shaped rims. Tho whole was completed one night at ten o'clock, and so eager were both father and son to test tho new device that the boy went out for a run in the moonlight and returned triumphant at midnight. A racing cyclist who was shown the novelty expressed his doubts about it, so Dunlop challenged him to a race on his thin solid tyres against the nine-year-old boy on the home-made tricycle equipped with pneumatics. The lad won. Although Dunlop revolutionised cycling and made motor-cars possible, there is no record that he ever rode a bicycle himself.. SAVED BY GLASS. A new glass has been invented that withstands pressure, heats, and acids better than any yet known. It was first used for making glass tube water-gauges and glass bars, and it is claimed that it will sustain a cold-water pressure of 20, 45, 65, 80, and 100 atmospheres. It is also used in weaving and silk-spinning mills to replace bobbins of wood, which frequently became splintered and rough, tearing the threads of the material. Original attempts to substitute glass bars for the wooden bobbins were unsuccessful because the glass ased would not

withstand fluctuations of temperature. The new glass, however, will stand a sudden change from 160 degrees to 0 degrees centigrade without damage. HUMAN 3>OWER STATIONS. Human life has been revealed as a wonderful electric power plant and system of transmission lines. Two experimenters in psychology declare that they have listened to messages flashed over tlie network of nerves in the human body, translating the impulses of nerve currents into sound waves that human ears can hear. Im pulses are detected by electrodes attached to the body. These nerve messages, magnified eight hundred times by a powerful amplifier, can be broadcast by wireless! DANGERS IN DUST. The recent deaths of two girls in Britain from silicosis has drawn attention to the various trades in which workers are exposed to the dangers of this condition. Silicosis, caused by the inhalation of dust, gives rise to symptoms exactly similar to tuberculosis, and to make a differential diagnosis between the two is extremely difficult. The particles of dust may be coal dust, bits of fine steel or iron, as with men who grind metals, pulverised stono in the case of stone cutters, and occasionally fine particles of grain. In coal miners the disease is called miner's phthisis. A moderate amount of dust, however, may be deposited in the lung tissues without giving rise to trouble. AN ELECTRICAL PLOUGH. Enormous crops are said to have resulted from the use of a new electrical plough. It not, only destroys weeds and insect pests, but enriches the soil by fixing nitrogen in the ground, and if is expected that it will replace fertiliser. The plough, fitted with an electric generator, coils, and other apparatus con nccted with two plough blades, is attached to a tractor. As the blades pass through the soil, art electrical field is created between them, producing an effect like lightning. Pests arc killed by the current; in the first ploughing, and the second treatment kills weeds and fixes nitrogen into the soil.