SCIENCE OF THE DAY.

New Zealand Herald, Volume LXVII, Issue 20626, 26 July 1930, Page 5 (Supplement)

SCIENCE OF THE DAY.

RESEARCH IN THE AIR.

There is nothing, alive or dead, that moves, articulates, flows, slides, oscillates, rotates, or reverberates in Britain that tho experts of the National Physical Laboratory do not at once get tho measure of. Even Scotland Yard itself has been under observation—for vibration.. Let there be tho merest suspicion of noise, vibration on a rubber road, flutter of aeroplane wings, friction around a jewel bearing, or, graver still, of turbulence and surface roughness in the air flow around circular cylinders, and the gifted men and women will rapidly place a finger upon the seat of tho trouble.

The department mado valuable contributions to tho designs of tho Schneider aeroplanes and tho airship 11101 by air tunnel tests with models. Tho predictions of top speeds mado as the result of those tests wore in close agreement with tho results attained by tho aeroplanes in flight. ]n the case of tho airship tho novel shape adopted as tho result of model tests on Stream-line foims had been amply justified. The drag co-efficient was much lower than on previous ships, and the fins and control surfaces, designed in the wind tunnel, had given tlio desired stability and control on the full scale.

Experiments were made with a model of tho llock of Gibraltar to determine tho distribution of wind currents in its vicinity. Tho method adopted enabled a rapid survey of the region to tho leeward of the Rock to be made, and yielded information of the greatest importance to pilots flying in the neighbourhood. Wing flutter in aeroplanes, it is claimed, is now understood, and can bo prevented.

LOSS OP HAIR AND DIET

If one's hair is falling out it may be a sign that tho diet 13 deficient in Vitamin G, the latest addition to tho recognised family of diet principles introduced to a recent meeting of the American Chemical Society by Professor 11. C. Sherman of Columbia University. Although Vitamin G has been identified for only about ono year, physiological chemists at Columbia liave conducted elaborate experiments of tho effects of its presence of absence in the diet of rats. In these animals tho vitamin is directly connected with growth. Lack of it, said Dr. Sherman, may retard §rowth, stop it, or in extreme cases cause cath. In some rats the shortage caused premature old ago. Loss of hair is one of its most commonplace danger signals. Its lack is suspected as a cause of pellagra. " Tho growth requirements of rats," he said, "presumably apply to other mammals also. Vitamin G must play a prominent part in any adequately comprehensive conception of food values from now on.

ELECTRICITY AND TREES. Leakage of electric currents from highpower transmission lines often cause serious injury to trees, according to tree specialists in the United States Department of Agriculture. Another common typo of injury to trees and shrubs is scorching or burning as a result of (he plants being located where whitewashed or light-coloured walls reflect the heat of tiie sun. Other types <>f injury to trees aro caused by dense shade or too intense sunlight.

DESTROYING POISON IVY. Low-grade kerosene or crude oil, sprayed on the poison ivy vine, suffocates the plant tissues and causes destructive chemical action so that the plant dies. Jligh-grade kerosene is not so good for it volatilises too rapidly. Best results aro obtained in hot weather. If possible, it is also advisable to cut the stems near the ground and repeat the cutting frequently until the plants aro starved. Through lack of foliage the plant, once it lias used up the food stored in the roots, cannot manufacture more food for re growth.

USEFUL INVENTION FOR MINES. A contrivance for use in mines has been invented by .1 woman in Paris. Whenever tho quantity of gas in the atmosphere is greater than 1.3 per cent., the instrument sounds a warning by ringing a bell and flashing a tiny electric lamp. Tests made in England, as well as France, are said to have indicated that tho invention infallibly detects the presence of gas in tho air. In France it is being used to trace leaks in household gas lines, and fixtures, and to ensure that 110 gas escapes from loose plumbing joints, when new meters are installed. The London street gas explosions of .some months ago inspired tho inventor.

FUTURE AVIATION MARVELS. How long will it take before one nia.V strap a five horse-power motor on jus back open ft reinforced umbrella over his head, and proceed to his office, via the air route? Recent aeroplane developments appear to forecast something of this character. Only lately, a parasol tvpo all-metal monoplane propelled by a Wasp 45 h.p. engine flew from Seattle to Omaha, at an average speed of 157 miles an hour. Lighter ami cheaper aeroplanes are inevitable, but tho ultimate type of family aerial motop cycle must remain, in the realm of speculation for some time yet.