RANDOM NOTES

Dominion, Volume 31, Issue 151, 23 March 1938, Page 10

RANDOM NOTES

Sidelights On Current Events

(By

KICKSHAWS.)

A visitor, says that there are feuplaces more arresting than New Zea-land-Russia excepted, of course. ♦ * * Freedom of speech may be a British privilege, as suggested, but golfers seem to bold the monopoly. * * * We suspect that if someone had been brave enough to drop a few bombs on Valencia a year or so ago, not even music-lovers would have protested. » ♦ ♦ “At the foot of the enclosed outline map of South America and its component countries there appears a drawing of the German swastika which, I venture to suggest, is incorrect,” writes “Ebor.” “I have understood that the swastika chosen as the emblem of Germany is formed by placing the initial letters of the words ‘Socialist State’ one across the other. If I am right, then the illustration is wrong, because the crossed signs, when separated, do not make the letters ‘S.S.’ Is the swastika originally a Japanese sign, and does the illlustration follow the Japanese form?’’ [The swastika has a history as old as civilisation, and possibly older. It is supposed to have originated in India. It is even to-day a sacred sign in the Buddhist religion. Ancient Greek pottery foun/1 round the ruins of Troy was engraved with this emblem. Hundreds of swastikas are to be found on the) sculptures of the catacombs of Rome. In the first place, the swastika is supposed to have represented a primitive instrument for making fire by friction, possibly used 10,000 years ago or more. Caucasian rugs depict the swastika with feet, as if the left top of a letter “T” had been eliminated, as do most old representations of the symbol. In Germany the symbol is depicted in a similar manner, which appears to be the usual. In some designs the crossed letter “S” is used.]

An aviation expert declares that we stand on the threshold of tremendous new developments in aviation. The man in the street, as he gazes curiously at the noise above, may well wonder when this progress will end. Are we to be presented with aeroplanes that will travel faster and faster until eventually they can chase the sun across the face of the world at 1000 miles an hour? An idea of -what has happened may be obtained by comparing well-known machines. In the Fairey Fox of 1930, an engine of 540 horse-power drove a machine weighing 47501 b. at a top speed of 152jniles an hour. Four years later the famous Comet used an engine with 70 fewer horse-power to drive a machine that weighed 8001 b. more 83 miles an hour faster. Since then machines have been made that can travel from Edinburgh to London at 400 miles an hour. One may well begin to wonder if there is any limit in the sky.

The chief obstacle Jo higher speeds in the air is that the air rubbing against the surfaces of the machine slows it down. Streamline perfection has reduced the resistance caused by eddies and the like to a very small figure. Air drag, however, is a bogy that at present appears to limit further increases of speed. One of the most surprising discoveries in this connection is that a roughness in the wing surface of only one-thousandth of an inch has a noticeable affect on the speed of the very fast machine. This means that highly-polished surfaces may be expected in ultra-modern machines, which will shine more highly than a soldiers, button, which, after all, never did travel very fast. Methods have already been found to remove part of the drag by diverting the air stream to cool the engine. The National Physical Laboratory has shown how this may be done. As air drag for cooling purposes consists of 10 per cent, of the total drag, this means higher speeds.

Aeroplane designers are well aware jhat in their fight to reduce air drag in fast machines there is still a CO per cent, margin for reduction. It is highly improbable that means will be found to reduce the total to zero. Netertheless, there is reasonable hope that eventually 40 per cent, may be realised in practice. That clone, designers will have to sit back while they contemplate an ever-growing list of obstacles to higher speed. Further increases in speed do not depend on huge increases in engine power, because, after a certain speed doubling, the engine power adds only a few miles an hour to the top speed. ' The next problem to solve is how to make air flow smoothly along a surface of appreciable length. The ideal is the air flowing past the wings so smoothly that there are no eddies and producing an even gradation of movement between adjacent lajeis oair Eddies are wasteful of power, but SO far no method has been found that will eliminate them.

A curious feature about ultra-design in aeroplanes is that there appears to be no mathematical reason why air should 'not flow smoothly past an appreciable length of surface. It is probable that there is some quite simple solution to the problem. Even if the air could be made to flow smoothly until half the exposed surface had been passed, the increase in speed would be verv considerable. Even when this problem has been solved, there is a further obstacle awaiting solution. There is reason to believe that the practical limit for aeroplhues as we. know them to-day will be encountered at about 700 miles an hour—the speed of sound. Professor Hill revealed this obstacle when he pointed out that, At present speeds every exposed part of the aeroplane pushes what may be loosely called a bow-wave in front of it; that‘is, the air which is going to pass near the wing or body has some warning that the aeroplane is coming.’ At speeds approaching the speed of sound the air no longer gets this warning and can no longer marshal itself into the desired streamline flow. This produces a shock like a sea wave breaking over the bow of a ship. The result is to increase the resistance to motion so sharply that further speeds would be impossible even with engines ten times more powerful.

“Recently mention was made in your column of some early hotels in Wellington,” writes “A Reader.” “One of the early ones must have been the ‘Commercial,’ as my late grandfather was associated in some way with a Mr. Mclntosh, or Macintosh. It would be some time between 1849 and 186 a, as my grandfather died that year. He, however, actually arrived in Wellington in 1843. Can any old resident of Wellington recall Mr. Mclntosh?” ♦ » ♦

Regarding long drifts by bottles “H.E.R.” has forwarded a cutting dated February 24. 1891. that gives details about a" bottle that drifted from the south of Iceland to the Lofoden Islands. The distance is about 1000 miles, and the drift about six months. /