Science Siftings

New Zealand Tablet, 6 October 1910, Page 1639

Science Siftings

BY 'VOLT' Light as an Aid to Civilisation. Light is the greatest enemy of criminals and evildoers. A city lighted well is a city well policed, for it may almost be said that an arc lamp is as good as a policeman any night. That this fact was fully realised in the very beginning of electrical development, as we know it today, is shown by an old woodcut reproduced from the Electrical Review of March 7, 1885. They were just beginning to think about central stations and electric street lighting systems in those days, and undoubtedly the argument, ' Light prevents crime,' was as effectively used then as now. Falling Asleep. How do we go to sleep How does Mother Nature charm away our consciousness ? First of all, she throws her spell on those centres of our bodies that preside over the muscular system, causing one group of muscles after another gradually to collapse. Thereafter various powers of mind succumb in regular order. First we lose attention and judgment. Then memory goes, and imagination wanders away in revelries of its own. Ideas of time and space cease to control thought as gentle sleepthe nurse of our life—draws nearer. Then comes the turn of the special senses, beginning with sighteyelids close and eyeballs turn upward and inward, as if to shut out all light, the pupils contracting more and more as slumber steals over us. The turn of the ears comesthe power of hearing fades away. The heart beats and breath is drawn more and more slowly. The heart beats from ten to twenty times less frequently each minute, or five thousand times less during the night, while breathing is not only slower, but much more shallow than during waking hours. Temperature falls by perhaps two degrees, and the body loses three times less heat than when awake. And so at last sleep covers a man all over — that shuts up sorrow's eye. To Find Your Way Out of the Busn. It's a strange thing, but when a man gets lost in the bush the first thing he usually does is to start out and run as fast as he can in a sort of a panic-stricken way. This is the very worst thing he can do. Nine times out of ten he will go around in a circle and meet his own tracks. He only exhausts his strength to no purpose. I remember before I went into the bush I had an idea that there were great bald spots, and you could find your way from open to open as easy as walking the streets of a city. But my guide soon disabused me of that idea. He took me up on a high hill, and then told me to climb a big tree. He Went ahead, and I followed him. As far as our eyes could see there was nothing but bush, bush, bush. There were tiny openings here , and there that looked like the mouths of bushel baskets, but my guide told me that they were only small ponds. These openings were sometimes five miles and sometimes ten miles apart, as near as we could judge. I made up my mind that there would be bush enough to last after I was gone. When you are lost in the bush, as I hope you never will be, there is one sure way to get out, if you are lucky. Travel until you come to a little stream and follow it down. Nine times out of ten it will bring you to a larger stream, which will show you your way out, or it will lead you out by its own windings. I have been spared many a long, cold* night in the bush without food or shelter by this manoeuvre. The Esquimaux Dogs. Of the various breeds of dogs indigenous to the polar regions the most familiar are the Samoyedes and the Esquimaux (writes Dr. R. Lankester in the London Daily Telegraph). Both are of inestimable value for draught purposes, alike to the natives and explorers. For their size their strength is remarkable, and it is astonishing what they can do in the way of dragging heavy burdens. The Esquimaux bear a marked resemblance to the wolf, and they have a temper which suggests but short contact with civilising influences. Those who have kept them say that a thrashing is always remembered, and revenged. Travellers' relate that a team of Esquimaux will cover nearly sixty miles a day, even with a substantial load behind them. They are cobbily built, with powerful quarters and heavy bone. The coat is an admiraole illustration of the kindly way in which Nature adapts animals to their surroundings. The undercoat is dense, soft, and warm, through which comes the hard, wiry outer coat, the whole forming an excellent protection against the inclemency of the Arctic weather. The color of the coat varies, including white, white with black patches, silver grey, and dark red. The back and sides are always of a darker shade than the under Earts. A great virtue of the Esquimaux is that they never ark. Of course this handicaps them in their usefulness as watchdogs, but it is a great recommendation to town dwellers. .."'.""• ',._•'