Science Siftings

New Zealand Tablet, 8 February 1917, Page 47

Science Siftings

By ‘Volt.’

The Strength of a Soap Bubble. -" v Professor Boys, in a lecture on ‘ Soap Bubbles . and Other Things,’ at the Royal Society of Arts the other • day, showed that an ordinary soap bubble will support a house sparrpw’s egg on the rim of a china teacup in such a manner, that it will not roll off. With the aid of a basin of soap and water Professor Boys produced an astonishing number of bubbles of every # conceivable shape and globular, tapering, . large and small. Some of them were more than a foot in diameter, and floated through the hall for several minutes without breaking. When You Fall Far. ' •. ~. It is quite a mistake to think that when a person falls from a great height his heart stops before ever his body touches the ground. Breathing may be suspended for a few minutes, but if artificial respiration is applied at once, life can be restored in many cases. This was proved in America, when a girl fell a distance of 200 feet, with no more serious results than some fractured bones and a few internal injuries. She compares her sensations while falling to the faintness one feels when travelling downwards in a jerky lift. It was only in the moment of landing that she lost consciousness. Doctors assert that such accidents would not so often prove fatal if artificial respiration were more generally tried. Just because the patient’s pulse is not beating it is a fatal error to think he must therefore be dead. Treat him as you would a man rescued from drowning, and in nine cases out of ten you will save his life. What is Horse-Power? To lift 5501 b Ift in one second requires what is known as one horse-power. Similarly a horse-power is able to raise twice that weight Ift in twice the time, or ift in just that time. Moreover, it can raise half 5501 b Ift in half a second, or 2ft in a second, and so on. - Therefore, when we lift one-fourth of that weight, 4ft in one second, we are exerting a horsepower, Accordingly, when a person who weighs 137£1b runs upstairs at the rate of 4ft a second, he is exerting the equivalent of a horse-power. For a man weighing twice that much, 2751 b, it would be necessary to climb at the rate of only 2ft a second to exert a horse-power. It is possible to do much more. As a matter of fact, a horse often exerts many times a horse-power. The average horse can draw a waggon up a hill where a ten horse-power engine with the same load would fail. A horse-power does not represent the greatest momentary strength of the average horse, but is a measure of the power which he can exert continuously. Singing Shellfish. Contrary to the general belief, fish are not all dumb. Quite a number of them make some kind of noise. The common red gurnard of our coasts, on being hooked and hauled rudely out of the sea, will grunt loudly and indignantly, as a fisherman will tell you (says a Home exchange). It is a strange, croaking sort of noise, such as one might -expect a young rook to make. Then there is a fish called the butterman, which is found off the Scottish coast. This fish, which is fat and comfortable looking, about a foot long as a rule, makes a distinct hooting noise from the back of his throat when landed in a net or caught on a long line. A netful of these fish, though they are rather rare, is sometimes caught, and when they are hauled in the chorus of sharp, siren-like hoots is very startling to a stranger. But in Ceylon - there is a shellfish, a kind of mussel, which positively sings. In still weather, when the water has ebbed away from the mussel-beds for a few hours, these shell-fish can be heard producing a long, low, fluty sound. How they do , it, no one knows, but they make a quite distinct attempt at singing ; and, as they have no throats, they must produce this

... . , . , , 1 , ~ sound by some manipulation of their double shells. The sound is low and not at all unpleasant-in fact, it is rather sweet to the ear on a still summer’s night.