A HUMAN CORK,

Auckland Star, Volume LXIV, Issue 18, 23 January 1933, Page 6

A HUMAN CORK,

LITTLE-KNOWN FACTS ABOUT BUOYANCY.

(By P.H.U.)

The mechanical explanation why Mr. Buslinell is able to float on his back with his arms stretched above him out of the water, a* photograph and account of which in a recent issue of the "Star," may be that for some reason the weight of water his body when submerged would displace is considerably greater than the weight of his body. Possibly Mr. Buslmell may have very light bones. The normal human body, living, weighs" slightly less than the weight of the amount of water it will displace. Therefore the live human body floats. Whether it floats horizontally or vertically depends upon how the weight of the body is distributed. There is nothing unusual in the body floating in an upright positioi}., No effort Is required oil the part of a person whose body floats upright to remain in that position. Upright in the water (sea) with head held' lightly back, the average person will float in smooth water with the water below his mouth. He can breathe normajjy without effoit. If he withdraw his hands out of the water slowly and gently so as to avoid causing any momentum, his head will commence to submerge. Long before his arms are uncovered his head will be under. The explanation is, of course, that the buoyancy of his body, measured by its displacement, is not sufficient to support the weight of his arms. By.quietly lowering his hands beneath the water again his head will emerge to its former position. The extraordinary thing about Mr. Busbnell is that his body has buoyancy sufficient, not only to support the full length of his arms, but also, judging from the photograph, a considerable portion of the body itself. However, this is not being written to try to explain Mr. Bushnell, but because of the loss of life occurring year by year, which in many cases could or should be avoided. Why is it that he who is regarded as the mos(; intelligent of creatures should with few exceptions, be the only one to drown when he finds himself in deep water? Why should man drown when cows and camels, cats and other unlikely creatures swim to shore? May not the explanation be that man is obsessed with the idea that unless he has been taught to swim he must drown, while the camel labours under no such delusion, so propels' itself to land? Many years ago a writer in the "Nineteenth Century" advanced a theory to explain why man sinks instead of floating. It was founded on this scientific fact. A person who, owing, say, to education or change of environment has lost a habit is liable in time of extreme peril to revert to it. A good' example is dialect. A man of Yorkshire birth, for instance, removed in his infaney, say, to, London, where he lost every trace of accent, might be expected on the top of a burning building with its staircases in flames to cry for help, not in the Oxford tones of his daily life, but in broadest Yorkshire. • In deep water in dire peril owing to not having learnt to swim, man's instinct goes so far back that he tries to climb. As his arms leave the water, down he goes. A swimmer would do likewise if by leg movement he did not keep himself afloat. And it is no easy task for a swimmer to support himself with, arms out of the water. If the cancel and the cow raised their legs they would also go down. What might be termed a converse example of the above theory may be found in the hoatzin. We come, then, to this. -Is hot a fundamental blunder made in drilling it into the mind of every child from infancy that it will drown if not taught to swim? Should it not .be demonstrated to every child, as soon as it is capable of understanding, that .the human body will float as will a piece of wood or cork, that its margin of buoyaney is narrow, that the weight of the forearms will remove it, and that until one has learned to propel oneself in the manner called •swimming, bands, must be kept below the waters With the fact injpralned in the mind of the child that the human body floats provided it is not called upon to support any weight, even that of its own hands, will not a great stride have been taken in the direction of placing the human being on a par, say, with the pig in avoiding drowning? It would follow that swimming would become as commonplace as walking, and no person, any more than a horse, would be capable of saying, "I can't swim." Encouragement may be found in the fact "that although the seal as a swimmer has few superiors, the young seal lias ,to be taught to swim. Its mother is to explain what buoyaney means, but succeeds in teaching it to swim.

A simple method of proving the buoyancy of the body is to walk ever'so slowly into deep water dowrr a shelving beach or bath. As the water reaches the neck the head should be held slightly back so that one looks up. Every muscle should be relaxed—the most important thing both in floating and- swimming. Taking, then, the shortest of steps so as to avoid Causing body momentum, it will be found that this foot then that is off the bottom, and the person who says he cannot swim has demonstrated to himself that his body floats. The annual loss of life through drowning in this country with its semi-tropical climate and facilities for bathing is not a credit to our intelligence.