( Originally Published Early 1900's )
THE people of Africa and Oceanica still use the javelin as well as the bow; but of all the projectiles employed by savages the most curious is the boomerang, a sort of club bent at almost a right angle, smooth on one side, slightly hollowed on the other. It is necessary that it should be made of a single piece of wood, in order not to get out of the form upon which its wonderful properties depend. At first sight, and with-out examining it closely, one would say it was a sword of wood rudely and unskilfully shaped. The first Australian explorers were deceived, but their error was pardonable, for the boomerang, though a weapon of war, is also equally used in hunting.
The specially interesting and original feature of the boomerang is that when thrown by the natives it describes the most extraordinary curves, and performs the most unaccountable evolutions. "When thrown by the natives," we say, for, whether from ignorance of the principle of the boomerang, or from want of skill, Europeans have never been able to use it. Thrown by strangers it flies and falls like any ordinary piece of wood.
In hurling this curious weapon the native takes it in the right hand by a species of handle into which one of the two branches is fashioned, and throws it either into the air at some distance above the ground, as one might throw, for example, a reaping-hook, or upon the ground, like a pair of compasses with the legs extended, which a schoolboy might throw to the distance of some paces from him out of spite. In the latter case the projectile strikes the ground at a little distance from where the thrower stands, but, owing to its bent form, and the elasticity which it gives, it rebounds immediately, and continues to rebound in successive ricochets, with a force which is most destructive to any body, organic or inorganic, that happens to lie in its course. Thrown thus among a flock of wild ducks, the boomerang commits the greatest havoc, striking many of the fowls, and killing wherever it strikes. The other mode of using the boomerang, much more curious, but at the same time more practicable than that described, consists in hurling the weapon at an object standing sometimes at a great distance. The thrower waits calmly till the boomerang, having accomplished its work of destruction, returns, describing an ellipse, and falls at the spot (or at the most a few paces from it) from which it was discharged.
Very few boomerangs have been brought to Europe, and, indeed, very many people are in ignorance of the existence of the weapon. When it becomes better known, when men of science shall have examined it with intelligent care, perhaps some means of applying it usefully will be found. The case of the boomerang proves clearly that the most simple laws of nature have not, even among civilized nations, been sufficiently utilized. And it is not flattering to our amour-propre that this lesson in mechanics comes to us from Australia, from a country the inhabitants of which are among the least civilized and the least capable of civilization. One is perfectly nonplussed in attempting to explain how savage tribes, utterly ignorant of physics and the laws of dynamics, could have conceived the idea of an instrument at once so ingenious and so simple. It was no doubt chance that first made them acquainted with the properties of a piece of wood thus shaped; and one can imagine how, in the chase, an Australian, having in his hand a curved stick, and throwing it at the wild fowl, was astonished to see it come back to his side; how, being a keen observer, the strange fact made a deep impression upon him; and how, after end-less trials, he arrived at a satisfactory result, and fashioned another instrument like the one chance had put into his hands.
However this may be, the natives use this instrument with extraordinary skill, and travellers recount incredible feats performed by them. Thus, a native throws his boomerang with his right hand, and catches it again with his left, and vice versa. They hit unerringly objects concealed by other bodies—strike down, for example, birds or other small animals hidden behind trees or houses. Nearer objects they also hit by a back-stroke. The perfection of skill is to strike the enemy with a double boomerang—that is, with one discharged with the right and another sent by the left hand. The unhappy man who serves as target thus finds himself between two fires, or rather between two clubs, which, after describing eccentric courses, both infallibly strike him, unless he is sufficiently skilful to escape by a ruse, or is possessed of a shield of a particular shape, behind which he may shelter himself.
It is possible to calculate mathematically the curve which the boomerang describes. Commodore Wilkes, who commanded the celebrated scientific expedition of the United States round the World, made experiments with this instrument, and has traced the curves described by it when discharged at the angles of 22°, 45°, and 65°. The most singular movement is that which is performed when the weapon is thrown at the angle of 45°. Its flight is then effected from behind—the thrower turning his back to the object which he wishes to strike.
But by virtue of what principle is the phenomenon accomplished? Travellers who have visited Australia, either do not try to investigate the cause, or give an insufficient explanation, or plainly say that the thing is incomprehensible. Willingly would they leave it alone as a prodigy; but in these scientific days prodigies are no longer the fashion. In the first place, how comes it that the boomerang does not follow the straight line like other bodies thrown in the same manner? Its particular form is the cause, and as the straight line in which the force of projection tends to drive it does not pass through the centre of gravity—which lies outside the mass, a little nearer the longer than the shorter leg of this unequal pair of compasses—the instrument rotates continuously around the centre of gravity. The force of this movement is so great that it diminishes but little before the weapon falls. The boomerang, by means of its level surface, easily cuts the air which sustains it, and, so to speak, carries it. For example, if the weapon is thrown with a slightly upward tendency, it mounts considerably upwards, a phenomenon which, perhaps, has led to several travellers believing that the natives always throw it higher, whereas they project it only a slight distance above, and indeed sometimes close to the earth. In any case, it is by the influence of the air that the upward movement is caused; but, on the other hand, centrifugal force exercises its influence, and tends to sweep the mass round in an orbit. This makes the boomerang describe an ellipse, which attains its maximum of curve when the movement is arrested by the resistance of the air.