There are several species of this very curious fish spread over the warmer parts of the world, and their remarkable mode of obtaining prey is very well known in all. There is, indeed, scarcely any phenomenon in Nature more remarkable than the fact of a fish being able to shoot a fly with a drop of water projected through its tubular beak, if we may use that expression for so curiously modified a mouth.
Indeed, so certain is the fish of its aim, that in Japan it is kept as a pet in glass vases, just as we keep gold fish in England, and is fed by holding flies or other insects to it on the end of a rod a few inches above the surface of the water. The fish is sure to see the insect, and equally sure to bring it down with a drop of water propelled through its beak.
It is worthy of remark that the same principle was once, though unsuccessfully, employed in the propulsion of carriages, under the name of the Pneumatic Railway. Some of my readers may remember the railway itself, or at all events the disused tubes which lay for so many years along the Croydon Railway. Speed was obtained, as I can testify from personal experience, but the expense of air-pumps and air-tight tubing was too great to be covered by the income, especially as the rats ate the oiled leather which covered the valves.
I find some little difficulty in arranging the subject which comes next in order. It might very properly be ranked among the Levers, which will be treated of in another chapter; or it might be placed among the examples of centrifugal force, together with the sling, the “governor” of the steam-engine, &c., all of which will be more fully described in their places. However, as we are on the subject of Projectiles, we may as well take it in the present place.
It is the Throwing-stick, by which the power of the human arm is enormously increased, when a spear is to be hurled. Perhaps the most expert spear-throwers in the world are to be found among the Kafir tribes of Southern Africa, and yet the most experienced among them could not make sure of hitting a man at any distance above thirty or forty yards. But the throwing-stick gives nearly double the range, and I have seen the comparatively slight and feeble Australian hurl a spear to a distance of a hundred yards, and with an aim as perfect as that of a Kafir at one-fourth of the distance.
The mode in which this feat is performed is shown in the accompanying diagram. Instead of holding the spear itself, the native furnishes himself with a “Throwing-stick.” This weapon varies greatly in shape and size, but a very good idea of its form, and the manner of using it, may be obtained from the accompanying illustration, which was drawn from the actual specimen as held by an Australian native.
The throwing-stick is armed at the tip with a short spike, which fits into a little hole in the but of the spear. The stick and spear being then held as shown in the illustration, it is evident that a powerful leverage is obtained, varying according to the length of the stick. I possess several of these instruments, no two of which are alike.
It is rather remarkable that among the Esquimaux a throwing-stick is also used, exactly similar in principle, but differing slightly in structure, the but of the spear fitting into a hole at the end of the throwing-stick. Wood being scarce among the Esquimaux, these instruments are mostly made of bone. I possess one, however, which is made of wood, beautifully polished, and adorned with a large blue stone, something like a turquoise, set almost in its middle. One of the most curious points in the formation of the Esquimaux weapon is, that the but is grooved and channelled so as to admit the fingers and thumb of the right hand. The average length of this instrument is twenty inches.
