Читать книгу Nature's Teachings - John George Wood - Страница 9

Propulsive Power.—The Pea-shooter and its Powers.—An Attack repulsed.—Clay Bullets.—Puff and Dart.—The Sumpitan of Borneo, and its Arrows.—The Zarabatana or Pucunha of South America, and its Arrows.—The Air-gun.—Modern Firearms.—The Chœtodon, or Archer-fish.—The Pneumatic Railway.—The Throwing-stick and its Powers.—Australians, Esquimaux, and New Caledonians.—Principle of the Sheath.—Waganda Spears.—Sheathed Piercing Apparatus of the Gnat, Flea, and Bombylius.—Indian Tulwar and Cat’s Claw.—The Surgeon’s Lancet, and Piercing Apparatus of the Gad-fly and Mosquito.

WE will now take some of the analogies between Projectile Weapons of Art and Nature, selecting those in which the propulsive power is air or gases within a tube. Whether the weapon be a blow-gun, an air-gun, or a firearm of any description, the principle is the same. We will take them in succession, choosing first those of the simplest and most primitive character.

Taking ourselves as examples, and looking upon the toys of children as precursors of more important inventions, we find that the simplest and most primitive of projectiles is the Pea-shooter, so familiar to all boys.

Insignificant as is the little tin tube, and small as are the missiles which are propelled through it, the blow which can be struck by a pea properly shot is no trifle. At college I have seen a night attack upon an undergraduate’s rooms successfully repelled by a pea-shooter made for the nonce of a glass tube, the owner of the rooms having a taste for chemicals, and possessing a fair stock of the usual apparatus. Though the assaulted rooms were on the top set, and the assailants began their storming approaches below, the peas were too much for the stones, taking stinging effect on the hands and faces, and preventing any good aim being taken at the windows. Only two panes of glass were broken through a siege that lasted for several hours.

There is another toy which is a development of the pea-shooter, and carries a small clay bullet instead of a pea. When the tube is quite straight and the balls fit well, the force of this missile is very great, as it can be used for killing small birds. Indeed, such an instrument is largely employed by the native hunters in procuring humming-birds for the European market. These weapons are generally lined with metal in this country, but a simple bamboo tube is sufficient for the native hunters.

A still further improvement occurs where the place of the bullet is taken by a small dart or arrow, which is usually made to fit the bore by having a tuft of wool, or some similar substance, at the butt. The arrow is aimed at a target, and the toy is popularly known as “Puff and Dart.”

With us this apparatus is only a toy, but in several parts of the world it becomes a deadly weapon, namely, in Borneo and over a large part of tropical America. In both cases the arrows are poisoned, as has already been mentioned when treating of poisoned weapons.

The first and best known of these weapons is the dreaded Sumpitan, or Blow-gun, of Borneo, the arrows of which are poisoned with the deadly juice of the upas-tree. Here I may as well mention that the scientific name of the upas-tree is Antiaris toxicaria. It belongs to a large group of plants, all of which have an abundance of milk-like and sometimes poisonous juice. We are most of us familiar with the old story of the upas-tree and its deadly power, and how the tree stood in a valley, in which nothing else could live, and that condemned criminals might compound for their inevitable fate by venturing into the valley of death and bringing back a flask of the dread poison. Even birds were supposed to be unable to fly over the valley, but to fall into it, being poisoned by the exhalations of the tree.

Now, there is a saying that there is no smoke without fire, and though this account is evidently incredible, it is not altogether without foundation. In Java, as in many other parts of the world, there are low-lying places where carbonic acid gas exudes from the earth, and no living creature can exist in them. Even in this country scarcely a year passes without several deaths occurring from inhalation of the same fatal gas, which has collected in some disused excavation. That there is, therefore, a deadly valley in Java may be true enough, and it is also true that the juice of the upas-tree is poisonous when it mixes with the blood. But the two have no connection with each other, and, so far from the upas-tree poisoning the valley by its exhalations, it could not exist in such an atmosphere.

Now for the Sumpitan and the arrows. The former is a tube, some seven feet in length, with a bore of about half an inch in diameter, and often elaborately inlaid with metal. I have one in which the whole of the mouthpiece is brass, and the other end of the weapon has been fitted with a large spear-head, exactly on the principle of the bayonet.

The arrows are very slight, and, in order to make them fit the tube, are furnished at their bases with a conical piece of soft wood. In themselves they would be almost useless as weapons, but when the poison with which their points are armed is fresh, these tiny arrows, of which sixty or seventy are but an ordinary handful, carry death in their points. Though they have no great range, they are projected with much force, and with such rapidity that they cannot be avoided, their slender shafts being almost invisible as they pass through the air.

The second weapon is the still more dangerous blow-gun of tropical America, called Zarabatana, or Pucunha, according to the locality. Some of these tubes measure more than eleven feet in length, and through them the arrow can be propelled with wonderful force. I have often sent an arrow to a distance of a hundred yards, and with a good aim.

A native, however, can send it much farther, knack, and not mere capacity of lung, supplying the propelling power, just as it is with the pea-shooter. When the arrow is properly blown through the zarabatana a sharp “pop” ought to be heard, like the sound produced by a finger forced into a thimble and quickly withdrawn, or a cork drawn from a bottle.

As to seeing the diminutive arrow in its flight, it is out of the question, and no agility can be of the least use in avoiding it. One of my friends, a peculiarly sharp-sighted officer of artillery, has often tested this point, and although there was but one arrow to watch, and it was blown in the open air, he could not see it until it either struck or passed him (of course the poisoned end was cut off). What, then, would be the result of a number of these deadly missiles hurled out of a dense bush may easily be imagined.

An account of the poison with which these arrows are armed will be found on p. 64.

The reader will please to remember that in all these cases the missile is propelled by air which is compressed by the aid of the lungs, and forced into the tube behind the bullet or arrow. Now, the Air-gun, which really can be made a formidable weapon, is constructed on exactly the same principle as the pea-shooter and the blow-guns, except that the air is compressed by the human arm instead of the human lungs. There are various modifications of this weapon, but in all of them air is driven into a strong chamber by means of a forcing syringe, and is released by the pull of the trigger, so as to drive out the missile which has been placed in the barrel.

It is worthy of notice that the term “noiselessly destructive” weapon, as applied to the air-gun, is entirely false. I have already mentioned that with the blow-gun of tropical America a definite explosion accompanies the flight of each arrow. The same result occurs with the air-gun, the loudness of the report being in exact proportion to the force of the air, each successive report becoming slighter and the propulsive power weaker until a new supply of air is forced into the chamber.

However dissimilar in appearance may be the cannon, rifle, pistol, or any other firearm, to the pea-shooter and its kin, the principle is exactly the same in all. It has been already mentioned that in the blow-guns the air is compressed by the exertion of human lungs, and in the air-gun the compression is achieved by human hands.

But with the firearm a vast volume of expansible gas is kept locked up in the form of gunpowder, gun-cotton, fulminating silver, or other explosive compound, and is let loose, when wanted, by the aid of fire.

In the illustration are represented on the right hand the blow-guns of America and Borneo, and below them is the cannon as at present made. On the left hand of the same illustration is seen a representation of a natural gun which has existed for thousands of years before gunpowder was invented, and very long before the savage of Borneo or America discovered the blow-gun.

It is the Archer-fish (Chœtodon), which possesses the curious power of feeding itself by shooting drops of water at flies, and very seldom failing to secure its prey.

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.

In New Caledonia the natives use a contrivance for increasing the power of the spear, which is based on exactly identical principles, though the mode of carrying them out is different. A thong or cord of some eighteen inches in length is kept in the right hand, one end being looped over the forefinger, and the other, which is terminated by a button, being twisted round the shaft of the spear. When the weapon is thrown, the additional leverage gives it great power; and it is a noteworthy fact that the sling-spear of New Caledonia has enabled us to understand the otherwise unintelligible “amentum” of the ancient classic writers.

Passing from Art to Nature, we have in the jaw of the serpent an exact type of the peculiar leverage by which the spear is thrown. If the reader will refer to the illustration, he will see that the lower jaw of the snake, instead of being set directly on the upper jaw, is attached to an elongated bone, which gives the additional leverage which is needful in the act of swallowing prey, after the manner of serpents.

In War and in Peace we have been long accustomed to shield the edges and points of our sharp weapons with sheaths, and even the very savages have been driven to this device. I have in my collection a number of sheathed weapons from nearly all parts of the world, and it is a remarkable fact that the Fan tribe, who are themselves absolutely naked, sheathe their daggers and axes as carefully as we sheathe our swords and bayonets. In some points, indeed, they go beyond us; for the most ignorant Fan savage would never think of blunting the edge of his weapon by sheathing it in a metal scabbard. Their sheaths are beautifully made of two flat pieces of wood, just sufficiently hollowed to allow the blade to lie between them, and bound together with various substances. For example, the sheaths of one or two daggers in my possession are made of wood covered with snake-skin, while others are simply wood bound with a sort of rattan. Even the curious missile-axe which the Fan warrior uses with such power is covered with a sheath when not in actual use.

The figure on the right hand of the illustration represents the heads of two spears of Waganda warriors. When they present themselves before their king, the warriors must not appear without their weapons, and it would be contrary to all etiquette to show a bare blade except in action. The sheath can be slipped off in a moment, but there it is, and any man who dared to appear before his sovereign without his weapon, or with an unsheathed spear, would lose his life on the spot, so exact is the code of etiquette among these savages.

The sheathed spears of Nature are shown in the same illustration. On the left is a side view of the piercing apparatus of the common Gnat.

In the middle is the compound piercing apparatus of the common Flea, with which we are sometimes too well acquainted, the upper figure showing the lancets and sheaths together, and the lower exhibiting them when separated.

On the right is shown the group of mouth-lancets belonging to one of the Humble-bee flies (Bombylius). These flies do not suck blood like the Mosquito, the Flea, and the Gad-fly, but they use the long proboscis for sucking the sweet juices out of flowers, and in consequence it is nearly of the same form as if it were meant for sucking blood. Indeed, there are some insects which do not seem to care very much whether the juice which they suck is animal or vegetable.

On the right hand of the illustration is seen an Indian sword, or “Tulwar,” drawn from one of my own specimens. I have selected this example on account of the structure of the sheath. It is evident, from the form of the blade, that the sword cannot be sheathed point foremost, and that therefore some other plan must be used. In this weapon the sheath is left open on one side, the two portions being held together by the straps which are shown in the figure. Of course there is loss of time in sheathing and drawing such a sword, but the peculiar shape of the blade entails a necessity for a special scabbard.

On the other side is shown one of the fore-claws of a cat, which, as we all know, can be drawn back into its simple sheath between the toes, when it is not in use. This sheath is exactly the same in principle as that of the Indian tulwar, and any one can examine it by looking at the foot of a good-tempered cat. I have done so even with a chetah, which is not a subject that would generally be chosen for such a purpose.

On the next illustration is shown an ordinary Lancet, in which the blade is guarded between a double sheath, the two halves and the blade itself working upon a common pivot. As for the ordinary sword and dagger sheaths, it is not worth while to figure them.

Turning to the opposite side of the illustration, we shall see a few of the innumerable examples in which the principle of the sheath was carried out in Nature long before man came on the earth.

The reader should compare this figure with the side view of the Gnat’s lancets given on p. 81.

They represent the cutting and piercing instruments of several insects, all of which are very complicated, and are sheathed after the manner of the lancet. Indeed, they are popularly known as “mouth-lancets,” and with reason, as the reader may see by reference to the illustration.

On the extreme left are shown the head and closed lancets of a foreign Gad-fly, the lancets being all in their sheaths, and showing the character of the weapon which enables a small fly to be master, or rather mistress, of the forest. I say mistress, because in all these cases it is the female alone that possesses these instruments of torture.

Next it is a magnified representation of the lancets of the common Mosquito, as seen from above, both lancets being removed from their sheaths and separated.