Miscellanea.
By slow degrees, mankind, as they advance in civilisation, have robbed warfare of many horrors. Non-combatants, for example, are now left unharmed. Poisoned weapons have, by common consent, been abolished, and so have those instruments of warfare which, though they do not simply poison the blood by means of bodily wounds, do so by means of noxious vapours poured into the lungs.
It is sometimes rather unfortunate when civilisation and semi-barbarism meet in battle; the former respecting the customs of honourable warfare, and the latter ignoring them. For example, in olden times, one of the most potent weapons in naval combat was the “stink-pot”—i.e. a vessel filled with sulphur and other ingredients, and emitting a smoke which was death when inhaled. Among the American Indians the well-known Chili-plant was much used for this purpose, the very first breath that was taken of the thin and almost invisible smoke causing the throat to contract as if clutched by a strong hand. If then any enemies had taken refuge in a cave, or were suspected of having done so, a fire was lighted at the entrance, a quantity of chilis thrown on it, and the rest left to time. No being could endure that smoke and live, and they must either stay in the cave and die, or come out and deliver themselves up to their foes. The former was the better part to take, as suffocation, however slow, is only an affair of a few minutes, while death by torture is prolonged through hours.
In the late Chinese war the stink-pot was extensively used, and our sailors took it in very bad part that the enemy should be allowed to employ such weapons, and they should be debarred from using them.
Whether this principle is still retained in the defence of fortresses I do not know. I recollect, however, some twenty years ago, going over a fortress in which suffocation was employed as a means of defence. A long gallery was so placed that the assailants were tolerably sure to force their way into it, thinking that it led to the interior of the fort.
It was, however, nothing but a trap, for it had no exit. As soon as a number of the assailants had poured into this trap, their exit was suddenly cut off by machinery provided for the purpose, and at the same time a quantity of sulphur and lighted charcoal was shot into the gallery from above, and the aperture instantly closed. It would be absolutely impossible that any one who had been enclosed in that terrible chamber should escape with life, for the first breath of that deadly vapour would render the strongest man insensible.
Nature, as usual, has anticipated Art even in this particular.
In several parts of England, and especially along the shores of the Thames towards Gravesend, a little beetle is to be found under the flat stones of the river bank. Its scientific name is Brachinus crepitans. When this insect is alarmed, it has the power of ejecting a peculiar liquid, which, when it comes in contact with the atmosphere, bursts into a sort of pale blue-green flame, followed by a kind of smoke. Sometimes, when a tolerably large stone is lifted, the little explosions will go popping about in a most curious manner. Indeed, they carry reminiscences of school days, when it was a joy to distribute single grains of coarse gunpowder on the bars of the grate, and watch them melt, take fire, explode, and send forth little clouds of smoke. The insect is popularly called the Bombardier-beetle. Whether or not this capability be given as a means of defence I cannot say, but it assuredly answers that purpose.
There are several of the voracious Carabidæ, or Ground-beetles, which would be very glad to make a meal of the Brachinus. When, however, the Bombardier-beetle finds itself on the point of being overtaken, it elevates the abdomen with a peculiar gesture, and ejects the liquid. The effect on the pursuer is remarkable. It seems overwhelmed and stupefied by the sudden attack, moves about for awhile as if blinded, and, by the time that it has recovered its sense, the Bombardier-beetle is out of sight.
In some of the hotter parts of the world there are several species of Bombardier-beetles which attain considerable size, and their discharge is powerful enough to discolour the skin of the human hand.
I have felt some little difficulty in classifying the curious invention which will now be described, but, as it is used for the purpose of making bullets, I have placed it in the category of War.
In the days of “Brown Bess,” as the old musket used to be called, precision of aim was not required, for no commander dreamt of opening fire until the enemy were at comparatively close quarters. In those days the bullets were spherical, and cast in moulds. After a time, when the Enfield rifle displaced the musket, and did double the execution at three times its range, bullets were still cast, though their shape was altered, and they took a sugar-loaf form instead of being spherical.
The rifle-testing machine at Woolwich, however, soon showed that at long ranges a cast bullet was nearly useless, one part being always lighter than another, and air-bubbles often taking the place of lead. After being cast, therefore, the bullets were placed in a “swedge,” or “swage,” i.e. a machine by which the lead was forcibly compressed until it was of a tolerably uniform density. Even this process, however, did not insure absolute exactness, and then a machine was invented by means of which the process of casting was superseded, and the bullets were pinched or squeezed, so to speak, out of cold lead.
On the right hand of the illustration is a plan of the ingenious apparatus by which the lead is supplied to the machine which actually forms the bullets. The sketch is not meant as a drawing of the actual machine, but is merely intended to show the principle.
The chief parts in this machine are a hollow cylinder, a piston, and a delivery tube. The cylinder is shown at A, and when used, is filled with melted lead. The piston, B, is then forced upwards by hydraulic pressure, driving the lead through the delivery tube. As it issues into the air it hardens, and thus forms a solid rod of lead, C. This rod is then passed into the next machine, where it is cut into regular lengths, and these pieces are then placed in moulds, and forced into form by enormous pressure. Were it not for this ingenious machinery, the wonderful scores which are now made at long distances would be impossible.
Now let us compare Art with Nature, as seen on the left hand of the illustration, which is a chart or plan of the spinning apparatus of the Silkworm.
When I first saw the bullet-making machine at work, I at once perceived that it was nothing more than a repetition in metal of the beautiful mechanism which I had so often admired in this insect. In order to show the close analogies of the two objects, I have marked them with similar letters.
A represents the upper part of the reservoir or vessel which contains the silk in a liquid state, B B are the muscles which contract the reservoir and force the liquid matter out. It will be seen that both these vessels terminate in a delivery tube, identical in office with that of the bullet-making machine. As soon as the liquid silk passes into the air it is hardened, and is formed into a silken rod, C, just as is the lead in the machine. The only difference between the two, if it can be called a difference, is, that in the silkworm the rod is double, whereas in the machine it is single. The principle, however, is identical in both cases. The webs of spiders, and the threads by which so many caterpillars suspend themselves, and with which they make their nests, are all formed on the same design, namely, a reservoir containing a liquid which is squeezed through a tube, and hardens when it comes in contact with the air.
ARCHITECTURE.
CHAPTER I.
THE HUT, TROPIC AND POLAR.—PILLARS AND FLOORING.—TUNNEL ENTRANCE OF THE IGLOO.—DOORS AND HINGES.—SELF-CLOSING TRAP-DOORS.
Primitive Architecture evidently borrowed from the Lower Animals.—Roof Hut of the Nshiego Mbouvé of Western Africa.—Platform Hut of the Orang-outan of Borneo.—Lake Dwellers and their Huts.—Tree-huts of Southern Africa, and their Uses.—Ascendancy of the Wild Beast over Man.—Snow-hut of the Seal copied by Esquimaux, and its Value shown.—Pillars and Flooring.—Crypt and Cathedral.—The Cuttle “Bone” and its many-pillared Structure.—The Wasp-nest, its Pillars and Floors.—Tunnel Entrances to Igloo.—Sudden Formation of Snow.—Nest of the Fairy Martin.—The Sand-wasp and its Mode of Building.—Doors and Hinges.—Eggs of the Gnat and Rotifer.—Cocoons of Ichneumon-flies.—Habitations of Microgaster.—Trap-doors in Nature and Art.—Habitation of the Trap-door Spider.—A Nest upon a Pillar.