Nature's Teachings

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did not insure absolute exactness, and then a machine was invented by means of which the process of casting was superseded, and the bullets were pinched or squeezed, so to speak, out of cold lead.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.

The Hut

THERE can be little doubt that mankind has borrowed from the lower animals the first idea of a dwelling, and it is equally true, as we shall presently see, that not only primitive ideas of Architecture are to be found in Nature, but that many, if not all, modern refinements have been anticipated.

To begin at the beginning. The first idea of a habitation is evidently a mere shelter or roof that will keep off rain from the inhabitant. When Mr. Bowdich was travelling in Western Africa, he was told that the Njina—another name for the Gorilla—made huts for itself from branches, the natives also saying that it defended these huts with extemporised spears. A more truthful account is given of the Mpongwe and Shekiani, namely, that the animal builds a hut, but lives on the roof, and not under it.

Although this information has since proved to be false, there was a foundation of truth in it, for there really is an ape in that part of Africa which makes huts, or rather roofs, for itself. This animal is the Nshiego Mbouvé (Troglodytes calvus).

This remarkable ape has a curious way of constructing a habitation. Choosing a horizontal branch at some distance from the ground for its resting-place, the animal erects above it a roof composed of fresh branches, each laid over the other in such a way that rain would shoot off them as it does from a thatched roof. M. du Chaillu gives the following account of this habitation:—

“As we were not in haste, I bade my men cut down the trees which contained the nests of these apes. I found them made precisely as I have before described, and as I have always found them, of long branches and leaves laid one over the other very carefully and thickly, so as to render the structure capable of shedding water.

“The branches were fastened to the tree in the middle of the structure by means of wild vines and creepers, which are so abundant in these parts. The projecting limb on which the ape perched was about four feet long.

“There remains no doubt that these nests are made by the animal to protect it from the nightly rains. When the leaves begin to dry to that degree that the structure no longer sheds water, the owner builds a new shelter, and this happens generally once in ten or fifteen days. At this rate the Nshiego mbouvé is an animal of no little industry.”

The roof which this ape builds is from six to eight feet in diameter, and is tolerably circular, so that it looks something like a large umbrella. When the animal is at rest it sits on the branch with one arm thrown round the stem of the tree, in order to support itself during sleep. In consequence of this attitude the hair is rubbed away on one side, thus earning for the ape the specific title of calvus, or bald.

It is rather remarkable that the Orang-outan of Borneo is likewise a house-builder, though not in the same manner as the African ape which has just been mentioned. This animal has a way of weaving together the branches of trees, so as to make a platform on which it can repose, its enormously powerful arms being of great service in this task. The animal seems to make its platform in quite a mechanical manner, and it has been noticed that when an Orang-outan has been mortally wounded, it has expended its last energies in twisting the branches together so as to form a couch on which it can lie down and die.

Putting aside those cases where huts have been erected in trees by way of amusement, we may find instances where human beings have been forced to make their habitations in trees.

In some places, such as certain parts of South America, the natives are forced to make their houses in trees, partly on account of the climate, and partly for the purpose of avoiding the mosquitoes.

The delta of the Orinoco River is nearly half as large as England, and for a considerable part of the year is deep in water. Yet this tract is inhabited by the Warau tribe, who find in it their only mode of escape from the tiny but terrible mosquito. We in England know but little of the miseries inflicted by these insects, which are so plentiful in some parts of America that they are gathered in bags, pressed into thick cakes about as large as ordinary dinner-plates, and an inch in thickness, and then cooked and eaten.

Now it is found that although the mosquito infests the banks of rivers, it cannot venture far from land. The Waraus, therefore, make for themselves habitations which are far enough from land to baffle the mosquitoes, and near enough to be easily reached in canoes.

Fortunately for them, there is a tree called the Ita Palm, belonging to the genus Mauritia, which loves moisture, and grows abundantly in this delta. The Waraus, therefore, make their habitations in these trees, connecting several of them together with cross-beams, and laying planks upon them so as to form the flooring of their simple huts. Here they maintain themselves chiefly by fishing, but are sometimes obliged to visit the mainland, in spite of the mosquitoes. When, however, they return, they halt at some distance from the shore, and with green boughs carefully beat out every mosquito from the canoe before they dare to approach their dwellings.

The once-celebrated Lake Dwellers of Switzerland evidently lived after a similar fashion.

In this case insects drive human beings into trees, but there are instances where nobler animals have produced the same effect.

Some years ago there lived in Southern Africa a powerful chief called Moselekatze, who spent his whole life in warfare, converting all the male inhabitants into soldiers, dividing them into regiments, ruling them with the extreme of discipline, and by their aid devastating the neighbouring countries. He swept off all the cattle, which constitutes the wealth of the Kafir tribes, and either killed the male inhabitants or pressed them into his service.

The land was in consequence deprived of its natural defenders, and the wild beasts, especially the lions, increased rapidly, so that the position of the survivors was a really terrible one. They had no cattle to furnish the milk which is the chief food of the Kafir tribes; their weapons had been taken by Moselekatze; and they were forced to live almost entirely on locusts and wild plants. By degrees the lions became so numerous and daring, that the slight Kafir huts were an insufficient protection during the night, and the disarmed and half-starved inhabitants were perforce obliged to make their habitations in trees.

Dr. Moffat, the well-known missionary, saw one tree in which there were no less than twenty huts. They were conical, and made of sticks and grass, the base resting upon a platform or scaffold laid upon the fork of a horizontal branch. The only mode of approach to these huts was by notches cut in the trunk of the tree.

How needful were these precautions was shown by the fact that the missionary himself spent a night in one of these aërial huts, and had the pleasure of hearing a number of lions snarl and growl all night over a rhinoceros hump which he had placed in an oven made of a deserted ant-hill. The oven, however, was too hot for the lions, and they had to retreat at daylight.

Passing from the tropics to the polar regions, we now take an instance where man has acknowledgedly copied an animal in the construction of his dwelling.

In Esquimaux-land, where no trees can grow, where for months together the sun never rises above the horizon, where the temperature is many degrees below zero, and where the land and ice are alike covered with a mantle of snow so thick that every landmark is abolished, it would seem that no human beings could support life for one week. There is neither timber for house-building nor wood for fuel, so that shelter, warmth, and cookery seem to be equally impossible, and as these are among the prime necessities of human life, it is not easy to see how mankind could exist.

Yet these very regions are inhabited by sundry animals, and it is by copying them that Man can keep his place. We have already seen how the Esquimaux hunter copies the Polar Bear, and we have now to see how he copies the Seal in the material and form of his dwelling-house, and not only contrives to live, but to enjoy life all the more for the singular conditions in which he is placed. Captain Hall mentions, in his “Life with the Esquimaux,” that one of the natives, named Kudlago, who was returning to his native country after visiting the United States, died while on board the ship. Towards the end of his life he was yearning for ice, and his last intelligible words were, “Do you see ice? Do you see ice?”

On the vast plains of ice that are formed in the winter-time the snow lies thickly, and yet upon such an inhospitable spot the mother seal has to make a home for her tender young. This she does in the following manner:—

She has already preserved a “breathing hole” in the ice, through which she can inhale air. How she finds so small a hole under the surface of the ice, where there are no landmarks to guide her, is a marvel to every swimmer. She has to chase fish and follow them in all their winding courses, and yet, when she is in want of air, is able to go straight to her breathing hole, and there take in a fresh supply of oxygen.

When she is about to become a mother, she enlarges this breathing hole so as to make it into a perpendicular tunnel. She then, with the sharp nails of her fore-paws, or flippers, scoops away the snow in a dome-like form, as shown in the illustration, taking the snow down with her through the ice, and allowing it to be carried away by the water. By degrees she makes a tolerably large excavation of a hemispherical shape, and when her young is born she deposits it on the ice-ledge around the tunnel. From ordinary foes the young Seal is safe, and nothing can discover the position of the house unless guided by the sense of smell.

How the Polar Bear and the Esquimaux hunter discover the dwelling and capture the inmates we have already described in the chapter treating of War and Hunting. Our present business is with the dwelling itself. Comparatively few of these snow-houses, or igloos, as they are called, are discovered, and they remain intact until the summer sun melts the roof and exposes the habitation. By this time, however, the young Seal has grown sufficiently to shift for itself, and no longer needs the shelter of a dwelling.

The winter hut, or igloo, of the Esquimaux is made of exactly the same shape and of similar materials to the dwelling of the Seal, the chief difference being that it is built instead of excavated.

In order to save time, the igloo is generally erected by two men, one of whom supplies the material, and the other acts as bricklayer and architect in one. Each begins by tracing a suitably sized circle in the snow, which he clears away to some depth, so as to preserve a firm surface, either as a floor or as the material for the wall. In this work both men are equally valuable, for the skill required to cut the slabs of snow into such a shape that they can be formed into a hemispherical dome is quite as much as that which is needed for putting them together. I will call them the cutter and the builder. Sometimes a young hand is employed by way of labourer, and passes the snow slabs to the builder as fast as they are cut.

The builder receives the slabs, and arranges them in regular order, always taking care to “break the joints,” just as do our bricklayers of the present day. Always remaining within the circle, he gradually builds himself in, and when he has quite finished the house, he cuts a hole through the side, emerges, and, by the help of his partner, puts on the finishing touches. He usually also adds a sort of tunnel to the door, through which any one must creep on his hands and knees if he wishes to enter the igloo. This part of Esquimaux architecture will presently be noticed more in full.

Perhaps the reader may wish to know what provision there is for ventilation. The answer is simple enough. There is none, the Esquimaux not requiring ventilation any more than they require washing. The two, indeed, generally go together; and it may be observed, even in our own country, that those who object to fresh air, and are always complaining of draughts, have a very practical aversion to the use of fresh water, and but little confidence in what Thackeray calls the “flimsy artifices of the bath.”

The Esquimaux never washes, and knows not the use of linen. Consequently, it is no matter of surprise that a sailor of Captain Hall’s crew could not make up his mind to enter an igloo. “Whew!” exclaimed the man, “by thunder, I’m not going in there! It’s crowded, and smells horribly. How it looms up!”

Considering that there were inside that igloo a dozen Esquimaux, all feasting on a raw, newly killed, and yet warm seal, the sailor had reason enough to decline a visit. Captain Hall, however, determined, in his character of explorer, to brave the strange odours, and moreover to join the inmates in their feast, knowing that as he would have to live among the Esquimaux for some two years, he would be forced to live as they did, and might as well begin at once. Consequently on this resolve, he drank the still steaming blood, and quaffed it from a cup which an Esquimaux woman had just licked clean.

Floors and Pillars

One decided step in Architecture is the invention of the Pillar, and its capabilities of aiding to sustain another floor above it. We see this principle carried out in our great cathedrals, where the use of the Pillar is almost infinite. Take, for example, Canterbury Cathedral. A heedless visitor might easily pass through the nave, enter the choir, visit the various side-chapels, and “Becket’s Crown,” without thinking that under his feet is a vast chamber, and that the floor on which he stands is, in fact, the roof of a great crypt.

The weight of the Cathedral, with its lofty towers, is so tremendous, that the building could not be erected simply upon the ground, but rests upon a complicated substratum of pillars and arches, whereby the weight is spread over a large surface. In fact, the Cathedral is really two buildings, the one erected upon the other.

In Nature there are many instances of pillars supporting different floors. One of the most beautiful examples is to be seen in the common Cuttle-bone, as it is called, this being the internal skeleton, if it may be so termed, of the common Sepia (Sepia officinalis), which is so often found on our coasts, especially after a gale. This year (1875) I found eight of these Cuttle-bones on the Margate sands, and all within a space of some twelve feet square.

This so-called bone is really composed of the purest chalk, for which reason it is in great request as a dentifrice, being easily scraped to almost impalpable powder when wanted, and not liable to be spilled, as is the case with any ordinary tooth-powder.

It is exceedingly light—so light, indeed, that it floats like a cork, even in fresh water. Now, as chalk is very much heavier than water, we may naturally ask ourselves how this lightness is obtained. If the upper surface be examined, it will be seen to be traversed by a vast number of wavy lines, something like the markings of “watered” silk. These show the lines of demarcation between the multitudinous rows of pillars of which the whole structure is formed.

If the “bone” be sharply snapped in the middle, and the particles of white dust blown away, a wonderful structure presents itself, which can be partially discerned by the naked eye, though a microscope is required to bring out its full beauties.

Even with an ordinary pocket lens we can make out some of its wonders. The object looks like a vast collection of basaltic columns, except that the pillars are white instead of black, and they are arranged in rows with the most perfect accuracy, just as if the place of each had been laid down with rule and compass. They are scarcely thicker than ordinary hairs, but they are beautifully perfect, and rise in tier after tier as if they were parts of a many-storied building. As a definite space exists between the pillars, the reader will understand why the whole structure should be so much lighter than water. In order, however, to see these wonderful pillars in perfection, a very thin section should be taken, and viewed with polarised light.

Another excellent example of Pillars and Flooring is to be found in the nests of various Wasps, including that of the Hornet.

In these nests the combs are arranged horizontally, and not vertically, like those of the bees, and in consequence they have to be supported in some way. This object is achieved by means of multitudinous pillars made of the same papier-mâché of which the combs are formed, and attached to the successive rows of combs. There is, however, one curious point of difference between the Wasp-comb and human architecture, namely, that the pillars do not support floors, or rest upon them, but sustain the weight of those which hang from them. The mouths of the cells are all downwards, and the combs are therefore suspended from the pillars, instead of being supported by them.

Tunnel Entrance to the Dwelling

We have already found occasion to treat of the snow-house, or igloo, of the Esquimaux, and have now to speak of a subsidiary, though necessary, part of Esquimaux architecture.

Perhaps the reader may have been unfortunate enough to travel by rail in the depth of winter, and to be associated with fellow-passengers who will insist on closing every window, even though the carriage be crowded. Suppose that on such a day, the weather being perfectly fine, the train stops at a station, and the guard outside opens the door to see if another passenger can be accommodated with a place.

No sooner is the door opened than a shower of snow at once fills the carriage. This is simply the moisture suspended in the air and generated by human lungs. The rush of cold air at once freezes this moisture and converts it into snow, thus showing those who will condescend to learn, that they have been breathing and re-breathing the air that has passed through a variety of human lungs, and is charged with their different moistures. I have seen the same phenomenon at a dinner party, where, after the withdrawal of the ladies, one of the windows was opened.

Now, in Esquimaux-land, it is absolutely necessary to conserve every atom of heat, for the cold is so intense that if a cask of water be near a coal fire, only the part next the fire will be thawed, the rest being ice. Cold, therefore, is a foe which has to be fought and kept away from the household. Then there are other foes—such as Polar Bears, for instance—which would be only too glad to get into an igloo and make a meal of its inhabitants. The Esquimaux architect, therefore, avails himself of an ingenious device by which he can set both foes at defiance.