But these people are all of them almost entirely naked; and they are dripping with perspiration, they are so warm. Outside of the hut, in the dim starlight, the air is actually a hundred degrees colder than freezing water. Yet inside, in the nearly as dim lamp light, there are almost as many degrees of warmth. The air is there as hot as the hottest summer day in England! All this heat is produced in the slow furnaces of those twelve individuals’ own living bodies. They have lost the sunshine for months, and everything around them is much colder than ice. They are living upon the flesh and blubber of seals, and sea-horses and white bears, animals which they killed before the sun went away, the meat being kept for them through their long winter by the preserving power of the frost. The sunshine of past away summers has given its heat to plants; the seals and sea-horses have fed on those plants, or upon smaller animals which have done so, and have transferred the heat into their own blubber; and now the benighted savages are getting the heat out of the blubber to keep their own flesh and blood warm and unfrozen. In that close hut, where no sunshine can come for months, the savage inmates have nevertheless abundant stores of the warmth of sunshine, which have been laid up and preserved for their service. Such care Providence takes even of these, the rude and barbarous children, whose lot he has cast in the desolate outskirts of the world!
The rude people who dwell in the cold frost-land of the north, remain warm through their long, severe winter, without the aid of artificial fires, because they economize the warmth which is produced in the slow furnaces of their bodies, and prevent it from being scattered away as quickly as it is generated. If they were to set themselves down in the open air, instead of in their close huts, the warmth produced in their bodies would be thrown off from the outer surfaces of these as fast as it was set free from the fuel. In the close huts, on the other hand, this warmth first heats the air contained within the stone walls, and is then a very long time in getting any further, and so prevents more heat from being rapidly scattered from the internal furnace.
These human inhabitants of the northern ice land have a companion in their desolate haunts, who does not build himself a hut after their fashion, but who has instead a somewhat similar protection against the severe cold of the long northern winter, provided by nature. This creature goes upon four legs, sometimes swimming in the water, and sometimes stalking along upon the ice. He is very powerful and fierce, is armed with sharp claws two inches long, and has teeth which can bite through thick and hard metal. He is able to tear iron and tin to pieces as if they were merely paper or pasteboard, and he feeds upon seals, birds, foxes and deer, which he manages to catch by his cunning and address. This savage creature is often killed by the rude natives, who hunt him with dogs and spears, but in the absence of man he is the fell tyrant of the domain. He prowls about on the snow-wastes, destroying every living body which comes within his reach; and he remains exposed to the severest cold of the long dark winter, lying upon the ice and snow, without having his life-blood frozen by its chill power. The reason of his safety is that he wears a nature-provided great coat of very warm fur. His skin is every where covered by long shaggy hair of a yellowish-white color, which has a thick down-like under-growth closely packed beneath. This coat of soft fur is so long and thick, that it prevents the heat produced in the slow furnace of his body from escaping into the cold air. It answers the same purpose to him, that the snow-covered hut does to his human neighbors.
Men have no warm shaggy coats of this kind furnished for their use by nature, but they are enabled to supply the deficiency through the exertion of their own intelligence and ingenuity. They borrow warm covering from other creatures whenever they stand in need of such aid. Thus the rude human inhabitant of the ice land hunts and kills the bear and then before he feasts upon its flesh, he strips the fur robe from the carcass, and adapts it to his own naked body. So soon as the northern ice-people come out from their huts into the cold air, they put on coats and trousers of bear-skin, with the long sharp claws pointing out as toes to their boots. These odd savages look almost like small bears themselves when their white fur hoods are drawn over their heads, and their limbs are compactly muffled up in the claw-tipped robes which they have taken from the bodies of their prey.
Men in civilized lands do not put the skins of other animals upon their own bodies, but they do what is precisely the same thing in effect. They borrow silk from the worm, or cotton from the grass, or flax from the linen-plant, or wool from the sheep, and by their constructive skill, they spin and weave these substances into cloths, which are much more convenient than raw skins for the fabrication of garments, and which can be made as warm, when this is required. In every case, however, this artificial clothing acts in the same way as natural fur. It is warm, because it prevents the heat, which is produced in the slow furnace within the body from escaping quickly from the little chambers of the living laboratory. Clothing does not really warm the body, it merely keeps it warm; prevents it from being cooled as it would be if this covering were not placed between its surface and the outer air.
Warm bodies constantly grow colder, when situated in spaces which are more chill than themselves, provided always that there be no furnaces, quick or slow, within them, for generating new supplies of heat. They do so, because they give the excess of heat which they contain to the neighboring space, in the attempt to make it as warm as themselves. Warm bodies are always very generous, and disinclined to keep what substances near to them are less freely supplied with. If a metallic pint pot, filled with boiling water, be placed on the ground in air which has only the warmth of a March English day—some fifty degrees of the heat scale,—the water gets colder minute by minute until it remains no warmer than the air and ground which are around it. The rapidity with which warm bodies are cooled depends upon how much colder than themselves the space around them is. If one pint pot of boiling water be placed in out-of-door air that is cold as freezing water, and another be placed at the same time in a room where the air has the warmth of a mild summer day, the former will be deprived of all its excess of heat much sooner than the latter.
Warm bodies lose their excess of heat in two ways. They shoot it off into surrounding space. This is what learned men call “raying” or “radiating” it away. The sun, you know, shoots or rays its heat off to the earth, and so does the fire to your body when you stand before it. But warm bodies also communicate their heat to substances which touch them, provided those substances be colder than themselves. Place your hand upon a cold metal knob, and you will feel that your hand grows colder as it gives portions of its heat to the knob. This is what learned men call “conveying” heat.
[To be concluded.]
