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Geyser

A geyser is a hot spring which at regular or irregular intervals throws a column of steam and hot water into the air. Geyser water usually builds up in underground tubes formed from siliceous[?] sinter[?]. It has been proven that geyser water is primarily vadose[?] with approximately 10% of juvenile or magmatic water. Geyser action is the result of vadose water coming in contact with steam arising from solidifying magma, and periodically returning to the surface through the geyser tube. The principal geyser fields on Earth are found in Wyoming (Yellowstone National Park), New Zealand, and Iceland. The name "geyser" comes from the Icelandic Geysir, which is the name of the best known of Icelandic geysers. The word gjósa means "to gush."

The little mound, from the top of which the jet appears to rise, is composed of a substance named siliceous sinter, and is a deposit from the water of the fountain. At the top of this mound, which is between six and seven feet in height, there is an oval basin, measuring about fifty-six feet in one direction, and about forty- six in the other; its average depth is about three feet. In the centre of this basin is a round hole, about ten feet in diameter, out of which the water springs. This hole is the mouth of a circular well, between seventy and eighty feet in depth. It is down this well that the jet retires on its disappearance; and it drags along with it all the water out of the basin, leaving both basin and well quite empty, without even a puff of steam coming out of the hole. In this state of emptiness the basin and well remain for several hours. Suddenly the water begins to rise in the well, overflowing till it fills the basin. Loud explosions are heard from below, and the ground trembles. Then, with amazing violence, up springs a vast column of boiling water, surmounted by clouds of steam, which obscure the air. This first jet is followed by several others in rapid succession, to the number of sixteen or eighteen; the last jet being usually the greatest of all, and attaining a height of nearly a hundred feet. In some instances it has risen to a height of a hundred and fifty feet; and one particular jet was measured which rose to the amazing height of two hundred and twelve feet.

The action of the fountain seldom continues more than about five minutes at a time, and then a repose of several hours ensues. If left to itself, the periods of the fountain's activity, though not quite regular, generally recur at intervals of six or seven hours. But they may be hastened by throwing big stones down the well. This not only hurries the eruption of the jet, but increases its energy, and the stones are thrown out with great force by the column of boiling water; the loudness of the explosions being also considerably augmented.

There are several other geysers in the island besides this big one. Their jets are smaller, but to compensate this deficiency, they are more frequent in their ascent; so that travellers who are too impatient to await the eruptions of the Great Geyser, content themselves with visiting the little ones.

A very hot Bath

Would it not be very convenient to live near a geyser? We might have our victuals cooked by it, and have pipes led from it all round our house, to keep us comfortable in winter; and we might have nice hot baths in our dressing-rooms, arid even a little steam-engine to roast our meat and grind our coffee. But perhaps you may think it might not be altogether pleasant to be kept so continually in hot water.

Were any of the water from the geyser to fall on your hands, you would doubtless feel it rather sore; still more so, were you to be so rash as to thrust your hand fairly into the jet of boiling water, as it ascends into the air. Nevertheless, strange as it may seem, it would be possible for you, without feeling any pain or sustaining any injury, to thrust your hand right into the glowing lava as it flows from the crater of Hekla. The only precaution needful to be observed, is first to plunge the hand into cold water, and then dry it gently with a soft towel, but so as to leave it still a little moist. This discovery was made by a French philosopher, M. Boutigny, and has been practically proved both by him and M. Houdin, the celebrated conjuror, by thrusting their hands into molten iron, as it flowed from the furnace. The latter describes the sensation as like what one might imagine to be felt on putting the hand into liquid velvet. The reason why this experiment proves so harmless is that between the skin and the glowing substance there is formed a film of vapour, which acts as a complete protection. It is this elastic cushion of vapour which imparts that feeling of softness described by M. Houdin; for it is with it alone that the hand comes into contact.

Californian Geysers

Geysers have been discovered in California; but the jets do not rise higher than twenty or thirty feet. They are, however, very numerous, there being upwards of a hundred openings within a space of half a mile square. The vapour from the whole group rises to upwards of a hundred and fifty feet into the air. The boiling water issues from conical mounds, with great noise. The whole ground around them is a mere crust, and when it is penetrated the boiling water is seen underneath. The Californian geysers, however, are impregnated, not with silica, like those of Iceland, but with sulphur, of which they form large deposits. The sulphurous vapours from the water corrode the rocks near the fountains; nevertheless trees grow, without injury to their health, at a distance from them of not more than fifty feet.

Geysers on Triton

Geysers of liquid nitrogen have been observed on Neptune's moon Triton. It is not known what drives these geysers, but it is thought that solar heating plays a major role. Other bodies in the solar system may have active geysers of water, such as the moon Europa.



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