the volcano is nothing more than a local fire, as much in connection with the earth’s surface as the furnace fire built in a man’s basement to warm his house, or in his stove to cook his breakfast. when the fuel that is used in either one is consumed, the fire goes out, which is a common result in both cases. of all the volcanoes known to have existed as evidenced by their craters, fully three-fourths have become extinct.
now what causes the volcano? the earth is filled with immense supplies of fuel, consisting in stores of coal, sulphur, oil, gas, limestone, etc. while it is claimed that at the imaginary axis of the earth there can be no friction, yet when the surface is approached with all its weight of mountains and continents, here friction begins to put in its work. it is very doubtful if any volcano exists, or ever has existed whose fires[41] go to the depth of 500 miles, and more likely not half that distance.
on the outside of this circle, of 25,000 miles it is only reasonable to expect an enormous strain. the abrasion of limestone found in huge masses will, by process of heat, convert them into lime. the contact with water, universal throughout the earth, will start the volcano, which by slaking, this small amount of rock converted into lime will generate a heat that may ignite and produce more lime, or reach other combustibles, which may be set on fire by this; or when in contact with other substances, this would lead to reservoirs of oil and gas, and deposits of coal and sulphur. these when ignited may remain in a slight slumbering condition and burn for ages, but water will be the constant aggressor and from time to time will manifest itself by coming in contact with these burning forces thus producing the volcanic eruptions and in time will be the conqueror, and the crater of the volcano will become a lake, of which evidences exist all over the earth. that volcanoes are only local, the same as fires in our houses, is fully evident from the fact that they burn, and go out. this theory of producing volcanic eruptions can be easily demonstrated in every kitchen or casting shop in the country.[42] kettles of hot fat or melted metals when brought in contact with water will cause a miniature eruption at short notice. it is common to speak of volcanoes emitting smoke, but it is rare that such cases are ever a fact, but instead of smoke, we should say steam. the result of friction to produce effects, we claim, is well illustrated in shipments of cotton. cotton shipped from india in the vessel’s hold, rarely, if ever, takes fire. from this country it is no unusual thing, and why? in india they bind the bales with jute or hemp, while in this country with straps of iron. in the ship’s hold, there is, of course, a constant motion and rubbing together of great weight of bales which ofttimes generates the fire in the cargo. this is the way the volcano is started, but sooner or later, water will put it out. all volcanic eruptions are credited with throwing out great volumes of water, steam, mud, ashes, stones, lava and sulphur. during earthquake convulsions which generally precede volcanic eruptions, the world over there is a bursting out of fresh springs as well as an increase in the present existing flows.
what are volcanoes for?
if they are, as is claimed by some, for vents to the interior molten condition, why do they become[43] extinct, so many of them, and almost invariably become lakes inside their craters?
with the whole center of the earth a molten mass, there ought to be fire enough to keep them going incessantly. where does the water come from to keep up a constant outpour of steam and vapor in locations where it seldom rains?
it would seem as if the small amount of rain or snow that fell would get pretty well dried out before it arrived at a point to create an eruption by contact with melted rock, or that such a quantity could keep up steam in such an immense cauldron. there is no reason to presume that a drop of rain water ever enters a volcanic crater, except what may fall into its open mouth, which will be impossible.
have volcanoes any specific use in earth economics? do they tend to open up water courses from the interior and by their upheavals on the continents and islands of the earth create natural elevated reservoirs from which the lower regions of earth can be irrigated? do they not send out certain gases to mingle in the atmosphere, producing favorable results in vegetation and animal life? are not the vicinities of volcanoes noted for the fine fruits and wines in latitudes in which they grow?
