Edwin J. Houston

“ When at a safe distance the sight is certainly magnificent. There is no light from the sun. All would be in pitch darkness but for the reddish glare thrown upwards by the red hot lava, by the glowing showers of ashes that are being rained down on the sides of the mountain, or by terrific lightning flashes, due to the discharge of the immense quantities of electricity produced by the forces of the eruption. ”

“ You may possibly be ignorant of the fact that the moon always turns exactly the same face towards the earth. Not only has no man ever seen the opposite side of the moon, but he never can hope to see it while he remains on the earth. This is because the moon turns or rotates on its axis in exactly the same time that it revolves in its orbit.
When I say that the time of rotation is the same as the time of revolution of the moon, I do not mean that it is almost the same, but that it is exactly the same. ”

“ Their houses were violently shaken to and fro, and on all sides were heard the awful crashings of falling walls, chimneys, and buildings, together with the death-shrieks of those caught in the ruins. Rushing madly into the streets they could see on every side evidences of destruction; for, in almost every direction, were heaps of fallen buildings, still being violently shaken by the earthquake waves that rapidly passed through the solid earth. Huge cracks or crevices had been formed in the streets, while the heavy rails of the trolley tracks had been bent and twisted by the mighty forces. ”

“ The ascent at first appears easy, but a thin layer of ashes, formed into a crust by the action of rain and moisture, is not strong enough to sustain a man's weight. At every step my feet crushed through the outer covering and I sank at first ankle-deep and later on knee-deep into a soft, almost impalpable dust which arose in clouds and nearly suffocated me. ”

“ Every now and then a bubble is formed on the surface of this liquid. The bubble swells to a gigantic size, and suddenly bursts. The steam it contained escapes, carrying fragments of scum which are thrown high into the air. The masses of steam, formed below the surface of the sticky, boiling, lava, in endeavoring to escape, force their way through the mass, blow huge bubbles, which, on bursting, produce the roaring sounds that are heard, and throwing great columns of vapor in the air, produce the rounded masses of clouds you can see floating high up in the air over the mountain. ”

“ Whole mountains, indeed, fall in, and in an instant from the mighty shock tremblings spread themselves far and wide from that centre. And with good cause, since buildings beside a road tremble throughout, when shaken by a wagon of not such very great weight; and they rock no less, where any sharp pebble on the road jolts up the iron tires of the wheels on both sides. ”

“ As the molten lava cools and falls in the form of prodigious clouds of ashes, cinders and dust, for many miles around the volcano, even the light of the sun is obscured, and one cannot see the hand before the face. ”

“ But to establish as a fact the occurrence of an earthquake at so remote a time in the earth's history is far more difficult than to detect the occurrence of a volcano at that time. While the earthquake shocks may produce fissures in the earth's crust, and may be accompanied by great changes of level, yet the great time that has elapsed between such occurrences and the present would permit the various geological agencies that are at work either to cover these fissures completely, or completely to remove by erosion, or in other similar ways, the rocks in which they occurred. ”

“ Some liken it to the sighing of pine-trees in the wind, or to falling rain; others to the distant roar of the surf; others to the far-off rumble of the railway train; others to distant thunder. It grows louder. The earth begins to quiver, then to shake rudely. Soon the ground begins to heave. Then it is actually seen to be traversed by visible waves somewhat likes waves at sea, but of less height and moving much more swiftly. The sound becomes a roar. It is difficult to stand, and at length it becomes impossible to do so. ”

“ If you have ever watched common ants at work clearing out or enlarging their underground homes, in a piece of smooth gravel walk in your garden, you can form some idea why the mountain immediately around a volcanic crater is conical in shape. If the colony of ants happens to be fairly large, you can see an almost unbroken stream of these industrious little animals, each bearing in its mandibles a small grain of sand or gravel brought up from some place below the surface. ”

“ An explosive volcanic eruption is a very terrifying and wonderful phenomenon. Frightful roaring sounds are suddenly heard, the earth shakes for many miles around, when suddenly a vast quantity of molten rock, and sometimes huge stones, are thrown out of the crater high up into the air. So great is the force that throws these materials out of the opening that heavy masses of rocks often are ejected very much faster than the projectiles from the largest guns that are used in any of the navies of the world. ”

“ Many of the great volcanic mountains of the world began as submarine volcanoes. A crater first opened on the floor of the ocean, and lava escaping, was heaped up around the opening, until it emerged above the surface as an island. As we have seen, the island of Iceland is believed to have begun in this way. Such, too, in all probability, was the origin of Hawaii, Vesuvius, Etna, and Santorin.
But besides the volcanic mountains that were thrown up during the geological past, there are others that have been called into existence while man has been living on the earth. ”

“ In order that our earth should be able to violently throw off a large portion of its mass, it is only necessary that at the time this separation occurred, its motion of rotation on its axis was sufficiently great to enable it to make one complete revolution in rather less than three hours instead of in the twenty-four hours it now requires. At this velocity of rotation, objects would fly off the earth in the neighborhood of the equator, under the influence of the high centrifugal force. Let us, then, endeavor to see if it was at all probable that the earth ever did turn so rapidly on its axis. ”

“ The story goes on to tell how when the time approached for the great experiment, and all were ready to shout as loud as they could, that each person reasoning to himself or herself, that amid so great a noise no one could notice whether his or her voice was omitted, determined to remain silent, so as to be able to hear the noise and the better to observe what the man in the moon would do when the sound reached him. The result was that every person on the earth remained silent and simply listened, so that the earth was never so quiet before. ”

“ It may sound queer to say that a volcano has its crater so corked up as to prevent the escape of the lava, but the idea is nevertheless correct and helpful. To realize the size of these huge volcanic corks one must remember that the craters of some volcanoes are several miles across. A volcano thus choked or corked up is said to be extinct.
When we speak of an extinct volcano we do not mean that the volcano will never again become active. ”

“ Thereupon, one of the priests, who was of very great age, said: 'O Solon, Solon, you Hellenes are but children, and there is never an old man who is an Hellene.' Solon, hearing this, said, 'What do you mean?' 'I mean to say,' he replied, 'that in mind you are all young; there is no old opinion handed down among you by ancient traditions, nor any science which is hoary with age. ”

“ We will imagine an extensive area to have slowly appeared above the ocean. In due process of time this land surface, which we will assume to have continental dimensions, gradually becomes covered with plant and animal life. If it remains above the water for a sufficient length of time, its simple plants and animals acquire more and more complex forms, so as to make it difficult to detect any traces of the original species from which they have descended, or, more correctly, ascended. ”

“ Even now that the moon is probably solid throughout, the time of its rotation and revolution exactly agree because, while in a molten condition, the action of the earth changed its shape from that of an exact sphere to a spheroid, with its longest axis in the direction of the earth. Even, therefore, if the moon at any time began to rotate faster than the earth, the earth acting on its projecting surface retarded it until the time of its rotation agreed exactly with the time of its revolution. ”

“ To attempt by the unaided senses a determination of the direction in which earthquake shocks reach any certain spot, the velocity with which they are travelling, their degree of intensity, their general character, whether horizontal or vertical, or any peculiarities which might show them to be exceptional would be futile for more reasons than one. Even a skilled scientific observer, familiar with what has already been discovered and eager to discover more, might in the excitement of an earthquake become so excited himself as to make him unable to take reliable observations. ”

“ To learn when quakes occur on the sea is a much harder task, since on the land we can use seismoscopes, seismographs, or seismometers to indicate, record, or measure the shakings of the crust, while on the sea, where the water is always in more or less motion and the surface so far from the ocean's bed this is impossible, or, rather shall it be said, has hitherto been found so; for that the mind of man may surmount this obstacle is not impossible to conceive. ”

“ Immense quantities of ashes, stones, vapor and gases are thrown upwards for great distances into the air, while, at the same time, a lava stream pours over the lowest side of the crater. As the column of ashes and cinders reaches its greatest height in the air, it begins to spread outward on all sides, rapidly growing like a huge dark mushroom. This soon shuts out the light of the sun, and from it showers of red hot ashes and cinders fall to the earth.
It would be extremely dangerous to be on the side of the volcanic mountain during an explosive eruption ”

“ Of this opinion it may perhaps be unnecessary to say anything, as being foolish, for it is absurd to suppose that things would thus exist above and beneath, and that the parts of bodies which have weight would not on every side be borne to the earth, and those which are light, and fiery, rise; especially since we see the surface of the earth to be convex and spherical, the horizon constantly changing as we change our place, at least as far as we know. ”

“ A volcano does not cease to erupt because there are no more molten materials in the earth to escape, but simply because its cork or crust of hardened lava has been driven in so tightly that the chances of its ever being loosened again seem to be very small. But small as the chances may seem we must not forget that the volcano may at [Pg 23] any time become active, or go into its old business of throwing out materials through its crater. A volcano in an extinct condition is not unlike a steam boiler, the safety valve of which has been firmly fixed in place. ”

“ Sometimes, too, when an enormous mass of soil through age rolls down from the land into great and extensive pools of water, the earth rocks and sways with the undulation of the water just as a vessel at times cannot rest, until the liquid within has ceased to sway about in unsteady undulations.... ”

“ It might surprise you to hear that one of the commonest substances that is found in solution in the waters of many hot springs is silica; for silica is practically sand, and sand does not easily dissolve in water as does sugar. The very hot water, however, which comes from the hot spring, whose temperature below the earth's surface is very much higher than it is when it comes out of the spring, possesses the power of readily dissolving silica from the rocks over which it flows. ”

“ Now let us see how volcanoes can be explained on the assumption that the interior of the earth is hot enough to melt, but remains solid only because there is no room for the heated mass to expand in. Such a heated interior as we have imagined, must be constantly losing its heat and, therefore, shrinking. ”

“ You will understand that if the interior of the earth were melted like a huge central sea of fire that each volcano would necessarily affect all the others. Now, as we have seen, this is never the case, so that this is one reason we cannot believe in the existence of a melted interior. ”