 Section 19 of The San Francisco Calamity by Earthquake and Fire. This is a LibriVox recording. All LibriVox recordings are in the public domain. For more information or to volunteer, please visit LibriVox.org, recording by Avae in April 2010. The San Francisco Calamity by Earthquake and Fire by Charles Morris, Chapter 19. Theories of Volcanic and Earthquake Action. Though the first formation of a volcano, Italian Vulcano from Vulcan, the Roman god of fire, has seldom been witnessed, it would seem that it is marked by earthquake movements, followed by the opening of a rent or fissure, but with no such tilting up of the rocks as was once supposed to take place. From this fissure, large volumes of steam issue accompanied by hydrogen, nitrogen, carbon dioxide, hydrochloric acid and sulfur dioxide. The hydrogen, apparently derived from the dissociation of water at a high temperature, flashes explosively into union with atmospheric oxygen and, having exerted its explosive force, the steam condenses into cloud, heavy masses of which overhang the volcano, pouring down copious rains. This naturally disturbs the electrical condition of the atmosphere, so that thunder and lightning are frequent accompaniments of an eruption. The hydrochloric acid probably points to the agency of seawater. Besides the gases just mentioned, sulphurated hydrogen, ammonia and common salt occur, but mainly as secondary products, formed by the union of the vapors issuing from the volcano, and commonly found also in the vapors rising from cooling lava streams or dormant volcanic districts. It is important to notice that the vapors issue from the volcano spasmodically, explosions succeeding each other with great rapidity and noise. All substances thrown out by the volcano, whether gaseous, liquid or solid, are conveniently united under the term ejectamenta, Latin, things thrown out, and all of them are in an intensely heated, if not an incandescent state. Most of the gases are incombustible, but the hydrogen and those containing sulfur burned with a true flame, perhaps rendered more visible by the presence of solid particles. Much of the so-called flame, however, in popular descriptions of eruptions, is an error of observation due to the red hot solid particles and the reflection of the glowing orifice on the overhanging clouds. Enormous force displayed. Solid bodies are thrown into the air with enormous force and to proportionally great heights, those not projected vertically falling in consequence at considerable distances from the volcano. A block weighing 200 tons is said to have been thrown 9 miles by Kotopaxi, masses of rock weighing as much as 20 tons to have been ejected by Mount Ararat in 1840 and stones to have been hurled to a distance of 36 miles in other cases. The solid matter thrown out by volcanoes consists of lapili, scoriae, dust and bombs. Though on the first formation of the volcano, masses of non-volcanic rock may be torn from the chimney or pipe of the mountain, only slightly fused externally owing to the bad conducting power of most rocks and hurled to a distance, and though at the beginning of a subsequent eruption the solid plug of rock which has cooled at the bottom of the crater, or in fact any part of the volcano, may be similarly blown up, the bulk of the solid particles of which the volcano itself is composed is derived from the lake of lava or molten rock which see this at the orifice. Solid pieces rent from this fused mass and cast up by the explosive force of the steam with which the lava is saturated are known as lapili. Cooling rapidly so as to be glassy in texture externally, these often have time to become perfectly crystalline within. Gases and steam escaping from other similar masses may leave them hollow when they are termed bombs, or may pit their surfaces with irregular bubble cavities when they are called scoriae or scoriaeces. Such masses whirling through the air in a plastic state often become more or less ablately sphereoidal in form, but as often the explosive form of their contained vapours shatters them into fragments producing quantities of the finest volcanic dust or sand. This fine dust darkens the clouds overhanging the mountain, mixes with the condensed steam to fall as a black mud rain or lava di acqua, Italian water lava, or is carried up to enormous heights and then slowly diffused by upper currents of the atmosphere. In the eruption of Vesuvius of Anodomini 79, the air was darkest midnight for 12 or 15 miles round, the city of Pompeii was buried beneath a deposit of dry scoriae or ashes and dust and Herculaneum beneath a layer of the mud like lava di acqua, which on drying sets into a compact rock. Rocks formed from these fragmentary volcanic materials are known as tough. Volcanic cones have similar curvatures. It is entirely of these cindery fragments heaped up with marvellous rapidity round the orifice that the volcano itself is first formed. It may, as in the case of Urullo in Mexico in 1759, form a cone several hundred feet high in less than a day. Such a cone may have a slope as steep as 30 or 40 degrees, its incline in all cases depending simply on the angle of repose of its materials, the inclination that is at which they stop rolling. The great volcanoes of the Andes, which are formed mainly of ash, are very steep. Owing to a general similarity in their materials, volcanic cones in all parts of the world have very similar curvatures, but all the volcanic mountains in which lava streams have broken through the cone, secondary cones have arisen, or portions have been blown up, are more irregular in outline and more gradual in inclination. In size, volcanoes vary from mere mounds a few yards in diameter, such as the Salces or mud volcanoes near the Caspian, to Etna, 10,800 feet high, with a base 30 miles in diameter, Kotopaxi in the Andes, 18,887 feet high, Omauna Loa in the Sandwich Isles, 13,700 feet high, with a base 70 miles in diameter and two craters, one of which, Kilauea, the largest active crater on our earth, is 7 miles in circuit. Larger extinct craters occur in Japan, but all our terrestrial volcanic mountains are dwarfed by those observed on the surface of the moon, which, owing to its smaller size, has cooled more rapidly than our earth. It is, of course, the explosive force from below which keeps the crater clear as a cup-shaped hollow, truncating the cone, and all stones falling into it would be only thrown out again. It may at the close of an eruption cool down so completely that a lake can form within, such as Lake Averno, near Naples, or it may long remain a seething sea of lava, such as Kilauea, or the lava may find one or more outlets from it, either by welling over its rim, which it will then generally break down as in many of the small extinct volcanoes, Puis, of Averno, or more usually by bursting through the sides of the cone. Lava varies very much in liquidity. It is not generally until the volcano has exhausted its first explosive force that lava begins to issue. Several streams may issue in different directions. Their dimensions are sometimes enormous. Lava varies very much in liquidity and in the rate at which it flows. This much depends, however, upon the slope it has to traverse. A lava stream at Vesuvius ran three miles in four minutes, but took three hours to flow the next three miles, while a stream from Mauna Loa ran eighteen miles in two hours. Glowing at first as a white-hot liquid, the lava soon cools at the surface to red and then to black. Cindalike-scoracious masses form on its surface and in front of the slowly advancing mass. Clouds of steam and other vapor rise from it, and little cones are thrown up from its surface, but many years may elapse before the mass is cooled through. Thus, while the surface is glassy, the interior becomes crystalline. As to what are the causes of the great convulsions of nature known as the volcano and the earthquake, we know very little. Various theories have been advanced, but nothing by any means sure has been discovered, and considerable difference of opinion exists. In truth we know so little concerning the conditions existing in the earth's interior that any views concerning the forces at work there must necessarily be largely conjectural. Sir Robert S. Ball says in this connection, quote, Let us take, for instance, that the primary question in terrestrial physics as to whether the interior of the earth is liquid or solid. If we were to judge merely from the temperatures reasonably believed to exist at a depth of some 20 miles, and if we might overlook the question of pressure, we should certainly say that the earth's interior must be in a fluid state. It seems at least certain that the temperatures to be found at depths of two-square miles and still more at greater depths must be so high that the most refractory solids, whether metals or minerals, would at once yield if we could subject them to such temperatures in our laboratories. But none of our laboratory experiments can tell us whether, under the pressure of thousands of tons on the square inch, the application of any heat whatever would be adequate to transform solids into liquids. It may indeed be reasonably doubted whether the terms solid and liquid are applicable in the sense in which we understand them to the materials forming in the interior of the earth. A principle already well-known in the arts is that many, if not all, solids may be made to flow like liquids if only adequate pressure be applied. The making of lead tubes is a well-known practical illustration of this principle, for these tubes are formed simply by forcing solid lead by the hydraulic press through a mold which imparts the desired shape. If then a solid can be made to behave like a liquid, even with such pressures as are within our control, how are we to suppose that the solids would behave with such pressures as those to which they are subjected in the interior of the earth? The fact is that the terms solid and liquid, at least as we understand them, appear to have no physical meaning with regard to bodies subjected to these dependuous pressures, and this must be carefully borne in mind when we are discussing the nature of the interior of the earth. The Volcano, a Safety Valve Whatever be the state of affairs in the depth of the earth's crust, we may look upon the volcano as a sort of safety valve, opening a passage for the pent-up forces to the surface and thus relieving the earth from the terrible effects of the earthquake through which these imprisoned powers so often make themselves felt. Without a volcanic vent, there might be no safety for men on the earth's unquiet face. Professor J. C. Russell of Michigan University presents the following views concerning the status and action of volcanoes. When reduced to its simplest terms, a volcano may be defined as a tube or conduit in the earth's crust through which the molten rock is forced to the surface. The conduit penetrates the cool and rigid rocks forming the superficial portion of the earth and reaches its highly heated interior. The length of volcanic conduits can only be conjectured, but, judging from the approximately known rate of increase of heat with depth, on an average one degree Fahrenheit for each 60 feet, and the temperature at which volcanic rocks melt from 2300 to 2700 degrees Fahrenheit when not under pressure, they must seemingly have a depth of at least 20 miles. There are other factors to be considered, but in general terms it is safe to assume that the conduits of volcanoes are irregular openings, many miles in depth, which furnish passage ways for molten rock, lava, from the highly heated sub-crust portion of the earth to its surface. Eruptions of Quiet Type During eruptions of the quiet type, the lava comes to the surface in a highly liquid condition, that is, it is torrefly fused and flows with almost a freedom of water. It spreads widely, even on a near-level plane, and may form a comparatively thin sheet, several hundred square miles in area, as has been observed in Iceland and Hawaii. On the Snake River Plains in southern Idaho, there are sheets of once molten rock, which were poured out in the manner just stated, some four hundred square miles in area, and not over seventy-five feet in average thickness. When an eruption of highly liquid lava occurs in a mountainous region, the molten rock may cascade down deep slopes and flow through narrow valleys for fifty miles or more, before becoming chilled sufficiently to arrest its progress. Instances are abundant, where quiet eruptions have occurred in the midst of a plane and built up lava cones, or low mounds, with immensely expanded bases. Illustrations are furnished in southern Idaho, in which the cones formed are only three hundred or four hundred feet high, but have a breath at the base of eight or ten miles. In the class of eruption illustrated by these examples, there is an absence of fragmental material, such as explosive volcanoes hurl into the air, and the person may stand within a few yards of rushing stream of molten rock, or examine closely the opening from which it is being poured out, without danger or serious inconvenience. The quiet volcanic eruptions are attended by the escape of steam or gases from the molten rock, but the lava being in a highly liquid state, the steam and gases dissolved in it, escape quietly and without explosions. If, however, the molten rock is less completely fluid or in a viscous condition, the vapours and gases contained in it find difficulty in escaping and may be retained until becoming concentrated in large volume, they break their way to the surface, producing violent explosions. Volcanoes in which the lava extruded is viscous, and the escape of steam and gases is retarded until the pent-up energy bursts all bounds, are of the explosive type. One characteristic example is Vesuvius. When steam escapes from the summit of a volcanic conduit, which, in plain terms, is a tall vessel filled with intensely hot and more or less viscous liquid, masses of the liquid rock are blown into the air and on falling build up a rim or crater about the place of discharge. Commonly, the lava in the summit portion of a conduit becomes chilled and perhaps hardened, and when a steam explosion occurs, this crust is shattered and the fragments hurled into the air and contributed to the building of the walls of the enclosing crater. The solid rock blown out by volcanoes consists usually of highly vesicular material which hardened on the surface of the column of lava within a conduit and was shattered by explosions beneath it. These fragments vary in size from dust particles up to masses several feet in diameter, and during violent eruptions are hurled miles high. The larger fragments commonly fall near their place of origin and usually furnish the principal part of the material of which craters are built, but the gravel-like kernels, lapili, may be carried laterally several miles if a wind is blowing while the dust is frequently showered down on thousands of square miles of land and sea. The solid and usually angular fragments manufactured in this manner vary in temperature and may still be red-hot on falling. Volcanoes of the explosive type not uncommonly discharge streams of lava, which may flow many miles. In certain instances, these outwellings of liquid rock occur after severe earthquakes and violent explosions and may have all the characteristics of quiet eruptions. There is thus no fundamental difference between the two types into which it is convenient to divide volcanoes. In extreme examples of explosive volcanoes, the summit portion of a crater, perhaps several miles in circumference and several thousand feet high, is blown away. Such an occurrence is recorded in the case of the volcano Coseguina, Nicaragua, in 1835, or an entire mountain may disappear, being reduced to lapili and dust and blown into the air, as in the case of Carcatoa in the Straits of Sunda in 1883. The essential feature of a volcano, as stated above, is a tube or conduit leading from the highly heated sub-crossed portion of the earth to the crater and through which molten rock is forced upward to the surface. The most marked variations in the process depended the quantity of molten rock extruded and on the freedom of escape of the steam and gases contained in the lava. The cause of the rise of the molten rock in a volcano is still a matter for discussion. Certain geologists contend that steam is the sole motive power, while others consider that the lava is forced to the surface owing to pressure on the reservoir from which it comes. The view perhaps most favorably entertained at present, in reference to the general nature of volcanic eruptions, is that the rigid outer portion of the earth becomes fractured, owing principally to movements resulting from the shrinking of the cooling in a mass and that the intensely hot material reached by the fissures, previously solid owing to pressure, becomes liquid when pressure is relieved and is forced to the surface. As the molten material rises, it invades the water-charged rocks near the surface and acquires steam or the gases resulting from the decomposition of water and a new force is added which produces the most conspicuous and at times the most terrible phenomena accompanying eruptions. End quote. The active agency of water is strongly maintained by many geologists and certainly gains support from the vast clouds of steam given off by volcanoes in eruption and the steady and quiet emission of steam from many in a state of rest. The quantities of water in the liquid state to which is due to frequent enormous outflows of mud leads to the same conclusion. Many scientists indeed, while admitting the agency of water, look upon this as the acquires material originally pent up within the rocks. For instance, Professor Scheyler, Dean of the Lawrence Scientific School says, quote, volcanic outbreaks are merely the explosion of steam under high pressure, steam which is bound in rocks buried underneath the surface of the earth and they are subjected to such tremendous heat that when the conditions are right its pent up energy breaks forth and it shatters its stone prison walls into dust. The process by which the water becomes buried in this manner is a long one. Some contend that it leaks down from the surface of the earth through fishers in the outer crust but this theory is not generally accepted. The common belief is that water enters the rocks during the crystallization period and that these rocks through the natural action of rivers and streams become deposited in the bottom of the ocean. Here they lie for many ages becoming buried deeper and deeper under masses of like sediment which are constantly being washed down upon them from above. This process is called the blanketing process. Each additional layer of sediment while not raising the level of the sea bottom buries the first layers just so much the deeper and adds to their temperature just as does the laying of extra blankets on a bed. When the first layer has reached a depth of a few thousand feet the rocks which contain the water of crystallization are subjected to a terrific heat. This heat generates steam which is held in a state of frightful tension in its rocky prison. Wrinklings in the outer crust of the earth's surface occur caused by the constant shrinking of the earth itself and by the contraction of the outer surface as it settles on the plastic centers underneath. Fishers are caused by these foldings and as these fishes reach down into the earth the pressure is removed from the rocks and the compressed steam in them being released explodes with tremendous force. This view is very probably applicable to many cases and the exceedingly fine dust which so often rises from volcanoes has doubtless for one of its causes the sudden and explosive conversion of water into steam in the interior of ejected lava thus rending it into innumerable fragments. But that this is the sole mode of action of water and volcanic eruptions is very questionable. It certainly does not agree with the immense volumes at times thrown out while explosions of such extreme intensity as that of Kakatoa very strongly lead to the conclusion that a great mass of water has made its way through newly opened fishers to the level of molten rock and exploded into steam with a suddenness which gave it the rending force of dynamite or the other powerful chemical explosives. As the earthquake is so intimately associated with the volcano the causes of the latter are in great measure the causes of the former and the forces at work frequently produce a more or less violent quaking of the earth's surface before they succeed in opening a channel of escape through the mountain's heart. One agency of great potency and one whose work never ceases has doubtless much to do with earthquake action. In the description of this we cannot do better than to quote from the earth's beginning of Sir Robert S. Ball, cause of earthquakes. As to the immediate cause of earthquakes there is no doubt considerable difference of opinion but I think it will not be doubted that an earthquake is one of the consequences though perhaps a remote one of the gradual loss of internal heat from the earth. As this terrestrial heat is gradually declining it follows from the law that we have already so often had occasion to use that the bulk of the earth must be shrinking. No doubt the diminution in the earth's diameter due to the loss of heat must be exceedingly small even in a long period of time. The cause however is continually in operation and accordingly the crust of the earth has from time to time to be accommodated to the fact that the whole globe is lessening. The circumference of our earth at the equator must be gradually declining a certain length in that circumference is lost each year. We may admit that loss to be a quantity far too small to be measured by any observations as yet obtainable but nevertheless it is productive of phenomena so important that it cannot be overlooked. It follows from these considerations that the rocks which form the earth's crust over the surface of the continents and the islands or beneath the bed of the ocean must have a lessening accreage year by year. These rocks must therefore submit to compression either continuously or from time to time and the necessary yielding of the rocks will in general take place in those regions where the materials where the materials of the earth's crust happen to have comparatively small powers of resistance. The acts of compression will often and perhaps generally not proceed with uniformity but rather with small successive shifts and even though the displacements of the rocks in these shifts be actually very small yet the pressures to which the rocks are subjected are so vast that a very small shift may correspond to a very great terrestrial disturbance. Suppose for instance that there is a slight shift in the rocks on each side of a crack or fault at a depth of 10 miles. It must be remembered that the pressure 10 miles down would be about 35 tons to the square inch. Even a slight displacement of one extensive surface over another decides being pressed together with a force of 35 tons on the square inch would be an operation necessarily accompanied by violence greatly exceeding that which we might expect from so small a displacement if the force is concerned had been of more ordinary magnitude. On account of this great multiplication of the intensity of the phenomenon merely a small rearrangement of the rocks in the crust of the earth in pursuance of the necessary work of accommodating its volume to the perpetual shrinkage might produce an excessively violent shock extending far and wide. The effect of such a shock would be propagated in the form of waves through the globe just as a violent blow given at one end of a bar of iron by a hammer is propagated through the bar in the form of waves. When the effect of this internal adjustment reaches the earth's surface it will sometimes be great enough to be perceptible in the shaking it gives that surface. The shaking may be so violent that buildings may not be able to withstand it. Such is the phenomenon of an earthquake. When the earth is shaken by one of those occasional adjustments of the crust which I have described, the wave that spreads like a pulsation from the center of agitation extends all over our globe and is transmitted right through it. At the surface lying immediately over the center of disturbance there will be a violent shock. In the surrounding country and often over great distances the earthquake may also be powerful enough to produce destructive effects. The convulsion may also be manifested over a far larger area of country in a way which makes the shock to be felt though the damaged rod may not be appreciable. But beyond a limited distance from the center of the agitation the earthquake will produce no destructive effects upon buildings and will not even cause vibrations that would be appreciable to ordinary observation. The radius of disturbance In each locality in which earthquakes are chronic it would seem as if there must be a particularly weak spot in the earth some miles below the surface. A shrinkage of the earth in the course of the incessant adjustment between the interior and the exterior will take place by occasional little jumps at this particular center. The fact that there is this weak spot at which small adjustments are possible may provide, as it were, a safety valve for other places in the same part of the world. Instead of a general shrinking the materials would be sufficiently elastic and flexible to allow the shrinking for a very large area to be done at this particular locality. In this way we may explain the fact that immense tracks on the earth are practically free from earthquakes of a serious character while in the less fortunate regions the earthquakes are more or less perennial. Now suppose an earthquake takes place in Japan. It originates a series of vibrations through our globe. We must here distinguish between the rocks. I might almost say the comparatively pliant rocks which form the earth's crust and those which form the intensely rigid core of the interior of our globe. The vibrations which carry the tidings of the earthquake spread through the rocks on the surface from the center of the disturbance in gradually enlarging circles. We may liken the spread of these vibrations to the ripples in a pool of water which diverge from the spot where a raindrop has fallen. The vibrations transmitted by the rocks on the surface or on the floor of the ocean will carry the message all over the earth. As these rocks are flexible at all events by comparison with the earth's interior the vibrations will be correspondingly large and will travel with vigor over land and on the sea. In due time they reach, say the Isle of Wight where they set the pencil of the seismometer at work. But there are different ways around the earth from Japan to the Isle of Wight the most direct route being across Asia and Europe the other route across the Pacific, America and the Atlantic. The vibrations will travel by both routes and the former is the shorter of the two. Some brief repetition may not here be a miss as to the products of volcanic action of which so much has been said in the preceding pages especially as many of the terms are to some extent technical in character. The most abundant of these substances is steam or water gas which as we have seen issues in prodigious quantities during every eruption. But with the steam a great number of other volatile materials frequently make their appearance. Though we have named a number of these at the beginning of this chapter it will not be out of order to repeat them here. The chief among these are the acid gases known as hydrochloric acid sulfurous acid, sulfurated hydrogen, carbonic acid and boracic acid. And with these acid gases their issue hydrogen nitrogen ammonia the volatile metals arsenic, antimony and mercury and some other substances. These volatile substances react upon one another and many new compounds are thus formed. By the action of sulfurous acid and sulfurated hydrogen on each other the sulfur so common in volcanic districts is separated and deposited. The hydrochloric acid acts very energetically on the rocks around the vents uniting with the iron in them to form the yellow ferric chloride which often coats the rocks around the vent and is usually mistaken by casual observers for sulfur. Some of the substances emitted by volcanic vents such as hydrogen and sulfurated hydrogen are inflammable and when they issue at a high temperature these gases burst into flame the moment that they come into contact with the air. Hence when volcanic fishes are watched at night faint lambant flames are frequently seen playing over them and sometimes these flames are brilliantly colored through the presence of small quantities of certain metallic oxides. Such volcanic flames however are scarcely ever strongly luminous and the red glowing light which is observed over volcanic mountains in eruption is due to quite another cause. What is usually taken for flame during a volcanic eruption is simply as we have before stated the glowing light of the surface of a mass of red hot lava reflected from the cloud of vapor and dust in the air as much as the lights of a city are reflected from the water vapor of the atmosphere during a night of fog. Besides the volatile substances which issue from volcanic vents mingling with the atmosphere or condensing upon their sides there are many solid materials ejected and these may accumulate around the orifices until they build up mountains of vast dimensions like etna, tenerife and chimborazo. Some of these solid materials are evidently fragments of the rock masses through which the volcanic fissure has been rent. These fragments have been carried upwards by the force of the steam blast and scattered over the sides of the volcano. But the principal portion of the solid materials ejected from volcanic orifices consists of matter which has been extruded from sources far beneath the surface in highly heated and fluid or semi-fluid condition. It is to these materials that the name of Lavas is properly applied. Lavas presented general resemblance to the slags and clinkers which are formed in our furnaces and brickey kilns and consist like them of various stony substances which have been more or less perfectly fused. When we come to study the chemical composition and the microscopical structure of Lavas however we shall find that there are many respects in which they differ entirely from these artificial products. They consisting chiefly of feldspar or of this substance in association with ogite or hornblend. In texture they may be stony, glassy, resin-like, vesicular or cellular and light in weight as in the case of pumice or scoria. Floating pumice. The steam and other gases rising through liquid lava are apt to produce bubbles yielding a surface froth or foam. This froth varies greatly in character according to the nature of the material from which it is formed. In the majority of cases the Lavas consist of a mass of crystals floating in a liquid magma and the distention of such a mass by the escape of steam from its midst gives rise to the formation of the rough, sundry-looking material to which the name of scoria is applied. But when the lava contains no ready formed crystal but consists entirely of glassy substance in a more or less perfect state of fusion, the liberation of steam gives rise to the formation of the beautiful material known as pumice. Pumice consists of a mass of minute glass bubbles. These bubbles do not usually, however, retain their globular form but are elongated in one direction through the movement of the mass while it is still in a plastic state. The quantity of this substance ejected is often enormous. We have seen to what a vast extent it was thrown out from the crater of Krakatoa. During the year 1878 masses of floating pumice were reported as existing in the vicinity of the Solomon Isles and covering the surface of the sea to such extent that it took ships three days to force their way through them. Sometimes this substance accumulates in such quantities along coasts that it is difficult to determine the position of the shore within a mile or two as we may land and walk about on the great floating raft of pumice. Recent deep sea soundings carried on in the Challenger and other vessels have shown that the bottom of the deepest portion of the ocean, far away from the land, is covered with volcanic materials which have been carried through the air or have floated on the surface of the ocean. Fragments of scoria or pumice may be thrown hundreds or thousands of feet into the atmosphere, those that fall into the crater and are flung up again being gradually reduced in size by friction. Thus it is related by Mr. Poulet Scrope who watched a Vizuvian eruption of 1822 which lasted for nearly a month that during the earlier stages of the outburst fragments of enormous size were thrown out of the crater but by constant re-ejection these were gradually reduced in size till at last only the most impalpable dust issued from the vent. This dust filled the atmosphere producing in the city of Naples a darkness that might be felt. So excessively finely divided was it that it penetrated into all drawers, boxes and the most closely fastened receptacles filling them completely. The fragmentary materials ejected from volcanoes are often giving the name of cinders or ashes. These however are terms of convenience only and do not properly describe the volcanic material. Sometimes the passages of steam through a mass of molten glass produces large quantities of a material resembling spun glass. Small particles of this glass are carried into the air and leave behind them thin glassy filaments like a tail. At the volcano of Kilauea in Hawaii this substance as previously stated is abundantly produced and is known as Pele's hair Pele being the name of the goddess of the mountain. Birds nests are sometimes found composed of this beautiful material. In recent years an artificial substance similar to this Pele's hair has been extensively manufactured by passing jets of steam through the molten slag of iron furnaces. It resembles cotton wool but is made up of fine threads of glass and is employed for the packing of boilers and other purposes. The lava itself as left in huge deposits upon the surface assumes various forms some crystalline others glassy. The latter is usually found in the condition known as obsidian ordinarily black in color and containing few or no crystals. It is brittle and splits into sharp edged or pointed fragments which were used by primitive peoples for arrow heads, knives and other cutting implements. The ancient Mexicans used bits of it for shaving purposes it having an edge of razor-like sharpness. They also used it as the cutting part of their weapons of war. End of Section 19 Section 20 of the San Francisco Calamity by Earthquake and Fire This is a LibriVox recording. All LibriVox recordings are in the public domain. For more information or to volunteer please visit LibriVox.org. This recording is by Robert Parker of Story City, Iowa. The San Francisco Calamity by Earthquake and Fire by Charles Norris Chapter 20 Active Volcanoes of the Earth It is not by any means an easy task to frame an estimate of the number of volcanoes in the world. Volcanoes vary greatly in their dimensions from vast mountain masses rising to a height of nearly 25,000 feet above sea level to mere mole hills. They likewise exhibit every possible stage of development and decay. While some are in a state of chronic active eruption, others are reduced to the condition of sulfataras, or vents emitting acid vapors, and others again have fallen into a more or less complete state of ruin through the action of denuding forces. The number of active volcanoes, even if we confine our attention to the larger volcanoes, which merit the name of mountains, and such of those as we have reason to believe to be in a still active condition, our difficulties will be diminished, but not by any means removed. Volcanoes may sink into a dormant condition that at times endures for hundreds or even thousands of years, and then burst forth into a state of renewed activity. And it is quite impossible, in many cases, to distinguish between the conditions of dormancy and extinction. We shall, however, probably be within the limits of truth in stating that the number of great habitual volcanic vents upon the globe, which we have reason to believe are still in active condition, is somewhere between 300 and 350. Most of these are marked by more or less considerable mountains, composed of the materials ejected from them. But if we include mountains which exhibit the external conical form, crater-like hollows, and other features of volcanoes, yet concerning the activity of which we have no record or tradition, the number will fall little, if anything, short of one thousand. The mountains composed of volcanic materials, but which have lost through denudation the external form of volcanoes, are still more numerous. And the smaller temporary openings, which are usually subordinate to the habitual vents that have been active during the periods covered by history and tradition, must be numbered by thousands. There are still feebler manifestations of the volcanic forces, such as steam jets, geysers, thermal and mineral waters, spouting saline and muddy springs, and mud volcanoes, that may be millions. It is not improbable that these less powerful manifestations of the volcanic forces, to a great extent make up in number what they want in individual energy. And the relief which they afford to the imprisoned activities within the Earth's crust may be almost equal to that which results from the occasional outbursts at the great habitual volcanic vents. In taking a general survey of the volcanic phenomena of the globe, no facts come out more strikingly than that of the very unequal distribution both of the great volcanoes and of the minor exhibitions of subterranean energy. Thus, on the whole of the continent of Europe, there is but one habitual volcanic vent, that of Vesuvius. And this is situated upon the shores of the Mediterranean. In the islands of that sea, however, there are no less than six volcanoes, namely Stromboli and Volcano, in the Lipari Islands, Etna in Sicily, Graham's Isle, a submarine volcano off the Sicilian coast, and Santorin and Nysairos in the Aegean Sea. The African continent is at present known to can hang about 10 active volcanoes, four on the west coast and six on the east coast, while about 10 other active volcanoes occur on islands close to the African coasts. On the continent of Asia, more than 20 active volcanoes are known or believed to exist, but no less than 12 of these are situated in the peninsula of Kamchatka. No volcanoes are known to exist in the Australian continent. The American continent contains a greater number of volcanoes than the continents of the old world. There are 20 in North America, 25 in Central America, and 37 in South America. Thus, taken together, there are about 117 volcanoes situated on the great continental lands of the globe, while nearly twice as many occur upon the islands scattered over the various oceans. Asiatic Volcanoes Upon examining further into the distribution of the continental volat canos, another very interesting fact presents itself. The volcanoes are in almost every instance situated either close to the coasts of the continent or at no great distance from them. There are, indeed, only two exceptions to this rule. In the great and almost wholly unexplored table land lying between Siberia and Tibet, four volcanoes are said to exist, and in the Chinese province of Manchuria, several others. More reliable information is, however, needed concerning those volcanoes. It is a remarkable circumstance that all oceanic islands, which are not coral reefs, are composed of volcanic rocks, and many of these oceanic islands, as well as others lying near the shores of the continents, contain active volcanoes. Through the midst of the Atlantic Ocean runs a ridge, which, by the soundings of the various exploring vessels sent out in recent years, has been shown to divide the ocean longitudinally into two basins. Upon this great ridge, and the spurs proceeding from it, arise numerous mountain masses, which constitute the well-known Asiatic Islands and groups of islands. All of these are of volcanic origin, and among them are numerous active volcanoes. The island of Jan Mayan contains an active volcano, and Iceland contains 13, and not improbably more. The Azores have six active volcanoes. The Canaries three, while about eight volcanoes lie off the west coast of Africa. In the West Indies there are six active volcanoes, and three submarine volcanoes have been recorded within the limits of the Atlantic Ocean. Altogether, no less than 40 active volcanoes are situated upon the great submarine ridges which traverse the Atlantic longitudinally. But along the same line, the number of extinct volcanoes is far greater, and there are not wanting proofs that the volcanoes which are still active are approaching the condition of extinction. The volcanoes of the Pacific if the great medial chain of the Atlantic presents us with an example of a chain of volcanic mountains verging on extinction. We have in the line of islands separating the Pacific and Indian oceans an example of a similar range of volcanic vents which are in a condition of the greatest activity. In the peninsula of Kamchatka there are 12 active volcanoes. In the Aleutian Islands 31, and in the peninsula of Alaska 3. The chain of the Kuriles contains at least 10 active volcanoes. The Japanese islands and the islands to the south of Japan 25. The great group of islands lying to the southeast of the Asiatic continent is at the present time the grandest focus of volcanic activity upon the globe. No less than 50 active volcanoes occur here. Further south, the same chain is probably continued by the four active volcanoes of New Guinea, one or more submarine volcanoes, and several vents in New Britain, the Solomon Isles, and the New Hebrides, the three active volcanoes of New Zealand, and possibly by Mount Erebus and Mount Terror in the Antarctic region. Altogether, no less than 150 active volcanoes exist in the chain of islands which stretch from Bering's Straits down to the Antarctic Circle. And if we include the volcanoes on Indian and Pacific islands, which appear to be situated on lines branching from this particular band, we shall not be wrong in the assertion that this great system of volcanic mountains includes at least one half of the habitually active vents of the globe. In addition to the active vents, there are here several hundred very perfect volcanic cones, many of which appear to have recently become extinct, though some of them may be merely dormant, biding their time. A third series of volcanoes starts from the neighborhood of Bering Straits and stretches along the whole western coast of the American continent. This is much less continuous, but nevertheless very important, and contains with its branches nearly a hundred active volcanoes. On the north, this great band is almost united with the one we've already described by the chain of the Aleutian and Alaskan volcanoes. In British Columbia, about the parallel of 60 degrees north, there exist a number of volcanic mountains, one of which Mount St. Elias is believed to be 18,000 feet in height. Farther south, in the territory of the United States, a number of grand volcanic mountains exist, some of which are probably still active, for geysers and other manifestations of volcanic activity abound. From the southern extremity of the peninsula of California, an almost continuous chain of volcanoes stretches through Mexico and Guatemala, and from this part of the volcanic band a branch is given off, which passes through the West Indies, and contains the volcanoes which have so recently given evidence of their vital activity. In South America, the line is continued by the active volcanoes of Ecuador, Bolivia, and Chile. But at many intermediate points in the chain of the Andes, extinct volcanoes occur, which to a great extent fill up the gaps in the series. A small offshoot to the westward passes through the Galapagos Islands. The great band of volcanoes, which stretches through the American continent, is second only in importance and in the activity of its vents to the band which divides the Pacific from the Indian Ocean. The third volcanic band of the globe is that, already spoken of, which traverses the Atlantic Ocean from north to south. This series of volcanic mountains is much more broken and interrupted than the other two, and a greater proportion of its vents are extinct. It attained its condition of maximum activity during the distant period of the myocene, and now appears to be passing into a state of gradual extinction. Beginning in the north, with the volcanic rocks of Greenland and Bear Island, we pass southwards, by way of Jan Mayen, Iceland, and the Faroe Islands, to the Hebrides and the north of Ireland. Thence by way of the Azores, the Canaries, and the Cape de Verde Islands, with some active vents, we pass to the ruined volcanoes of St. Paul, Fernando de Hinerona, Ascension, St. Helena, Trinidad, and Tristan de Cunha. From this great Atlantic band, two branches proceed to the eastward, one through central Europe, where all the vents are now extinct, and the other through the Mediterranean to Asia Minor, the great majority of the volcanoes along the latter line now being extinct, though a few are still active. The volcanoes on the eastern coast of Africa may be regarded as situated on another branch from this Atlantic volcanic band. The number of active volcanoes on this Atlantic band and its branches, exclusive of those in the West Indies, does not exceed 50. Tian Shan and Hawaiian Volcanoes From what has been said, it will be seen that the volcanoes of the globe not only usually assume a linear arrangement, but nearly the whole of them can be shown to be thrown up along three well-marked bands and the branches proceeding from them. The first and most important of these vans is nearly 10,000 miles in length, and with its branches contains more than 150 active volcanoes. The second is 8,000 miles in length and includes about 100 active volcanoes. The third is much more broken and interrupted, extends to a length of nearly 1,000 miles and contains about 50 active vents. The volcanoes of the eastern coast of Africa with Mauritius, Bourbon, Rodriguez, and the vents along the line of the Red Sea may be regarded as forming a fourth and subordinate band. Thus we see that the surface of the globe is covered by a network of volcanic bands, all of which traverse it in sinuous lines with the general north and south direction, giving off branches which often run for hundreds of miles, and sometimes appear to form a connection between the great bands. To this rule of the linear arrangement of the volcanic vents of the globe and their accumulation along certain well-marked bands, there are two very striking exceptions which we must now proceed to notice. In the very center of the continent formed by Europe and Asia, the largest unbroken land mass of the globe, there rises from the great central plateau, the remarkable volcanoes of the Tian Shan range. The existence of these volcanoes, of which only obscure traditional accounts have reached Europe before the year 1858, appears to be completely established by the researchers of recent Russian and Swedish travelers. Three volcanic vents appear to exist in this region, and other volcanic phenomena have been stated to occur in the great plateau of Central Asia. But the existence of the latter appears to rest on very doubtful evidence. The only accounts of which we have of the eruptions of these Tian Shan volcanoes are contained in Chinese histories and treatises on geography. The second exceptionally situated volcanic group is that of the Hawaiian islands. While the Tian Shan volcanoes rise in the center of the largest unbroken land mass, and stand on the edge of the loftiest and greatest plateau in the world, the volcanoes of the Hawaiian islands rise in the northern center of the largest ocean, and from almost the greatest depths in that ocean. All around the Hawaiian islands, the sea has a depth of from 2,000 to 3,000 fathoms, and the island group culminates in several volcanic cones, which rise to the height of nearly 14,000 feet above the sea level. The volcanoes of the Hawaiian islands are unsurpassed in height and bulk by those of any other part of the globe. With the exception of the two isolated groups of the Tian Shan and the Hawaiian islands, nearly all the active volcanoes of the globe are situated near the limits which separate the great land and water masses of the globe. That is to say, they occur either on the parts of continents not far removed from their coastlines, or on islands in the ocean not very far distant from the shores. The fact of the general proximity of volcanoes to the sea is one which has frequently been pointed out by a geographer's, and may now be regarded as being thoroughly established. Volcanoes parallel to mountain chains. Many of the grandest mountain chains have bands of volcanoes lying parallel to them. This is strikingly exhibited by the great mountain masses, which lie on the western side of the American continent. The Rocky Mountains and the Andes consist of folded and crumbled masses of altered strata, which, by the action of denuding forces, have been carved into series of ridges and summits. At many points, however, along the sides of these great chains, we find that fissures have been opened and lines of volcanoes formed, from which enormous quantities of lava have flowed and covered great tracts of country. This is especially marked in the Snake River plain of Idaho in the western United States. In this, and the adjoining regions of Oregon and Washington, an enormous tract of country has been overflowed lava in a great geological period, the surface covered being estimated to have a larger area than France and Great Britain combined. The Snake River cuts through it in a series of picturesque gorges and rapids, enabling us to estimate its thickness, which is considered to average 4,000 feet. Looked at from any point on its surface, one of these lava planes appears as a vast level surface, like that of a lake bottom. This uniformity has been produced either by the lava rolling over a plain, or lake bottom, or by the complete effacement of an original, undulating contour of the ground under hundreds or thousands of feet of lava in successive sheets. The lava rolling up to the base of the mountains has followed the sinuosities of their margin, as the waters of a lake follow its promontories and bays. Similar conditions exist along the Sierra Nevada range of California, and to some extent placer mining has gone on under immense beds of lava by a process of tunneling beneath the volcanic rock. In some localities, the volcanoes are of such height and dimensions as to overlook and dwarf the mountain ranges by the side of which they lie. Some of the volcanoes, lying parallel to the Great American Axis, appear to be quite extinct, while others are in full activity. In the eastern continent, we find still more striking examples of parallelism between great mountain chains and the lands along which volcanic activity is exhibited. Volcanoes, active or extinct, following the line of the great east and west chains which extend through southern Europe and Asia. There are some other volcanic bands which exhibit a similar parallelism with mountain chains. But, on the other hand, there are volcanoes between which and the nearest mountain axis no such connection can be traced. Areas of upheaval and subsidence. There is one other fact concerning the mode of distribution of volcanoes upon the surface of the globe, to which we must elude. By a study of the evidences of coral reefs, raised beaches, submerged forests, and other phenomena of a similar kind, it can be shown that certain wide areas of the land and of the ocean floor are at the present time in a state of subsidence, while other equally large areas are being upheaved. And the observations of the geologists prove that similar upward and downward movements of portions of the Earth's crust have both been going on through all geological times. Now, as Mr. Darwin has so well shown in his work on coral reefs, if we trace upon a map the areas of the Earth's surface which are undergoing upheaval and subsidence respectively, we shall find that nearly all the active volcanoes of the globe are situated upon rising areas, and that volcanic phenomena are conspicuously absent from those parts of the Earth's crust, which can be proved at the present day to be undergoing depression. The remarkable linear arrangement of volcanic vents has a significance that is well worthy of fuller consideration. There are facts known which point to the cause of the state of affairs. It is not uncommon for small cones of scoriae to be seen following lines on the flanks or at the base of a great volcanic mountain. These are undoubtedly lines of fissure caused by the subterranean forces. In fact, such fissures have been seen opening on the sides of Mount Etna, in whose bottom could be seen the glowing lava. Along these fissures, in a few days, scoriae cones appeared. On one occasion, no less than 36 in number. It is believed by geologists that the linear systems of volcanoes are ranged along similar lines of fissure in the Earth's crust. Enormous breaks extending for thousands of miles, and the result of internal energies acting through vast periods of time. Along these immense fissures in the Earth's rock crust, there appear, in place of small scoriae cones, great volcanoes, built up through the ages by a series of powerful eruptions, and only ceasing to spout fire themselves when the portion of the great crack upon which they lie is closed. The greatest of these fissures is that, along the vast, sinuous band of volcanoes extending from near the Arctic Circle at Bering Straits to the Antarctic Circle at South Victoria land, not far from half round the Earth. It doubtless marks the line of mighty forces which have been active for millions of years. End of Chapter 20 Recorded by Robert Parker of Story City, Iowa Section 21 of The San Francisco Calamity by Earthquake and Fire. This is a LibriVox recording. All LibriVox recordings are in the public domain. For more information or to volunteer, please visit LibriVox.org. The San Francisco Calamity by Earthquake and Fire, edited by Charles Morris, Chapter 21, The Famous Vesuvius and the Destruction of Pompeii. The famous volcano of southern Italy named Vesuvius, which is now so constantly interruption, was described by the ancients as a cone-shaped mountain with a flat top, on which was a deep circular valley filled with vines and grass and surrounded by high precipices. A large population lived on the sides of the mountain, which was covered with beautiful woods, and there were fine flourishing cities at its foot. So little was the terrible nature of the valley on the top understood that in AD 72 Spartacus, a rebellious Roman gladiator, encamped there with some thousands of fighting men, and the Roman soldiers were let down the precipices in order to surprise and capture them. There had been earthquakes around the mountain and one of the cities had been nearly destroyed, but no one was prepared for what occurred seven years after the defeat of Spartacus. Suddenly, in the year 79 AD, a terrific rush of smoke, steam, and fire belched from the mountain summit, one side of the valley in which Spartacus had encamped was blown off, and its rocks, with vast quantities of ashes, burning stones, and sand, were ejected far into the sky. They then spread out like a vast pall and fell far and wide. For eight days and nights this went on, and the enormous quantity of steam sent up, together with the deluge of rain that fell, produced torrents on the mountainside, which, carrying onward the fallen ashes, overwhelmed everything in their way. Sulphurus Vapors filled the air and violent tremblings of the earth were constant. A city six miles off was speedily rendered uninhabitable, and was destroyed by the falling stones, but two others, Herculaneum and Pompeii, which already had suffered from the downpour of ashes, were gradually filled with the flood of water, sand, and ashes, which came down the side of the volcano, and covering them entirely. Buried cities excavated. The difference in ease of excavation is due to the following circumstance. Herculaneum, being several miles nearer the crater, was buried in a far more consistent substance, seemingly composed of volcanic ashes cemented by mud. Pompeii, on the contrary, was buried only in ashes and loose stones. The casts of the statues found in Herculaneum show the plastic character of the material that fell there, which time is hardened to rock-like consistency. These statues represented Hercules and Cleopatra, and the theater proved to be that of the long lost city of Herculaneum. The site of Pompeii was not discovered until forty years afterward, but work there proved far easier than at Herculaneum, and more progress was made in bringing it back to the light of day. The less solid covering of Pompeii has greatly facilitated the work of excavation, and a great part of the city has been laid bare. Many of its public buildings and private residences are now visible, and some whole streets have been cleared, while a multitude of interesting relics have been found. Among those are casts of many of the inhabitants, obtained by pouring liquid plaster into the ash molds that remained of them. We see them today in the attitude and with the expression of agony and horror with which death met them more than eighteen centuries ago. In succeeding eruptions much lava was poured out, and in AD 472 ashes were cast over a great part of Europe, so much that fear was caused at Constantinople. The buried cities were more and more covered up, and it was not until about AD 1700 that, as stated above, the city of Herculaneum was discovered, the peasants of the vicinity being in the habit of extracting marble from its ruins. They had also in the course of years found many statues. In consequence, an excavation was ordered by Charles III, the earliest result being the discovery of the theatre, with the statues above named. The work of excavation, however, has not progressed far in this city and on account of its extreme difficulty. Though various excellent specimens of artwork have been discovered, including the finest examples of mural painting extant from antiquity, the library was also discovered, 1,803 papyri being found. Though these had been charred to cinder and were very difficult to unroll and decipher, over 300 of them have been read. Pliny's Celebrated Description Pliny the Younger, to whom we are indebted for the only contemporary account of the great eruption under consideration, was, at the time of its occurrence, resident with his mother at Mizanem, where the Roman fleet lay, under the command of his uncle, the great author of the Historia Naturalis. His account, contained in two letters to Tacitus, is not so much a narrative of the eruption as a record of his uncle's singular death, yet it is of great interest as yielding the impressions of an observer. The translation which follows is adopted from the very free version of Melmoth, except in one or two places, where it differs much from the ordinary text. The letters are given entire, though some parts are rather specimens of style than good examples of description. Your request that I should send an account of my uncle's death, in order to transmit a more exact relation of it to posterity, deserves my acknowledgments, for if this accident shall be celebrated by your pen, the glory of it, I am assured, will be rendered forever illustrious. And, notwithstanding he perished by a misfortune which, as it involved at the same time a most beautiful country in ruins, and destroyed so many populous cities, seems to promise him an everlasting remembrance. Notwithstanding he has himself composed many enlasting works, yet I am persuaded the mention of him in your immortal works will greatly contribute to eternize his name. Happy I esteem those to be, whom Providence has distinguished with the abilities either of doing such actions as are worthy of being related, or of relating them in a manner worthy of being read. But doubly happy are they who are blessed with both these talents, in the number of which my uncle, as his own writings in your history will prove, may justly be ranked. It is with extreme willingness, therefore, that I execute your commands, and should, indeed, have claimed the task if you had not enjoined it. He was at that time with the fleet under his command at Mazzanum. On the twenty-fourth of August, about one in the afternoon, my mother desired him to observe a cloud, which appeared of a very unusual size and shape. He had just returned from taking the benefit of the sun, and, after bathing himself in cold water and taking a slight repast, had retired to his study. He immediately arose and went out upon an eminence, from whence he might more distinctly view this very uncommon appearance. It was not at that distance discernible from what mountain the cloud issued, but it was found afterward to ascend from Mount Vesuvius. I cannot give a more exact description of its figure than by comparing it to that of a pine tree, for it shot up to a great height in the form of a trunk, which extended itself at the top into a sort of branches, occasioned, I imagined, either by a sudden gust of air that impelled it, the force of which decreased as it advanced upwards, or the cloud itself being pressed back again by its own weight, and expanding in this manner. It appeared sometimes bright and sometimes dark and spotted, as it was more or less impregnated with earth and cinders. This extraordinary phenomenon excited my uncle's philosophical curiosity to take a nearer view of it. He ordered a light vessel to be got ready, and gave me the liberty, if I thought proper, to attend him. I rather chose to continue my studies, for, as it happened, he had given me an employment of that kind. As he was passing out of the house he received dispatches. The marines at Retna, terrified at the imminent peril. For the place lay beneath the mountain, and there was no retreat but by ships, entreated his aid in this extremity. He accordingly changed his first design, and what he began with a philosophical, he pursued with a heroic turn of mind. The voyage to Stabier. He ordered the galleys to put to sea, and went himself on board with an attention of assisting not only Retna, but many other places, for the population is thick on that beautiful coast. When hastening to the place from whence others fled with the utmost terror, he steered a direct course to the point of danger, and with so much calmness and presence of mind, as to be able to make and dictate his observations upon the motion and figure of that dreadful scene, he was now so nigh the mountain that the cinders, which grew thicker and hotter than nearer he approached, fell into the ships, together with pumice stones and black pieces of burning rock. They were in danger of not only being left aground by the sudden retreat of the sea, but also from the vast fragments which rolled down from the mountain and obstructed all the shore. Here he stopped to consider whether he should return back again, to which the pilot advised him. Fortune, said he, favours the brave. Carry me to Pomponianus. Pomponianus was then at Stabier, separated by a gulf which the sea, after several insensible windings, forms upon the shore. He, Pomponianus, had already sent his baggage on board, for though he was not at that time in actual danger, yet being within view of it, and indeed extremely near, if it should in the least increase, he was determined to put to sea as soon as the wind should change. It was favourable, however, for carrying my uncle to Pomponianus, whom he found in the greatest consternation. He embraced him with tenderness, encouraging and exhorting him to keep up his spirits, and the more to dissipate his fears he ordered, with an air of unconcern, the baths to be got ready, when, after having bathed, he sat down to supper with great cheerfulness, or at least, what is equally heroic, with all the appearance of it. In the meantime the eruption from Mount Vesuvius flamed out in several places with much violence, which the darkness of the night contributed to render still more visible and dreadful. But my uncle, in order to sue the apprehensions of his friend, assured him it was only the burning of the villages which the country people had abandoned to the flames. After this he retired to rest, and it was most certain he was so little discomposed as to fall into a deep sleep. For, being pretty fat, and breathing hard, those who attended without actually heard him snore. The court which led to his apartment being now almost filled with stones and ashes, if he had continued there any longer it would have been impossible for him to have made his way out. It was thought proper, therefore, to awaken him. He got up and went to Pomponianus and the rest of his company, who were not unconcerned enough to think of going to bed. They consulted together whether it would be most prudent to trust to the houses, which now shook from side to side with frequent and violent concussions, or to fly to the open fields where the calcined stone and cinders, though light indeed, yet fell in large showers and threatened destruction. In this distress they resolved for the fields as the less dangerous situation of the two, a resolution which, while the rest of the company were hurried into it by their fears, my uncle embraced upon cool and deliberate consideration. Death of Pliny the Elder They went out, then, having pillows tied upon their heads with napkins, and this was their whole defence against the storm of stones that fell around them. It was now day everywhere else, but there a deeper darkness prevailed than in the most obscure night, which, however, was in some degree dissipated by torches and other lights of various kinds. They thought proper to go down further upon the shore, to observe if they might safely put out to sea, but they found that the waves still ran extremely high and boisterous. There, my uncle, having drunk a draught or two of cold water, threw himself down upon a cloth which was spread for him, when immediately the flames and a strong smell of sulfur, which was the forerunner of them, dispersed the rest of the company and obliged him to rise. He raised himself up with the assistance of two of his servants and instantly fell down dead, suffocated, as I conjecture, by some gross and noxious vapor, having always had weak lungs and being frequently subject to a difficulty of breathing. As soon as it was light again, which was not till the third day after this melancholy accident, his body was found entire, and without any marks of violence upon it, exactly in the same posture as that in which he fell, and looking more like a man asleep than dead. During all this time my mother and I were at Mazzanum, but this has no connection with your history and your inquiry went no farther than concerning my uncle's death. With that therefore I will put an end to my letter. Suffer me only to add that I have faithfully related to you what I was either an eyewitness of myself, or received immediately after the accident happened, and before there was any time to vary the truth. You will choose out of this narrative such circumstances as shall be most suitable to your purpose, for there is a great difference between what is proper for a letter and a history between writing to a friend and writing to the public, farewell. In this account which was drawn up some years after the event, from the recollections of a student eighteen years old, we recognize the continual earthquakes, the agitated sea with its uplifted bed, the flames and vapors of an ordinary eruption, probably attended by lava as well as ashes, but it seems likely that the author's memory, or rather the information communicated to him regarding the closing scene of Pliny's life was defective. Flames and sulfurous vapors could hardly be actually present at Stabier, ten miles from the center of the eruption. That lava floated off from Vesuvius on this occasion has been usually denied, chiefly because at Pompeii and Herculaneum the causes of destruction were different, ashes overwhelmed the former, mud concreted over the latter. We observe indeed phenomena on the shore near Torre del Graco, which seems to require the belief that currents of lava had been solidified there at some period before the construction of certain walls and floors and other works of Roman date. In the Oxford Museum, among the specimens of lava to which the dates are assigned, is one referred to AD 79, but there is no mode of proving it to have belonged to the eruption of that date. Pliny's Second Letter A second letter from Pliny to Tacitus was required to satisfy the curiosity of that historian, especially as regards the events which happened under the eyes of his friend. Here it is according to Melmoth. The letter which, in compliance with your request, I wrote to you concerning the death of my uncle, has raised, it seems your curiosity to know what terrors and danger attended me while I continued at Mizzanum. For there I think the account in my former letter broke off. Though my shocked soul recoils, my tongue shall tell. My uncle having left us, I pursued the studies which prevented my going with him till it was time to bathe, after which I went to supper and from thence to bed, where my sleep was greatly broken and disturbed. There had been, for many days before, some shocks of an earthquake, which the less surprised us as they are extremely frequent in Campania, but they were so particularly violent that night that they not only shook everything about us, but seemed, indeed, to threaten total destruction. My mother flew to my chamber, where she found me rising in order to awaken her. We went out into a small court belonging to the house, which separated the sea from the buildings. As I was at that time but eighteen years of age, I know not whether I should call my behavior in this dangerous juncture, courage, or rashness, but I took up Livy and amused myself with turning over that author, and even making extracts from him, as if all about me had been in full security. While we were in this posture, a friend of my uncles, who has just come from Spain to pay him a visit, joined us, and observing me sitting with my mother with a book in my hand, greatly condemned her calmness at the same time that he reproved me for my careless security. Nevertheless, I still went on with my author. Though it was now morning, the light was exceedingly faint and languid. The buildings all around us tottered. And, though we stood upon open ground, yet as the place was narrow and confined, there was no remaining there without certain and great danger. We therefore resolved to quit the town. The people followed us in the utmost consternation, and, as to a mind distracted with terror, every suggestion seems more prudent than its own, pressed in great crowds about us in our way out. Being got to a convenient distance from the houses, we stood still, in the midst of a most dangerous and dreadful scene. The chariots which we had ordered to be drawn out were so agitated backwards and forwards, though upon the most level ground, that we could not keep them steady, even by supporting them with large stones. The seas seemed to roll back upon itself, and to be driven from its bank by the convulsive motion of the earth. It is certain, at least, that the shore was considerably enlarged, and many sea animals were left upon it. On the other side a black and dreadful cloud, bursting with an igneous serpentine vapor, darted out a long train of fire, resembling flashes of lightning but much larger. Upon this the Spanish friend, whom I have mentioned, addressed himself to my mother and me with great warmth and earnestness. If your brother and your uncle, said he, is safe, he certainly wishes you to be so too. But if he is parish, it was his desire, no doubt, that you might both survive him. Why, therefore, do you delay your escape a moment? We could never think of our own safety, we said, while we were uncertain of his. Hereupon our friend left us, and withdrew with the utmost precipitation. Soon afterward the clouds seemed to descend and cover the whole ocean, as it certainly did the island of Capriet, and the promontory of Mazzanum. My mother strongly conjured me to make my escape at any rate, which, as I was young, I might easily do. As for herself, she said, her age and corpulency rendered all attempts of that sort impossible. However she would willingly meet death if she could have the satisfaction of seeing that she was not the occasion of mine. But I absolutely refused to leave her, and taking her by the hand I let her on. She complied with great reluctance, and not without many reproaches to herself for retarding my flight. The ashes now began to fall upon us, though in no great quantity. I turned my head and observed behind us a thick smoke, which came rolling after us like a torrent. I proposed, while we yet had any light, to turn out of the high road lest she be pressed to death in the dark by the crowd that followed us. We had scarce stepped out of the path when darkness overspread us, not like that of a cloudy night, or when there is no moon, but of a room when it is all shut up and all the lights are extinct. Nothing then was to be heard but the shrieks of women, the screams of children and the cries of men, some calling for their children, others for their parents, others for their husbands, and only distinguishing each other by their voices, one lamenting his own fate, another that of his family, some wishing to die from the very fear of dying, some lifting their hands to the gods, but the greater part imagining that the last and eternal night was to come, which was to destroy the gods and the world together. Among them were some who augmented the real terrors by imaginary ones, and made the frightened multitude believe that mizanum was actually in flames. At length a glimmering light appeared, which we imagined to be rather the forerunner of an approaching burst of flames, as in truth it was, than the return of day. However, the fire fell at a distance from us. Then again we were immersed in thick darkness and a heavy shower of ashes rained upon us, which we were obliged every now and then to shake off, otherwise we should have been crushed and buried in the heap. I might boast that during all this scene of horror, not a sigh or expression of fear escaped me, had not my support been founded in that miserable, though strong, consolation that all mankind were involved in the same calamity, and that I imagined I was perishing with the world itself. At last this dreadful darkness was dissipated by degrees, like a cloud of smoke. The real day returned and soon the sun appeared, though very faintly, and as when an eclipse is coming on. Every object that presented itself to our eyes, which were extremely weakened, seemed changed, being covered over with white ashes, as with a deep snow. We returned to mizanum, where we refreshed ourselves as well as we could, and passed an anxious night between hope and fear, for the earthquake still continued, while several greatly excited people ran up and down, heightening their own and their friend's calamities by terrible predictions. However, my mother and I, notwithstanding the danger we had passed, and that which still threatened us, had no thoughts of leaving the place till we should receive some account of my uncle. And now you will read this narrative without any view of inserting it in your history, of which it is by no means worthy, and indeed you must impute it to your own request if it shall not even deserve the trouble of a letter. Farewell. Dion Cassius on the Eruption The story told by Pliny is the only one upon which we can rely. Dion Cassius, the historian, who wrote more than a century later, does not hesitate to use his imagination, telling us that Pompeii was buried under the shower of ashes while all the people were sitting in the theater. This statement has been effectively made use of by Bulwer in his last days of Pompeii. In this he pictures for us a gladiatorial combat in the arena, with thousands of deeply interested spectators occupying the surrounding seats. The novelist works his story up to a thrilling climax in which the volcano plays a leading part. This is all very well as a vivid piece of fiction, but it does not accord with fact since Dion Cassius was undoubtedly incorrect in his statement. We know now from the evidence furnished by the excavations that none of the people were destroyed in the theaters, and indeed that there were very few who did not escape from both cities. It is very likely that many of them returned and dug down for the most valued treasures in their buried habitations. Dion Cassius may have obtained the material for his accounts from the traditions of the descendants of survivors, and if so he shows how terrible must have been the impression made upon their minds. He assures us that during the eruption a multitude of men of superhuman nature appeared, sometimes on the mountain and sometimes in the environs, that stones and smoke were thrown out, the sun was hidden, and then the giants seemed to rise again, while the sounds of trumpets were heard. Lake Avernus Not far from Vesuvius lay the famous Lake Avernus, whose name was a long popular synonym for the infernal regions. The lake is harmless today, but its reputation indicates that it was not always so. There is every reason to believe that it hides the outlet of an extinct volcano, and that long after the volcano ceased to be active it emitted gases as fatal to animal life as those suffocating vapors which annihilated all the cattle on the island of Lanserot in the Canaries in the year 1730. Its name signifies bird lists, indicating that its ascending vapors were fatal to all birds that attempted to fly above its surface. In the superstition of the Middle Ages, Vesuvius assumed the character which had before been given to Avernus, and was regarded as the mouth of hell. Cardinal Damiano, in a letter to Pope Nicholas II, written about the year 1060, tells the story of how a priest, who had left his mother ill at Beneventum, went on his homeward way to Naples past the crater of Vesuvius, and heard issuing therefrom the voice of his mother in great agony. He afterward found that her death coincided exactly with the time at which he had heard her voice. A trip to the summit of Vesuvius is one of the principal attractions for strangers who are visiting Naples. There is a fascination about that awful slayer of cities which few can resist, and no less attractive is a city of Pompeii, now largely laid bare after being buried for 18 centuries. We are indebted to Henry Haney for the following interesting description. Once seen, it will never be forgotten. It is full of suggestions. It kindles emotions that are worth the kindling, and brings on dreams that are worth the dreaming. Of the three places overwhelmed, Herculaneum, Pompeii, and Stabier, the last scarcely repays excavation in one sense, and the first in another. But to watch the diggers at Pompeii is fascinating, even when there is no reasonable expectation of a find. Herculaneum was buried with lava, or rather with tufa, and it is so very hard that the expense of uncovering of only a small part of that city has been very great. How Pompeii impresses its visitors. Pompeii was smothered in ashes, however, and most of it is uncovered now. But while there is much that is fascinating, and all of it is instructive, there is nothing grand or awe-inspiring in the ruins of Pompeii. No visitor stands breathless as in the great Hall of Carnac, or in the once dreadful Coliseum at Rome, or dreams with sensuous delight as before the Jasmine Corded Agra. The weirdness of the scene possesses us as a haunted chamber-mite. We have before us the narrow lanes, paved with tufa, in which Roman wagon-wheels have worn deep ruts. We cross streets on stepping-stones which sandaled feet ages ago polished. We see the wine-chops with empty jars, counters stained with liquor, stone mills where the wheat was ground, and the very ovens in which bread was baked more than eighteen centuries ago. Welcome is offered us at one silent broken doorway, at another we are warned to beware of the dog. The painted figures, some of them so artistic and rich in colors that pictures of them are disbelieved. The mosaic pavements, the empty fountains, the altars, and household gods, the marble pillars, and the small gardens are there just as the owners left them. Some of the walls are scribbled over by the small boys of Pompeii and strange characters which mock modern erudition. In places we read the advertisements of gladiatorial shows, never to come off, the names of candidates for legislative office who were never to sit. There is nothing like this elsewhere. The value of Pompeii to those classic students who would understand, not the speech only, but the life and the everyday habits of the ancient world is too high for reckoning. Its inestimable evidence may be seen in the fact that any high school boy can draw the plan of a Roman house, while ripest scholars hesitate on the very threshold of a Greek dwelling. This is because no Hellenic Pompeii has yet been discovered, but thanks to the silent city close to the beautiful Bay of Naples, the Latin house is known from Ostium Deporticus, from the front door to the back garden wall. Streets and Houses of Pompeii The streets of Pompeii must have had a charm unapproached by those of any city now in existence. The stores, indeed, were wretched little dens. Two or three of them commonly occupied the front of a house on either side of the entrance, the Ostium. But when the door lay open, as was usually the case, a passer-by could look into the atrium, prettily decorated and hung with rich stuffs. The sunshine entered through an aperture in the roof, and shone on the waters of the Impluvium, the mosaic floor, the altar of the household gods, and the flowers around the fountain. As the life of the Pompeians was all outdoors, their pretty homes stood open always. There was, indeed, a curtain betwixt the atrium and the peristyle, but it was drawn only when the master gave a banquet. Thus a wayfarer in the street could see, beyond the hall described, and its busy servants, the white columns of the peristyle, with creepers trained about them, flowers all around, and jets of water playing through pipes which are still in place. In many cases the garden itself could be observed between the pillars of the further gallery and rich paintings on the wall beyond that. But how far removed those little palaces of Pompeii were from our notion of well-being is scarcely to be understood by one who has not seen them. It is a question strange in all points of view where the family slept in the houses, nearly all of which had no second story. In the most graceful villas the three to five sleeping chambers round the atrium and four round the peristyle were rather ornamental cupboards than ought else. One did not differ from another, and if these were devoted to the household, the slaves, male and female, must have slept on the floor outside. The master, his family, and his guest used these small dark rooms, which were apparently without such common luxuries as we expect in the humblest home. All their furniture could hardly have been more than a bed and a footstool. But it should be remembered that the public bath was a daily amusement. The kitchen of each villa certainly was not furnished with such ingenuity, expense, or thought, as the stories of Roman gormandizing would have led us to expect. In the house of the a-deal, so called from the fact that pansome ed is inscribed in red characters by the doorway, the cook seems to have been employed in frying eggs at the moment when increasing danger put him to flight. His range, four partitions of brick, was very, very small. A knife, a strainer, a pan lay by the fire just as they fell from the slave's hand. Value of the Discovery of Pompeii This description strongly presents to us the principal value of the Discovery of Pompeii. Interesting as are the numerous works of art found in its habitations, and important as is their bearing upon some branches of the art of the ancient world, this cannot compare in interest with the flood of light which is here thrown on ancient life in all its details, enabling us to picture to ourselves the manners and habits of life of a cultivated and flourishing population at the beginning of the Christian era, to an extent which no amount of study of ancient history could yield. Looking upon the work of the volcano as essentially destructive, as we naturally do, we have here a valuable example of its power as a preservative agent, and it is certainly singular that it is to a volcano we owe much of what we know concerning the city's dwellings and domestic life of the people of the Roman Empire. It would be very fortunate for students of antiquity if similar disasters had happened to cities in other ancient civilized lands, however unfortunate it might have been to their inhabitants, but doubtless we are better off without knowledge gained from the ruins thus produced.