It contains the capital, Jakarta.
Java is almost entirely of volcanic origin, and contains no less than thirty-eight mountains of that conical form which indicates their having at one time or other been active volcanoes. Only a few of them, however, have been in activity in more recent times. The most remarkable eruption was that of the mountain named Papandayang, which occurred in 1772. During this convulsion the greater part of the mountain, which was formerly one of the largest in the island, was completely swallowed up in some great underground gulf.
On the night between the 11th and 12th of August of that year, the mountain appeared to be wholly enveloped in a remarkable luminous cloud. The inhabitants fled in consternation; but before they could all escape, the mountain began to totter, and the greater part of it tumbled down and disappeared. The crash with which it fell was dreadful, the noise resembling the discharge of volleys of artillery. Besides that part of the mountain which thus fell in, a large extent of ground in its neighbourhood was ingulfed. The space measured fifteen miles in length and six in breadth. The ground for many miles round this space was covered with immense quantities of ashes, stones, cinders, and other substances thrown out by the volcano. These were, on many parts of the surface, accumulated to the height of three feet; and even at the end of six weeks, the layers thus deposited retained so much heat as to render the mountain inaccessible. By this dreadful occurrence forty villages were destroyed, some ingulfed with the ground on which they stood, others buried under the loose materials which had been ejected. Not far short of three thousand of the inhabitants perished.
Another of the volcanoes of Java, called Galoen-gong, burst into eruption in 1822, commencing with a terrible explosion of stones and ashes, followed by a stream of hot mud, which overspread a large tract of ground. This eruption proved still more fatal to human life, about four thousand persons having been destroyed.
So lately as September 1849, Mount Merapia, another volcano in this island, which had been supposed to be quite extinct, burst forth into an eruption, which lasted three days. It was accompanied by a violent hurricane. The bed of a river was filled up by the matter thrown out from the crater, and the destruction of property in crops, &c., was immense. Fortunately the inhabitants succeeded in making their escape, so that no lives were lost. A second eruption of this mountain however, in January 1864, was more disastrous, three hundred and fifty people having perished.
Java likewise contains a remarkable mud volcano. When viewed from a distance, there are seen to rise from it large volumes of vapour, like the spray from the billows dashing against a rocky shore, and there is heard a loud noise like distant thunder. On a nearer approach, the source of these phenomena is seen to be a hemispherical mound of black earth mixed with water, about sixteen feet in diameter, and which at intervals of a few seconds is pushed upwards by a force acting from beneath to a height of between twenty and thirty feet. It then suddenly explodes with a loud noise, scattering in every direction a quantity of black mud, which has a strong pungent smell resembling that of coal-tar, and is considerably warmer than the air. With the mud thus thrown out there has been formed around the mound a large perfectly level and nearly circular plain, about half a mile in circumference. The water mixed with the mud is salt, and the salt is separated from it by evaporation for economical purposes. During the rainy season the action of this mud volcano becomes more violent, the explosions are louder, and the mud is thrown to a greater height.
The crater of Tangkuban-Prahu, another of the volcanoes of Java, presents a remarkable appearance. On approaching its edge, nothing is seen but an abyss, from which dense clouds of vapour continually arise, with hideous sounds, like the steam rushing from the open valves of hundreds of steam-engines. This great abyss consists really of two craters, separated the one from the other by a narrow ridge of rock, to which it is possible to descend and view them both. Each of them is elliptical in form, and surrounded by a crater-wall. That of the western, which the natives call the poison-crater, is a rapid slope nearly a thousand feet in depth, and is densely covered with brushwood almost to the bottom. The flat floor of this deep basin is continually sending out vapours, and in its centre is a pool of boiling water of a sulphur yellow colour. The floor itself is nothing but a crust of sulphur full of rents and holes, whence vapours constantly arise. This crust covers a surface of boiling hot bitter water, and by breaking it beautiful crystals of sulphur may be obtained.
The eastern is called by the natives the king's-crater; its walls are only between five and six hundred feet in depth, and are perfectly bare from top to bottom. The surfaces of the rocks composing them are grayish white, an effect produced upon them by the action of the vapours, to which they are continually exposed. The bottom of this crater consists of mud mixed with sulphur; but round the edges are some stones and hard masses. These are the remnants of an eruption which took place from this crater in 1846, when there was thrown up a great mass of sulphurous boiling mud, accompanied by quantities of sand and stones. This mountain, therefore, seems to be also more of the nature of a mud volcano, than of one which throws out burning lava.
Considerably to the eastward of Sumbáwa lies the Island of Timor, in which there was for a long time a volcanic peak, whose perpetual fires served as a lighthouse to mariners navigating those seas. But in the year 1637 there took place a great eruption of the mountain, which ended in its being gobbled up whole and entire, leaving nothing behind it but a lake, in which its fires were quenched, and which now occupies its place.
To the north of Timor lie the Molucca Islands, several of which are volcanic. In one of them, named Machian, there occurred in the year 1646 an extraordinary event. A mountain was rent from top to bottom, sending out great columns of fire and dense vapours. The two parts now remain two distinct mountains.
In the Island of Sangir, another of the Moluccas, there was a violent eruption in March 1856. A large portion of the mountain fell down, and tremendous floods of water issued forth. The destruction that ensued was dreadful, upwards of two thousand persons having perished.
In another part of the Indian Ocean, near Madagascar, lies the little Isle of Bourbon, containing the volcano Salazes, which occasionally throws out volcanic silk; a curious thready substance, so strongly resembling spun glass.