The mountains of Java are very high, so that many of them can be seen at the distance of thirty or forty leagues. That which is called the _Blue Mountain_ is by far the highest, being seen from the greatest distance at sea. Java is subject to frequent and terrible earthquakes, which the inhabitants believe are caused by the mountain of Parang, which is full of sulphur, salt-petre, and bitumen, which take fire by their intestine commotions, causing a prodigious struggle within the bowels of the earth, whence proceeds the earthquake; and they assert that it is common, after an earthquake, to see a vast cloud of smoke hanging over the top of that mountain. About thirty years before Roggewein was in Batavia, Mynheer Ribeck, then governor-general, went with many attendants to the top of this mountain, where he perceived a large cavity, into which he caused a man to be let down, to examine the inside. On his return, this man reported that the mountain was all hollow within, that he heard a most frightful noise of torrents of water on every side, that he here and there saw flames bursting out, so that he was afraid of going far, from apprehension of either being stifled by the noxious vapours, or falling into one of the chasms. The waters in the neighbourhood of this mountain are unwholesome, and even those in the neighbourhood of Batavia are impregnated with sulphur, those who drink much of them being liable to several disorders, particularly the dysentery. But when boiled, their water is entirely freed from the sulphur, and does no manner of harm, though drank copiously. The fruits and plants of Java are excellent and numberless. Among these the cocoa-nut tree is by far the most valuable, as besides its fruit already described, the bark makes a kind of hemp which is manufactured into good ropes and cables; the timber serves to build houses and ships, and the leaves serve to cover the former. It is said that the father of a family in this country causes a cocoa-nut tree to be planted at the birth of each of his children, by which each may always know his own age, as this tree has a circle rising yearly on its stem, so that its age may be known by counting these circles: and when any one asks a father the ages of his children, he sends them to look at his cocoa trees.