At a distance inland of not more than thirty or forty miles, where the ascent is gradual, and of fifteen or twenty or less where it is rapid, the thermometer falls from five to ten degrees lower. At _Chi-serúa_, situated about 40 miles inland of Batavia, and _Chi-pánas_, about twelve miles further, on the opposite slope of the mountain _Gedé_, the thermometer ranges generally between 60 and 70°. In the morning, at six o'clock, it is sometimes as low as 57°; and in the afternoon, at three, its usual height is from 67 to 70°, but seldom rising to 72°. On some of the hills inland of _Semárang_, on which Europeans frequently reside during the dry season, at an elevation of about four thousand feet, the thermometer is frequently seen as low as 45°, and generally, in the clear season, ranges from 50 to 62°, and on the summit of one of the mountains (_Sindóro_) it has been observed as low as 27°[27]. Ice, as thick as a Spanish dollar, has been found; and hoar-frost, denominated _bóhon úpas_, or the poisonous dew, has been observed on the trees and vegetation of some of the higher regions.
By its insular situation, the climate of Java enjoys the benefit of land and sea breezes, which in its least favoured parts subdue the fierceness of the tropical rays, while the great elevation of its interior affords the rare advantage, that from the sea-shore up to the tops of the mountains, there is, almost from one end of the island to the other, a regular diminution of the temperature, at the rate of two or three degrees of Fahrenheit for every ten miles.
The general inference which has been drawn by professional men, from the experience which the occupation of Java by the British has afforded, is, that with the exception of the town of Batavia, and some parts of the northern coast, the island of Java stands on a level, in point of salubrity, with the healthiest parts of British India, or of any tropical country in the world.
The principal stations of the British army, composed of Europeans and Sepoys, were at Weltevreden, within three miles of the town of Batavia, and at _Semárang_ and _Surabáya_, spots certainly less favourable to health than the rest of the island taken generally; but detachments from it have occasionally done duty in every district of the island.