Notwithstanding the most careful examination of this part
of the coast, we could not discover the spot, which in the Danish charts is marked as furnishing water fit for drinking, but perceived nothing save mangrove swamps, with numerous water-courses filled with brackish water, the two largest of which we navigated in our gondola as far as was practicable.
The island of Kondul in St. George's Channel forms another very fair anchorage; and similarly on the N. side of Great Nicobar, one finds several suitable bays, the most easterly of which, called Ganges Harbour, is fringed with coral banks, rendering it proportionately difficult of access. The anchorage of Kondul may be selected for one reason, namely, that it is land-locked towards both N.E. and S.W., besides having the additional advantage of being airy, and distant from the mangrove swamps, whereas in the bays on the N. coast of Great Nicobar these are of immense extent. One of these mangrove swamps in the central cove was traversed by one of the naturalists, the result of which was that he found a river debouching into the sea through the very heart of the swamp, which, however, so long as the sea-water could find entrance, was not of course drinkable.
On the west side of Great Nicobar, along the whole length of which we sailed, but which we could not visit more carefully, owing to want of time and the heavy S.W. swell of the ocean, several other promontories and coves are apparently available as harbours, and moreover may be supposed to be the embouchures of rivers. At the south point of Great Nicobar there is a large bay, which however being quite exposed from
S.W. to S.E. must be anything but a safe anchorage during the S.W. monsoon. During the prevalence of the N.E. monsoon it seems tolerably well suited for an anchorage, if the eastern promontory be kept S.E. by S., and the anchor be cast in soundings of from 10 to 13 fathoms. Landing, however, is at all times a matter of difficulty, as the surf is very boisterous and the swell of the sea pretty heavy. Its most remote point is the mouth of the river Galatea, which, however, is closed by a sand-bar, and for that reason cannot be easily reached. This bay, owing to its configuration, is excessively hot and sweltering, and with reference to its salubrity cannot be recommended as a suitable abode.
The climate of the Archipelago, though tropical, is not nevertheless to be ranked among the hottest, in consequence of its insular position, and of the whole of the islands being thickly clothed with forest. Hence the quantity of rain, which, as has been seen, is sufficient to keep the rivers full even in the dry season. According to the meteorological observations made on these islands by various observers at different periods of the year, the average temperature does not exceed 77° Fahr., much about the temperature of the fluid found in the fresh unripe cocoa-nut. But during the months of April and October respectively, at which period calms prevail in these islands, the maximum temperature of 86° to 88° Fahr. is reached.
Considering the violence with which rain falls, and that the dry season of the N.E. monsoon from November to March,
and the damp season of the S.W. monsoon from April to October, are by no means so sharply defined on these islands as on the adjoining coasts of the mainland, the quantity of annual rainfall must be enormous. At certain times it is not much less than 100 or even 150 inches, and yet it probably is not so high as that presented by other localities, which experience the regular changes of the monsoons, as for instance, in the Straits of Malacca, where the annual rainfall is 208 inches, or Mahableshwur south of Bombay, where it amounts to no less than 254 inches! March is the dryest month in the year. During the whole of the month, which we spent on the islands or in their immediate vicinity, we only had three sharp thunder-storms. These become more frequent and severe during April, until about May or June the S.W. monsoon sets in and envelopes the islands in rain-clouds. Where some special physical configuration of the soil does not admit of the rapid carrying off of the redundant deluge of rain, the island must necessarily be unusually well off for water. Of the correctness of this theory we were enabled thoroughly to satisfy ourselves, since the close of the dry season is necessarily unfavourable to there being any water remaining in the streams and brooks; notwithstanding which even the smallest of the islands, Pulo Milù and Kondul, although their rivulets had ceased to flow, possessed a sufficient supply of sweet drinkable water among the numerous basin-shaped pools that occur in the beds of the various streams. From the forest-covered slopes of Tillangschong also, small streams of fresh
water are continually trickling. The insignificant brooks and rivers of the large well-wooded islands lying further to the south of Great and Little Nicobar, are in like manner kept full the whole year by the blessed abundance of the watery element. On the other hand, the northern islands, so far at least as the marl-formation extends, seem to be but scantily supplied with water, especially on Kamorta, Nangkauri, Tringkut, and apparently Teressa and Bampoka as well. All the small streams on the two first-named islands, which fall into the Nangkauri harbour, were found to be very nearly dried up.
The principal beverage of the natives of these islands is the fluid contents of the unripe cocoa-nut, while it should seem that they fetch the water required for house purposes from the pools of sweet water, which they find scattered here and there among the river-courses. Springs we saw none, with the exception of the old ruined one of the Moravian Brethren near the village of Malacca on the island of Nangkauri. Kar-Nicobar, although likewise belonging to the same marl-formation as the before-mentioned islands, has nevertheless no lack of drinkable water, since the expanse of land raised from eight to twelve feet above the level of the ocean constitutes the site of those singular springs, the sweet water in which rises and falls with the ebb and flow of the tide. The explanation of this singular phenomenon must not be sought for in the filtration of the sea-water by the coral rock, but is simply due to the rain-water, being the lighter, floating