soil in its passage, and the sandy plains are covered with a low and scanty vegetation, chiefly fed by the night dews and whatever moisture is brought by the on-shore wind.  The total rain of the year does not exceed thirty inches; and the inhabitants live in frequent apprehension of droughts and famines.  These conditions attain their utmost manifestation at the extreme north and in the Jaffna peninsula:  there the temperature is the highest[1] in the island, and, owing to the humidity of the situation and the total absence of hills, it is but little affected by the changes of the monsoons; and the thermometer keeps a regulated pace with the progress of the sun to and from the solstices.  The soil, except in particular spots, is porous and sandy, formed from the detritus of the coral rocks which it overlays.  It is subject to droughts sometimes of a whole year’s continuance; and rain, when it falls, is so speedily absorbed, that it renders but slight service to cultivation, which is entirely carried on by means of tanks and artificial irrigation, in the practice of which the Tamil population of this district exhibits singular perseverance and ingenuity.[2] In the dry season, when scarcely any verdure is discernible above ground, the sheep and goats feed on their knees—­scraping away the sand, in order to reach the wiry and succulent roots of the grasses.  From the constancy of this practice horny callosities are produced, by which these hardy creatures may be distinguished.

[Footnote 1:  The mean lowest temperature at Jaffna is 70 deg, the mean highest 90 deg; but in 1845-6 the thermometer rose to 90 deg and 100 deg.]

[Footnote 2:  For an account of the Jaffna wells, and the theory of their supply with fresh water, see ch. i. p. 21.]

Water-spouts are frequent on the coast of Ceylon, owing to the different temperature of the currents of air passing across the heated earth and the cooler sea, but instances are very rare of their bursting over land, or of accidents in consequence.[1]

[Footnote 1:  CAMOENS, who had opportunities of observing the phenomena of these seas during his service on board the fleet of Cabral, off the coast of Malabar and Ceylon, has introduced into the Lusiad the episode of a water-spout in the Indian Ocean; but, under the belief that the water which descends had been previously drawn up by suction from the ocean, he exclaims:—­

  “But say, ye sages, who can weigh the cause,
  And trace the secret springs of Nature’s laws;
  Say why the wave, of bitter brine erewhile,
  Should be the bosom of the deep recoil,
  Robbed of its salt, and from the cloud distil,
  Sweet as the waters of the limpid rill?”

(Book v.)

But the truth appears to be that the torrent which descends from a water-spout, is but the condensed accumulation of its own vapour, and, though in the hollow of the lower cone which rests upon the surface of the sea, salt water may possibly ascend in the partial vacuum caused by revolution; or spray may be caught up and collected by the wind, still these cannot be raised by it beyond a very limited height, and what Camoens saw descend was, as he truly says, the sweet water distilled from the cloud.]