In the south-west monsoon the current changes its direction; and, although it flows steadily to the northward, its action is very irregular and unequal till it readies the Coromandel coast, after passing Ceylon. This is accounted for by the obstruction opposed by the headlands of Ceylon, which so intercept the stream that the current, which might otherwise set into the Gulf of Manaar, takes a south-easterly direction by Galle and Donedra Head.[1]
[Footnote 1: For an account of the currents of Ceylon, see HORSBURGH's _Directions for Sailing to and from the East Indies, &c._; vol i. p. 516, 536, 580; KEITH JOHNSTON's _Physical Atlas_, plate xiii. p. 50.]
There being no lakes in Ceylon[1], in the still waters of which the rivers might clear themselves of the earthy matter swept along in their rapid course from the hills, they arrive at the beach laden with sand and alluvium, and at their junction with the ocean being met transversely by the gulf-streams, the sand and soil with which they are laden, instead of being carried out to sea, are heaped up in bars along the shores, and these, being augmented by similar deposits held in suspension by the currents, soon extend to north, and south, and force the rivers to flow behind them in search of a new outlet.
[Footnote 1: Pliny alludes to a lake in Ceylon of vast dimensions, but it is clear that his informants must have spoken of one of the huge tanks for the purpose of irrigation. Some of the _Mappe-mondes_ of the Middle Ages place a lake in the middle of the island, with a city inhabited by astrologers; but they have merely reproduced the error of earlier geographers. (SANTAREM, _Cosmog_. tom. iii. p. 336.)]
These formations once commenced, their growth proceeds with rapidity, more especially on the east side of the island; as the southern current in skirting the Coromandel coast brings with it quantities of sand, which it deposits, in tranquil weather, and this being carried by the wind is piled in heaps from Point Pedro to Hambangtotte. Hence at the latter point hills are formed of such height and dimensions, that it is often necessary to remove buildings out of their line of encroachment.[1]
[Footnote 1: This is occasioned by the waste of the banks further north during the violence of the N. E. monsoon; and the sand, being carried south by the current, is intercepted by the headland at Hambangtotte and thrown up these hills as described.]