1: The barrier known as Adam's Bridge, which obstructs the navigation of the channel between Ceylon and Ramnad, consists of several parallel ledges of conglomerate and sandstone, hard at the surface, and growing coarse and soft as it descends till it rests on a bank of sand, apparently accumulated by the influence of the currents at the change of the monsoons. See an Essay by Captain STEWART on the Paumbem Passage. Colombo, 1837. See Vol. II. p. 554.
On the north-west side of the island, where the currents are checked by the obstruction of Adam's Bridge, and still water prevails in the Gulf of Manaar, these deposits have been profusely heaped, and the low sandy plains have been proportionally extended; whilst on the south and east, where the current sweeps unimpeded along the coast, the line of the shore is bold and occasionally rocky.
This explanation of the accretion and rising of the land is somewhat opposed to the popular belief that Ceylon was torn from the main land of India[1] by a convulsion, during which the Gulf of Manaar and the narrow channel at Paumbam were formed by the submersion of the adjacent land. The two theories might be reconciled by supposing the sinking to have occurred at an early period, and to have been followed by the uprising still in progress. But on a closer examination of the structure and direction of the mountain system of Ceylon, it exhibits no traces of submersion. It seems erroneous to regard it as a prolongation of the Indian chains; it lies far to the east of the line formed by the Ghauts on either side of the peninsula, and any affinity which it exhibits is rather with the equatorial direction of the intersecting ranges of the Nilgherries and the Vindhya. In their geological elements there is, doubtless, a similarity between the southern extremity of India and the elevated portions of Ceylon; but there are also many important particulars in which their specific differences are irreconcilable with the conjecture of previous continuity. In the north of Ceylon there is a marked preponderance of aqueous strata, which are comparatively rare in the vicinity of Cape Comorin; and whilst the rocks of the former are entirely destitute of organic remains[2]; fossils, both terrestrial and pelagic, have been found in the Eastern Ghauts, and sandstone, in some instances, overlays the primary rocks which compose them. The rich and black soil to the south of the Nilgherries presents a strong contrast to the red and sandy earth of the opposite coast; and both in the flora and fauna of the island there are exceptional peculiarities which suggest a distinction between it and the Indian continent.
1: LASSEN, Indische Alterthumskunde, vol. i. p. 193.
2: At Cutchavelly, north of Trincomalie, there exists a bed of calcareous clay, in which shells and crustaceans are found in a semi-fossilised state; but they are all of recent species, principally Macrophthalmus and Scylla. The breccia at Jaffna contains recent shells, as does also the arenaceous strata on the western coast of Manaar and in the neighbourhood of Galle. The existence of the fossilised crustaceans in the north of Ceylon was known to the early Arabian navigators. Abou-zeyd describes them as, "Un animal de mer qui resemble à l'écrevisse; quand cet animal sort de la mer, il se convertit en pierre." See REINAUD, Voyages faits par les Arabes, vol. i. p. 21. The Arabs then; and the Chinese at the present day, use these petrifactions when powdered as a specific for diseases of the eye.
Mountain System.—At whatever period the mountains of Ceylon may have been raised, the centre of maximum energy must have been in the vicinity of Adam's Peak, the group immediately surrounding which has thus acquired an elevation of from six to eight thousand feet above the sea.[1] The uplifting force seems to have been exerted from south-west to north-east; and although there is much confusion in many of the intersecting ridges, the lower ranges, especially those to the south and west of Adam's Peak, from Saffragam to Ambogammoa, manifest a remarkable tendency to run in parallel ridges in a direction from south-east to north-west.
1: The following are the heights of a few of the most remarkable places:—
| Pedrotallagalla | 8280 English feet. |
| Kirrigalpotta | 7810 English feet. |
| Totapella | 7720 English feet. |
| Adam's Peak | 7420 English feet. |
| Nammoone-Koolle | 6740 English feet. |
| Plain of Neuera-ellia | 6210 English feet. |
Towards the north, on the contrary, the offsets of the mountain system, with the exception of those which stretch towards Trincomalie, radiate to short distances in various directions, and speedily sink down to the level of the plain. Detached hills of great altitude are rare, the most celebrated being that of Mihintala, which overlooks the sacred city of Anarajapoora: and Sigiri is the only example in Ceylon of those solitary acclivities, which form so remarkable a feature in the table-land of the Dekkan, starting abruptly from the plain with scarped and perpendicular sides, and converted by the Indians into strongholds, accessible only by precipitous pathways, or steps hewn in the solid rock.