Page:Madras Journal of Literature and Science, series 1, volume 6 (1837).djvu/143

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1837.]
for widening the Pamban Passage.
121

country match having failed. The divers and boatmen had not entirely recovered from the effects of the festival. Removed 652 feet of stone.

21st. Only half a day's work was done, as the weighing boat and tackle required repair; fifteen charges fired, and 597 feet of stone removed.

22d. The current was to-day exceedingly strong, and the divers gave up early; six charges were fired, and 350 cubic feet of stone removed.


At day-light proceeded to examine the passage through the sand bank. Its figure, as well as the soundings, do not appear to have varied in the slightest degree since the survey made under Major Sim. The channel is precisely where it then existed, with a depth of five and a half feet at the lowest tides, and about eight high water. It gradually increases to twenty feet, which is found near the shore close to the island of Ramisseram, and the greatest depth close to the edge of the bank on its eastern side; the remainder of this space has seldom more than ten and twelve feet water; bottom, rocks mixed with coarse sand, broken coral, &c. All vessels are obliged to pass over this part. Those proceeding to Ceylon have an open passage, with eighteen feet water; the channel to the coast of India is round the southern extremity of the bank, and has only twelve feet at low tides. Vessels can, however, gain the open sea by the Ceylon passage, which is seldom done except when commanded by Europeans. This route is well sheltered by a chain of coral reefs and islands, which protect it from the S. W. winds. I followed the whole extent of the bank, and found in no place but the one above mentioned more than three and three and a half feet. Near the eastern side, close to Tonitora, the bank is only a few yards in extent. It is said an opening was forced by the storm of 1814 through this point, of equal depth to the other, which gradually closed up, and it is now such as I saw it in the year 1809.

Having thus ascertained that no other passage existed, I returned to the point before mentioned, and commenced a minute examination of its composition. Contrary to the opinion I had previously formed, the centre and most shallow part was composed of fine sand, mixed with blue mud, and covered with marine plants, abounding with insects and sea worms, which would appear to indicate that it never suffers any material change, and is not, according to the reports of the masters of the dhonies, covered with sand to nearly a foot in depth during the S. W. monsoon. I remained on this point till the tide had commenced to flow from the north, running at the rate of nearly five miles an hour over the reef; here the rapidity was trifling, never exceeding one and a half miles per hour, the velocity being lost in the great expanse of water over which it spreads on passing the reef.