Page:Madras Journal of Literature and Science, series 1, volume 6 (1837).djvu/145

1837.] level with low water, and on some places salt water still stands in pools. The distance across is only two thousand one hundred and thirty feet, and the soil perfectly easy to work. A canal would therefore be readily excavated, offering only the difficulty of pumping out the water to gain a depth of eighteen feet below the level of the sea, and would be a work of less difficulty than cleaning the ditch of Fort St. George, or even the canal across the esplanade. The beds of sandstone would rather assist than retard the excavation, amd furnish an excellent material to line the banks of the canal; a precaution absolutely necessary to prevent its filling up with the sand of which the soil consists. Thus much of the work would therefore be performed with certainty; the expence would be considerable, but still much less than works of this scale and importance generally cost. The most formidable part of the undertaking still remains, viz. continuing the canal into deep water on the northern side, where the rock shelves gradually into twenty feet, at a distance of one thousand two hundred yards, covered with coral in every form, and approaching in some places to within a few feet of the surface. This is, however, a simple question of expence, and not of difficulty; the execution is perfectly easy and certain, with time and means. But I fear that nothing less than piers on each side would effectually protect the canal, or enable vessels to pass along it at all times, and lock gates must be formed at each extremity of the land cut, to prevent a current, and consequently any deposit or passage of sand. Should a small quantity by any means lodge at the mouth of the outer canal, the water retained by the gates, and discharged by means of under sluices, would effectually remove such an obstruction. The appearance of the rock, as also of the coral, would indicate that no such deposit takes place; and, if no current is allowed through the passage, it appears probable, and even certain, that the cause of an accumulation of sand would be prevented.

The only point to be decided is, if, with a channel of twelve feet, which may be obtained at this place, there will remain any object in having another of eighteen. This is a question I am not competent to decide; as it must depend on the importance attached to the commerce of the country, as also regarding the passage of steam vessels or ships of war by the shortest and most practicable route at all seasons.

23d. Both weighing boats in full work, and by 2 had removed 1130 cubic feet of stone, about 75 tons. The explosions had not so great an effect as usual, having come on a flat bed of rock, extending across the whole channel, affording no weak points from which a line of least resistance could be found; the tamping was generally blown out. Directed the holes should be made five feet deep, quite through the