Fig. [128] shows these two converging breakwaters, which have been built out into the Mediterranean from the coast, the larger and more westerly one being one mile and a half long, the shorter about a mile and a quarter, and the distances between the two lighthouses erected on the extremities of the breakwater being half a mile.
The piers are made of concrete which was cast in blocks weighing 10 tons each. This composition has of late years been greatly approved by engineers where stone cannot be procured. The sea-face of the great canal in Holland is composed of a similar artificial stone, and it is found to bear the wear and tear of the waves almost, if not quite, as well as ordinary stone. It is stated that 25,000 blocks, each weighing 10 tons, were used. They were not laid with the regularity of ordinary masonry, but had been dropped from large barges, so that they presented a very rugged and uneven appearance (Fig. [129]); but the object of throwing out these great bulwarks is for the purpose of preventing the sand brought down by the Nile silting in and closing up the canal. Along the western pier there is, from this cause, a constant settlement of sand, which was partially washed through the interstices left between the blocks of artificial stone, and might have given some trouble by forming sandbanks in the harbour; but this was prevented by the introduction of smaller stones, which could readily be carried out in boats at the low tide.
Fig. 128.—Bird’s-eye View of Port Saïd.
Beginning with the Mediterranean Sea and Port Saïd, there is a run of 28 miles to Kantara, through Lake Menzaleh. Although called a lake, it is, in truth, nothing but a shallow lagoon or swamp, in which water-fowl of all kinds are very abundant, the great flocks of white pelicans and pink flamingoes being especially striking. The waters of this lagoon cover lands that once were fertile, and the salt sea-sands doubtless conceal the remains of many an ancient town.
Fig. 129.—One of the Breakwaters at Port Saïd.
Of all portions of the undertaking, this one, M. Lesseps states, was the most arduous and difficult, though, at the time, it attracted the least attention. A trough had to be dredged out of the bed of the shallow lagoon, and on either side of this hollowed out space high sandbanks had to be erected, and the difficulty of making a solid foundation for these sand banks was found to be extreme. The difficulty, however, was surmounted, and such is the excellence of the work, that the water neither leaks out, nor does any of the brackish water of the lagoon infiltrate and undermine the great embankments.
Fig. 130.—Lake Timsah and Ismaïlia.