The price per _cubic metre_ was 24 _piast._ (6 _fr._) for extraction, and 18 _piast._ (4 _fr._ 50) for carriage; in all 10 _fr._ 50. For the works of the Maritime Canal, stone will be used coming from quarries now in work on the banks, at the level of high water for the whole extent of the Gulf of Suez, and also from quarries on the shore of the Red Sea, at a distance of about 10 _kil._ from Suez, which furnish a shelly calcareous stone, soft when extracted, but hardening by exposure to the air, and also in sea water. This stone has been successfully employed in building the Grand Hotel of Suez, and has cost 33 _piast._ (8 _fr._ 25.) the _cubic metre_, hewn and delivered at the quay. We have adopted this price, increased by 60 _per cent._ in order to cover the distance, and to arrive more easily at the comparison which we wish to establish. BRICKS.—The bricks used in the barrage were made by steam machines, and cost, on account of extraordinary circumstances, 26 _fr._ per thousand. Those which will be made by hand or by means of bullock machines in the _Wady Tomilat_, will not cost half so much; for they can be made in the whole of that valley at the rate of 6 to 7 _fr._ per thousand, on account of the great quantity of combustibles found in that locality. We have however assumed, that on account of the expense of transport, from Pelusium to Suez, the bricks will come to the same price, as at the barrage, which is evidently an excess. LIME.—The lime cost at the barrage, 8 _fr._ 70 the _cubic metre_, delivered on the spot. That which is made at Suez comes to 7 _fr_. 75 delivered. This lime is made in the valley of Guébé, with the combustibles found there in abundance, and which only cost the labour of cutting and transport. POZZOLANO.—As the lime used in the barrage was fat lime, it was necessary to make artificial Pozzolano, which came to 45 _piast._ (11 _fr._ 25) the _cubic metre_. This Pozzolano could not be used for sea work, for we are convinced by experience that it is affected by the magnesia which is found in sea-water. It can, therefore, only serve for the works of the canal of communication, and, like the bricks, it will cost less than at the barrage. For the sea masonry, we have happily discovered solid masses in the harbour of Suez, anciently formed at the time of the Caliphs, or more probably at that of the Ptolemies. These masses of masonry are so compact, that when fragments are detached, the stone breaks more easily than the mortar, which is simply composed of sand and hydraulic lime.