What we have said of the gulf of Pelusium we may repeat, still more forcibly, with regard to the roadstead of Suez. The sands have long ceased to accumulate in any perceptible manner. And if maritime alluvium is still brought up by the ground swell and the current, it is driven by the west and south-west winds on to the eastern shore, without reaching the extremity of the gulf. In fact, the plan of the roadstead was taken in 1799, and the soundings of the channel are marked, as well as the shape of the sandbank, which forms a kind of bar at its extremity towards the roadstead. In 1847, the plan was taken again with the same soundings, and it is impossible to find the least difference between the two results, which also agree with those given by Commander Moresby, in his excellent chart of the Red Sea. There is, then, nothing to fear on that side, either from the sand or the violence of the sea. The jetties will be of the simplest construction, and as the materials are, as it were, at hand, their erection will present no difficulty. With regard to the excavation of the Canal to a depth of 6 _m._, 50 below low water in the Mediterranean, in a very porous soil, the task, at first sight, presents what appear to be considerable difficulties. We cannot, indeed, hope to accomplish the whole of the excavation in the dry, or by pumping, on account of the nature of the ground. It will be necessary, then, for all that portion below water, to have recourse to dredging; and, as the quantity of earth to be removed by this means is 57,205,342 _cubic metres_, at first sight it is difficult to conceive how the work is to be accomplished. But, upon examining the matter more closely, nothing is found to frighten the most timorous. In fact, a single steam dredging machine, of twenty horse power, such as those which have been employed on the Nile, working night and day, can, in twenty-four hours, raise 1000 _cubic metres_ of sand, from a depth of seven _metres_. According to this calculation, and supposing the year to consist of only 270 working days, it would take forty dredging machines five years to complete the labour; but if, instead of such small machines, dredges of thirty to thirty-five horse power were adopted, it would be easy to raise 1500 _cubic metres per diem_, and the dredging would be more economical. The quantity of earth to be raised by manual labour amounts to 17,473,790 _cubic metres_, and the deepest cutting does not exceed 10 _metres_ above the water. This is a small matter when compared with the earth-works performed in many canal and railway undertakings, and even with those accomplished before the present century; such, for example, as the one mentioned by Michel Chevalier, in his investigations concerning the maritime canal of the Isthmus of Panama (_Recherches sur la Canalisation maritime de l’Isthme de Panama_).