So that the considerable super-elevation of the Red Sea cannot be reckoned on for facilitating the approaches from the Mediterranean at the other extremity of the Canal; there is only the difference of the tides. As a depth of 7 _met._ 50 to 8 _met._ is not found before Pelusium or Tineh, but at a distance of 6000 _met._ into the sea, it is assumed that it is practically impossible to prolong the jetty of the Canal to that distance, because the waters are but _liquid mud_, and that _clouds of earth_ would interfere with the progress of the vessels and the solidity of the works. This is a complete mistake. Because Herodotus has said, that the Delta is a present from the Nile, his inaccurate assertion has been repeated without verifying it, and his metaphor has passed for an incontestable truth. But it is an absolute fact, and it is only necessary to ask those who have been at Pelusium, that the water there is as limpid as at Alexandria or Jaffa. The banks of _travelling mud_ seen by Admiral Sir Sidney Smith have no more reality than the _present from the Nile_, and for the twenty years that these coasts have been traversed in every direction by steam boats, no one has ever met again with those muddy banks. The truth is, that the waters of the Nile, which, at the time of the inundation are distinguished for more than ten leagues into the sea, carry far out into the Mediterranean and deposit in its depths, the masses of earthy matter which they hold in suspension (near 1/8000) which do not reappear on the coasts but in imperceptible quantities; the truth is, that a handful of sand may be taken up from the sea beach, at Pelusium, without finding the least particle of mud. The Viceroy’s engineers have proved that the coast, from El-Arish to Tripoli, is pure sand, and the soundings taken along the shore give the same result. Far from the Nile forming accretions at Pelusium, it is an axiom now admitted by science that the muddy or sandy deposits observed at the mouths of rivers are entirely owing to matters brought by the tide. The rivers have no part therein; and the excellent observations made by most able hydrographers at the bay of Mount St. Michael, at the mouths of the Scheld, the Meuse, the Rhine, the Yssel, have superabundantly proved it. The accumulations of sand at Pelusium and Suez, like the whole Isthmus, have been formed by the maritime deposits of the Mediterranean and the Red Sea. The thorough investigation of the motion of the waves has demonstrated that the bars of rivers are due to the ground swell alone. The Nile, therefore, has no influence upon the approaches to Pelusium, as Herodotus supposed, and as is still the common opinion; and this is so true, that for 20 _kilometres_ above its mouth there are accretions of mud, while below there is nothing but sand. Finally the accumulations of sand are more considerable in proportion as the waters of the river are less abundant.