The German Ocean is deepest on the Norwegian side, where the soundings give one hundred and ninety fathoms; but the mean depth of the whole basin may be stated at no more than thirty-one fathoms. {36} The bed of this sea is traversed by several enormous banks: one of which, occupying a central position, trends from the Frith of Forth in a north-easterly direction, to a distance of one hundred and ten miles; others run from Denmark and Jutland, upwards of one hundred and five miles to the north-west; while the greatest of all, the Dogger Bank, extends for upwards of three hundred and fifty-four miles from north to south. {37a} The whole superficies of these enormous shoals is equal to about one-fifth of the whole area of the German Ocean, or to about one-third of the whole extent of England and Scotland. {37b} The average height of the banks measures, according to Mr. Stevenson, about seventy-eight feet; the upper portion consisting of fine and course silicious sand, mixed with comminuted corals and shell. {37c} Some long narrow ravines are found to intersect the banks. One of these varies from seventeen to forty-four fathoms in depth and has very precipitous sides: in one part, called the “Inner Silver Pits,” it is fifty-five fathoms deep. The shallowest parts of the Dogger Bank were found to be forty-two feet under water, except in one place, where the wreck of a ship had caused a shoal. These sands receive fresh increase every day; so that in time the place bids fair to become habitable earth. The kingdom of Holland seems to be a conquest upon the sea, and in a manner rescued from its bosom. The surface of the earth, in this country, is below the level of the bed of the ocean; and I remember, observes Buffon, upon approaching the coast, to have looked down upon it from the sea, as into a valley: however, it is every day rising higher by the depositions made upon it by the sea, the Rhine and the Meuse, and those parts which formerly admitted large men of war, are now known to be too shallow to receive ships of very moderate burden. The formation of new lands by the sea’s continually bringing its sediment to one place, and by the accumulation of its sands in another, is easily conceived. We have had many instances of this in England. The island of Oxney, which is adjacent to Romney-marsh, was produced in this manner. This had for a long time been a low level, continually in danger of being overflown by the river Rother; but the sea, by its depositions, has gradually raised the bottom of the river, while it has hollowed its mouth; so that the one is sufficiently secured from inundations, and the other is deep enough to admit ships of considerable burthen. On many parts of the coasts of France, England, Holland, Germany, and Prussia, the sea has been sensibly known to retire. {38a}