If bulb roots were to reach down to within a foot of this layer of peat they would be spoilt, and the bulbs would perish. The depth of the sand-layer over the peat is unequal and different in parts. By measuring it they test the value of the ground, and not less is the value measured by the length of time the sea has withdrawn from the surface. There is no doubt this sand is from the sea-bottom, whether it was the sea’s action that brought it, or whether it has been blown and driven by the wind. The dunes have so often shifted that a knowledge of the variations due to the shifting of the sand in the dunes is enough to account for sand-layers, for it can be driven very far indeed by wind from the sea.
A little while ago the village of Sheveling, near the Hague, was surrounded by the dunes, which were at that time some distance from the church, now it is much nearer,—the church cannot have moved. On the same coast the mouth of the Rhine has been choked with sand, and the sea now covers the castle of Bret, facing Catwick-sur-Mer. The castle can still be seen at certain seasons at low tide. The sea has remade other dunes, half a league farther inland. All along the coast near Haarlem, beyond the canal which connects Haarlem with Leyden, the main road cuts through these dunes in several places. In the island of Walcheren, in Zealand, at very low tide can be seen vestiges of the ancient town of Domburg, where they fish up statues of Nehellenia, a heathen goddess, and also early Roman inscriptions.
In the present day dunes 100 feet high separate the new Domburg from the one invaded by the sea, and the Zealanders, through their marvellous and inventive industry, have succeeded not only in fortifying themselves against encroachments from the sea, but have made very extraordinary dykes, like the one at West Cappel, which you cannot see when you are standing upon it, as it is nothing but a very long sloping bank or glacis of timber-work, but the slope is so gradual that the only resistance the water meets with is the long journey it has to go to reach to the summit of the dyke, which, at its level, is much higher than the sea.[7] But besides this they covered miles of the sea-shore with platted straw matting, which they plat on the shore itself,—this is to prevent the sea from carrying the sand away from its own shores. These mats have to be renewed almost yearly.