4. Then, too, he will see that the larger clapper bridges are merely flat cromlechs built over water, and that it matters not when the present ones were put up, since their main interest is their descent from those rude monuments of stone in which the Iberian people commemorated their cult of ancestors, their reverence for the sacred dead. Near Postbridge, over the East Dart, there is a very bold clapper with three heavy table slabs, each of which is about 15 ft. long and 6 ft. wide. Two piers rise out of the water; each is a pile of granite menhirs that lie flat in the river with their ends looking up-stream and downstream. The abutments also are layers of granite, and in one abutment the stones are long enough to support on land a very large cromlech. Samuel Smiles believed that this bridge had “withstood the fury of the Dart for full twenty centuries,” but there was no need to challenge antiquaries by making a rash statement. For the rest, we must bracket these Dartmoor structures with two other kinds of slab-bridges--those in the valley of Wycollar (p. 60), and those in Spain, at Fuentes de Oñoro. My friend Mr. Edgar Wigram writes to me as follows about the Spanish variety:-- [Illustration: THE OLD BRIDGE OVER THE AUDE AT CARCASSONNE IN FRANCE] “I include this very rough sketch because it does give some idea of one of the ‘Clapper’ slab-bridges at Fuentes de Oñoro. The bigger stone would be about 8 ft. long. As to the more important slab-bridge over the Dos Casas rivulet, it stands in a glen where large slabs lie handy. I can speak of it from recollection only, but think it has four spans, about 3 ft. 6 ins. high, or perhaps 4 ft.; the lintel-stones perhaps 7 ft. or 8 ft. long, centre to centre of piers, and the piers of single stones planted in the river bed, with the longer axes up- and down-stream. A causeway led up to the bridge at each end. Even at the time the solidity of the structure aroused in me a suspicion that it _might_ be very old. On the other hand, it may be a recent work of convenience, not of necessity, for the stream in summer is often dry, and in winter it would not be unfordable (except for children) till it had submerged the bridge.”