“This bridge, over which no doubt Chaucer himself passed, was of stone, the arches were narrow and the piers thick; strong angular buttresses supported them and broke the force of the current; these formed at the upper part a triangle or siding which served as a refuge for foot-passengers, for the roadway was so narrow that a carriage sufficed to fill the way. When it was pulled down in 1839, it was found that the method of construction had been very simple. To ground the piers in the bed of the river the masons had simply thrown down stones and mortar till the level of the water had been reached. It was remarked also that the ill-will of Pratt or the Abbot or of their successors must have rendered the bridge almost as dangerous at certain moments as the primitive ford had been. The wheels of vehicles had hollowed such deep ruts in the stone and the horses’ shoes had so worn the pavement that an arch had been at one time pierced through.”[32] This perforated arch proves pretty conclusively that Bow Bridge was never rebuilt; but I look upon doubt as an excellent thing in one’s attitude to matters of this kind, partly because fresh evidence may be discovered, and partly because facts are woefully elusive even when they are tackled by judges, and barristers, and juries. There is one more controversy to be considered: it centres around the famous bridges on Dartmoor, and I will try to put all the main points both clearly and fairly. In this dispute architects contend against antiquaries, and their arguments hold the field. Let me sum them up:-- The “clapper” bridges over Dartmoor rivers are not difficult to study; their construction resembles that of cromlechs and Stonehenges. Their piers were evolved from menhirs, and their table slabs from the mass of rock forming the horizontal member of a cromlech. Nor is it difficult to suggest the evolution through which the clapper bridges have passed, for on Dartmoor itself the evolution is plainly suggested by the rude bridge at Okery and by the single slab at Walla Brook. Any primitive farmer of the Bronze Age had sense enough not merely to put a ledge of granite across the Walla Brook, but to span wider rivers by using menhirs to support large blocks of granite. Timber would not be used, since trees were very scarce on Dartmoor, while granite was so abundant that it must have been very troublesome to farmers.