56 CORNWALL above a forest, but that was in a prehistoric period. But if the sea gains on the land but imperceptibly in one way, it gains in another on the north coast, by the action of the wind carrying the sand inland, and overwhelming field after field. It is not a little curious to mark, nevertheless, how a small dribble of a stream will arrest the onward march of the sand-dunes. At Constantine by Padstow as already said the old church is enveloped in sand-hills, so is that of St Enodoc. The Perran Sands have so encroached that they extend over a mile and a half inland and have in process of time swallowed up two churches and a village. The Gear Sands have even climbed a hill to the height of 300 ft. The Godrevy, Upton and Phillack towans have moved inland from St Ives' Bay and engulfed the residence of the ancient kings of Cornwall at Riviere. The same phenomenon has not taken place in the south, but there the estuaries have been silted up by the wash from the stream tin works. Formerly boats could come up to Tregony. Now the Fal is choked with detritus for miles down. Restronguet creek bore vessels to Perranarworthal. Now it is completely silted up, only a trickle of water running down through desolate morasses and flats resulting from the workings of the miners.