Most of the south coast estuaries, as has already been pointed out, have been more or less blocked up by banks of sand or shingle, some of which are still undergoing change. The Warren, for example, the great bar at the mouth of the Exe, now connected with the western shore, was in the seventeenth century joined to the Exmouth side of the river, and was still reached from there by stepping-stones as late as 1730. The Warren is now being slowly washed away, at the rate, it is said, of an acre in a year; and the river has within historic times encroached upon the site of Newenham Abbey. Great as has been the loss of land on the south coast, there have been some gains. More than 170 acres of land, for instance, have been reclaimed from the Laira near Plymouth; and the village of Penny-come-quick, lower down, whose anglicised Celtic name means "the house at the head of the creek," is no longer at the water's edge. In 1805 some thirty acres were recovered from the Charleston marshes, on the Salcombe estuary. The Bristol Channel is one of the most stormy and dangerous parts of the British seas, and is the scene of about one-tenth of all the shipping disasters that happen on our coasts every year. In its upper reaches navigation is made difficult by banks of mud and sand which are continually altering in shape and position. On the north coast of Devonshire, however, there are no outlying sandbanks. There is a small patch of sand off Lynmouth, 1-1/2 miles N.N.W. of Countisbury Foreland, and the estuary of the Taw and Torridge is obstructed by a dangerous and shifting sandbank known as Barnstaple Bar, upon which ("the harbour bar" of Kingsley's song), many vessels have been wrecked. But the dangers of this stormy shore lie mainly in the iron-bound coast itself, and in the rocks that stretch seaward from the bases of the cliffs. From Bull Point to Baggy Point, especially off Morte Point, and again from Clovelly to the border of Cornwall, particularly off Hartland Point, the shore is fringed with reefs and sharp edges of rock. Lundy, again, is a constant source of danger to sailors; partly because of the many rocks that stretch out from it, especially the Hen and Chickens at the north end and the Lee Rocks at the south; partly because of the strong currents that, off the south point of the island, run five knots an hour; and partly because of the fogs that so frequently envelope it. It was all three clauses combined that, in 1906, occasioned the loss of the first-class battleship _Montagu_, which, carried out of her course by the current, and deceived by the fog, became a total wreck on the Shutter Rock, the southern extremity of the island. Off Lundy, too, are the only banks of importance. Over the Stanley Bank, which lies to the north-east, where the depth at one point is only four and a half fathoms, there run, in heavy weather, the dangerous "tide-rips" known as the White Horses.