When a vessel is stranded in shallow water, it usually becomes the nucleus of a sand-bank, as has been exemplified in several of our harbours, and this circumstance tends greatly to its preservation. Between the years 1780 and 1790, a vessel from Purbeck, laden with three hundred tons of stone, struck on a shoal off the entrance of Poole harbour, and foundered; the crew were saved, but the vessel and cargo remain to this day at the bottom.—Since that period, the shoal at the entrance of the harbour has so extended itself in a westerly direction, towards Peveril Point, in Purbeck, that the navigable channel is thrown a mile nearer that point. The cause is obvious; the tidal current deposits the sediment with which it is charged, around any object which checks its velocity. Matter also drifted along the bottom, is arrested by any obstacle, and accumulates round it, just as the African sand-winds raise a small hillock over the carcase of every dead camel exposed on the surface of the desert. {49a} Upon the 18th day of February, in the year 1807, the Hunter cutter, {49b} during a heavy gale, struck on a shoal of sand in the offing, and finally drifted into a shallow near the shore, about a quarter of a mile to the northward of the old cart gap, at Hasborough, the stern part towards the cliff. In a very short time, sand, shingle, &c., accumulated around her, and completely filled the shallow to its utmost length. Within twelve months after, several shoals and shallows showed themselves opposite the town gap, evincing that the flowing of the tide had received a check, which proved an inconvenience to fishermen, as they had to heave their boats much farther before they could launch them into the sea; they were so aware that the Hunter cutter was the cause of this circumstance, that many a harsh expression did they utter towards her. In less than two years, more than one hundred yards could be paced from her bows on the ebbing of the tide to low water mark, and a large mound of sand accumulated between her stern and the cliff, which existed upwards of twenty years, and arrested the devastation of the sea directly opposite. From subsequent gales, however, the cliffs were taken away to the northward, the water intruded behind the mound of sand, and entirely removed it. A greater proof of the check the waves had received was observed at low water mark, a ridge of gravel was deposited and left undisturbed on the ebbing of the tide, extending from the Hunter cutter to Bacton coal gap, a distance of three miles to the northward; the first spring tide, however, swept away nearly the whole of the ridge of gravel, except that portion nearest the Hunter cutter.