Ch.XI. SecL] Revenue. 207 indeed such increase be so insensible that it cannot be by any means ascertained that the sea was there, the King has no claim to land so increased, and the owner of the adjacent property is entitled thereto (a). So the King by his prerogative is entitled to such lands as become derelict by the sudden desertion of the sea, or a river where there is a flow of the sea ; and such lands belong im- mediately to the King, because they never were apportioned out to any of his subjects {b). But the King is not entitled to lands left dry by a river in which there is no tide ; for such lands are supposed to have been distributed out as other lands, and therefore belong to the owners of the soil on both sides (c). Nor can the King claim such lands as are regained from the sea after having been covered by it several years, if the former owner can recognize the land which belonged to him, before his land was covered by the water ; for in this case an owner being found, the King's title which depended on the want of such owner, is excluded {d). As to the islands arising de novo in the King's seas, or the King's arms thereof (that is called an arm of the sea where the tide flows and reflows, and that only (e) ), these prim '^ Jacie and of common right also belong to the King, for th'ey are part of that soil of the sea that belonged before in point of propriety to the King ; for when islands de novo arise, it is either by the recess or sinking of the water, or by the exaggeration of sand and slab, which in process of time grow firm land environed with water ; and thus some places have arisen, and their original recorded, as about Ravesend in Yorkshire (/*). The King is also, by his prerogative, the prima Jacie owner of the shores, (that is the land which lies been high and low water mark, in ordinary tides (g) ), of the seas and navigable rivers, and arms of the seas, within his dominions {h), A sub- ject (a) Hale de jure Marls, c. 4. (h) Ibid. The shore may not only {b) 2 Rol. Ab. 170. Dyer, 326. Hale belong to a subject in gross, which pos- de jure Maris, c. 4. sibly may suppose a grant before time (f) 2 Rol. Ab. 170. of memory, but it may be parcel of a (d) 8 Co. Sir Francis Barrington's manor. And the evidences to prove Case. this fact are commonly these; constant (e) 29 Ass. 93. »"*! usual fetching gravel and sea-weed, (/) Hale de jure Maris, c.4. andsea-sand,betweenthch}gh-watcrand (g) Ibid. low-water mark, and licensing others to do I