492 MR MILNE ON THE GEOLOGY OF ROXBURGHSHIRE. 



it,) must have remained undisturbed for a long period ; for vegetation had become 

 active on it, as we see by those portions which remain uninjured, where turf and 

 even furze bushes have established themselves upon the shingles." The descrip- 

 tion of this bank, as in the former case, omits the height and slope of its sides ; 

 but a woodcut is given, which shews these to have been considerable. 



On the east coast of England, and particularly off Essex, there are great num- 

 bers of naiTow banks, composed chiefly of sand, both straight and curved. The 

 most remarkable of them are laid down on the ordinary sailing charts. 



There is the Gunfleet, about three miles from land, about fifteen miles long, 

 a quarter of a mile wide, and dry at low water. Its sides are steep, and close to 

 them, the depth of water at low tide varies from four to seven fathoms. This 

 bank is situated between the estuaries of the rivers Crouch and Black Water. 



A still more remarkable sand-bank for length and narrow width, lies farther 

 to the seaward than the Gunfleet. It is situated between the estuaries of the 

 Thames and the Medway. Its upper part is called, on the charts, " Oaze Edge ;" 

 its middle part " Knock John ;" and its lower part " The Sunk." It is altogether 

 about thirty miles long. The greater part is dry at low tide, whilst on each side 

 there is from four to eight fathoms, and which rapidly deepens to ten and twelve 

 fathoms. 



Parallel with this long sandy ridge, there are twenty or thirty smaller ones, 

 all laid down on the charts. 



These are examples of straight ridges of sand. The following is an instance 

 of one which is curved. It is situated off Reculver, in the Isle of Thanet, and is 

 known by the name of the Horse. It would form a complete ellipse, but for a 

 break in one small portion of it. The longer diameter of the enclosed basin is 

 about a mile and a quarter in length, and its shorter diameter half a mile. At 

 low tide the bank is dry, and is less than fifty yards in width, and there is from ten 

 to eighteen feet of water close on each side of it. There is also round a great por- 

 tion of this bank, an outer rampart, of similar shape, at a distance of 200 yards. 



These various cases compel every one to assent to the truth of the follow- 

 ing general proposition of Sir HENRY DE LA BECHE (with which he concludes 

 his account of shingle-beaches), " That if the present continents or islands were 

 elevated above the present ocean level, shingle-beaches would be found to fringe 

 the land, but not to extend far seaward." 



As it thus appears that ridges are formed by submarine currents, com- 

 posed partly of pebbles and partly of sand, having a considerable height and 

 steepness of sides, and extending for several miles, sometimes in straight and 

 sometimes in curved lines, may not the kaims of Berwickshire and Roxburghshire 

 have been formed in the same manner ? That they have been formed by water, in 

 some way or other, is unquestionable. That the waters in which they were depo- 

 sited, were in the ordinary state of the ocean, and not in a state of debacle, seems 



