and PhcBnomena of the County of Suffolk. 367 



and Roman brick being the principal materials. Lumps of the walls were 

 then visible upon the shore, and at low water in the sea. The cliffs were at 

 that time about 100 feet high. In 1740 some of the ruins still existed ; but in 

 1766, Grose says the remains of the castle were visible at low water, the cliff 

 being gone, and he adds, that a person, then living, remembered the ruins 

 50 yards within the cliff top. In 1829, when I had the cliffs measured, they 

 varied from 20 to 80 feet in height. According to the above statement, at 

 least 200 yards have been destroyed within the last century. 



In 941 the church at Walton Naze stood a considerable distance inland ; 

 about 50 years since the church and burial ground remained, but now not a 

 fragment of either is left. In 885 a battle was fought between Alfred and 

 the Danes at the mouth of the Stour, where the shingle bank now is. 



Harwich also is said to have arisen, in consequence of the destruction of 

 Orwell, which stood on the spot now termed the west rocks, and was swallowed 

 up by an inroad of the sea since the conquest. While this destruction is pro- 

 ceeding on one part of the coast, new sand banks are accumulating at others, 

 by which the ancient entrance in the estuary of the Stour and the Orwell has 

 been filled up, and those rivers compelled to make a new line of communica- 

 tion with the sea. 



The following conclusions I conceive may be deduced from the statements 

 given in the body of the memoir from which the above extracts are taken. 



1. The substratum of the whole of Suffolk, Norfolk, and Essex is chalk, 

 which appears to have been dislocated and worn into deep hollows by the 

 action of water, previously to the commencement of the tertiary era. 



2. On this abraded surface the plastic clays and sands were formed, but 

 not over the whole area. 



3. Partly on these beds and partly on the chalk the London clay was then 

 deposited, but to no very great thickness in Suffolk. 



4. Upon the London clay as well as the chalk the crag was next accumu- 

 lated upon sand banks produced by the tidal waters and currents, and around 

 projecting masses of chalk. 



5. While the crag still lay beneath the sea, a violent catastrophe broke up 

 many of the secondary strata, from the chalk to the lias inclusive, and the de- 

 bris thus caused, together with numerous masses of ancient rocks, was spread 

 by a rush of water over the surface of the tertiary formations and the chalk, 

 in some places to a depth of 400 feet, constituting the beds of drift clay, &c., 

 which occupy so great an area in Suffolk ; and it was extended to the edge 

 of the then existing sea coast, which appears to be defined by the western limit 

 of the crag. 



