222 NOTES RELATING TO COAST
enclosed to have been then subject to occasional overflow. There are also
curious isolated 'hills' of shingle and clay on some of the enclosed marshes,
evidently washed together by sea action. 'Dunes' of blown sand fringe the
coast of St. Osyth for 21/2 miles, infringing perhaps 50 to 150 yards on the
marshes; their height is 12 to 15 feet. He did not think that they were
increasing and they are prevented from spreading landways by a long salt"
water 'crick,' locally so-called, which runs close behind them inland.
In the same Report, Mr. Peter S. Bruff, M. Inst. C. E., gave evidence
relating to the Suffolk and Essex coasts, from the river Deben to near the
river Colne. He described the nature of the coast as varying—cliff, flat
'denes' and embanked marshes. The Cliffs are London Clay, sometimes
capped with crag, gravel or sand ; their greatest height above H.W.M. being
68 feet, and least 6 feet; an average of 37 feet. The coast-line lies N.E. to
S.W. and the prevailing wind is S.E. to S.W. In raising high waves the
most important wind is the N.E. to S.W. ; in piling up shingle the most
important wind varies locally from E. to W. (N. to W. at Walton), and in
travelling of shingle the N.E. to E. is most efficient. The set of the tidal
currents is N.E. to S.W. The range of tide in vertical feet at springs is
11 ft. 6 in., and at neaps, 8 feet. The width of spring tide between high and
low water is from the Deben to the Orwell 25 yards, at Walton-on-Naze
230 yards, and at Clacton 150 yards. From the Deben to the Orwell the
area covered by the tide consists of sand and shingle with occasional layers of
cement stone at the foot of the beach. From the Orwell to the Colne
there is a clay flat at foot of the beach uncovered at low water. The shingle is
about 30 to 40 yards broad at Felixstowe and Clacton. With respect to the
tide mark it is sometimes evenly distributed, and sometimes in patches with
sand between, and it travels from N.E. to S.W. A small proportion of the
pebbles are as large as hens' eggs, the majority much less. A ridge of shingle
is formed by the spring and neap tides, the height above the respective tide
marks varying according to the state of the wind. The average height would
be about 2 feet above the tide marks Where not protected by groynes the
shingle is diminishing, by natural causes.. The groynes of timber-piles and
planks are 30 or 40 yards long, generally at right angles to the shore line, at
varying distances apart, and of very diverse heights ; there are some stone
ones at Walton-on-Naze. Between the Deben and the Orwell, they arrest the
shingle very effectually, and prevent the loss of foreshore and land. At
Walton the same is true in a less degree; A considerable quantity of shingle
has been taken from the beach at Clacton at about high-water mark, for road-
making and for concrete for building. It is said that some 40 or 50 years ago
cement stone was dredged and otherwise removed in front of Felixstowe, which
removal had an injurious effect upon the coast, but the practice has long been
discontinued. The coast is being worn back by the sea at Felixstowe,
between the 'Lodge Point' and Martello Tower P., and also at Walton
and Frinton. At Felixstowe the greatest loss was where there was 'flat
(' Benthill') at the foot of cliffs. At Walton and Frinton there are London
Clay cliffs 40 to 68 feet above high water. At places as much as 100 feet is
lost by erosion in 10 years, but a fair average would be about half that
amount. The loss at Felixstowe is practically stopped by the groynes on the
beach For data, the Tithe-maps of the parishes in question may be compared