AND OTHER WATER WAVES 199 



proper place from which to commence the study 

 of the great accumulation of shingle, and I decided 

 to supplement my observations by a visit to the 

 shore between Lyme and Bridport Harbour. I went 

 in a boat, rowing close under the shore, and landing 

 from time to time. I found that the accumulation 

 of -beach material began at Charmouth. From 

 thence to Golden Cap the size of the shingle 

 and the height of the beach increase. Golden Cap 

 is only slightly a promontory at high water, but 

 there is a considerable ledge projecting above low- 

 water mark, so that on the whole its effect as a 

 groyne is considerable. Eastward of Golden Cap 

 there is a curved beach as far as the promontory 

 of Thorncombe Beacon, which again is prolonged 

 by a ledge of rocks above low-water mark. On 

 this piece of coast we see again the increase of 

 height of beach and size of shingle in the angle 

 under the west side of the promontory. Close 

 under the east side of the promontory the sea 

 reached the cliffs at high water, 1 but at low water 

 there was exposed a firm bed of particles of the 

 size of very coarse sand. This bed of material 



1 The same effect is seen on the lee side of groynes which 

 have been btiilt up to the highest reach of the waves, and 

 erosion results. The groyne should be low enough to allow 

 shingle to be washed freely over its shoreward end so that the 

 foreshore on the lee side may be kept covered and protected. 



