ON THE EROSION OF THE SEA-COASTS OF ENGLAND AND WALES. 369 



In a similar manner the shingle carried from the front of the houses 

 known as the East Cliff some years previously was not replaced by 

 shingle from the west, owing to the Admiralty Pier intercepting it. This 

 is also the case still farther to the east, where a tunnel was made, about 

 twenty-two years ago, for the footpath that had been destroyed through 

 the protecting shingle beach having travelled eastwards, and not having 

 been replaced l)y fresh shingle from the westward. On February 23, 

 1891, an extensive fall of chalk took place from the clift" above Crab Bay, 

 about 300 yards east of the Cornhill Coastguard Station. At one o'clock 

 the same day a small quantity of chalk fell, and at five o'clock a huge 

 mass slid from the top of the clifi' with a thundering noise like the report 

 of an explosion, the earthquake-like shock being felt in the Coastguard 

 houses. The cliff at this place is 320 feet high. This fall was reported 

 in the ' Dover Standard ' of the same date. I passed along this clitf at 

 four o'clock, or scarcely an hour before the fall, which was distinctly 

 heard by a gentleman walking on the Admiralty Pier at Dover, two 

 miles and a half distant. I noticed fissures on the top, from seven feet 

 wide to a few inches, running S.E. fifty-five yards, and thirty yards 

 in length, then one parallel to the edge of the clitf for sixty-two 

 yards, and three others, forty-five yards, forty-one yards, and about 

 thirty yards, running S.W. from the parallel fissure to the edge of the 

 cliff. For the whole distance of 330 yards from the Coastguard Station 

 eastwards there is evidence of a subsidence and many minor cracks or 

 fi.ssures. 



This fall occurred in calm weather, the winter having been remarkably 

 free fi"om storms and the weather dry. There had, however, been a great 

 deal of snow about the middle of the previous month, with intense frost, 

 the ground having been frozen to a depth of eighteen inches. 



Still farther to the east at St. Margaret's Bay, about four miles and 

 a half from Dover, the chalk on the sea line was without perceptible 

 erosion. One part of the south cliff overhangs in a 

 manner. 



most threatening 



The marks are i in. holes 3 in. deep, drilled in chalk. 



East of Dover (ahoitt 1^ mile) : Cornhill Stairs. 



1. AYhite soft chalk. S. G., 



1-92. Absorption 15-3G, 

 per cent. 



2. Same bed as No. 1 . 



3. Same bed as No. 1 . 



4. Larpre mass of nodular 



chalk slipped from 

 above. S. G.,2-25. Ab- 

 sorption, 1.5 94 percent. 



5. Same bed as No. 1 . 



6. Ra-ne bed as No. 1 . 

 1895. 



Erosion in 12 months, 



i inch 

 Erosiou, i in. in 12 



months 

 Erosion, i in. in 5 



months, covered by 



fall of cliff in 12 



months 

 Intact in 12 months. 



Erosion, ^ in. in 12 



months 

 Intact in 12 months. 



About li in. in 2 



years 

 Eroded 3 in. in 2 



years 

 Covered by fall of 



cliff. 



About 3 in. in 2 years 



Erosion, 1^ in. in 2 



years 

 Ij in. in 2 yexrs 



B B 



