KATE OF EEOSION OF THE SEA-COASTS OF ENGLAND AND WALES. 857 



remarkable manner, like a honeycomb, sometimes perforated as if by large 

 boring drills, evidently the work of hundreds of years. 



The stone when burned in kilns makes excellent white lime for building 

 and agricultural purposes, and there are a few quarries for these uses. 



In some places the large courses are quite horizontal ; at other places the 

 beds are pitched on end vertically. They also lie at every possible angle, 

 sometimes grading ofE from one angle to another, and are sometimes abruptly 

 broken. 



The slate clifEs of North Pembrokeshire do not stand up bold and upright, 

 like these of limestone; but at the distance look like the red sandstone cliffs, 

 viz., rounder, bluffer, and more receding in figure. In colour and vegetable 

 covering they much resemble the red sandstone. 



It remains to tell of the coal-measures where they meet the sea. The water 

 works out the bottom, the top falls down, the loose stones make a beach 

 wearing into pebbles, and the finer material becomes sand on a flat slope to 

 seaward : this is the case at St. Bride's Bay, and at Amroth, between Tenby and 

 Caermarthen. These coal strata are mostly mixed with grey sandstone, clay, 

 and various loose materials over which the sea has made considerable advances. 

 There can be no doubt but that St. Bride's Bay has surrendered much of its 

 land to the water in years gone by ; but the progress of the sea appears now to 

 be arrested by the rocks that take the wash at the south end of the bay, and 

 also by a remarkable ridge of pebbles at Newgale Sands, which has been driven 

 before the waves, and thus made a barrier against themselves. This pebble- 

 ridge is of great size, about a couple of miles long, great width and height, 

 the individual pebbles being of all sizes up to about 12 inches diameter, 

 and of various kinds of rock 



b. Greatest height of cliff about 200 feet. Least, a wash at high water. 

 Average about 150 teet. 

 3. Coast line very irregular ; there is no considerable length of any given direction. 

 •1. The prevailing wind is rvesteiiy, but not due west. It varies from south-west to 

 north-west. 



Storms (when it blows hard) invariably begin from the E.S.E. and work 

 round by west to north-west, from which quarter they finish or blow them- 

 selves out. Our principal gales always come from this westerly direction, viz., 

 from off the Atlantic, and the south-west coast bears the brunt of these gales. 



5. a. South-west wind raises high waves. 



b. West. 



c. Our shingle does not travel [beyond the baj^s in which it occurs]. 



6. There is a strong tide passing the coast six hours northward and six hours 



southward alternately. As it affects the coast it is most felt at St. Govan's 

 Head, the sound between Skomer and Skokham and the mainland, and about 

 Kamsey Island and its sound. Where the current is running contrary to a 

 strong wind a very heavy sea is raised : this is often the case off St. Ann's 

 Head when the tide out of Milford Haven runs out against a westerly gale, and 

 produces high and broken waves. 



7. At spring tides 21 feet 6 inches ; at the equinoxes often up to 26 feet. 



At neap tides about 14 feet. 



No figures can be given for width in j'ards from high to low water, as it 

 differs from to, say, half a mile in width. 



8. The area covered by the tide in the harbour of Milford is mostly shingle or mud. 



Mud of a slimy nature is formed in the upper reaches. The area on the sea- 

 coast is bare rock or sand. No mud there. 



9. a. &. b. The shingle is generally found from high water to about half tide 

 of very various breadths. 



c. It does not travel. 



d. About a hen's egg is the largest size of pebble in the harbour. Outside 

 at Newgale about 12 inches diameter. 



e. Shingle is alwaj's in one continuous slope — not a ' neap full ' and a 

 ' spring full.' 



10. Stationarjr, to all human observation. 



11. Very little is removed from the coast ; some is from the harbour, but only in small 



quantities. Inappreciable results. 



12. No groynes on any part of the Pembrokeshire coast. 



