CHAP. XIX. VIOLENCE OF THE SEA. . 419 



terrace being three times interrupted by embankments 

 in its course of about a mile and a quarter. The road 

 lies so close under the steep mountain face, that it was 

 even found necessary at certain places to protect it 

 a gainst possible accidents from falling stones, by means 

 of a covered way. The terrace on the east side of the 

 headland was, however, in some measure protected 

 against the roll of the sea by the mass of stone run 

 out from the tunnel, and forming a deep shingle bank 

 in front of the wall. 



The part of the work which lies on the westward of 

 the headland penetrated by the tunnel, was exposed to 

 the full force of the sea ; and the formation of the road 

 at that point was attended with great difficulty. While 

 the sea wall was still in progress, its strength was 

 severely tried by a strong north-westerly gale, which 

 blew in October, 1846, with a spring tide of 17 feet. 

 On the following morning it was found that a large 

 portion of the rubble was irreparably injured, and 200 

 yards of the wall were then replaced by an open viaduct, 

 with the piers placed edgeways to the sea, the openings 

 between them being spanned by ten cast-iron girders 

 each 42 feet long. This accident induced the engineer 

 to alter the contour of the sea wall, so that it should 

 present a diminished resistance to the force of the waves. 

 But the sea repeated its assaults, and made further havoc 

 with the work ; entailing heavy expenses and a complete 

 reorganisation of the contract. Increased solidity was 

 then given to the masonry, and the face of the wall under- 

 went further change. At some points outworks were 

 constructed, and piles were driven into the beach about 

 15 feet from the base of the wall, for the purpose of 

 protecting its foundations and breaking the force of the 

 waves. The work was at length finished after about 

 three years' anxious labour ; but Mr. Stephenson con- 

 fessed that if a long tunnel had been made in the first 

 instance through the solid rock of Penmaen Mawr, a 



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