FOR GREA T BRITAIN AND IRELAND. 57 



successive trials. It should not be forgotten, in connection 

 with this subject, that in some cases there are qualifying 

 elements to which special attention requires to be given." 



" The waves, for example, may often be noticed, when 

 approaching the land obliquely, to alter their direction when 

 they get close to the shore, in consequence of the depth 

 changing, and from this cause they strike more nearly at 

 right angles to the general line of the beach. Although 

 experimental observations are still wanted, we are not 

 without practical proof of the reduction of the force of the 

 waves where the obstacle lies obliquely to their direction. 

 At the harbour works of Lybster, in 1851, during the 

 erection of the pier-head, which stands parallel to the 

 waves, occasional damage took place, and during one 

 gale three stones, about a ton each, were thrown down, 

 while the wharf wall immediately adjoining, which was 

 parallel to the motion of the waves, was never injured in 

 the slightest degree, although it was of far inferior strength. 

 From the repeated injuries that the pier-head sustained 

 while it was in progress, it was found necessary to connect 

 together the whole of the stones with bolts. The late Mr. 

 James Bremner, of Wick, who had much experience in sea 

 works, recommended that piers should be laid out so as 

 to form a horizontal angle of not more than 25 with the 

 heaviest billows." 



DIRECTION OF THE GENERAL COAST-LINE IN RELA- 

 TION TO THE LINE OF EXPOSURE. 



" In 1857 I issued," observes Mr. S., " a series of queries 

 among fishermen and others at various parts of the coast of 

 Scotland, as to the direction from which the heaviest seas 

 come upon the coast Though there are some apparent 



