5 o IMPROVED FISHERY HARBOUR ACCOMMODATION 



" What follows is an attempt to assist the engineer in the 

 solution of some, at least, of these and other questions 

 affecting the construction of harbours." 



" The local characteristics which at the outset demand our 

 consideration are ist, the geological peculiarities of the 

 shore ; 2nd, the exposure ; 3rd, the force of the waves 

 due to the exposure ; 4th, the strength, direction, and 

 range of the tides ; 5th, the depth of water of the bay or 

 sea in which the harbour is to be placed ; 6th, the 

 proximity of deep water to the pier itself, which of course 

 depends on the slope of the fore-shore ; and /th, the angle 

 which the coast-line makes with the direction in which the 

 heaviest waves come." 



Although by the terms of the competition no limits are 

 set to the length of any essay, it is necessary that no essay 

 should run to an unreasonable length ; the writer therefore 

 is compelled to say, that extracts and remarks can alone 

 be made, as it would be impossible in a moderate space to 

 follow Mr. Stevenson or other engineers through the whole 

 of their observations, for on this subject of the " general 

 principles upon which harbours should be constructed," 

 many volumes have been written. 



DANGER FROM CONCENTRATION OF UNDULATIVE 

 FORCE OR GORGING. 



In connection with this matter, Mr. Stevenson, p. u, 

 quotes Sir Henry de la Beche, * Manual of Geology,' p. 71. 

 He says : " In many situations on the southern coasts of 

 Devon and Cornwall, the slaty rocks dip in such a manner 

 towards the sea that the waves have never effected more 

 than the removal of some loose superficial matter, the 

 same that covers all the hills in the vicinity. In fact, 



