164 HARBOUR CONSTRUCTION. 



to which no general rule can be laid down. Much will depend 

 upon the size and shape of the bay under consideration, and the 

 general trend of the coast. The existence, or otherwise, of 

 strong littoral currents, the direction of prevalent gales, the 

 depth of water, and many such -like considerations, will all 

 affect the question; and it may be safely assumed that they 

 will not be the same in any two cases. Excepting, perhaps, 

 in large undertakings of a national character, facilities for local 

 trade will largely influence the question. 



The subject of silting is also one which must not be over- 

 looked, a harbour placed in the bight of a bay being much more 

 liable to silt up than one occupying a more prominent position, 

 where its threshold would be swept by the shore currents. 



