90 IMPROVED FISHERY HARBOUR ACCOMMODATION 



Scrabster, Leith, and Invergordon ; and the writer has 

 observed the same destruction go on in localities at both 

 sides of the English Channel on the English side where 

 a powerful freshwater river forms its estuary, and on the 

 French side, where no brook entered the harbour. At 

 the latter locality the destruction, as might have been 

 expected, was much more rapid than at the former. 



ADVANTAGES OF TIMBER AS A MATERIAL. 



On this subject Mr. Stevenson speaks very strongly. 

 " It is much to be regretted," he says, " that greenheart is 

 so expensive in this country, and that some simple and 

 economical specific against the worm has not been discovered 

 for protecting Memel and the cheaper kinds of pine. The 

 grand desideratum in harbour works, which is the want of 

 continuity in the structure, would then be supplied. It follows 

 from the known laws of fluids, that each individual stone 

 in a pier, which is equally exposed throughout its whole 

 length, is subjected to a force which it can only resist 

 by its own inertia and the friction due to its contact with 

 the adjoining stones. The stability of a whole hydraulic 

 work may therefore be imperilled by the use of small 

 stones in one part of the fabric, while it may be in no way 

 increased by the introduction of heavier stones into other 

 parts. By the use of long logs of timber, carefully bolted 

 together, a new element of strength is obviously obtained. 

 A pier could be erected almost free of sea risk if constructed 

 of rectangular or other shaped prisms, consisting of logs of 

 timber treenailed and bolted together so as to form boxes, 

 say 10 feet square, and 30 or 40 feet long. The interior of 

 the boxes would be filled with rubble or beton? Mr. 

 Stevenson, at p. 152, gives the following: 



