THE MADRAS HARBOUR. 



65 



But "where the element of 24 feet depth, the limit of 

 stability of sand, — of 12 feet depth, the limit of stability of 

 rubble stone, — of depth enough even for a big block of con- 

 crete, — where these elements were wanting, we could not 

 carry out our well- devised section with its different materials 

 at their proper depths. We were driven, per force, to some 

 other system, or rather succession of systems, as we got nearer 

 and nearer to our ultimate requirement of a depth of upwards 

 of 24 feet. 



Thus then the work divides itself into two great divisions * 

 that in which we can apply our system in its integrity, and 

 that in which we cannot do so. It is, perhaps, for some 

 reasons unfortunate that the last-named division had neces- 

 sarily to be executed first, as it is the division adjoining the 

 shore, being in fact the first 1,000 feet out of a total of about 

 4,000 at each pier. 



This division of the work, which is based on first principles 

 and not from our special experience on this particular work, 

 will perhaps recall to recollection the fact that three or four 

 years ago, when the work was in its earlier stages, its progress 

 was by no means so rapid, or to the view of the outsider 

 so apparently successful as it has since been. The cause 

 is now obvious. We really had a much more complicated 

 problem to solve. We had to force our way through and 

 over sand where it was liable to be disturbed by the waves ; 

 we had to push out rubble stone where every wave was 

 liable to roll it about in every direction ; we had to place 

 concrete blocks on a foundation necessarily so little below the 

 surface that the waves could undermine them. All these 

 difficulties became apparent to the outside critic when they 

 were actually encountered, and we must excuse him if he 

 failed at the time to recognise the fact that they were antici- 

 pated by the engineers and provided against as far as it was 

 possible to do so, 



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