THE MADRAS HARBOUR. 



71 



the 31st March, after two or three days of rough weather, 

 the rubble base was found to be buried in sand ; and so it 

 remained with but little intermission for nine tedious 

 months. 



I have already said that disturbance of some kind was not 

 unexpected, but what form it would take we could not anti- 

 cipate. I never doubted, nor I believe did my colleagues on 

 the spot, that if we could once get over the accumulation 

 and reach deep water, we should leave the trouble behind 

 us ; but I am bound to confess that to a casual observer 

 who did not go deeply into the principles of the matter it was 

 very like carrying the sand out with us, which was the result 

 so often predicted. It was true that no intelligible ground 

 for such a conclusion had ever been suggested ; still repeated 

 assertion, however groundless, does carry weight, and, though 

 I had the firmest confidence in my own theory, I could not 

 but feel that it was so far only theory, however sound ; and 

 others, those who held the purse-strings, might not weigh 

 it so carefully as I had done. I confess that I felt at this 

 time very anxious as to whether the authorities would main- 

 tain the same confidence which I myself felt in the ultimate 

 success of the Madras Harbour Works. 



My own reason for feeling confident that this accumu- 

 lation was a result entirely distinct from that which formed 

 the accumulation at the shore line was shortly this. The 

 motion of the sand under the influence of the waves must be 

 in the same direction as the movement of the waves them- 

 selves, that is, transverse to the shore until diverted by the 

 shore itself. It is the impinging of the wave on the shore 

 which causes the alongshore movement. This component of 

 the movement therefore must have its maximum at the water 

 line. It must become less and less as we recede from the 

 shore, till it vanishes altogether in that depth of water where 

 the wave is not affected by the bottom. It followed that 



