BY G. H. HALLIGAN. 639 



the absence of a littoral current of sufficient velocity to transport 

 the beach-material. This is, as already stated, due to a variety 

 of causes; firstly, the original southerly current, never a very 

 powerful one, is diminishing by friction over the shallow sea- 

 bottom; secondly, the prevailing north-easterly winds, which 

 accelerated it in low latitudes, are diminishing in force; thirdly, 

 it is beginning to feel the reaction due to the impact of the 

 powerful north-easterly current from the Southern Ocean, and 

 this becomes more pronounced as we proceed to the south; and 

 fourthly, the trend of the shore being slightly to the west, while 

 the current is being impelled to the east, the effect is to diminish 

 its influence on the littoral until, as we have seen, it is wholly 

 ineffective below, say, Montague Island in lat.36° 15'. 



It is to be hoped that our legislators will some day be 

 impressed with the necesssity for a complete current survey of 

 the coast, in the interests of commerce and science. In other 

 countries of the world information of this character is looked 

 upon as absolutely necessary before any scheme of harbour- 

 construction or river-entrance improvement is undertaken; the 

 small amount spent on such surveys enabling engineers to design 

 with safety works of considerable magnitude, while the value to 

 the mariner cannot, perhaps, be over-estimated. New South 

 Wales must in the future, as in the past, depend very largely on 

 her means of communication by sea with the rest of the world for 

 her success, and the more safe this means of communication is 

 made the more rapid will be the advancement of the country. 

 If looked upon in the light of insurance only, the comparatively 

 small expenditure for the complete investigation of the tides and 

 currents on this coast would appear to be amply justified. When 

 we know the forces of nature we have to contend with, we may 

 with confidence enter upon the largest engineering schemes, and 

 be tolerably certain of success; but it is rash and unscientific to 

 attempt to coerce nature instead of controlling her, and this we 

 are always liable to do unless the most complete data are at 

 our command. 



