624 SAND-MOVEMENT ON THE NEW SOUTH WALES COAST, 



Plate liii. is a copy of the Admiralty charts from Point 

 Danger to Cape Howe in one sheet, showing the direction of the 

 ocean current, and the deflections and counter currents or eddies 

 caused by each projecting headland. 



It must be here stated that, owing mainly to the lack of funds 

 for detailed survey work on the coast, and also perhaps to a want of 

 appreciation of the importance of hydrographic work in a country 

 which must always depend so largely on its harbours and on the 

 maintenance of its mercantile marine for its success, the currents 

 here shown are largely speculative, and I am entirely responsible 

 for the drawing. Some ocean current observations have been 

 taken at Byron Bay, Coff's Harbour, and Trial Bay by the late 

 Captain F. Howard, R.N.: at Norah Head by Mr. E. Kenny; 

 and off Solitary Island, Port Macquarie, Seal Rocks, Newcastle, 

 Wollongong, Port Kembla and Twofold Bay by nryself; but as 

 the information obtained was, in each case, confined to one 

 portion of the year, and has not been followed up by further 

 observations, it is almost useless. However, the laws governing 

 the flow of water are so well known that, given a current 

 of know velocity and direction, and a plan showing the salient 

 points of a coast, the existence and direction of the counter 

 currents and eddies may be indicated with a fair degree of 

 accuracy. It should be borne in mind that the current immedi- 

 ately adjacent to the shore on this coast is so sluggish, even when 

 accelerated by favourable winds, that its speed rarely exeeeds 1£ 

 knots within two miles of the beach. It remains to be seen, 

 therefore, if the winds, monsoonal or cyclonic, are of sufficient 

 strength and persistence to cause currents which might affect to 

 any great extent the travel of btach sand and shingle. 



Through the kindness of Mr. H. A. Lenehan, F. H.A.S., 

 Acting Government Astronomer, I have been able to analyse the 

 wind records made at the Sydney Observatory during the ten 

 years, 1804-1903, with the following interesting results : — 



