THE OCEAN CURRENTS AROUND AUSTRALIA. 195 



velocity and direction, being complicated witli the strong 

 tidal currents which prevail at those parts of the coast. 

 The range of the tides between Van Diemen's Gulf, in 

 Longitude 132° East, and Dampier Archipelago in Longi- 

 tude 116° 30' East is abnormally great, ranging from 19 

 feet to 38 feet at springs, the average of twenty-two sta- 

 tions being 26 feet. The greatest rise and fall on this coast 

 is 38 feet at Hanover Bay, in Longitude 124° 45' East, but 

 at neaps, the range is reported to be only 2 feet at times. 



Such large masses of water entering and leaving the gulfs 

 and bays, necessarily cause serious indrafts and extensive 

 outdrafts which being further complicated by great diurnal 

 inequality, are a menace to safe navigation. 



Owing to the predominance of offshore winds on the 

 north-west and west coasts, the tendency is to keep the 

 heated water away from the shore ; the outward surface 

 drift being replaced by a counter flow or upwelling of cold 

 water from below. On this account the temperature, in 

 the immediate vicinity of the shore, is made more bearable, 

 while the increased warmth of the water in the offing, con- 

 duces to the growth of fish, and thus adds to the commercial 

 prosperity of the country. 



It will be noticed that the words 'probably' and 'about' 

 are used in this paper more often than they should be in 

 dealing with a subject of such vast importance to the 

 community. They are rendered necessary on account of 

 the very meagre information at our disposal, and in the 

 author's opinion, this unfortunate and undesirable state of 

 affairs should be remedied as soon as possible, quite apart 

 from the commercial value of a complete knowledge of our 

 ocean currents as affecting our fish supply and our climatic 

 conditions upon which our farming industries so much 

 depend. 



