122 G. H. HALLIGAN. 



Botany Bay nearly the whole of the stream-bed from Liver- 

 pool to the mouth must be filled, and this as we know is 

 far from being the case. That a large amount of sediment 

 is being deposited can be readily seen just below the 

 Liverpool Dam. At this spot the old steamer "Phantom" 

 which drew about eight feet used to ply with coal for the 

 Liverpool residents until about forty years ago. This part 

 of the river is now so sanded up that one can walk across 

 it in places almost dry footed at low tide. Several other 

 places lower down the stream also shows signs of sand 

 accumulation due to floods, but the total quantity, although 

 large enough to seriously interfere with navigation, is 

 insignificant when compared with the enormous deposits on 

 the shores of Botany Bay. 



The total length of Cook's River is about 11 miles, and 

 from its source to the point where it meets the highwater 

 level of the ocean, is four and a half miles. The catch- 

 ment area, which is almost wholly in Wianamatta shale 

 country, naturally does not produce much sand, the flats 

 at Marrickville and Tempe being composed of hard mud. 

 Dams are erected at Canterbury, about six and a half miles, 

 and at Tempe which is about three miles from the mouth, 

 and at neither place is any sand accumulation visible. 



Quite apart from other considerations, it will thus be 

 seen that the sand in Botany Bay could not have been 

 deposited in its present position by the waters of George's 

 and Cook's Rivers. 



First, because the quantity now visible, which has been 

 brought down during historic times, is so insignificant that 

 countless ages would be necessary to account for the 

 enormous accumulation at Botany Bay, and neither the 

 growth of timber nor the depth of humus on the sand flats 

 referred to, indicates the lapse of any such very lengthy 

 period. 



