22 president's address. 



features of youthfuhiess iu middle age. The peueplaiu on 

 which they rise is old, the shelf on which they discharge is 

 old, but the coastal ranges through which they cut their 

 gorges are new. An exceptional history is required for these 

 exceptional features and such I have endeavoured to supply. 

 The fate that apparently overtook other streams, during the 

 crumpling of the coast, of being broken in the middle and 

 reversed thi-eatened them also. But the partial protection 

 of the submarine buttress rendered the attack less severe than 

 it was either north or south. So these rivers survived as 

 radials, but not without a hard struggle. The isolated sheets 

 of alluvial deposited by the Fitzroy at Gogango and by the 

 Burdekin above Mount Dalrymple, show where they stag- 

 gered in their course. The gorges through which they pass, 

 not at the commencement of their career like ordinary rivers, 

 but towards their close, show where they were almost over- 

 powered. 



It is submitted that a perfect correspondence is now shown 

 between the age and the length of the rivers on the one hand 

 and the opposite breadth of the shelf on the other. If move- 

 ments of the land occurred as vertical uplifts or downthrows 

 or as folding from the land seawards, such correspondence 

 should be mere chance. But on the hypothesis of lateral 

 pressure folding from the sea landwards, this correspondence 

 is a natural consequence. It is therefore a strong argument 

 in support of that explanation. 



In contrast to the radial river running its course behind 

 the shelter of a broad shelf, we will consider a great marginal 

 stream unprotected within its narrow shelf. From Montagu 

 Island east to the hundred fathom line is five miles. West 

 from Montagu Island to the main divide is forty-five miles. 

 Here we have the extreme of marginal drainage opposib3 the 

 narrowest extreme of the continental shelf in New South 

 Wales. A remarkable section is obtained by following the 

 thirty-fifth parallel across the continent. Starting from 

 Jervis Bay, after an ascent of seventy miles the Pacific water- 



