18 president's address. 



movement is renewed or continued, as seems probable, then it 

 may be the fate of the site of Sydney to sink under the sea. 



Section across New Zealand, in the latitude of Mt. Cook. 



Continuing the Ulladulla section eastwards across the Tasman 

 Sea, the ocean floor rises very gradually till the South Island of 

 New Zealand is reached. Mark how South New Zealand con- 

 forms in shape and motion to a westward rolling wave as in the 

 above diagram. Not only does the steep face front Australia, 

 the hogs-back slope behind and the crest advance before the 

 centre, but the forefoot sinks under the sea in drowned land 

 vallej'^s and the rear rises in elevated Tertiary plains. 



Again, New Caledonia may be pictured as another earth- wave 

 of the first magnitude, rolling in upon the Australian continent. 

 Its south-west coast, bordered by the narrowest shelf and plung- 

 ing into deep water, represents the face, and the broad shelf 

 upon which the recently elevated Loyalty Islands stand, the rear. 

 Further north, the elevated reefs of British New Guinea are 

 contrasted with the subsidence of the Great Australian Barrier 

 Reef on the opposite coast. Professors Haddon, Sollas and Cole 

 "distinctly see in Australia and its islands " . . . "the vast 

 folds of the earth's crust roll slowly inwards upon the central 

 continental mass."* 



This rolling wave of New Zealand is complementary to the 

 trough of the Tasman Sea, forced down against the resistance 

 of the continent. Thus the trough is distorted by the resistance 

 it has encountered from the I'egular zeta-curve of a trough 

 moving between rolling waves. 



• Trans. Roy. Irish Academy, xxx., 1894 p.473. 



