CussEN. — On the Waikato Biver Basins. 415 



place, the Waikato ■would for a time flow through the 

 Hinuera Valley, but subsequently would resume its former 

 course into the middle basin, when surface-denudation had 

 washed the detritus from the old bed. But, as we have before 

 seen, the events in the gi'eat middle basin cannot be accounted 

 for without the hypothesis of local oscillation in the level of 

 the land. On the other hand, if we can believe that gradual 

 general elevation has been going on, and that it was accom- 

 panied by local movements on a smaller scale, it would be 

 easy to account for the Waikato's changes. If, for instance, 

 the axis of upheaval was along the main range in a south- 

 east direction, from Te Aroha to Eotorua (which seems 

 probable), with a slight anticline to the westward, we 

 should find the Waikato first filling all its valleys as a lake, 

 through elevation to the eastward, and the water seeking a 

 new outlet in the lowest or weakest point in the gorges to the 

 west. 



That the movements in the earth's crust are complicated — 

 here an upheaval, there a depression, faults, crushing, and 

 corrugation of the rocks on the surface, the efforts of the 

 earth's crust to adapt itself to the form of the cooling nucleus 

 — seems to be the doctrine of our wisest geologists ; but 

 whether these movements are applicable to areas so small as 

 those we have been describing is a matter of conjecture. 

 Charles Darwin, whilst contemplating great events in South 

 America, came to the conclusion that to volcanic action must 

 be attributed the force by which mountain-chains are elevated ; 

 and that the efforts of the earth's crust and the contracting 

 nucleus to conform themselves to one another by deforming 

 the spheroid, counteracted by the earth's rotation acting to 

 maintain the spheroidal form, cause most of our volcanic 

 phenomena. Elie de Beaumont, the great apostle of secular 

 refrigeration, defines these volcanic phenomena as " a struggle 

 between the deformation of the spheroid by the loss of 

 internal heat and volume, and the earth's rotation, which con- 

 stantly tends to cause it to revert to the true spheroidal 

 figure." 



Mr. W. L. Green says, in his work "Vestiges of the 

 Molten Globe," published last year, " When we find, in one 

 short experience, that Chili and its Cordillera can be jerked 

 up several hundred feet at one stroke, we may well be careful 

 how we limit the magnitude of such catastrophes in all past 

 time." It is in reference to these great changes of surface- 

 configuration, so copiously noted elsewhere in the world, and 

 to which sources of information New Zealand might con- 

 tribute a good deal, that I hope these notes may be of some 

 interest. If the conclusions I have drawn are not satisfactory, 

 the simple facts recorded will still remain independently, as 



