Tkavebs. — On the great Floods of February, 1868. 87 



the line of road along the main terrace, in order to permit the wool-drays 

 to pass over across the beds of these streams in places which had pre- 

 viously been forded without the slightest trouble. In several places, more- 

 over, where the old channels had proved insufficient to carry the enormous 

 quantity of flood-waters suddenly poured into them, these had burst over 

 their banks and cut subsidiary channels through the gravels of the main 

 terrace down to the solid rock on which they rest, and had then fallen in 

 cascades into the great river below. Now I submit, that if any such flood 

 as that of February, 1868, had occurred in this locality since these several 

 gravel terraces had been formed, it must have left marks similar to those 

 which I have described, marks which, looked upon from a geological point 

 of view, are practically indehble ; and the non-existence of such marks in 

 any part of the gorge prior to the occurrence of the flood in question, is 

 sufficient to indicate that no such flood had taken place since the river had 

 flowed at the foot of the terraces fronting the lateral valleys. 



It is not necessary that I should specially notice the effects of the flood in 

 the valley of the Clarence on the Upper Waiau-ua. Though palpable enough, 

 they were not of a class to afford strong evidence of its being unprecedented 

 in extent, for both these localities are high above sea-level, are very rugged 

 and bare, and the marks left were not sufficiently distinctive to require 

 special notice. 



In the gorge of the Wairau the case was different. There, as before 

 observed, the river flowed for miles over a bed filled with huge boulders, 

 but the immediate effect of the tremendous rainfall referred to had been, 

 that all the loose angular detritus previously lying in the beds of the 

 lateral torrents was washed out of them, forming, in some instances, 

 enormous mounds, the bases of which were cut away by the waters of the 

 main river, the effect being that the interstices between the boulders in its 

 bed were filled up, for many miles of its course, changing the surface of 

 this bed from one of great ruggedness to the smoothness of a macadamized 

 road, and giving to the river the appearance of a beautiful purhng stream 

 instead of that of an impetuous brawling torrent. In process of time the 

 major portion of the small stuff thus distributed over the bed of the river 

 will be removed, but when I last passed through the gorge, eight years after 

 the occurrence of the flood in question, the places where I forded the river 

 stiU retained the even smoothness which had followed from the great flood. 



Such are the principal grounds upon which I have based the opinion 

 expressed in the earlier part of this paper, and I have Httle doubt that, had I 

 been able to devote time to a more extended examination of the district in 

 which my observations were made, I should have found abundant additional 

 evidence in support of it. I am aware of the danger of drawing general 



