436 Transactions. 



beds, and militates strongly against accurate predictions being made as to 

 the precise depth at which water will be struck in any particular locality. 



(3.) That the level of the land was gradually depressed for at least 600 ft., 

 probably much more, while the beds were being laid down. This fact has 

 considerable bearing on the explanation of the advance and retreat of 

 glaciers within recent times, and also on the formation of terraces in the 

 Canterbury District. In the face of the positive evidence for depression, 

 the explanation of the formation of the river-terraces as a result of eleva- 

 tion must be taken with great reserve, and the present writer does 

 not believe that elevation was the determining cause for their formation. 

 The reason for the depression of the land is uncertain. It may be the 

 result of a loading of the crust with detritus, or it may be due to some 

 great crustal movement whose prime cause can hardly be indicated 

 at present, considering our scanty knowledge of the changes which affect 

 the body of the earth as a whole. 



These are the main results of this inquiry up to the present, but there 

 are several further lines of investigation which could be indicated, such as 

 (1) the chemical properties of the water in relation to the geological con- 

 ditions, (2) the various interesting hydraulic problems dependent on 

 pressure and supply, and (3) the purely geological one of the actual order 

 and arrangement of the various beds in their bearing on the general mode 

 of construction of delta deposits. 



Art. XLI. — The Effects of the Disappearance of the New Zealand Bush. 

 By Archdeacon Walsh. 



[Read before the Auckland Institute, 26ih September, 1910.] 



On the 19th July, 1896, I read before the Auckland Institute a paper in 

 which I attempted to trace the principal causes which are combining to pro- 

 duce the extensive and rapid disappearance of our native forest. This was 

 followed in 1898 by another, in which I endeavoured to forecast what will 

 be the future condition of the forest M^hen something like a balance shall 

 have supervened between the destructive agents on the one hand and the 

 resilient powers of nature on the other. It may be well to follow up the 

 subject a stage further, and try to point out sonje of the more notable 

 effects which are already following on the deforestation of the country, 

 and which, as time goes on, must increase in an accelerating degree. 



In order to present the matter as clearly as possible I shall recapitulate 

 once more the argument of the first paper :— 



The two principal destructive agents, besides the axe of the bushman, 

 are cattle and fires. Any one of these acting alone is sufficient to do a great 

 deal of damage ; but when they all act in conjunction — as they generally 

 (Jo — the destruction is greatly accelerated and intensified. 



