72 DISCUSSION. 



extreme importance. I have given this matter of ring-barking 

 much attention, and have come to the conclusion just enunciated 

 by Mr. Russell, that the forests can have little or no influence 

 whatever upon the rainfall. I think people as a rule confound 

 cause and effect. I know that on the eastern coast we have large 

 forests and heavy rainfall. It is not the forests that cause the 

 rainfall, but the heavy rainfall that causes the forests. I am 

 also aware that the statements made by Mr. Mann can be borne 

 out. I know of two instances in which ring-barking has caused 

 springs to flow where they were not known before. I account 

 for it in this way. When trees have been killed, the rain instead 

 of falling only partially upon the earth falls wholly upon it, and 

 falling upon the decayed leaves of these trees forms large 

 reservoirs and breaks out into springs. Another curious matter. 

 On the higher mountains, Mount Wilson for instance, when you 

 denude the country of trees you make it very much drier. That 

 is not the rainfall. It is the mists coming up from the sea. After 

 a warm summer's day a cool wind springs up from the sea and 

 brings up a mist. This mist is caught by the trees and vegetation, 

 and hangs upon these and produces a large amount of fall. The 

 ground is quite wet, and where there has been a denudation of 

 trees the ground is quite dry. I am a believer in ring-barking ; 

 I do not believe it has any effect on the rainfall, but it tends 

 rather to produce more moisture in the soil than was previously 

 present. 



Mr. Henson : — While listening to Mr. Abbott's paper at the 

 last Meeting, the thought occurred to me that the permanence of 

 the flow of the water in the streams after the forests had been 

 cut down, was largely due to the decay of the roots as mentioned 

 by the last speaker. The ramifications of the roots of forest trees 

 are very extensive, and after the trees have been cut down these 

 roots decay, and form channels through which the water readily 

 passes into the ground. The formation that surrounds us in the 

 western suburbs is dense shale formation. The upper portion has 

 been comminuted by rootlets. Many know the large forests 

 that formerly grew in these districts. As those trees have been 

 cut down, the water has penetrated along the rootlets and found 

 its way into the ground. Of course the clay, which has been 

 formed from the shale, retards the lateral travel of the water, but 

 still the ground does absorb an immense amount of water after the 

 trees have been cut away. Another thought occurs to me. A 

 rain gauge placed at ground level I believe records a larger amount 

 of rain than one at some height above the ground. Would a rain 

 guage in a forest amongst the trees record as much as on a plain 

 adjoining? A portion of the rain must be intercepted by the 

 foliage ; the twigs and the trunk become thoroughly wetted, this 



