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FORESTS CONSIDERED IN THEIR RELATION TO RAINFALL AND 
THE CONSERVATION OF MOISTURE. 
SYNOPSIS. 
1. Introductory. 
2. The Historical Method. 
(a) General observations. 
(6) The case " Forest destruction does diminish the rainfall." 
(c) The case " Forest destruction does not diminish the rainfall." 
3. The vastness of rainfall conditions. 
4. Clouds may strike against trees and deposit moisture. 
5. Not merely a question of large trees. 
6. Rainfall measurements in forests and open country. 
7. Physiological action of trees transpiration. 
8. Some uses of forests : 
(a) To temper floods. 
(I) To conserve springs, and to aid in the more even distribution of 
terrestrial waters. 
(c) The relation of forests and snow. 
(d) To prevent evaporation of water. 
(e) To give shelter to stock, crops, &c. 
(/) The leaves of forest trees, &c., afford manure and mulch. 
1. INTRODUCTORY. 
I bring before you the subject which is often conventionally known under the 
title of " Forests and Rainfall," and in regard to which it may be fairly said that there 
still exists, in New South Wales at least, a considerable amount of misapprehension. 
Even the clear-cut statements of Mr. Russell, our late Government Astronomer, 
that forests do not increase rainfall, have failed to carry conviction to some people, 
for the reason, I take it, that the broader subject of the effect of vegetation on the 
conservation of moisture has not been f ally considered in some of the public discus- 
sions that have taken place. The term " Forests and Rainfall " has been adopted 
by many writers, because of its compactness, but if its use becomes misleading, then 
it should be amplified. We want to carefully separate two issues : 
1. The effect of forests and other vegetation in increasing the rainfall. 
2. The effects of the same in conserving moisture. 
I approach the subject with but elementary meteorological knowledge, but I 
have had much experience of Australian forestry. Taking an extensive territory, 
it appears to be indisputably proved that forests do not increase rainfall ; it is as fully 
well proved that they conserve the rain that falls, and therefore every effort should 
be made to save them from unnecessary destruction. 
