198 A. G. HAMILTON. 
But when the effect of tempering climate is taken into con- 
sideration, there is a general consensus of opinion that forests 
have a most decided effect, and also that they prevent the flow of 
surface water. Trees take up heat more slowly than the ground, 
the amount of evaporation from their leaves keeping their temper- 
ature down; the air and soil reach their maximum about four 
o'clock in the afternoon, but the trees go on heating till sunset, 
and then begin to part with the heat again, thus lowering the 
temperature in the daytime and raising it at night. 
“‘ While there appears ample proof that forests have no appreci- 
able effect on the rainfall, it is beyond question that they have a 
moderating effect on the temperature. This is well illustrated in 
the case of two places in the Punjaub Plains, situated at a distance 
of eighteen miles apart, one in open country, and the other in 
dense forest. It is found that in the hot season, the temperature 
at the latter is generally 6° or 8° lower than at the former.”* 
Mr. J. Ednie Brown also points out in his report for 1890, that 
‘Practical experience has shown wherever the experiment has 
been tried, the planting of belts of timber through the dry open 
country of Australia has been that the hot winds, which at present 
are the very scourge of such country, so far as their effect on 
vegetation is concerned, have very often been subdued altogether, 
but more often so softened and moderated by contact with the 
cooler atmosphere arising from the damper surface of the ground 
shaded by trees, as to pass almost harmlessly over the country.” + 
One effect of forests and an important one where the rainfall is 
light, is that slight showers of short duration do not reach the 
ground at all, the water clinging to the leaves, and after the 
shower being evaporated almost immediately. 
The effect of ringbarking and deforesting on the surface flow is 
considered by Mr. W. E. Abbott in a paper before quoted, and 
his conclusion is that the flow of water in the creeks is increased 
* First Report of Roy. Comm. on Water Conservation, Abr. Ed., p. 16. 
+ Op. cit., p. 3. 
