238 J. H. MAIDEN. 



are usually very particular, where the road is at all clamp, 

 to cut down the trees by the side of it, in order that the 

 sun and wind may play upon the road and dry it up. It is 

 quite true that trees by the side of water absorb some of 

 it during the process of growth and emit it into the atmo- 

 sphere by the process of transpiration as I have already 

 Stated, but as a very general rule it would effect economy 

 in water if dams and other receptacles for water were 

 surrounded by a thick belt of trees. The question of 

 diminution of evaporation should always be considered in 

 cutting down trees from the vicinity of any stagnant or 

 flowing water in this country. 



The matter of shade is stated in another way when we 

 draw attention to the fact that clumps of trees or forests 

 prevent desiccation of the ground, — the forest floor. 



d. To give shelter for stock, crops, etc. — This is a 

 mechanical action of forests and their value in that respect 

 is so evident as not to be open to argument. 



Professor M. W. Harrington (op. cit., pages 23-4) says 

 that the forest is to be considered, in its effects on climate 

 and weather, as a special form of surface covering. Its 

 effects are of the same order as those produced by a cover- 

 ing of sand, or sod, or water, but the forest effect has some 

 peculiar features which are due to the fact that the cover- 

 ing is elevated to some extent above the soil. This imparts 

 to the soil in some degree the climatic characteristics due 

 to a topographical elevation, and also causes a series of 

 wind-break effects which are not found with the other 

 forms of surface covering. On account of this distinctive 

 feature, the problem of forest climatology separates into 

 two problems, which must be considered each by itself. 

 The one relates to the climate of the interior of the forest, 

 and the other to the effects of the forest on the climate of 

 the country around it. The two are quite different; the 



