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forests arid forest trees in localities where are found the 

 sources of creeks, rivers, and the supply of water to lakes 

 and other fresh waters. 



For Great Britain this question has its greatest signifi- 

 cance with regard to future forest culture on barren heights 

 and the cultivation of shade and shelter trees along water- 

 courses. The greatest part of the forest land with which our 

 question has to deal is in the possession of large land- 

 owners, but as far as I can ascertain there are no laws in 

 existence giving a guarantee for the preservation and 

 proper management of these forests. Far more importance 

 has this question for the British Colonies, America, and 

 several other countries, where either the State, a number 

 of persons, and in some cases nobody, owns the land in 

 question. 



That the forests regulate the flow of the water in water- 

 courses, and ensure a steady supply during dry seasons, 

 while they prevent sudden and disastrous floods, is a fact 

 so often discussed and proved, that I need only refer to 

 it here. 



That the forests also increase the rainfall has often been 

 disputed, and this question has of late years received con- 

 siderable attention, particularly in France, but there is still 

 a great deal of uncertainty about the exact extent of the 

 effect of a forest on the rainfall, and it is only by very minute 

 observations of forests, consisting of the same species of 

 trees in various altitudes, that series of trustworthy results 

 can be attained. StiH there is no longer any doubt as 

 to the effect of the forest in conserving the water that falls, 

 or that the humidity of the air above a forest is considerably 

 larger than that of the air of the open country. Experiments 

 in the South of France showed that the rainfall in a forest as 

 compared with that in the open country was in the propor- 



