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NEW YORK STATE MUSEUM 



influence on stream flow. Yet this proposition has also been dis- 

 cussed pro and con and is likely to give rise to further discussion, 

 and the conclusion will therefore for the present be considered 

 tentative in its character. 



It seems to the writer that the removal of forests decreases 

 stream flow by allowing freer circulation of the air and by caus- 

 ing higher temperature and lower humidity in summer and so 

 producing greater evaporation from water surfaces, as well as 

 from the ground. 



That the removal of forests renders stream flow less equal 

 throughout the year and so causes floods and periods of dryness 

 in rivers seems to be beyond reasonable question, for the forest 

 litter and root masses serve as storage reservoirs, tending to 

 equalize the flow of streams. 



Space will not be taken to discuss these propositions, because 

 very little can be added to previous discussions. The reader is 

 referred to the Bulletin No. 7, of the Forestry Division of the- 

 Department of Agriculture on Forest Influences, as well as to Dr. 

 Hough's report on forests, for fairly complete discussions. 



Forestation of the Croton catchment area. In a paper 1 read 

 before the American Forestry Association in 1901, Mr Vermeule 

 proposes the question whether the forestation of the catchment 

 area of the Croton water supply is advisable. In considering this 

 question it may be pointed out that if the Croton catchment were 

 forested, there is no probability of reaping the full benefit under 

 from 75 to 150 years. 



For the sake of the argument we will assume that on this catch- 

 ment in 120' years the full effect of forestation would be realized. 

 This would give, as an average, an increase of from 4 to 6 inches 

 in runoff. For the purposes of this discussion we may assume it 

 at 5 inches. 



In order to forest the catchment it would be necessary to acquire 

 the entire area, which, so far as the writer can ascertain, could 

 hardly be done for less than $100 per acre. Probably the price, 

 would be much greater than this, but to avoid an overestimate 



'New Jersey Forests and their Relation to Water Supply, by C. C. Ver- 

 meule: The Engineering Record, Vol. XLII, No. 1 (Jul}', 1001). 



