REPORT ON FORESTS. i6i 



water, and with this increased capacity of the ground to absorb 

 rain comes also less frequent floods. Humus in the forest forms 

 a great sponge and of itself holds a large amount of water, and, 

 together with the inequalities caused by tree-roots, etc., tends to 

 prevent the water flowing over the surface, while the roots of 

 the trees provide ready channels for percolation into the sub- 

 soil. Consequently, forests will absorb a much larger amount 

 of rain than either barren or cultivated country. 



Cultivation undoubtedly has a tendency to increase the capacity 

 of the ground to absorb water, because of constant loosening of 

 the surface and the facilities provided for ready drainage. In this 

 way cultivation, like forests, tends to make floods less frequerit ; 

 but the effect of under-drainage is that the ground-water 

 absorbed is usually fed out more rapidly to the streams during 

 the early months of a dry season than is the case with forests, 

 consequently the ground-water is sooner exhaiisted and the 

 duration of the low stages of the rivers is longer. Barren water- 

 sheds offer the least capacity for the absorption of the rain-fall. 

 There is no humus or other matter on the surface to retain the 

 water, and the ground becomes hard and resists free percolation. 



The effect of cultivation in increasing the flow of springs has 

 been frequently remarked through the West, where tillage has 

 followed barren conditions. We have some testimony in this 

 State to the same effect where cultivation has succeeded forests. 

 At a meeting of the New Jersey State Board of Agriculture, 

 January 17th, 1900, the ' following statement was made by Mr. 

 Emmor Roberts, of Moorestown, a member of the Board of Man- 

 agers of the Geological Survey, during a discussion of this sub- 

 ject : "In my early boyhood I listened to old men talking about 

 certain streams having been dry in years past. They told me 

 that some seventy-five years ago they were all dry in the sum- 

 mer time. I thought about it, and I thought it was reasonable 

 that it should be so ; that the land was in timber then, while it 

 is all clear now. It looked to me reasonable that, the lands now 

 being tilled, the rain that falls goes through the soil to the 

 under-drains and into the streams, which run abundantly the 

 whole year through. I interviewed all of the old mill-owners 

 and every one I ever knew and approached on that subject 

 always said, ' My stream is better now than it was when I was a 



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