DISCUSSION : FORESTS, RESERVOIRS, AND STREAM FLOW 497 
the eastern section of our country and see the woodland in all direc- mr. Chitten- 
tions. In much of this the virgin timber has all been cut away. Let 
him visit the vast pine-stripped areas of Michigan and Minnesota and 
the Southern States, and in fact examine the country in almost any 
direction, and he will see that the original cutting down of much of 
cur timber has not been followed even proximately by cultivation. It 
is true that the extirpation of the forest is necessary to cultivation, 
but the erosion, where there is any, begins with and is caused by the 
cultivation. Mr. Pinchot says, in the same vein: “Whether one des- 
troys the forest to cultivate the soil, or cultivates the soil after the 
forest is destroyed, makes no difference.” As logically might he say 
that if the ground were cleared of trees for the building of a dam, the 
clearing would be the cause of water collecting in the reservoir. 
The point is often made that the trees break the violence of storms 
so that they do not strike the ground direct. This argument is al- 
together trivial and inconsequential. Wind-driven rain does not affect 
the soil of fields covered with grass, grain or other crops, much as it 
may “lodge” and play havoc with the crop itself. Most precipitation 
falls in winds of moderate power. Snow falling, no matter how fierce 
the wind, never produces erosion. Finally, the point is quite irrelevant, 
because it is impossible to have tree cover for our towns, cultivated 
fields, and pasture land, anyway, and there is of course no objection to 
its presence on the remainder of the land. 
The writer notes two instances in which officials of the Forestry 
Bureau and Geological Survey have confirmed the views expressed in 
his paper upon this subject. In a paper by Mr. W. W. Ashe, Forest 
Assistant, published in the preliminary report of the present Inland 
Waterways Commission, he says that, of the sediment borne along 
by our rivers, “agricultural lands contribute only a relatively in- 
significant part.” This is very different from the thousand million 
tons of soil from our fields, worth a dollar a ton, which we have read 
of so much during the past two years. @ 
In a recent well-prepared article* by Mr. Herman Stabler, Assistant 
Engineer, U. 8S. Geological Survey, it was shown that the soil erosion 
above the proposed reservoirs on the Ohio water-shed under present 
conditions would fill up these reservoirs, if built, at an average rate 
of only 10% in 835 years, or 50% in 4000 years. For the Monongahela, 
the period for 10% filling is 1260 years; and for the Allegheny, 2 410 
years; yet the water-shed of the first of these streams is over 50% 
deforested and that of the other over 60 per cent. These figures have a 
very important bearing upon the question here considered. They com- 
pletely refute the claim so strenuously put forth that deforestation at 
the sources of these streams is producing ruinous erosion, and that 
the preservation and extension of the forested areas is absolutely 
* Engineering News, December 10th, 1908. 
