DISCUSSION : FORESTS, RESERVOIRS, AND STREAM FLOW 483 
Both Professor Swain and Mr. Leighton have misunderstood the Mr. Ghatiers: 
writer’s argument in regard to the effect of forest storage in promoting : 
tributary combination, though each has criticized it from a different 
point of view. As they have understood it, the writer entirely agrees 
with both. The sketch illustrations given by Professor Swain are 
doubtless true for the conditions as he states them, and he could 
multiply such illustrations indefinitely and find conditions in Nature 
that would fit them all. The trouble with this method of reasoning is 
that it proves nothing because it proves everything. Any one who 
embarks upon this sea of confusion will “find no end, in wandering 
mazes lost,” and will soon throw up his hands in despair. Fully 
understanding the impossibility of coming at any definite result in 
this way, the writer did not go into it in his paper, but stood upon 
the indisputable fact, as shown by the records, that rainfall and floods 
and low waters are essentially the same now as they were before the 
forests were cut off. 
In like manner, Mr. Leighton’s point that any draft upon the 
storage in the forest bed leaves room for that much more is, of 
course, entirely correct, and the writer has nowhere said anything to 
the contrary. What the writer did say in elucidating this subject was: 
“When a period of heavy storms occurs, spreading over a great 
area, continually increasing in intensity, the forests, by retaining some 
portion of the earlier showers and paying them out afterward, do pro- 
duce a general high condition of the river which may greatly aggravate 
a sudden flood from some portion of the water-shed.”* 
This may be made clear, if there is really any doubt as to its mean- 
ing, by comparing it to a similar phenomenon with which all are 
familiar. Take the case of ground storage, acting through a longer 
period. After a long wet spell the superficial springs and underground 
sources become replenished, the small streams swollen, and the trunk 
stream assumes a high stage. Manifestly, this condition is less favor- 
able for the reception of a heavy flood from any portion of the water- 
shed than if the river were low. In like manner, to the extent to which 
it is effective, forest storage operates in the same way. If the writer 
were to re-write the sentence above quoted, he would omit the word 
“greatly,” because the more he considers it the less weight is he 
inclined to give to the forest bed as an agency for holding water. In 
fact, he did indicate this feeling to some extent in a later sentence in 
which he said: 
“Tt ig not contended that this increase is ever very great, but it is 
contended that forests never diminish great floods and that they 
probably do increase them somewhat.” 
* The phrase ‘some portion of the water-shed ’’ is used because it rarely, if ever, happens 
that, in a great river like the Ohio, the eon npone that brings the crisis of the flood covers 
all, or even the larger part, of the water-shed. 
