DISCUSSION : FORESTS, RESERVOIRS, AND STREAM FLOW 365 
of which mention is also made by Colonel Chittenden, is another 
river receiving important contributions from glaciers and snow fields. 
Unfortunately, the stream-gauging records of the Geological Survey 
do not afford data for a direct comparison of the White River with 
neighboring streams, the water-sheds of which are wholly forested. At the 
time of the 1906 flood, to which Colonel Chittenden refers, only two of 
the Cascade streams for which complete records are available failed 
to record the highest stage of water on November 15th. Of the two 
streams which reached their maximum flow on the day preceding, one, 
Johnson Creek, has an unforested drainage basin and the other, 
Tieton River, has its origin in glaciers on the main range, not 
many miles from the hedad-waters of White River. Were stream- 
gauging records available for White River, the writer is confident that 
they would show that this stream, like the Tieton, reached its maximum 
stage at least 24 hours earlier than the streams in the same general 
region having drainage basins altogether forested. 
Grorce F. Swain, M. Am. Soc. C. E. (by letter).—The Society 
should be grateful to Colonel Chittenden for the interesting paper 
which he has presented, and for the able and forceful way in which 
he has discussed the question of the effect of forests and reservoirs on 
stream flow. His remarks are so well presented that upon a first 
reading those who believe in forest preservation might feel that their. 
side of the case had received a severe blow, but a careful examination 
discloses many apparently contradictory statements, while the argu- 
ment seems quite as conjectural and the specific statements quite as 
much without proof as those given by the writers with whom the 
author disagrees. As a matter of fact, he seems to admit most of 
what is claimed for forests. So far as his paper may be considered a 
protest against extreme views, the writer agrees with him, though 
many of his statements are extreme in the other direction, and are 
certainly unsound. 
It is a characteristic of humanity to go to extremés, and at the 
present time, apparently, some people almost believe that if the country 
could be reforested there would be no freshets, and that our streams 
would be absolutely uniform in flow. On the other hand, occasionally 
but rarely a writer is found who denies their beneficial effect, and now 
the author seems to be attempting to convince us that, not only 
forests, but reservoirs, increase the violence of freshets. 
The author has stated very clearly the difficulties attending quanti- 
tative demonstration in regard to this matter. In fact, absolute proof 
is almost impossible, for the reason that the factor to be studied cannot 
be isolated in the way that is possible in many scientific investigations. 
In order ‘to demonstrate quantitatively beyond peradventure the effect 
of forests, it would be necessary to have the same area under identical 
conditions in every respect, except that at one time it should be wooded 
Mr. Smith. 
Mr. Swain. 
