512 DISCUSSION: FORESTS, RESERVOIRS, AND STREAM FLOW 
Mr. Chitten- like that of 1856, that it would produce a greater overflow than actually 
occurred in the lower stretches of the valley. This was due to the 
more extensive combination of tributary flow from prolonging the run- 
off of the various affluents. 
Professor Swain says, in reference to the writer’s statement that 
a greater forest area in Western Montana would have aggravated the 
flood of 1908, that this “is a mere statement of the author’s opinion, 
entirely without proof, and undoubtedly incapable of a proof.” It is 
not a matter of opinon at all, but a clear, logical deduction, as capable 
of proof as any proposition in mathematics. The facts are that there 
were extensive forest tracts in the region affected by this flood. These 
forests held the snow, and there was a large mass of it on the ground 
when the heavy rains came. The melting of these snows added ma- 
terially to the flood. If Professor Swain doubts these facts, he can 
corroborate them by reference to the Weather Bureau records. It is 
also a fact, which he can readily verify, that in the neighborhood of 
these forests there are extensive tracts of non-wooded lands similarly 
conditioned as to topography and altitude to the forested lands. Now if 
these tracts had also been covered with forests, the ground within them 
would have been covered with snow, as the ground in the existing 
forests was; that snow would have melted as the snow actually there 
did; and in the same way would have added its quota to the flood. 
Q. E. D. 
Professor Swain has cited Professor Carpenter on the subject of 
snow-melting. The writer has often drawn upon the ample fund of 
information which Professor Carpenter has accumulated, and has con- 
ferred with him on more than one occasion. It is a pleasure to bear 
testimony to the value of his opinions upon any subject. It is possi- 
ble, however, that he may not have studied closely the phase of this 
question presented by the writer. In any event, the citations given 
by Professor Swain are not sufficient to carry conviction. There are 
several important questions that need to be answered in that con- 
nection. The diurnal fluctuation of the streams due to snow-melting 
is precisely the matter upon which the writer has laid stress in his 
paper. The great safety device of Nature in letting down the snows 
_in these mountains is the sun and the open country drifts. It is as 
if a care-taker of some great reservoir hoisted the gates for an hour 
or so each day, letting out a quantity of water and not closing them 
again until it had flowed away. The diurnal rise and fall may be a 
source of some inconvenience at head-gates, but this is really a trivial 
matter after all, and a hundred miles down the stream largely disap- 
pears. The writer doubts whether Professor Carpenter ever saw a real 
flood from this cause; but he has seen many a flood which has come 
down when the forests gave up their snow. Why has not this fact 
made an impression? And has he not often seen drifts in the open 
