526 DISCUSSION: FORESTS, RESERVOIRS, AND STREAM FLOW 
Mr. Chitten- tion the drifts that he certainly found in the ravines and behind the 
den, 
shoulders of the hills. Has he not seen these drifts, within the alti- 
tudes at which timber grows, last until August? Has he ever seen 
snow in the forest at that late date, unless in some special situation 
where it has drifted or has been protected by a northern slope? 
Colonel Pickett’s reference to what he saw in the valley of Heart 
River, North Dokota, has a significance quite other than that which he 
has attached to it. These prairies are a living evidence of the efficiency 
of snow drifts in preventing floods. The deforested area of this water- 
shed is very great, compared with the small extent of the forested areas 
at the sources, yet the “April rise,’which marks the disappearance of 
the prairie snows and the break-up of the ice in the river, is nearly 
always inferior both in volume and duration to the “June rise.” Why 
should this be so? Because the snow that falls in the open country 
of the water-shed is nearly all blown into sheltered corners, or behind 
clumps of brush, and, in these Jater years, fences. The early spring 
sun in that clear atmosphere carries off the thin covering outside the 
drifts, and when the warm weather comes that brings the “April rise” 
the snow surface left to act upon is an exceedingly small proportion of 
the entire area. 
Colonel Pickett’s supposed benefits of mountain forests to the floods 
of the Lower Mississippi seem to the writer wholly visionary. If he 
will take any “June rise” that he may select, differentiate the portion 
that comes from the forests, arrive at any estimate that he may con- 
sider fair of the difference in the volume of this rise due to any prac- 
ticable change in forest areas, then trace this difference 3 000 miles to 
the mouth of the Ohio, he will have hard work to convince himself 
that it could amount to 10000 cu. ft. per sec., a quantity that would” 
be wholly lost in any great flood of the lower river. According to the 
writer’s view, however, the difference produced by the reduction of 
forest area would be beneficial. The flood crest would come but very 
little earlier (see Fig. 1), and it would be lower. In fact, so far as the 
effect upon the run-off from snow-melting is concerned, one could look 
with complacency upon the entire removal of the mountain forests. 
Colonel Pickett’s suggestion that trees be planted along the upper 
limit of their present zone of growth is open to the criticism that 
the timber itself would be of no economic value because of its inac- 
cessibility, and, so far as it might interfere with snow drifting in win- 
ter, it would be a positive detriment to stream-flow. [he writer, how- 
ever, has never gone to the length of suggesting a removal of our 
mountain forests in the arid regions, though the idea has been dis- 
tinetly put forth by three contributors to this discussion. The writer 
assumes that the economic value of these forests for timber will out- 
weigh their drawbacks in the distribution of snowfall. Then there is 
the uncertain effect upon precipitation, and until thig relation is 
