280 FORESTS, RESERVOIRS, AND STREAM FLOW 
natural visitations are less frequent and less extensive than they were 
before the white man cut away the forests. 
In summarizing below the foregoing argument, the writer would 
be particularly careful to guard against sweeping assertions in any of 
his conclusions. He well understands how little the subject is capable 
of precise demonstration. Snow, for example, does not always fall, 
even in the open country, under the influence of the wind, or it may 
fall in a wet condition that keeps it from drifting. Altitude comes 
in with its lower temperature and modifies the general result. There 
is a vast difference between a northern and a southern exposure even 
with the same slope and topographical conditions. Precipitation 
scarcely ever occurs twice alike on the same water-shed. The combi- 
nation of flow from tributaries is never the same in any two floods, 
and there is an endless variety of conditions that must qualify our 
rules and make us cautious in making claims in a matter of this kind. 
The writer objects solely to the contrary course pursued by many for- 
estry advocates—to the extreme claims that forests exert a regulating 
influence upon stream flow in times of great floods or extreme low 
water in our larger rivers. These claims stand to-day absolutely un- 
proven. The difference between past and present conditions is not 
great. One influence offsets another with such nicety that the change, 
if there is any, is hard to find. The “delicate balance” maintained by 
Nature where Man has not cut away the forests is replaced by other 
balances equally delicate and efficacious in the drainage of lands, the 
growing of crops, and the deposition of dew. 
In the following seven propositions the writer sums up the argu- 
ments presented in the foregoing pages: 
(1) The bed of humus and débris that develops under forest cover 
retains precipitation during the summer season, or moderately dry 
periods at any time of the year, more effectively than do the soil and 
crops of deforested areas similarly situated. It acts as a reservoir 
moderating the run-off from showers and mitigating the severity of 
freshets, and promotes uniformity of flow at such periods. 
(2) The above action fails altogether in periods of prolonged and 
heavy precipitation, which alone produce great general floods. At 
such times the forest bed becomes thoroughly saturated, and water 
falling upon it flows off as readily as from the bare soil. Moreover. 
the forest storage, not being under control, flows out in swollen 
