488 DISCUSSION: FORESTS, RESERVOIRS, AND STREAM FLOW 
Mr. Chitten- are carrying water on its way from the uplands to the sea; and he 
en. 
believes the truer ‘doctrine is, in the words of Colonel Roberts: “A 
river is a river, and a creek is a creek.” Let any one reflect but a 
moment upon the many and radical differences between these two 
classes of streams, and he will see that their practical relationship is 
often more fanciful than real. Only one feature of difference will 
be noted here, and that is the reservoir function of the trunk stream. 
A river is made up of tens of thousands of little tributaries. These 
are separate sources, often acted upon by separate causes—some ex- 
periencing freshets, while others are entirely undisturbed, and all 
changing in their flow more or less independently of one another. The 
river knows nothing of these irregularities. The freshet of a remote 
tributary causes scarcely a ripple on its surface. The river is a 
reservoir. It is uniform in a sense that little tributaries never are. It 
responds only to general causes that affect a great number of tribu- 
taries alike, and most readers of this paper will have no difficulty in 
understanding what is meant by uniformity of flow in a river, as dis- 
tinguished from any one of its numberless sources. It is therefore in 
the great river, where the infinitely variable elements of its supply 
are integrated into one definite result which can be observed and 
measured, that we should go to see whether the flow of our streams is 
smaller in volume than it used to be. Resorting to this tribunal, we 
find nothing to justify the popular theory. Whatever may be hap- 
pening to the springs and wells and little streams, as much water 
gets into the great rivers in low stages as used to, and apparently more. 
The low-water flow of the Monongahela at Pittsburg for 1908, about 
200 cu. ft. per sec., was certainly as great as in certain other extreme 
low waters, and if it could be corrected for losses for industrial uses 
that have come into existence in the past fifty years, its discharge at 
the height of this extraordinary drought would be found to be ma- 
terially larger than in the great drought years of 1838 and 1856. 
In fact, it is growing evident, as this matter is looked into more 
carefully, that the forest, in more ways than one, is a voracious con- 
sumer of water during periods of drought, and that it is not at all the 
source of low-water supply that it has been held to be. 
Proposition 4. 
“The effect of forests upon the run-off resulting from snow-melting 
is to concentrate it into brief periods and thereby i increase the severity 
‘of freshets. This results (a@) from the prevention of the formation of 
drifts, and (0) from the prevention of snow-melting by sun action in 
the spring, and the retention of the snow blanket until the arrival of 
hot. Weather.” 
As to the soundness of this proposition, the writer is quite con- 
tent to rest his case upon the judgment of those who will carefully read 
