DISCUSSION: FORESTS, RESERVOIRS, AND STREAM FLOW 487 
thought no effect was traceable; in another set of replies this minority mr. 
was much smaller; but in neither case was the vote by any means 
unanimous. The drawing of hard-and-fast conclusions upon evidence 
of this sort is open to the same criticism as was the verdict of a jury 
who acquitted a man of theft because six witnesses swore that they 
did not see him commit the theft, and only four that they did see him 
commit it. The simple fact is that our evidence in all these matters 
is not clear, and that the tendency has been to ignore or set aside many 
good and valid explanations of existing phenomena and attribute 
them to one cause alone—the cutting off of the forests. 
Coming back to his argument, the writer holds that the strong and 
permanent springs, which form the real sources of our low-water 
supply, have not changed appreciably with the development of the 
country; that the superficial springs possibly dry up more than 
formerly, but that the difference between their former and present 
condition is much exaggerated; and that in most cases the diminished 
flow of little streams is due to the increased use of the water more 
than to the clearing of the land. To offset this diminished flow where 
it exists there are several influences brought into effect by the settle- 
ment of the country. In towns, a portion of the water supply drawn 
from wells or springs, or stored in reservoirs during high water, finds 
its way back into the streams as sewage. In some towns cistern storage 
is sufficient to absorb a large part of the rain that falls on roofs, and 
a portion of this finds its way back into the streams in low water. 
But the principal compensating effect is the run-off from summer 
showers, to which the writer refers in his paper. In the low-water 
season the difference between the forest and the open country in the 
matter of restraining run-off is at a maximum. The forest prevents 
practically all such showers from reaching the streams, whereas the 
effect of roads, ditches, and pavements in the open country is to deliver 
some portion into the streams. Every one has witnessed this difference 
at such seasons, and its effect is at times considerable. Putting all 
these causes together, it is clearly not a proven fact that the aggregate 
flow of small streams in the open country during periods of low water 
is less than it was under forest conditions. It may. be more irregular. 
It may fall lower, but at the same time it may rise higher and the ag- 
gregate result may be very doubtful. 
Mr. Leighton repeats the old dictum, which is just now enjoying 
a revived popularity, that a “stream is a stream from its mouth to its 
source,” meaning thereby that no really comprehensive method of 
dealing with the lower course of a river is possible which does not take 
into account the extreme head-waters as well. This used to be a favor- 
ite doctrine with the writer, and, to a limited extent, is so still; but 
he has long since learned that the only real resemblance between a 
great river and any one of its innumerable sources is the fact that both 
Chitten- 
den. 
