Mr. Chitten- 
den. 
484 DISCUSSION: FORESTS, RESERVOIRS, AND STREAM FLOW 
In reviewing the wording of Proposition 2, the writer can see 
that, taken by itself, it may justify the interpretation of Professor 
Swain, but not if read in connection with the explanation in the text. 
It would convey the writer’s meaning more clearly if the words “may, 
and often does, bring the accumulated waters of a series of storms in 
one part of the water-shed upon those of another which may occur 
several days later,” were changed to read “may, and often does, pro- 
duce an increase of stage in a river, which may aggravate a later flood 
coming from some portion of the water-shed.” 
Proposition 3. 
“In periods of extreme summer heat forests operate to diminish 
the run-off, because they absorb almost completely and give off in 
evaporation ordinary showers which, in the open country, produce a 
considerable temporary increase in the streams; and therefore, while 
small springs and rivulets may dry up more than formerly, this is not 
true of the larger rivers.” 
The writer has already called Mr. Leighton to account for misstat- 
ing his position in regard to ground storage. He nowhere ignores its 
existence. Neither has he anywhere said what Mr. Le Baron implies 
he has said, that “if there were no springs, rivulets, or brooks,” there 
would still be rivers. What he did say is: “The difference between 
the former low-water flow of a spring or rivulet and what it is now is 
relatively an insignificant quantity.” He was dealing with relative, 
not absolute, quantities. Formerly streams were lower in autumn than 
in spring; the same is true now. The current theory is that they fall 
lower now than they once did. The writer simply said that, whatever may 
be the difference between the former time and now, it cuts very little 
figure in comparison with the total flow that makes up a river. And 
he will now add that he is more convinced than ever that the difference 
itself is very greatly exaggerated in the public mind. 
Springs are, of course, an exceedingly important factor in stream 
flow, possibly more important than the surface run-off. In time of 
flood the surface run-off is far the greater. In times of low water the 
spring supply is generally, though not always, the greater. In con- 
sidering the function of springs in the low-water flow of streams, it is 
necessary to take into account their origin and character. For this 
purpose they may be classified as deep and shallow springs—that is, 
those that come from deep subterranean sources and those that emerge 
in the near vicinity of their supply. The true spring—the spring of 
real economic importance—comes from deep and distant sources. Its 
course before emergence may lie for great distances between im- 
pervious strata, where it is entirely cut off from external influences. 
Springs of this class are generally permanent, respond slowly to pre- 
cipitation, and vary but little throughout the year. Every country 
