DISCUSSION: FORESTS, RESERVOIRS, AND STREAM FLOW 333 
The data presented by the author, as to the relation of stream Mr. Maltby. 
flow and reservoir effect, are also particularly valuable in refuting 
some of the extravagant statements made by reservoir enthusiasts. 
It is to be regretted that the presentation of facts, with the calm 
arguments and conclusions based on them, cannot be given the same 
publicity as some of the wild assertions and schemes of the magazine 
writers. This cannot be expected, as there is nothing sensational in a 
consideration of the facts and conditions. 
That much, very much, can and should be done in the direction 
of forestation, water supply for power purposes and navigation, and 
the control of floods, is undoubtedly true; and the engineering pro- 
fession is to be congratulated on having the underlying facts concern- 
ing the relations between the various subjects so clearly brought 
before it. 
J. Francois Le Baron, M. Am. Soc. CO. E. (by letter).—This paper 
is very timely, and the author has handled the subject in a very 
thorough manner. His observations in regard to snow run-off from 
forest and open areas, are borne out by the writer’s experience. In 
his early days, while running railroad lines in New England, in the 
early spring, he was often surprised to find the woods nearly devoid of 
snow, while deep drifts still remained under the road fences and stone 
walls, and in deep road cuts. 
The writer, however, must take exception to what he considers too 
sweeping a generalization of the statement that “there is really very 
little, theoretically, to support the claim that forests insure precipita- 
tion.” It is undoubtedly true that when warm, moisture-laden air 
strikes a cold air current, the moisture will be precipitated in the 
form of rain. Forests are sometimes warm and sometimes cold. In 
northern latitudes forests are warm in winter and cool in summer; 
in the tropics, they are always cooler than the open, where the sun’s 
rays are unimpeded. Take, for instance, the thick forests that clothe 
the eastern slopes of Nicaragua. For many months in the year, the 
warm trade-winds that have passed over the Caribbean Sea blow day 
after day from the coast over these forests, and the precipitation is 
phenomenal. It is common, when traveling on the larger rivers, to see 
spiral columns of vapor resembling the smoke of camp fires arising 
from the low hillsides when this warm wind from the sea is blowing 
over them. So perfect is the resemblance that at first the writer un- 
hesitatingly supposed the vapor columns to be the smoke from the fire 
of some lonely hunter or settler. 
There may be, as the author says, “very little to support the claim, 
theoretically”; but, practically, it is abundantly proven throughout the 
whole of that relatively narrow isthmus known as Central America, 
from Guatemala to Panama, as the writer has frequently observed. 
This phenomenon is particularly noticeable in Nicaragua, and the in- 
Mr. Le Baron. 
