INFLUENCE OF THE FOREST ON SPRINGS. 
197 
radiation of heat from the earth. These influences go far to 
balance each other; but familiar observation shows that, in 
summer, the forest soil is not raised to so high a temperature 
as open grounds exposed to irradiation. For this reason, and 
in consequence of the mechanical resistance opposed by the 
bed of dead leaves to the escape of moisture, w r e should expect 
that, except after recent rains, the superficial strata of wood¬ 
land soil would be more humid than that of cleared land. 
This agrees with experience. The soil of the forest is always 
moist, except in the extremest droughts, and it is exceedingly 
rare that a primitive wood suffers from want of humidity. 
How far this accumulation of water affects the condition of 
neighboring grounds by lateral infiltration, we do not know, 
but we shall see, in a subsequent chapter, that water is con¬ 
veyed to great distances by this process, and we may hence 
infer that the influence in question is an important one. 
Influence of the Forest on the Flow of Springs. 
It is well established that the protection afforded by the 
forest against the escape of moisture from its soil, insures the 
permanence and regularity of natural springs, not only within 
the limits of the wood, but at some distance beyond their bor¬ 
ders, and thus contributes to the supply of an element essen¬ 
tial to both vegetable and animal life. As the forests are 
destroyed, the springs which flowed from the woods, and, con¬ 
sequently, the greater watercourses fed by them, diminish 
both in number and in volume. This fact is so familiar 
throughout the American States and the British Provinces, 
that there are few old residents of the interior of those districts 
who are not able to testify to its truth as a matter of personal 
observation. My own recollection suggests to me many in¬ 
stances of this sort, and I remember one case where a small 
mountain spring, which disappeared soon after the clearing of 
the ground where it rose, was recovered about ten or twelve 
years ago, by simply allowing the bushes and young trees to 
grow up on a rocky knoll, not more than half an acie in 
