., Leighton. 
398 DISCUSSION: FORESTS, RESERVOIRS, AND STREAM FLOW 
of the contention that forests do not sustain stream flow during dry 
seasons ? 
It is of interest to pursue further the author’s reasoning. He 
contends that if all these small rivulets become dry the river will 
nevertheless, somehow, somewhere, get its water supply. Moreover, the 
conception implies that the normal supply of water in these rivers must 
appear suddenly, as if in response to the smite of Moses’ staff. If the 
course is followed, it will lead out of dry rivulets and brooks into 
a normally flowing stream. The transition from dry conditions to 
those of normal flow must be abrupt. Whence comes this providential 
supply? The facts are that the drying up of springs and little streams 
means simply that the ground storage has been drawn down or ex- 
hausted. The concept of the author is hopelessly involved. Between 
his admission of dry springs and little streams, and his assumption 
of normally flowing rivers, his argument is ground to pieces, as it 
were, between the upper and the nether millstones. 
The author further states that heavier showers, which make 
freshets in the open, are largely “absorbed in the leaves and forest 
bed and pass off in evaporation.” This concept is advanced without 
demonstrated proof; how does the author know that this is true? The 
demonstrated facts are all to the contrary. The showers which, falling 
in the open country, make freshets, must, when they fall on the 
forest, pass through the “leaves and forest bed” and enter the ground, 
merely because they have the opportunity, which opportunity is largely 
denied them in the open. The water which is absorbed in the leaves 
and forest bed from heavier showers is but an insignificant part of 
the total precipitation. 
Further along it is stated that it is better to have a good than a 
uniform flow in a river. It is difficult to imagine how one can be 
attained without the other. In order to have a good flow, it is neces- 
sary that the low extreme be prevented, and this very prevention means 
comparative uniformity. Good flow (and by this it is assumed that 
the author means abundant flow) is attained quite as much by the pre- 
vention of low periods as by the production of high ones. 
The final sentences of the paragraph* enunciate a curious doctrine. 
It is stated that “great rivers swallow up and equalize the small 
irregularities of their head-waters and actually experience somewhat 
larger low-water flow than if their water-sheds were still thickly 
forested.” This is not uniformly borne out by experience; but only the 
logic of the argument will now be considered. If it be true that the 
source of supply of great rivers is ultimately in the small rivulets, 
how is it possible, with lack of uniformity in those small rivulets, to 
secure uniformity in the large ones? Of course, if the lack of uni- 
formity took place in successive periods over an entire drainage area, 
* Pagel251, 
