DISCUSSION : FORESTS, RESERVOIRS, AND STREAM FLOW 50% 
The opening sentence in Mr. Collingwood’s criticism has a signifi- Mr. Chitten- 
cance which the writer probably did not intend. His reference to a] 
“conclusions” as “firmly established” indicates that he is under the 
impression that the current forestry theories are so established. A 
similar suggestion is made in a recent State paper in which the 
writer’s views are characterized as being “contrary to the experience 
of mankind” and “opposed to all the recent work of the scientific 
bureaus of the Government.” Professor Swain, in an elaborate paper 
prepared at the request of Governor Guild of Massachusetts to con- 
trovert the writer’s arguments, expresses the same opinion. What are 
the facts upon this point? 
Forestry has been a living issue in France for nearly a century. 
Between 1850 and 1870 the subject was much discussed pro et con, for- 
estry advocates being very pronounced in their views that forests 
exercise a marked regulative effect upon streams, and many prominent 
engineers taking exactly the opposite view. In 1857 M. F. Vallée 
published a paper upon this subject which was translated in 1873" 
by Captain Charles J. Allen, Corps of Engineers, U. S. A., and printed 
under the auspices of the Engineer Department of the Army. M. 
Vallée goes into the subject exhaustively, traversing the entire argu- 
ment that forests have a beneficial effect upon either high or low 
water. He cites many interesting examples, relating to floods, springs, 
low waters, etc. Professor Swain refers slightingly to this paper, say- 
ing that it had no effect on public opinion at the time. Be that as it 
may, M. Vallée was not alone in his views by any means, and an event 
occurred at about that time which shows that his views were adopted 
practically, whatever may have been the opinions of doctrinaires. 
After the great flood of 1856 in France, elaborate studies were 
made of the flood problems of several of the rivers, as related in the 
writer’s paper. The subject of reforestation, as a means of reducing 
flood heights, was considered for both the Rhéne and the Loire and 
rejected as impracticable. The comments upon the sources of popular 
opinion on the subject, its lack of foundation, the fact that the great 
floods cannot be modified by this or that change which Man may make 
on the surface of the earth, are all pointed out very effectively. This 
is probably the first example in which reforestation has been urged as 
a practical means of regulating the flow of great rivers, and it was 
rejected summarily. The example so set has been followed ever since. 
About this same time appeared an elaborate work by M. Champion, 
giving a history of the floods of French rivers since the sixth century. 
It showed that floods had been diminishing, so far as there was any 
change, this tendency in the case of the Seine being very pronounced. 
Thus the gauge at La Tournelle Bridge, Paris, showed the following 
mean heights for five half-centuries from the year 1600: 8.39, 8.03, 
7.72, 6.83 and 6.47 meters. 
* In the paper the writer erroneously gave the date of publication as 1873. 
