BASINS OF RECEPTION. AOL 
mena and their laws. Their causes, their history, their imme- 
diate and remote consequences, and the possible safeguards to 
be employed against them, have been carefully studied by the 
most eminent physicists, as well as by the ablest theoretical 
and practical engineers of France. Many hitherto unobserved 
facts have been collected, many new hypotheses suggested, and 
many plans, more or less original in character, have been de- 
vised for combating the evil; but thus far, the most competent 
judges are not well agreed as to the mode, or even the possi- 
bility, of applying an effectual remedy. 
I have noticed in the next preceding chapter the recent legis- 
lation of france upon the preservation and restoration of the 
forests, with reference to their utility in subduing torrents and 
lessening the frequency and diminishing the violence of river 
inundations. The provisions of these laws are preventive 
rather than remedial, but most beneficial effects have already 
been experienced from the measures adopted in pursuance of 
them, though sufficient time has not yet elapsed for the com- 
plete execution of the greater operations of the system. 
Basins of Lreception. 
Destructive inundations of large rivers are seldom, if ever, 
produced by precipitation within the limits of the principal 
valley, but almost uniformly by sudden thaws or excessive rains 
on the mountain ranges where the tributaries take their rise. 
It is therefore plain that any measures which shall check the 
flow of surface-waters into the channels of the affluents, or 
which shall retard the delivery of such waters into the princi- 
pal stream by its tributaries, will diminish in the same propor- 
tion the dangers and the evils of inundation by great rivers. 
The retention of the surface-waters upon or in the soil can 
hardly be accomplished except by the methods already men- 
tioned, replanting of forests, and furrowing or terracing. The 
current of mountain streams can be checked by various 
methods, among which the most familiar and obvious is the 
