INUNDATIONS IN WINTER. 239 
Inundations in Winter. 
In the Northern United States, although inundations are not 
very unfrequently produced by heavy rains in the height of sum- 
mer, it will be found generally true that the most rapid rise of 
the waters, and, of course, the most destructive “ freshets,” as they 
are called in America, are occasioned by the sudden dissolution 
of the snow before the open ground is thawed in the spring. 
It frequently happens that a powerful thaw sets in after a long 
period of frost, and the snow which had been months in accu- 
mulating is dissolved and carried off in a few hours. When 
the snow is deep, it, to use a popular expression, “takes the 
frost out of the ground” in the woods, and, if it lies long 
enough, in the fields also. But the heaviest snows usually fall 
after midwinter, and are succeeded by warm rains or sunshine, 
which dissolve the snow on the cleared land before it has had 
time to act upon the frost-bound soil beneath it. In this case, 
the snow in the woods is absorbed as fast as it melts, by the 
soil it has protected from freezing, and does not materially con- 
tribute to swell the current of the rivers. If the mild weather, 
in which great snow-storms usually occur, does not continue 
and become a regular thaw, it is almost sure to be followed by 
drifting winds, and tne inequality with which they distribute 
the snow over the cleared ground leaves the ridges of the surface- 
soil comparatively bare, while the depressions are often filled 
with drifts to the height of many feet. The knolls become 
frozen to a great depth; succeeding partial thaws melt the sur- 
face-snow, and the water runs down into the furrows of 
ploughed fields, and other artificial and natural hollows, and 
then often freezes to solid ice. In this state of things, almost 
the entire surface of the cleared land is impervious to water, 
and from the absence of trees and the general smoothness of 
its waters brought to a peaceful flow, by replanting its valley. See LABus- 
stmre, Revue Agric. et Forestiére de Provence, 1866, and Revue des aux et 
Foréts, 1866. 
