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masses are constantly set in motion and come to strand on the terraces, 
etc., thus reducing the danger. 
Some special conditions for the formation of slides exist, when days 
with a temperature above freezing which thaws the surface of the snow, 
alternate with cold nights when the surface freezes together. If fresh 
snow falis on such a surface, it is most liable to form into an avalanche, 
and sometimes if a heavy snow-fail occurs, it may break throngh the 
crust and carry the lower masses with it. This kind of slide occurs 
mostly on southern exposures. . 
As regards season and periodicity of slides the greatest diversity ex- 
ists. New tracks are opened every year, while in other places the old 
tracks become scenes of disaster In varying intervals, some yearly, 
some every half or every full century. It depends of course on the 
amount of snow fallen, in connection with weather conditions, espe- 
clally the direction and force of winds. The most regular falls-oecur in 
spring during time of thaws. 
In wind-still weather and warm sunshine, the time of fall occurs in 
the first hours of the afternoon, yet if a warm wind blows any time of 
day or night, the avalanches may start. 
PROGRESS OF AVALANCHES. 
The ground-slides follow more or less the contour of the ground, like 
running water. Usually the masses start sliding, later on they roll 
over when passing over steeper and rocky ground, and in rills and fun- 
nels they are compressed and compacted. 
As in a stream of water, the greatest velocity lies in the center of 
the slide, where in a straight track the iargest mass and the least fric- 
tion exists. If turned from the straight track the force is greatest on 
the outer curve, where trees, turf, soil, and rocks are torn up and swept 
away together. 
Dast-slides occur most frequently during snow-falls at low tempera- 
tures, especially in windy weather. “They occur oftener in clear weather 
than when the sky is clouded. 
RESCUE OF PERSONS BURIED BY AVALANCHES. 
After pointing out the different localities which are exposed to ava- 
lanches in the Alps, and giving an account of some special cases of dis- 
asters, which forms most interesting and instructive reading, a chap- 
ter is devoted to the measures to be taken in saving men lost in snow- 
slides. The procedure is somewhat like the following: 
First look over the surface of the snow, where the slide has come to 
rest, after signs of the unfortunate victims. If no parts of the body are 
visible outside, determine, according to the location and the track which 
the slide took, the place where most probably the entombed lie. Then 
let the rescuers take position in line, and with the handles of shovels, 




