CHAPTER XI

GLACIERS--AVALANCHES--MILITARY SKI-ING 264

A legacy from the past--The formation of glaciers and atmospheric conditions--Forests and glaciers--Our deficient knowledge--The upper ice and snow reservoirs--What is the annual snowfall and what becomes of it--How glaciers may be classed--Mechanical forces at work--Moraines and _séracs_--Avalanches--Periodic avalanches--Accidental avalanches--The general causes--The statics of snow--What happens to winter snow--_Strata_--How steep slopes may be classed--Excusable ignorance of strangers to the Alps--Those who write glibly in home magazines--Unsafe slopes--Avalanches when running across slopes--The probing-stick--Avalanche runs--Military ski-ing--The St. Gothard and St. Maurice districts--Military raids in the High Alps--The glaciers as military highways--Riflemen on foot as against marksmen on ski.