But the great danger of travelling here when the sun is up, proceeds from what they call the Valanches. These are balls of snow detached from the mountains which over-top the road, either by the heat of the sun, or the humidity of the weather. A piece of snow thus loosened from the rock, though perhaps not above three or four feet in diameter, increases sometimes in its descent to such a degree, as to become two hundred paces in length, and rolls down with such rapidity, that the traveller is crushed to death before he can make three steps on the road.