48 
THE PARALLEL ROADS OF 
found everywhere about disintegrating rocks, 
and they constantly mingle with the loose 
fragments brought from a distance by various 
agencies. They are found upon and among 
the glacier-worn pebbles, especially where the 
latter have themselves been disturbed since 
their accumulation. They are also found among 
water-worn pebbles, wherever the rocky beds 
of our rivers or the rocky bluffs of our sea¬ 
shores crumble down. In investigating the 
character of loose materials transported from 
greater or less distances, either by the agency 
of glaciers or by water-currents, it is im¬ 
portant at the very outset to discriminate 
between these deposits of older date and the 
local accessions mingling with them. 
Occasionally we may have also to distin¬ 
guish between all these deposits and the debris 
brought down by land-slides, or by sudden 
freshets transporting to a distance a vast 
amount of loose materials which are neither 
ice-worn nor water-worn. At Rossberg, for 
instance, in the Canton of Schwitz, the land¬ 
slide which buried the village of Goldau under 
a terrific avalanche, and filled a part of the 
Lake of Lauertz, spread an immense number 
