72 
THE PARALLEL ROADS OF 
field spread itself over the whole country, ex¬ 
tending in every direction toward the lower 
lands and the sea-shore. As the glaciers 
which now descend through all the valleys of 
the Alps, along their northern as well as their 
southern slopes, and in their eastern as well as 
their western prolongation, though limited, in 
our days, within the valley-walls, nevertheless 
once covered the plain of Switzerland and that 
of Northern Italy, so did the ice-fields of the 
Grampians during the greatest extension of 
the Scotch glaciers spread over the whole 
country. They also were, in course of time, 
reduced to local glaciers, circumscribed within 
the higher valleys of the more mountainous 
parts of the country, until they totally disap¬ 
peared, as those of Switzerland would also 
have done, had it not been for the greater 
elevation of that country above the level of the 
sea. Scotland nowhere rises above the pres¬ 
ent level of perpetual snow, while in Switzer¬ 
land the whole Alpine range has an altitude 
favorable to the preservation of glaciers. In 
the range of the Jura, however, which had at 
one time its local glaciers also, but which 
nowhere now rises above the line of perpetual 
