The mountain systems in the middle latitudes, with abundant snows and
alternate warm and cold seasons, are most favorable to the formation of
glaciers. The best known, and probably the most remarkable glaciers are
those of the high Alps, in the heart of which are Mont Blanc, Monte
Rosa, and the Bernese Alps. Late explorers have found large glaciers in
the Caucasus and in the Himalayas, the last being of the grandest
proportions. In the Scandinavia are many which descend, in the deep
western fiords, nearly to the sea level.
In the New World glaciers are less frequent. On Mount Shasta and Mount
Rainier fine examples are in evidence.
By far the most extensive glaciers however, are found on the
snow-covered islands of the polar oceans.
Vast masses of ice, broken from the ends of these glaciers, form the
enormous _icebergs_ (mountains of ice) which are so numerous in the
polar seas, and are transported by the currents even to middle
latitudes.