The long northward slope of the Alps in Switzerland and Tyrol, and the easy western grade toward France, have enabled Germanic and Gallic influences of various kinds to permeate the mountains.  A strong element of blond, long-headed Germans mingles in the population of the Aar and Rhine valleys up to the ice-capped ridge of the Glarner and Bernese Alps,[1230] while the virile German speech has pushed yet farther south to the insuperable barrier of the Monte Rosa group.  The abrupt southward slope of the Himalayas has repelled ethnic expansion from the river lowlands of northern India, except in the mountain valleys of the Punjab streams and Nepal, where the highland offered asylum to the Rajput race when dislodged by a later Aryan invasion, or when trying their energies in expansion and conquest.[1231] The Tibetan people, whose high plateaus rise almost flush with the Himalayan passes, have everywhere trickled through and given a Mongoloid mountain border to Aryan India,[1232] even though their speech has succumbed to the pervasive Aryan language of the piedmont, and thus confused the real ethnic boundary. [See map page 102.] The retarded and laborious approach of British “influence” up this steep ascent to Lhassa, as opposed to the long established suzerainty of the Chinese Emperor in Tibet, can be attributed in part to the contrasted accessibility from north and south.

[Sidenote:  Persistence of barrier nature.]

Mountains influence the life of their inhabitants and their neighbors fundamentally and variously, but always reveal their barrier nature.  For the occupants of one slope they provide an abundant rainfall, hold up the clouds, and rob them of their moisture; to the leeward side they admit dry winds, and only from the melting snow or the precipitation on their summits do they yield a scanty supply of water.  The Himalayas are flanked by the teeming population of India and the scattered nomadic tribes of Tibet.  Mountains often draw equally clear cut lines of cleavage in temperature.  The Scandinavian range concentrates upon Norway the warm, soft air of the Atlantic westerlies, while just below the watershed on the eastern side Sweden feels all the rigor of a sub-Arctic climate.  In history, too, mountains play the same part as barriers.  They are always a challenge to the energies of man.  Their beauty, the charm of the unknown beyond tempts the enterprising spirit; the hardships and dangers of their roads daunt or baffle the mediocre, but by the great ones whose strength is able to dwarf these obstacles is found beyond a prize of victory.  Such were Hannibal, Napoleon, Suvaroff, Genghis Khan, and those lesser heroes of the modern work-a-day world who toiled across the Rockies and Sierras in the feverish days of ’49, or who faced the snows of Chilkoot Pass for the frozen gold-fields of the Yukon.

[Sidenote:  Importance of mountain passes.]