ALPS, the most remarkable and interesting system of mountains in Europe. It covers a great part of northern Italy, several depart ments of France, nearly the whole of Switzer land and a large part of Austria, while its ramifications in Italy and Germany, and ex tending far toward the southeast, connect it with nearly all the mountain systems of Europe. The name is derived from the Celtic alb, which by some is made to signify white, by others height. In the immediate neighbor hood of the mountains alp has a peculiar mean ing, and signifies one of the high pastures for which the Alps are distinguished. This great congeries of mountains may be said to be in cluded between lat. 44° and 48° N.; and long. 5° and 18° E. The culminating peak of the whole system is Mont Blanc, 15,781 feet high, though the true centre is St. Gothard, or rather the mountains between the sources of the Rhone and the Inn, and the Swiss cantons Valais, Bern Uri and Grisons on the north; and cantons Tessin and Lombardy and Sardinia on the south. It is a curious fact that its great central mass is nearly equidistant from the pole and from the equator. From its slopes flow, either directly or by affluents, the great rivers of central Europe, the Danube, Rhine, Rhone and Po. Round the northern frontier of Italy the Alps form a remarkable barrier, shutting it off at all points from the mainland of Europe, so that, except in the valley of the Adige, where a remarkable break occurs in the chain, or at the opposite extremity at Nice, it can only be approached from France, Germany or Switzer land through high and difficult passes. Ac cordingly nearly all the great passes of the Alps are connected with roads from the north ern kingdoms into Italy. In this connection see ITALY: HISTORY AND MODERN DEVELOPMENT; 1, PHYSICAL GEOGRAPHY; Mountains.
As usual with mountain systems of great altitude, the highest peaks of the Alps are reached by a gradual ascent through a succes sion of outer ranges and elevated intermediate valleys. The total width of the system is there fore always great and can hardly anywhere be measured with precision, opinion •varying as to the points at which the outer limits should be fixed. Toward the east, however, the system,
while it diminishes in height, becomes more widely extended, some of the transverse valleys extending to 150 miles, while that of the Drave reaches 200. From Bellinzona, in the canton of Tessin, to Altdorf, in that of Uri, the dis tance is 50 miles. The outer range is called by the Italians Pre-alpi, by the Germans Voralpen. The main chain of the Alps, which commonly determines the watershed of the countries through which it passes, contains some of the highest peaks; but at several points there are extensive ramifications of the system proceeding at various angles the main chain, and more or less connected with it, and which some times exceed in mass and altitude the cor responding parts of the principal chain. Such are the Alps of Dauphine and Savoy, and the Bernese Alps. The principal valleys of the Alps run mostly in a direction nearly parallel with the principal ranges, and therefore east and west. The transverse valleys are commonly shorter. In the section called the Lepontine Alps, however, long ranges run north and south, forming valleys transverse to the divid ing line of the waters, and terminating in the great Italian lakes. The slopes toward the south are more precipitous than toward the north, and as most of the collateral ranges lie to the north of the main chain the great valleys are mostly to be found in the intervals between them. The transverse valleys of the Alps frequently lead up through a narrow gorge to a depression in the main ridge between two adjacent peaks. These are the passes or cols, which are found by tracing a stream which descends from the mountains up to its source. The col is usually found to receive the drainage of the neighbor ing peaks, and when it is of sufficient extent a small lake is generally formed, from which a stream flows down on each side. When the one stream has been traced up to its source the passage across the mountains is completed by following the course of the other. The prin cipal passes, now well known, are more than 50 in number; but there are many others more difficult and dangerous which have never had more than a local reputation.