There are internal differences in formation in every mountain range and in every plain, all of which have different influences on history. The steep fall of the Alps on the Italian side has rendered a descent into the plains of the Po far easier than a crossing in the opposite direction, where many obstacles in the shape of mountain steeps, elevated plateaus, and deep river valleys surround the outer border of the Alps. Again, penetration from the plains to the interior of the Alps is less difficult in the west, where there are no southern environing mountains, than in the east, where there is such a surrounding mountain chain. The compact formation of the Alps in the west crowds obstacles together into a small space, where they may be overcome with greater labour and in a shorter time than in the east, among the broadened-out chains of mountains, where there are numerous smaller hindrances to progression spread out over a wider territory. The route from Vienna to Trieste is twice as long as that from Constance to Como.
In mountain passes orographic differences are concentrated within very limited areas, and for this reason passes are of great importance in history. The value of gorges and defiles increases with their rarity, and their number varies greatly in different mountain chains. The Pindus range is broken but once, by the cleft of Castoreia, and an easy passage from Northern to Central Greece is possible only by way of Thermopylæ; the short overland route from Persia to India is through the Khyber or Bolan Passes. The Rhætian Alps are rich in defiles and gorges; but the mountain ridges are poor in crossing-places, and, as a rule, the elevation of the passes decreases towards the east.
Nature’s Place in History
The possibility of journeying over the Himalayas increases as we travel westward. During the Seven Years’ War the great difference between the accessible, sloping Erz-Gebirge of the Bohemian frontier and the precipitous, fissured, sandstone hills of the Elbe was very apparent. Mountain passes are always closely connected with valleys and rivers; the latter form the ways leading to and from the former. The valleys of the Reuss and the Tessin are the natural routes to the pass of St. Gothard; and were it not for the gorges of the Inn and the Etsch in the northern and the southern Alps, the Brenner Pass would not possess anything like its present supreme importance. Wherever such entrances to passes meet together or cross one another, important rallying-points either for carrying on traffic or for warlike undertakings are formed; such places are Valais, Valteline, and the upper valley of the Mur. Coire is a meeting-point of not less than five passes—the Julier, Septimer, Splügen, St. Bernardin, and Lukmanier. The value of passes varies according to whether they cross a mountain range completely from side to side, or extend through only a part of it. When the Augsburgers, on the way to Venice, had got through the Fern Pass, or that of Leefeld, the Brenner still remained to be crossed; but when the Romans had surmounted the difficulties of Mont Genevre, the ridges of the Alps were no longer before them; they were in Gaul.
There are also passes through cross ridges that connect mountain chains, such as the Arlberg, that pierces a ridge extending between the northern and the central Alps. Passes of this sort are of great importance to life in the mountains, for, as a rule, they lead from one longitudinal valley to another, such valleys extending between ridges being the most fertile and protected districts in mountainous regions. In this manner the Furka Pass connects Valais, the most prosperous country of the Alps during the time of the Romans, with the upper Rhine valley; and the Arlberg connects the Vorarlberg with the upper valley of the Inn.
Value of Mountain Passes
Mountain passes are not only highways for traffic, they are the arteries of the mountains themselves. Commerce along the mountain ways leads to settlements and to agriculture at heights where they would hardly have developed had it not been for the roads; and the highest permanent dwellings are situated in and about passes. The Romans established their military colonies in the neighbourhood of passes, and the German emperors rendered the Rhætian gorges secure through settlements. There are political territories that are practically founded on mountain passes. The kingdom of Cottius, tributary to the Romans, was the land of the defiles of the Cottian Alps; Uri may be designated as the country of the north Gothard, and the Brenner Pass connects the food-producing districts of the Tyrol with one another.
Battlefields of Mountain Borderlands
The transition point from one geological formation to another is invariably the boundary line between two districts that have different histories. The movements in one region bring forces to bear on the movements in the other. Hence the remarkable phenomena which occur on mountain borderlands. The historical effects of mountainous regions are opposed by forces that thrust themselves in from without; external powers anchor themselves, as it were, in the mountains, seeking to obtain there both protection and frontier lines. Rome encroached more and more upon the Alps, first from the south, and then from the west and the north, by extending her provinces. Austria, Italy, Germany, and France have drawn up to the Alps on different sides; they merely fall back upon the mountains, however; their centres lie beyond. The same phenomenon is shown in the regions occupied by different races. Rhætians, Celts, Romans, Germans, and Slavs have penetrated into the Alps; but the bulk of their populations have never inhabited the mountainous districts. The question as to which nation shall possess a mountain chain or pass is always decided on the borders. Here are the battlefields; here, too, are the great centres of traffic whose locations put one in mind of harbours situated at points where two kinds of media of transmission come into contact with each other. This margin, like that of the sea, also has its promontories and bays.
