[Sidenote:  Brenner route.]

The Pass of Dariel, owing to its situation in a retarded Brenner corner of Asia, has never attained the historical importance which attaches to the deep saddle of the Brenner Pass (4470 feet) in the Central Alps.  Uniting the reentrant valleys of the Inn and Adige rivers only 2760 feet above the Inn’s exit from the mountains upon the Bavarian plateau, it forms a low, continuous line of communication across the Central Alps.  The Brenner was the route of the Cimbri invading the Po Valley, and later of the Roman forces destined for frontier posts of the Empire on the upper Danube.  In the Middle Ages it was the route for the armies of the German Emperors who came to make good their claim to Italy.  By this road came the artists and artisans of the whole north country to learn the arts and crafts of beauty-loving Venice.  From the Roman road-makers to the modern railroad engineer, with the concomitant civilization of each, the Brenner has seen the march of human progress.

[Sidenote:  Pass of Belfort.]

Farther to the west, the wall of highlands stretching across southern Europe is interrupted by a deep groove formed by the mountain-flanked Rhone Valley and the Pass of Belfort, or Burgundian Gate, which lies between the Vosges and Jura system, and connects the Rhone road with the long rift valley of the middle Rhine.  This pass, broad and low (350 meters or 1148 feet) marks the insignificant summit in the great historic route of travel between the Mediterranean and the North Sea, from the days of ancient Etruscan merchants to the present.  This was the route of the invading Teuton hordes which the Roman Marius defeated at Aquae Sextiae, and later, of the Germans under Ariovistus, whom Caesar defeated near the present Muehlhausen.  Four centuries afterward came the Alamannians, Burgundians and other Teutonic stocks, who infused a tall blond element into the population of the Rhone Valley.[1227] The Pass of Belfort is the strategic key to Central Europe.  Here Napoleon repeatedly fixed his military base for the invasion of Austria, and hither was directed one division of the German army in 1870 for the invasion of France.  The gap is traversed to-day by a canal connecting the Doubs and the Rhine and by a railroad, just as formerly by the tracks of migrating barbarians.

[Sidenote:  Mohawk route.]

The natural depression of the Mohawk Valley, only 445 feet (136 meters) above sea level, is the only decided break across the entire width of the long Appalachian system.  This fact, together with its ready accessibility from the Hudson on the east and Lake Ontario on the west, lent it importance in the early history of the colonies, as well as in the later history of New York.  It was an easy line of communication with the Great Lakes, and gave the colonists access to the fur trade of the Northwest, then in the hands of the French.  So when French and English fought for supremacy in the New World, the Mohawk and Hudson