The Alpine Road over the Stelvio Pass (Part 1)

Appendix.

The Alpine Road over the Stelvio Pass*) 1/6

(From J. G. Sommer's Pocket-Book for the Dissemination of Geographical Knowledge for the Year 1832.)

The topographical importance of the Valtellina (die Valtellina) or Adda Valley, with respect to the Kingdom of Lombardy, and the multitude of connecting roads leading to it as toward a common center, drew the attention of His Majesty, our august Monarch, from the very first moment the states of Northern Italy returned under Austrian rule. Immense sums were expended upon the improvement of the highways of this kingdom and upon various works designed to protect residential buildings threatened by the numerous torrents rushing down from the mountains. The excellent and magnificent road from Chiavenna over the Splügen to the village of the same name in Switzerland, where it joins the road leading from the Rhine Valley to Chur, was one of the first undertakings of this kind. But a land connection between the Valtellina and the lowlands of Lombardy was still lacking. It became evident that such a road, once constructed, could be connected with the one over the Splügen and, by ascending the Adda Valley, would also establish a direct connection between Milan and Tyrol. In order to achieve this purpose, the government readily granted the necessary sums with the greatest generosity.

The design for this new undertaking encountered diverse difficulties regarding the natural conditions of the terrain through which the road was to pass, independently of several other requirements that had to be fulfilled. Besides the condition that the road should have such width and gradient as to make it passable for freight wagons and military transports, it was also to provide suitably distributed stations as far as possible and not be interrupted by any obstacle necessitating a change of transport; finally, it was to remain entirely on Austrian soil. To accomplish these ends, especially the latter, which indisputably constitutes the principal advantage of a great national road, it was necessary to cut through the mountain ridge of the Stelvio (Stilfs), whereby the road was led to an altitude that no other has reached hitherto, namely up to 260 meters (= 800 Parisian feet) above the snow line **).

The new road begins at the bridge of Lecco ***). This bridge connects the two banks of the eastern arm of Lake Lario or Lake Lecco, which, although of limited use, is nonetheless the principal link in the chain of communication between the heart of Lombardy and the Valtellina, Switzerland, Tyrol, Germany, and Austria. At the beginning of the bridge, on the right bank following the flow of the water, one finds two roads, of which the upper comes from Como and from the charming hills of Brianza, while the lower passes through Monza, Osnago, Olginate, etc., and is the post road from Milan to Lecco. The latter has a length of 54,929 meters (= 169,097 Parisian feet). Beyond the bridge, on the left bank, a third road goes through the San Martino Valley toward Bergamo, while the second, just mentioned, leads in the opposite direction almost immediately to Lecco. This large and prosperous market town, with an ancient, formerly fortified castle recalling the civil wars of the Middle Ages, is celebrated nowadays for its ironware manufactories and silk mills. The surroundings are very fertile and, owing to the conveniences of every sort offered by the town, afford a most agreeable residence.

From Lecco onward, the new road proceeds without interruption, now closer, now farther along the eastern shore of the lake, passing through the villages of Abbadia, Fonzanico, Olcio, Lierna, Varenna, Bellano, Dervio, and Corenno, and, having traversed a distance of 41,790 meters (= 128,650 Parisian feet), reaches the market town of Colico, at the northernmost foot of Mount Legnone and at the uppermost end of Lake Lario. Colico possesses a spacious and convenient harbor, but is in bad repute on account of its unhealthful location, since the mouth of the Adda creates vast swamps here. However, the industriousness of several inhabitants has already transformed a large portion of them into fertile fields, and the works yet to be undertaken along the Adda to connect the new road with that over the Splügen will soon clear away all the rest that still renders the place unhealthful, so that in a few years it will be an important emporium both for land and water trade. For the rest, the road from Lecco to Colico was in 1827 completed only for a length of 14,525 meters (= 44,715 Parisian feet), up to beyond the Sasso d'Olcio, as the principal construction had first to be undertaken in the most difficult and important part, in the Adda Valley and the high mountains.

The Sasso d'Olcio is a considerable mass of high mountains on the southwest side of the Sassina Valley, forming along the lake a precipitous and inaccessible shore 880 meters (= 2,709 Parisian feet) in length. This rock, consisting of irregularly and almost vertically stratified calcareous schist, was blasted in many places to a considerable height, and the road along the lake supported by large retaining walls that reach down to the bottom of the water, resting here upon the same calcareous schist. At other points, three galleries have been cut through the rock, measuring altogether 120 meters (= 370 Parisian feet) in length, 4.5 meters in width, and the same in height. In this manner, it proved possible to combine the greatest feasible economy of space with the durability and safety of the road. The greater part of this stretch enjoys a most agreeable situation, affording ever-changing and increasingly delightful vistas. It almost always follows the curves of the lake shore, yet in such a way that it frequently proceeds in a straight line. The elevation is nowhere less than one meter above the highest water level, and the width is five meters throughout. The gradient is generally three to four meters per 100 meters in length, with the exception of only a few and short stretches where it reaches up to five percent ****). (Continuation follows.)

*) After an article in the Biblioteca italiana, year 1827, March issue, p. 353 et seq., communicated by the Bulletin des Sciences géographiques etc., February issue 1830, p. 247 et seq.

**) The snow line is situated, at the geographical latitude of those regions, at an altitude of 2,550 meters (= 7,815 Parisian feet) above the Mediterranean Sea.

***) The bridge of Lecco is a work of the fourteenth century, measures 128 meters in length, and consists of 10 masonry arches.

****) A gradient of three percent corresponds to an angle of 1 degree 43' 6'', four percent = 2° 17' 26'', and five percent = 2° 51' 44''; this gradient is consequently extremely slight and by no means reaches the maximum of 4° 46', beyond which, for example in France, the gradient of highways is not permitted to go. On an incline of 15° no carriage can travel any longer; one of 37° is almost inaccessible on foot if the ground is bare rock or turf so dense that no steps can be cut. The most inclined plane that can be ascended in loose soil is 4°. (See v. Humboldt's Personal Narrative of Travels to the Equinoctial Regions etc., Vol. I, p. 224).