Main chain of the Alps

In the case of every mountain system geographers are disposed to regard, as a general rule, the watershed (or boundary dividing the waters flowing towards opposite slopes of the range) as marking the main chain, and this usage is justified in that the highest peaks often rise on or very near the watershed. Yet, as a matter of fact, several important mountain groups are situated on one or other side of the watershed of the Alps, and form almost independent ranges, being only connected with the main chain by a kind of peninsula: such are the Dauphine Alps, the Eastern and Western Graians, the entire Bernese Oberland, the Todi, Albula and Silvretta groups, the Ortler and Adamello ranges, and the Dolomites of south Tirol, not to speak of the lower Alps of the Vorarlberg, Bavaria and Salzburg. Of course each of these semi-detached ranges has a watershed of its own, like the lateral ridges that branch off from the main watershed. Thus there are lofty ranges parallel to that which forms the main watershed. The Alps, therefore, are not composed of a single range (as shown on the old maps) but of a great "divide," flanked on either side by other important ranges, which, however, do not comprise such lofty peaks as the main watershed. In the following remarks we propose to follow the main watershed from one end of the Alps to the other.

Starting from the Col d'Altare or di Cadibona (west of Savona), the main chain extends first south-west, then north-west to the Col de Tenda, though nowhere rising much beyond the zone of coniferous trees. Beyond the Col de Tenda the direction is first roughly west, then north-west to the Rocher des Trois Eveques (9390 feet), just south of the Mont Enchastraye (9695 feet), several peaks of about 10,000 feet rising on the watershed, though the highest of all, the Punta dell' Argentera(10,794 feet) stands a little way to its north. From the Rocher des Trois Eveques the watershed runs due north for a long distance, though of the two loftiest peaks of this region One, the Aiguille de Chambeyron (11,155 feet), is just to the west, and the other, the Monte Viso (12,609 feet), is just to the east of the watershed. From the head of the Val Pellice the main chain runs north-west, and diminishes much in average height till it reaches the Mont Thabor (10,440 feet), which forms the apex of a salient angle which the main chain here presents towards.the west. Hence the main watershed extends eastwards, culminating in the Aiguille de Scolette (11,500 feet), but makes a great curve to the north-west and back to the south-east before rising in the Rochemelon (11,605 feet), which may be considered as a re-entering angle in the great rampart by which Italy is guarded from its neighbours. Thence the direction taken is north as far as the eastern summit (11,693 feet) of the Levanna, the watershed rising in a series of snowy peaks, though the loftiest point of the region, the Pointe de Charbonel (12,336 feet), stands a little to the west. Gnce more the chain bends to the north-west, rising in several lofty peaks (the highest is the Aiguille de la Grande Sassiere, 12,323 feet), before attaining the considerable depression of the Little St Bernard Pass. Thence for a short way the direction is north to the Col de la Soigne, and then north-east along the crest of the Mont Blanc chain, which culminates in the peak of Mont Blanc (15,782 feet), the loftiest in the Alps. A number of high peaks crown our watershed before it attains the Mont Dolent (12,543 feet). Thence after a short dip to the south-east, our chain takes near the Great St Bernard Pass the generally eastern direction that it maintains till it reaches Monte Rosa,whence it bends northwards, making one small dip to the east as far as the Simplon Pass. It is in the portion of the watershed between the Great St Bernard and the Simplon that the main chain maintains a greater average height than in any other part. But, though it rises in a number of lofty peaks, such as the Mont Velan ( 12,353 feet ), the Matterhorn (14,782 feet), the Lyskamm (14,889 feet), the Nord End of Monte Rosa (15,132 feet), and the Weissmies (13,226ft.), yet manyof the highest points of the region, such as the Grand Combin (14,164 feet), the Dent Blanche (14,318 feet), the Weisshorn (14,804 feet), the true summit or Dufourspitze (15,217 feet) of Monte Rosa itself, and the Dom (14,942 feet), all rise on its northern slope and not on the main watershed. On the other hand the chain between the Great St Bernard and the Simplon sinks at barely half a dozen points below a level of 10,000 feet The Simplon Pass corresponds to what may be called a dislocation of the main chain. Thence to the St Gotthard the divide runs north-east, all the higher summits (including the Monte Leone, 11,684 feet, and the Pizzo Rotondo, 10,489 feet) rising on it, a curious contrast to the long stretch just described. From the St Gotthard to the Maloja the watershed between the basins of the Rhine and Po runs in an easterly direction as a whole, though making two great dips towards the south, first to near the Vogelberg (10,565 feet) and again to near the Pizzo Gailegione (10,201 feet), so that it presents a broken and irregular appearance. But all the loftiest peaks rise on it: Scopi (10,499 feet), Piz Medel (10,509 feet), the Rheinwaldhorn (11,I49 feet), the Tambohorn (10,749 feet) and Piz Timun (10,502 feet).

From the Maloja Pass the main watershed dips to the south-east for a short distance, and then runs eastwards and nearly over the highest summit of the Bernina group, the Piz Bernina (13,304 feet), to the Bernina Pass. Thence to the Reschen Scheideck Pass the main chain is ill-defined, though on it rises the Corno di Campo (10,844 feet), beyond which it runs slightly north-east past the sources of the Adda and the Fraele Pass, sinks to form the depression of the Ofen Pass, soon hends north and rises once more in the Piz Sesvenna (10,568 feet).

The break in the continuity of the Alpine chain marked by the deep valley, the Vintschgau, of the upper Adige (Etsch) is one of the most remarkable features in the orography of the Alps. The little Reschen lake which forms the chief source of the Adige is only 13 feet below the Reschen Scheideck Pass (4902 feet), and by it is but 5 miles from the Inn valley. Eastward of this pass, the main chain runs north-east to the Brenner Pass along the snowy crest of the Oetzthal and Stubai Alps, the loftiest point on it being the Weisskugel (12,291 feet, Oetzthal), for the highest summits both of the Oetzthal and of the Stubai districts, the Wildspitze (12,382 feet) and the Zuckerhutl (11,520 feet) stand a little to the north.

The Brenner (4495 feet) is almost the lowest of all the great Carriage-road passes across the main chain, and has always been the chief means of communication between Germany and Italy. For some way beyond it the watershed runs eastwards over the highest crest of the Zillerthal Alps, which attains 11,559 feet in the Hochfeiler. But, a little farther, at the Dreiherrenspitze (11,500 feet) we have to choose between following the watershed southwards, or keeping due east along the highest crest of the Greater Tauern Alps. (a) The latter course is adopted by many geographers and has much in its favour. The eastward direction is maintained and the watershed (though not the chief Alpine watershed) continues through the Greater Tauern Alps, culminating in the Gross Venediger (12,008 feet), for the Gross Glockner (12,461 feet) rises to the south. Our chain bends north-east near the Radstadter Tauern Pass, and preserves that direction through the Lesser Tauern Alps to the Semmering Pass. (b) On the other hand, if from the Dreiherrenspitze we cleave to the true main watershed of the Alpine chain, we find that it dips south, passes over the Hochgall (11,287 feet), the culminating point of the Rieserferner group, and then sinks to the Toblach Pass, but at a point a little east of the great Dolomite peak of the Drei Zinnen it hends east again, and rises in the Monte Coghans (9128 feet, the monarch of the Carnic Alps). Soon after our watershed makes a last bend to the south-east and culminates in the Terglou (9400 feet), the highest point of the Julio Alps, though the Grintovc (8429 feet, the culminating point of the Karawankas Alps) stands more to the east. Finally our watershed turns south and ends near the great limestone plateau of the Birnbaumerwald, between Ljubljana and Gorizia.

As might be expected, the main chain boasts of more glaciers and eternal snow than the independent or external ranges. Yet it is a curious fact that the three longest glaciers in the Alps (the Great Aletsch, 16½ miles, and the Unteraar and the Fiescher, each 10 miles) are all in the Bernese Oberland. In the main chain the two longest are both 9¼ miles, the Mer de Glace at Chamonix and the Gomer at Zermatt. In the Eastern Alps the longest glacier is the Pasterze (rather over 6¼ miles), which is not near the true main watershed, though it clings to the slope of the Greater Tauern range, east of the Dreiherrenspitze. But the next two longest glaciers in the Eastern Alps (the Hintereis, 6½ miles, and the Gepatsch, 6 miles) are both in the Oetzthal Alps, and so close to the true main watershed.

The so-called alpine lakes are the sheets of water found at the foot of the Alps, on either slope, just where the rivers that form them issue into the plains. There are, however, alpine lakes higher up (e.g. the lake of Thun, and those in the Upper Engadine, in the heart of the mountains, though these are naturally smaller in extent, while the true lakes of the High Alps are represented by the glacier lakes of the Marjelensee (near the Great Aletsch glacier) and those on the northern slope of the Col de Fenetre, between Aosta and the Val de Bagnes. The most singular, and probably the loftiest, lake in the Alps is the ever-frozen tarn that forms the summit of the Roccia Viva (11,976 feet) in the Eastern Graians.

Among the great alpine rivers we may distinguish two classes: those which spring directly from glaciers and those which rise in lakes, these being fed by eternal snows or glaciers. In the former class are the Isere, the Rhone, the Aar, the Ticino, the Tosa, the Hinter (or main) Rhine and the Linth; while in the latter class we have the Durance, the Po, the Reuss, the Vorder and middle branches of the Rhine, the Inn, the Adda, the Ogho and the Adige. The Piave and the Drave seem to be outside either class.