Alps (possibly a Celtic word meaning 'high;' cf. Gaelic alp, 'a high mountain;' or connected with Lat. albus, 'white'), the most extensive system of lofty mountains in Europe, raising their giant masses on a basis of 90,000 sq. m., between and long., and extending in some places from the 44th to the 48th parallel of latitude. The Alpine system is bounded on the N. by the hilly ground of Switzerland and the upper plain of the Danube; on the E., by the low plains of Austria; on the S., by the Adriatic Sea, the plains of Lombardy, and the Gulf of Genoa; and on the W., by the plains of Provence and the valley of the Rhone. A string of lakes encircles both the northern and southern bases of these mountains, the former at an elevation of 1200 to 2000 feet; the latter, 600 to 700 feet. The varied natural scenery of France, Italy, Germany, and Austria has a common centre of union in this lofty region. Valleys open out in all directions, sending their melted snows on one side into the North Sea, on another into the Black Sea, and on another into the Mediterranean.
The water-system of the Alps may be thus briefly sketched: (1) In the basin of the Rhine there is the Rhine itself, which partly forms the Lake of Constance, at the north-eastern extremity of Switzerland, and receives on the left the important tributaries of the Thnn and the Aar; the latter of which flows through Lakes Brienz and Thun, and is itself augmented by various affluents, the largest of which are the Reuss and the Limmat. (2) In the basin of the Danube there flow from the south the Iller, Lech, Isar, and the Inn. Still farther east, the Danube has for its tributaries the Traun, the Ens, the Raab, the Drave, and the Save, the last three of which have their sources in the extreme Eastern Alps. (3) In the basin of the Po, there are numerous streams which rise in the Southern Alps; the principal of these are the Dora Baltea, the Ticino from Lake Maggiore, the Mincio from Lake Garda, and the Adige. (4) In the basin of the Rhone, there are the Rhone (flowing through the Lake of Geneva), and various Alpine tributaries, the most important of which are the Arve, the Isère, and the Durance. (5) The Var is the principal Ligurian coast-stream; the Piave, and the Tagliamento, the largest of those which fall into the Adriatic from the Southern Alps.
Divisions.—In order to give a clear view of the manifold ranges of this mountain-land, a distinction is generally made between the East, the West, and the Middle Alps; the last of which is again divided into a northern, central, and southern chain; while a natural separation by river-valleys into groups is also made. I. WEST ALPS.—The principal ranges of these are: (1) The Maritime Alps, extending from the middle Durance southwards to the Mediterranean, and rising in the Aiguille de Chambyron to a height of 11,155 feet. (2) The Cottian Alps, north of these, whose highest summit, Monte Viso, is 12,605 feet. (3) The Dauphiné Alps, separated by the valley of the Durance from the Cottian; their highest summit is the Pic des Ecrins, 13,462 feet. (4) The Graien Alps, forming the boundary between Savoy and Piedmont, and attaining in the Grand Paradis, an elevation of 13,300 feet. II. MIDDLE ALPS. Central Chain.—(1) The Pennine Alps, between the plains of Lombardy and the valley of the Rhone. Highest summits: Mont Blanc, 15,732 feet; Monte Rosa, 15,151 feet. (2) The Lepontian or Helvetian Alps, from the depression of the Simplon, along the plateau and masses of St Gothard, to the pass of Mont Splügen. (3) The Rhætian Alps, between the Inn, the Adda, and the Upper Adige. Northern Chain.—(1) The Bernese Alps, between the Rhone and the Aar. Highest summits: Finsteraarhorn, 14,026 feet; Aletschhorn, 13,803; Jungfrau, 13,671 feet. (2) The Alps of the Four 'Forest Cantons,' the Schwyz Alps, &c. The Southern Chain.—(1) The Ortler Alps, between the Adda and the Adige. (2) The Trientine Alps, between the Adige and the Piave. III. EAST ALPS.—The principal chains of these are: (1) The Noric Alps, between the plains of the Drave and the Danube. (2) The Carnian Alps, between the Drave and the Save. (3) The Julian Alps, between the Save and the Adriatic Sea.
A comprehensive classification leads to a division of the elevations into three regions: (1) The lower range forming the buttresses of the main masses, and reaching a height of 2500 to 6000 feet; that is, to the extreme limit of the growth of wood. (2) The middle zone lying between the former limit and the snow-line, at the elevation of 8000 to 9000 feet. (3) The high Alps, rising to 15,732 feet. The middle zone forms the region of mountain-pasturages, where the characteristic Alpine dairy-farming is carried on. These pastures consist of a rich carpet of grass and flowers. This threefold division of heights, however, does not everywhere coincide with the same phenomena of vegetation: the line of perpetual snow descends lower on the north side, and the boundaries of the zones above described vary accordingly. (1) The line of demarcation between the region of mosses and alpine plants and that of perpetual snow, is from 8000 to 9000 feet on the northern declivities; but on the southern, it approaches 10,000 feet. (2) The highest limit to which wood attains on the north is about 6000 feet, while on the south it is nearly 7000 feet. (3) Grain, beech, and oak, on the north, disappear at the elevation of 4000 feet; on the south, they contrive to exist some hundreds of feet higher. (4) The region of the vine, as well as of maize and chestnuts, extends to an elevation of 1900 feet on the northern declivity; and on the southern declivity to 2500 feet. The ranges of outlying lower mountains which flank the high central Alps on the north, east, and west, are mostly wanting on the south, especially where the Middle Alps descend into the plains of Lombardy. Thus the Alps rise in steep rocky precipices from the level of the flat plains of the Po, whilst they sink more gradually into the plains on the north; hence their mighty masses, closely piled together, present an aspect from the south more grand and awful; from the north, more extended and various.
Valleys.—The depth of the valleys, and their variety as to form and arrangement, are not less striking than their elevations. Most worthy of notice is the characteristic form of the wide longitudinal valleys that lie at the foot of the high central chains. On the east side, they open directly into the plain; on the north, they are connected with the plain through transverse valleys which often end in lakes. The transverse valleys on the south side are mostly in the shape of steep rocky ravines, forming in some parts long-stretching lakes. Besides the deep-sunk principal valleys, there are extensive series of basin-shaped secondary valleys, which are the scenes of Alpine life, properly so called. Many of the Alpine valleys have names distinct from the rivers flowing through them. Thus, the valley of the Rhone is styled the Upper and Lower Valais; that of the Adda, the Valtelline; of the Arve, Chamounix.
Communications—Passes.—The valleys of the high Alps form the natural means of communication. Some are more accessible than others. The entrance into a longitudinal valley is almost always smooth and easy; art has often had to force an entrance into a transverse valley. On many of the high-roads which link the principal with the secondary valleys, it has been found necessary to blow up long ridges of rock, to build terraces, to make stone bridges and long galleries of rock as a protection against avalanches, as well as to erect places of shelter (hospices) from storms. The construction of these roads may be reckoned among the boldest and most skilful works of man. In crossing the Alps, several defiles (usually seven) have to be traversed; for in addition to the pass of the main crest, there are other defiles on both sides, at the entrances of the different valleys. In the east, the number of these narrow passes or defiles is considerably increased. The names applied to the Alpine passes vary according to their natural features or the local dialect; as Pass, Sattel (Saddle), Joch (Yoke), Scheideck, Klause, Col, Chiusa. The traveller, in the course of a day's journey, experiences a succession of climatic changes, which is accompanied with an equal variety in the manners of the people.
No lofty mountains in the world are more easily crossed than the Alps; of late years the Mont Cenis, the Brenner, and the St Gothard railways into Italy from the north afford special facilities. Hence we can understand how the plains of Upper Italy, accessible from the French, German, and Austrian sides, have for ages been the theatre of bloody strife. The passage of the WEST ALPS is made by five principal roads: (1) The military road, La Corniche, a coast-road at the foot of the Alps from Nice to Genoa, parallel to which a railway now runs. (2) The causeway over the Col-ditenda, between Nice and Coni, made in 1778; highest point, 6158 feet. (3) The high-road over Mont Genève, connecting Provence and Dauphiné with Turin; highest point, 6102 feet. (4) The carriage-road made by Napoleon in 1805, over Mont Cenis, connecting Savoy with Piedmont; highest point, 6848 feet. Near this the chain is pierced by the railway tunnel opened in 1871 (see TUNNEL, and CENIS). (5) The pass of the Little St Bernard, connecting Geneva, Savoy, and Piedmont; highest point, 7190 feet. Besides these great roads, there are many smaller ones branching off from them, which form a pretty close network of communication. It has been debated whether Hannibal crossed the Cottian Alps by the Cenis, or the Graien by the Little St Bernard. The passage of the MIDDLE ALPS is made by eight principal roads. (1) That of the Great St Bernard, connecting the valley of the Rhone with Piedmont; highest point, 8120 feet. It was crossed by Napoleon in 1800. (2) The magnificent road over the Simplon, constructed by Napoleon, 1801-6, and connecting the Valais with the confines of Piedmont and Lombardy; highest point, 6595 feet. The project of effecting another junction of the Swiss and Italian railways by a tunnel through the Simplon, at a cost of 60,000,000 francs, has been long in contemplation. (3) Between the Great St Bernard and Monte Rosa is the Matterjöch, connecting Piedmont with the Valais. (4) The pass of St Gothard, connecting Lucerne with Lago Maggiore; highest point, 6936 feet. The St Gothard (q.v.) Railway tunnel was opened for traffic in 1882. (5) The Bernardino Pass, made 1819-23, by the Swiss Grisons and Sardinia; highest point, 6769 feet. (6) The Splügen Pass, repaired in 1822, connecting the sources of the Rhine with the Adda. This pass was the one used by the Romans in their intercourse with the countries bordering on the Danube and the Rhine, and also by the German armies on their marches into Italy in the middle ages. (7) The Wormser Joch, also called the Ortler Pass, or Road, opened by Austria in 1824. It connects the Tyrol with Lombardy. (8) The Brenner Pass, known to the Romans. It also connects the Tyrol with Lombardy; highest point, 4588 feet. It is now crossed by a railway. Besides these great roads, leading south into Italy, there are two which lead north from the valley of the Rhone, and cross the Bernese Alps, over the Grimsel Pass, 6500 feet high, and the Gemmi Pass, 7553 feet high. The roads over the EAST ALPS are much lower, and also much more numerous than those in the MIDDLE or WEST ALPS. The principal are: (1) The road from Venice to Salzburg, crossing the Noric Alps at an elevation of rather more than 5100 feet. (2) The road over the Carnian Alps, which divides into three branches—the first leading to Laybach; the second, to the valley of the Isonzo; and the third to the valley of the Tagliamento. (3) The roads from the Danube at Linz to Laybach.
Geology.—The rocks which enter into the composition of the Alps belong to many different geological systems, and occur for the most part as more or less interrupted belts or zones, which extend in the same general direction as the great chain itself—viz. from SW. to NE. The higher and central ranges consist principally of crystalline schists, such as gneiss and mica-schist, with which granite is occasionally associated. These crystalline Archæan rocks are flanked on either side by an irregular zone of various sedimentary strata, such as clay-slate, greywacke, &c., along with beds of limestone, dolomite, &c., the fossils in which show that this zone contains representatives of the Silurian, Devonian, Carboniferous, and Permian systems. The Triassic strata, occurring in irregular belts on both sides of the great chain, are developed chiefly in the East Alps, where they comprise massive limestones and dolomites of marine origin, remarkable for their fossils, which show a curious commingling of Palæozoic and Mesozoic forms. Liassic strata are poorly developed in the Alps, but they are noted at Schambelen (Aargau, Switzerland) for their abundant and beautifully preserved insect-remains. The Jurassic system is represented on both sides of the Alps, but is developed chiefly in the low grounds of Switzerland, whence it extends into the Jura Mountains. The Cretaceous system appears in like manner on both sides of the Alps, the most prominent feature of the system being its massive 'hippuritic limestones.' The Eocene is represented most prominently by massive 'nummulitic limestones,' and by certain unfossiliferous sandstones (Flysch), which extend along the northern part of the Alps from the SW. of Switzerland to the neighbourhood of Vienna. These sandstones are remarkable for their gigantic erratics of various crystalline rocks. The
Oligocene and Miocene are best developed in Switzerland, where they form some of the better-known mountains at the foot of the Alps, such as the Righi, the Rossberg, &c. They consist chiefly of conglomerates, sandstones, and similar strata. Patches of sands referable to the Pliocene occur here and there at the base of the Alps in North Italy. The Pleistocene is well represented by a great variety of superficial accumulations, of which the most noteworthy are the ancient moraines, erratics, and perched blocks, fluvio-glacial detritus, and other memorials of the glacial period.
The geological structure of the Alps clearly shows that these mountains are 'mountains of upheaval.' The strata of which they are composed must originally have been spread out in approximately horizontal positions, and they have since been folded, flexed, puckered, and fractured. In the Jura we see the strata folded into symmetrical 'anticlines' and 'synclines'—the strata form, in short, a succession of regular parallel arches and troughs. As we approach the Alps, however, the folds become more and more irregular, until at last in these mountains the strata are flexed and convoluted in the most perplexing manner—the strata being often completely overturned or reversed, so that the younger seem to be covered by the older formations. Evidently the rocks have been subjected to enormous compression and crushing. According to Professor Heim, the Alps have lost 72 miles of their breadth from compression; in other words, were the convoluted and wrinkled strata of the Alps to be smoothed or flattened out, their breadth, which is now about 130 miles, would reach not less than 200 miles. Since the great folds of the chain extend from SW. to NE., it is obvious that the Alps have been upheaved by tangential thrusts, acting from NW., or from SE., or from both directions. The mountains were not upheaved all at once. On the contrary, there is evidence to show that their upheaval took place at several epochs; they are the result of various earth-movements, separated from each other by wide intervals of time. The latest, most extensive elevation of the Alps took place after the Eocene period—the 'nummulitic limestones' of that system occurring folded and much altered at heights of 10,000 feet. It was probably in Oligocene times, therefore, that the most powerful convolution of the strata was effected. Another great movement of elevation took place after Pliocene times, but it does not seem to have been accompanied with much contortion and disturbance of strata.
Since their upheaval, the Alps have suffered excessive denudation. Enormous mountain-masses have been gradually removed by the action of ice, running water, &c. It is therefore often extremely difficult to trace any connection between the present configuration and that which must have obtained when the strata were first squeezed into great undulations. In fact, these mountains are not more an evidence and memorial of the stupendous effects produced by earth-movements, than they are of the potency of long-continued denudation. One of the most interesting questions connected with the physical geology of the Alps is that of the origin of the remarkable rock-basins which are occupied by the beautiful lakes of Switzerland and North Italy. By some geologists these rock-basins are believed to be due to unequal movements of elevation or depressions, while others have suggested that they may owe their origin to fractures and dislocations. Sir A. C. Ramsay, on the other hand, maintains that they have been excavated by glacial action.
Petrology and Mineralogy.—Crystalline rocks, such as gneiss, mica-schist, chlorite-schist, talc-schist, quartzite, hornblendic rocks, &c. with now and again some granite, are abundantly developed, chiefly in the higher and central ranges of the Alps. In the Graian, Pennine, and Rhætian Alps occur great masses of serpentine; in the north of Piedmont, and in the upper valley of the Adige, quartz-porphyry, diorite, &c. Crystalline limestone is often associated with the clay-slate and greywacke, which flank on either side the crystalline schists of the central ranges. Limestone also predominates in the mountains that extend on the south side from Lake Maggiore to Agram. The Julian Alps are, in fact, chiefly composed of this rock. In like manner, limestones are well developed in the corresponding region on the west and north sides of the Alps.
Precious stones are found in abundance amongst the crystalline rocks of the central ranges, especially in the region of the St Gothard. The rock-crystal of St Gothard has a world-wide reputation. Mining and smelting become more and more productive as we advance eastward. Switzerland itself is poor in useful ores. Gold and silver are found in Tyrol, Salzburg, and Carinthia; there are also silver-mines in Styria and Illyria, and one near Grenoble, in France. Copper is found in the French Alps, in Tyrol, and Styria. There are well-known lead-mines near Villach, in Carinthia. The yield of iron in Switzerland, Savoy, and Salzburg is trifling; Carinthia and Styria, on the other hand, produce large amounts; and a considerable quantity of quicksilver is extracted at Idria, in Carniola. The Alpine region is rich in salt, especially at Hall in Tyrol, and Hallein in Salzburg. Coal is found in Switzerland, in Savoy, and in the French Alps, but in no great quantity; the Austrian Alps are, again, richer in this important mineral. The mineral springs, hot and cold, that occur in the region of the Alps are innumerable. See AIX, ISCHL, LEUK, BADEN, &c.
Animals.—The Alpine mountains present many peculiarities worthy of notice in the animal as well as in the vegetable kingdom (see ALPINE PLANTS). On the sunny heights, the number of insects is very great; the butterflies are especially numerous. The great lakes of the Alps have a restricted, but broadly distributed fauna; they are often very rich in fishes, and salmon and trout are sometimes caught in ponds even 6000 feet above the level of the sea. The frog, newt, black salamander, and other amphibia occur at considerable elevations. Although the lofty mountains are inhabited by eagles, hawks, and various species of owls, yet the birds are few in comparison with the numbers in the plains, and those few are mostly confined to the larger valleys. Among the quadrupeds, the ibex or steinbok, a wild goat, is sometimes, though rarely, to be met with; the chamois is more frequently seen, chiefly in the eastern districts. The marmot (Arctomys marmotta) inhabits the upper Alpine regions. The Alpine hare (Lepus variabilis), which is white in winter, and the snow mouse or vole (Arvicola nivalis) may also be mentioned. Wolves are seen more frequently in the west than in the east; in the latter, on the other hand, bears, lynxes, and wild-cats are found, although constantly diminishing in number. The more characteristic Alpine forms are the survivors of a fauna much more widely distributed in the glacial periods. Of the domestic animals, goats and oxen are scattered everywhere in large herds. There are fewer sheep and horses, and these are not of good breeds. Mules and asses are used more frequently in the south than in the north, especially as beasts of burden. Swine and dogs are not common; the latter are used almost solely by the herdsmen, or are kept in the hospices, to assist in searching for the unfortunate wanderers who may be lost in the snow.
Inhabitants.—The population of the Alpine regions is estimated at 6,000,000 to 7,000,000, of whom perhaps one half are Teutonic, and the other half are of French, Italian, Roumansch (Romanic), or Slavonic origin. Six states share the Alps. The western portion is shared by France and Italy. Switzerland claims the Middle Alps almost exclusively for her own. Bavaria has only a small share. Austria has the largest share of the Alps—in the provinces of Tyrol, Illyria, Styria, and the archduchy. The wide valleys opening to the east allow the civilisation of the plains to enter easily among the mountains. The value of the minerals, and the fertility of the soil, have permitted mining, manufactures, and agriculture to take firm root, and a flourishing trade has caused large towns to usurp the place of mere Alpine villages. In the Tyrol, the pastoral life of the mountains has long been mixed up with the working of mines of salt or other minerals. The inhabitants of whole valleys are occupied in various branches of industry to a greater extent than in any other district of the Alps, and their sons travel far and near as artisans. The Alpine mountains are rich in singularly beautiful natural scenery, and attract such crowds of visitors that they have been called 'the playground of Europe' (see ALPINE CLUB). See works on the Alps by Agassiz, Schlagintweit (1850-4), Murchison, Tyndall (1860), and Umlauf (1888); also GLACIERS, MOUNTAINS, SWITZERLAND.