G. Studer and others, Berg- und Gletscherfahrten (2 series, 1859 and 1863); G. Theobald, Naturbilder aus den rhätischen Alpen (1860), and Das Bündner Oberland (1861); F. F. Tuckett, Hochalpenstudien (2 vols., 1873–1874); Miss L. Tuckett, How we Spent the Summer (1864), Pictures in Tyrol (1867), and Zigzagging amongst Dolomites (1871); J. Tyndall, The Glaciers of the Alps (1860), Mountaineering in 1861 (1862), and Hours of Exercise in the Alps (1871); J. J. Weilenmann, Aus der Firnenwelt (3 vols., 1872–1877); E. Whymper, Scrambles amongst the Alps (1871); Sir A. Wills, Wanderings among the High Alps (1856), and The “Eagle’s Nest” in the Valley of Sixt (1860); G. Yeld, Scrambles in the Eastern Graians (1900); H. Zschokke, Reise auf die Eisgebirge des Kantons Bern und Ersteigung ihrer höchsten Gipfel im Sommer von 1812 (1813); E. Zsigmondy, Im Hochgebirge (1889); M. Zurbriggen, From the Alps to the Andes (1899).
Many useful practical hints as to climbing are to be found in C. T. Dent and others, Mountaineering (1892, 3rd ed., 1900, “Badminton Library”); the Manuel d’Alpinisme (1904, publ. by the French Alpine Club); J. Meurer, Handbuch der alpinen Sport 1882), Katechismus für Bergsteiger (1892), and Der Bergsteiger im Hochgebirge (1893); and C. Wilson, Mountaineering (1893, “All England” series). As regards the dangers of Alpine climbing consult C. Fiorio and C. Ratti, I Pericoli dell’ Alpinismo (1889), and E. Zsigmondy, Die Gefahren der Alpen (1885, Fr. trans., 1889). There are also special guide-books for the use of climbers in the Alps—the “Climbers’ Guides” series, edited by Sir Martin Conway and W. A. B. Coolidge (10 vols., 1890—1894); W. A. B. Coolidge, H. Duhamel and F. Perrin, Guide du Haut Dauphiné (1887, with supplement in 1890, Eng. trans., 1892 and 1905); L. Purtscheller and H. Hess, Der Hochtourist in den Ostalpen (2 vols., 1894, 3 vols., 3rd ed., 1903); the 3 vols. publ. (1902–1905) by the Swiss Alpine Club under the name of Clubführer to the Alps of Glarus and Uri, and V. Wolf von Glanvell, Dolomitenführer (1898).
As regards the early history of Alpine exploration consult W. A. B. Coolidge, Josias Simler et les origines de l’alpinisme jusqu’en 1600 (1904), and F. Gribble, The Early Mountaineers (1899). For the later period see, besides the more general works of travel mentioned above, the publications (that date from 1863) of the various Alpine Clubs—the Alpine Journal (English A. C.), the Annuaire, Bulletin, La Montagne, and Revue alpine (French A. C.), the Jahrbuch, Mitteilungen, Verhandlungen, and Zeitschrift (German and Austrian A. C.), the Alpinista, Bollettino, and Rivista Mensile (Italian A. C.), and the Alpina, Écho des Alpes, Jahrbuch, Schweizer Alpen-Zeitung (Swiss A. C.), besides those of the smaller societies, such as the Österreichische Alpen-Zeitung (Austrian A. C.), the Annuaire (Société des Touristes du Dauphiné), and the Anunuario (Società degli Alpinisti Tridentini). Summaries of the Alpine history of the three great divisions of the Alps are given in (W. Alps) L. Vaccarone, Statistica delle Prime Ascensioni nelle Alpi Occidentali (3rd. ed., 1890—this work omits the Dauphiné Alps, as to which see the 1887 work or its Eng. version 1905, mentioned above); (Central and Swiss Alps) G. Studer, Über Eis und Schnee (2nd ed. 3 vols., 1896–1899); and (E. Alps) G. Gröger and J. Rabl, Die Entwickelung der Hochtouristik in den österreichischen Alpen (1890), and E. Pichter, Die Erschliessung der Ostalpen (3 vols., 1894). The detailed history of Mont Blanc has been written by Ch. Durier, Le Mont Blanc (1877, 4th ed., 1897), and C. E. Mathews, The Annals of Mont Blanc (1898). Lives of some of the most celebrated mountain guides have been written in C. D. Cunningham and W. de W. Abney, Pioneers of the Alps (2nd ed., 1888).
(2) Maps.—There is no good modern and fairly large-scale map of the entire chain of the Alps. But L. Ravenstein’s maps (scale 1:250,000) of the Swiss Alps (2 sheets) and of the Eastern Alps (8 sheets) include the whole chain, save that portion south of the range of Mont Blanc.
All the countries which include Alpine districts have now issued official Government maps. The French map on a scale of 1:80,000 is clearer and more accurate than that on a scale of 1:100,000. The Italian Government has published maps on scales of 1:50,000 and 1:100,000. the Austrian on a scale of 1:75,000, and the Bavarian on a scale of 1:50,000. But the most splendid Government map of all is that put forth by the Swiss Federal Topographical Bureau, under the title of Siegfried Atlas (scale 1:50,000 for the Alpine districts), which has quite superseded the Dufour Map (scale 1:100,000), the history of which was published in 1896. For maps of the Swiss Alps and their neighbours, see J. H. Graf, Literatur der Landesvermessung (1896 with a supplement).
A few of the best special maps of certain districts may be mentioned— such as H. Duhamel’s maps of the Dauphiné Alps (4 sheets on a scale of 1:100,000, 1889, 2nd ed., 1892), and that of the range of Mont Blanc (scale 1:50,000, 1896, 2nd ed., 1905), by X. Imfeld and L. Kurz. The German and Austrian Alpine Club is publishing a very fine set of maps (scale 1:50,000) of the Eastern Alps, which are clearer and better than the Austrian Government’s Topographische Detailkarten (11 sheets, scale 1:50,000). (W. A. B. C.)
10. Geology.—The Alps form but a small portion of a great zone of crumpling which stretches, in a series of curves, from the Atlas Mountains to the Himalayas. Within this zone the crust of the earth has been ridged up into a complex system of creases or folds, out of which the great mountain chains of southern Europe and Asia have been carved by atmospheric agencies. Superficially, the continuity of the zone is broken at intervals by gaps of greater or less extent; but these are due, in part at least, to the subsidence of portions of the folded belt and their subsequent burial by more recent accumulations. Such a gap is that between the Alps and the Carpathians, but a glance at a geological map of the region will show that the folding was probably at one time continuous. Leaving, however, the larger question of the connexion between the great mountain ranges of Europe and Asia, we find that the Alps are formed of a series of wrinkles or folds, one behind another, frequently arranged en échelon. The folds run, in general, in the direction of the chain, and together they form an arc around the plain of Lombardy and Piedmont. Outside this arc lies a depression along which the waters of the upper Danube and the lower Rhone find their way towards the sea; and beyond rise the ancient crystalline masses of Bohemia, the Black Forest and the central plateau of France, together with the intervening Mesozoic beds of southern Germany and the Jura. The depression is filled by Miocene and later beds, which for the most part lie flat and undisturbed as they were laid down. Beyond the depression also, excepting in the Jura Mountains, there is no sign of the folding which has raised the Alpine chain. Some of the older beds indeed are crumpled, but the folding is altogether different in age and in direction from that of the Alps.
To assist in forming a clear idea of the relations of the Alps to the surrounding regions, a simple illustration will suffice. Upon a table covered by a cloth lay two books in the relative positions shown in figure. The book A represents the central plateau of France and the book B represents the rocks of Bohemia and southern Germany. 
Fig. 1.—Looking down
on the table.If the two hands be placed flat upon the table, in the angle between the two books, and the cloth pushed towards the corner, it will at once be rucked up into a fold which will follow a curve not unlike that of the Alps. The precise character and form of the folds produced will depend upon the nature of the cloth and other accidental circumstances; but with a little adjustment not only a representation of the chain of the Alps, but even a subsidiary fold in front in the position of the Jura Mountains may be obtained. Imperfect though this illustration may be, it will serve to explain the modern conception of the forces concerned in the formation of the Alps. Within the crust of the earth, whether by the contraction of the interior or in any other way, tangential pressures were set up. Since the crust is not of uniform strength throughout, only the weaker portions yielded to the pressure; and these were crumpled up against the more resisting portions and sometimes were pushed over them. In the case of the Alps it seems natural enough that the crystalline masses of Bohemia, the Black Forest and the central plateau of France should be firmer than the more modern sedimentary deposits; but it is not so easy to understand why the Mesozoic rocks of southern Germany resisted the folding, while those of the Jura yielded. It should, however, be borne in mind that the resisting mass is not necessarily at the surface. Such is in outline the process by which the Alps were elevated; but when the chain is examined in detail, it is found that its history has not been uniform throughout; and it will be convenient, for purposes of description, to divide it into three portions, which may be called the Eastern Alps, the Swiss Alps, and the Western Alps.
The Eastern Alps consist of a central mass of crystalline and schistose rocks flanked on each side by a zone of Mesozoic beds and on the north by an outer band of Tertiary deposits. On the Italian side there is usually no zone of folded Tertiaries and the Mesozoic band forms the southern Eastern Alps.border of the chain. Each of these zones is folded within itself,
