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JURA

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Originally appearing in Volume V15, Page 567 of the 1911 Encyclopedia Britannica.
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JURA , a range which may be roughly described as the See also:

block of mountains rising between the See also:Rhine and the See also:Rhone, and forming the frontier between See also:France and See also:Switzerland. The See also:gorges by which these two See also:rivers force their way to the plains cut off the Jura from the Swabian and Franconian ranges to the See also:north and those of See also:Dauphine to the See also:south. But in very See also:early days, before these gorges had been carved out, there were no openings in the Jura at all, and even now its three See also:chief rivers—the See also:Doubs, the Loue and the See also:Ain—flow down the western slope, which is both much longer and but See also:half as steep as the eastern. Some geographers extend the name Jura to the Swabian and Franconian ranges between the See also:Danube and the See also:Neckar and the See also:Main; but, though these are similar in point of See also:composition and direction to the range to the south, it is most convenient to limit the name to the See also:mountain ridges lying between France and Switzer-See also:land, and this narrower sense will be adopted here. The Jura has been aptly described as a huge See also:plateau about 156 m. See also:long and 38 M. broad, hewn into an oblong shape, and raised by See also:internal forces to an See also:average height of from 195o to 2600 ft. above the surrounding plains. The See also:shock by which it was raised and the vibration caused by the See also:elevation of the See also:great See also:chain of the See also:Alps, produced many transverse gorges or " cluses," while on the plateaus between these subaerial agencies have exercised their See also:ordinary See also:influence. Geologically the Jura Mountains belong to the Alpine See also:system; and the same forces which crumpled and tore the strata of the one produced the folds and faults in the other. Both chains owe their origin to the See also:mass of crystalline and unyielding See also:rock which forms the central plateau of France, the See also:Vosges and the See also:Black See also:Forest, and which, between the Vosges and the central plateau, lies at no great See also:depth beneath the See also:surface. Against this mass the more yielding strata which See also:lay to the south and See also:west were crushed and folded, and the Alps and the Jura were carved from the ridges which were raised. But the folding decreases in intensity towards the north; the folding in the Alps is much more violent than the folding in the Jura, and in the Jura itself the folding is most marked along its See also:southern flanks. The Jura is composed chiefly of See also:Jurassic rocks—it is from this chain that the Jurassic system derives its name—but Triassic, Cretaceous and See also:Tertiary beds take See also:part in its formation. It may be divided into three zones which run parallel to the length of the chain and differ from one another in their structure.

The innermost See also:

zone, which rises directly from the See also:plain of Switzer-land, is the folded Jura (Jura plisse, Kettenjura), formed of narrow parallel undulations which diminish in intensity towards the See also:French border. This is followed by the Jura plateau (Jura tabulaire, Tafeljura), in which the beds are approximately See also:horizontal but are broken up into blocks by fractures or faults. Finally, along its western See also:face there is a zone of numerous dislocations, and the range descends abruptly to the plain of the See also:Saone. This is the Region du vignoble and is well shown at See also:Arbois. Owing to the convergence of the faults which See also:bound it, the plateau zone decreases in width towards the south, while towards the north it forms a large proportion of the chain. The folded zone is more See also:constant. Along its inner margin the folds are frequently overthrown, leaning towards France, but elsewhere they are See also:simple anticlinals and synclinals, parallel to the length of the chain, and as a See also:rule there is a remarkable freedom from dislocations of any importance, except towards See also:Neuchatel and See also:Bienne. The countless blocks of See also:gneiss, See also:granite and other crystalline formations which are found in such See also:numbers on the slopes of the Jura, and go by the name of " erratic blocks " (of which the best known instance—the See also:Pierre a Bot—is 40 ft. in See also:diameter, and rests on the See also:side of a See also:hill 800 ft. above the See also:Lake of Neuchatel), have been transported thither from the Alps by See also:ancient glaciers, which have See also:left their See also:mark on the Jura range itself in the shape of striations and moraines. The See also:general direction of the chain is from north-See also:east to south-west, but a careful study reveals the fact that there were in reality two main lines of upheaval, viz. north to south and east to west, the former best seen in the southern part of the range and the latter in the See also:northern; and it was by the See also:union of these two forces that the lines north-east to south-west (seen in the greater part of the chain), and north-west to south-east (seen in the Villebois range at the south-west extremity of the chain), were produced. This is best realized if we take See also:Besancon as a centre; to the north the ridges run east and west, to the south, north and south, while to the east the direction is north-east to south-west. Before considering the See also:topography of the interior of the Jura, it may be convenient to take a brief survey of its See also:outer slopes. 1.

The northern face dominates on one side the famous " Trouee " (or See also:

Trench) of See also:Belfort, one of the great See also:geographical centres of See also:Europe, whence routes run north down the Rhine to the North See also:Sea, south-east to the Danube See also:basin and Black Sea, and south-west into France, and so to the Mediterranean basin. It is now so strongly fortified that it becomes a question of great strategical importance to prevent its being turned by means of the great central plateau of the Jura, which, as we shall see, is a network of roads and See also:railways. On the other side it overhangs the " Trouee " of the Black Forest towns on the Rhine (Rheinfelden, Sackingen, Laufenburg and Waldshut), through which the central plain of Switzerland is easily gained. On this north slope two openings offer routes into the interior of the chain—the valley of the Doubs belonging to France, and the valley of the Birse belonging to Switzerland. Belfort is the military, See also:Mulhausen the See also:industrial, and See also:Basel the commercial centre of this slope. 2. The eastern-and western faces offer many striking See also:parallels. The plains through which flow the See also:Aar and the Saone have each been the See also:bed of an ancient lake, traces of which remain in the lakes of Neuchatel, Bienne and See also:Morat. The west face runs mainly north and south like its great See also:river, and for a similar See also:reason the east face runs north-east to south-west. Again, both slopes are pierced bymany transverse gorges or " cluses " (due to fracture and not to erosion), by which See also:access is gained to the great central plateau of See also:Pontarlier, though these are seen more plainly on the east face than on the west; thus the gorges at the exit from which Lons-le-Saunier, See also:Poligny, Arbois and See also:Salins are built See also:balance those of the Suze, of the Val de Ruz, of the Val de Travers, and of the Val d'Orbe, though on the east face there is but one See also:city which commands all these important routes—Neuchatel. This See also:town is thus marked out by nature as a great military and industrial centre, just as is Besancon on the west, which has besides to defend the route from Belfort down the Doubs. These easy means of communicating with the See also:Free See also:County of See also:Burgundy or Franche-See also:Comte See also:account for the fact that the See also:dialect of Neuchatel is Burgundian, and that it was held generally by Burgundian nobles, though most of the See also:country near it was in the hands of the See also:house of See also:Savoy until gradually annexed by See also:Bern.

The Chasseron (5286 ft.) is the central point of the eastern face, commanding the two great railways which join Neuchatel and Pontarlier. This See also:

ridge is in a certain sense parallel to the valley of the Loue on the west face, which flows into the Doubs a little to the south of See also:Dole, the only important town of the central portion of the Saone basin. The Chasseron is wholly Swiss, as are the See also:lower summits of the Chasseral (5279 ft.), the Mont See also:Suchet (5220 ft.), the See also:Aiguille de Baulmes (5128 ft.), the Dent de Vaulion (4879 ft.), the Weissenstein (4223 ft.), and the Chaumont (3845 ft.), the two last-named points being probably the best-known points in the Jura, as they are accessible by See also:carriage road from See also:Soleure and Neuchatel respectively. South of the Orbe valley the east face becomes a rocky See also:wall which is crowned by all the highest summits (the first and second Swiss, the See also:rest French) of the chain—the Mont Tendre (5512 ft.), the Dole (5505 ft.), the Reculet (5643 ft.), the Cret de la Neige (5653 ft.) and the See also:Grand Credo (5328 ft.), the uniformity of level being as striking as on the west edge of the Jura, though there the See also:absolute height is far less. The position of the Dole is similar to that of the Chasseron, as along the sides of it run the great roads of the See also:Col de St Cergues (3973 ft.) and the Col de la Faucille (4341 ft.), the latter leading through the Vallee See also:des Dappes, which was divided in 1862 between France and Switzer-land, after many negotiations. The height of these roads shows that they are passages across the chain, rather than through natural depressions. 3.. The southern face is supported by two great pillars—on the east by the Grand Credo and on the west by the ridge of Revermont (2529 ft.) above Bourg en See also:Bresse; between these a huge See also:bastion (the See also:district of Bugey) stretches away to the south, forcing the Rhone to make a long detour. On the two sides of this bastion the plains in which Amberieu and Culoz stand balance one another, and are the See also:meeting points of the routes which cut through the bastion by means of deep gorges. On the eastern side this great See also:wedge is steep and rugged, ending in the Grand See also:Colombier (5o33 ft.) above Culoz, and it sinks on the western side to the valley of the Ain, the district of Bresse, and the plateau of See also:Dombes. The junction of the Ain and the Surand at See also:Pont d'Ain on the west balances that of the Valserine and the Rhone at See also:Bellegarde on the east. The Jura thus dominates on the north one of the great highways of Europe, on the east and west divides the valleys of the Saone and the Aar, and stretches out to the south so as nearly to join hands with the great mass of the Dauphine Alps.

It therefore commands the routes from France into See also:

Germany, Switzerland and See also:Italy, and hence its enormous See also:historical importance. Let us now examine the topography of the interior of the range. This naturally falls into three divisions, each traversed by one of the three great rivers of the Jura—the Doubs, the Loue and the Ain. 1. In the northern See also:division it is the east and west See also:line which prevails—the Lomont, the Mont Terrible, the See also:defile of the Doubs from St Ursanne to St Hippolyte, and the " Trouee " of the Black Forest towns. It thus bars access to the central plateau from the north, and this natural wall does away with the See also:necessity of artificial fortifications. This division falls again into two distinct portions. (a) The first is the part east of the deep See also:gorge of the Doubs after it turns south at St Hippolyte; it is thus quite cut off on this side, and is naturally Swiss territory. It includes the basin of the river Birse, and the great plateau between the Doubs and the Aar, on which, at an average height of 2600 ft., are situated a number of towns, one of the most striking features of the Jura. These include Le See also:Locle (q.v.) and La Chaux de Fonds (q.v.), and are mainly occupied with See also:watch-making, an See also:industry which does not require bulky machinery, and is therefore well fitted for a mountain district. (b) The part west of the " cluse " of the Doubs: of this, the district east of the river Dessoubre, isolated in the interior of the range (unlike the Le Locle plateau), is called the Haute Montagne, and is given up to See also:cheese-making, curing of hams, saw-See also:mills, &c. But little watch-making is carried on there, Besancon being the chief French centre of this industry, and being connected with See also:Geneva by a chain of places similarly occupied, which fringe the west plateau of the Jura.

The part west of the Dessoubre, or the, Moyenne Montagne, a huge plateau north of the Loue, is more especially devoted to See also:

agriculture, while along its north edge See also:metal-working and manufacture of hardware are carried on, particularly at Besancon and Audincourt. 2. The central division is remarkable for being without the deep gorges which are found so frequently in other parts of the range. It consists of the basin of which Pontarlier is the centre, through notches in the rim of which routes converge from every direction; this is the great characteristic of the See also:middle region of the Jura. Hence its immense strategical and commercial importance. On the north-east roads run to Morteau and Le Locle, on the north-west to Besancon, on the west to Salins, on the south-west to Dole and Lons-le-Saunier, on the east to the Swiss plain. The Pontarlier plateau is nearly horizontal, the slight indentations in it being due to erosion, e.g. by the river Drugeon. The keys to this important plateau are to the east the Fort de Joux, under the walls of which meet the two lines of railway from Neuchatel, and to the west Salins, the meeting See also:place of the routes from the Col de la Faucille, from Besancon, and from the French plain. The Ain rises on the south edge of this plateau, and on a lower shelf or step, which it See also:waters, are situated two points of great military importance—Nozeroy and Champagnole. The latter is specially important, since the road leading thence to Geneva traverses one after another, not far from their See also:head, the chief valleys which run down into the South Jura, and thus commands the southern routes as well as those by St Cergues and the Col de la Faucille from the Geneva region, and a See also:branch route along the Orbe river from Jougne. The fort of See also:Les Rousses, near the See also:foot of the D61e, serves as an advanced See also:post to Champagnole, just as the Fort de Joux does to Pontarlier. The above See also:sketch will serve to show the See also:character of the central Jura as the meeting place of routes from all sides, and the importance to France of its being strongly fortified, lest an enemy approaching from the north-east should try to turn the fortresses of the " Trouee de Belfort." It is in the western part of the central Jura that the north and south lines first appear strongly marked.

There are said to be in this district no less than fifteen ridges See also:

running parallel to each other, and it is these which force the Loue to the north, and thereby occasion its very See also:eccentric course. The cultivation of See also:wormwood wherewith to make the tonic " See also:absinthe " has its head-quarters at Pontarlier. 3. The southern division is by far the most complicated and entangled part of the Jura. The lofty ridge which See also:bounds it to the east forces all its drainage to the west, and the result is a number of valleys of erosion (of which that of the Ain is the chief instance), quite distinct from the natural " cluses " or fissures of those of the Doubs and of the Loue. Another point of See also:interest is the number of roads which intersect it, despite its extreme irregularity. This is due to the great " cluses " of Nantua and Virieu, which See also:traverse it from east to west. The north and south line is very clearly seen in the eastern part of this division; the north-east and south-west is entirely wanting, but in the Villebois range south of Amberieu we have the See also:principal example of the north-west to south-east line. The plateaus west of the Ain are cut through by the valleys of the Valouse and of the Surand, and like all the lowest terraces on the west slope do not possess any considerable towns. The Ain receives three tributaries from the east: (a) The Biegne, which flows from the fort of Les Rousses by St See also:Claude, the industrial centre of the south Jura, famous for the manufacture of wooden toys, owing to the large quantity of See also:box-See also:wood in the neighbourhood. Septmoncel is busied with cutting of gems, and Morez with watch and spectacle making. Cut off to the east by the great chain, the industrial prosperity of this valley is of See also:recent origin.

(b) The Oignin, which flows from south to north. It receives the drainage of the lake of Nantua, a town noted for combs and See also:

silk See also:weaving, and which communicates by the " cluse " of the See also:Lac de Silan with the Valserine valley, and so with the Rhone at Bellegarde, and again with the various routes which meet under the walls of the fort of Les Rousses, while by the Val Romey and the Seran Culoz is easily gained. (c) The Albarine, connected with Culoz by the " cluse " of Virieu, and by the Furan flowing south with See also:Belley, the See also:capital of the district of Bugey (the old name for the South Jura). The " cluses " of Nantua and Virieu are now both traversed by important railways; and it is even truer than of old that the keys of the south Jura are See also:Lyons and Geneva. But of course the strategic importance of these gorges is less than appears at first sight, because they can be turned by following the Rhoneyin its great See also:bend to the south. The range is mentioned by See also:Caesar (See also:Bell. See also:Gall. i. 2–3, 6 (I), and 8 (I)), See also:Strabo (iv. 3, 4, and 6, II), See also:Pliny (iii. 31; iv. 105; xvi. 197) and See also:Ptolemy (ii. ix.

5), its name being a word which appears under many forms (e.g. Joux, Jorat, Jorasse, Juricns), and is a synonym for a wood or forest. The See also:

German name is Leberberg, See also:Leber being a provincial word for a hill. Politically the Jura is French (departments of the Doubs, Jura and Ain) and Swiss (parts of the cantons of Geneva, See also:Vaud, Neuchatel, Bern, Soleure and Basel); but at its north extremity it takes in a small See also:bit of See also:Alsace (Pfirt or Ferrette). In the middleages the southern, western and northern sides were parcelled out into a number of districts, all of which were gradually absorbed by the French See also:crown, viz., See also:Gex, Val Romey, Bresse and Bugey (exchanged in 16or by Savoy for the marquisate of See also:Saluzzo), Franche-Comte, or the Free County of Burgundy, an imperial See also:fief till annexed in 1674, the county of See also:Montbeliard (Mompelgard) acquired in 1793, and the county of Ferrette (French 1648–1871). The northern part of the eastern side was held till 1792 (part till 1797) by the See also:bishop of Basel as a fief of the See also:empire, and then belonged to France till 1814, but was given to Bern in 1815 (as a recompense for its loss of Vaud), and now forms the Bernese Jura, a French-speaking district. The centre of the eastern slope formed the principality of Neuchatel (q.v.) and the county of Valangin, which were generally held by Burgundian nobles, came by See also:succession to the See also:kings of See also:Prussia in 1707, and were formed into a Swiss See also:canton in 1815, though they did not become free from formal Prussian claims until 1857. The southern part of the eastern slope originally belonged to the house of Savoy, but was conquered bit by bit by Bern, which was forced in 1815 to accept its subject district Vaud as a colleague and equal in the Swiss See also:Confederation. It was See also:Charles the Bold's defeats at See also:Grandson and Morat which led to the See also:annexation by the See also:con-federates of these portions of Savoyard territory.

End of Article: JURA

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