The plateau under consideration stretches over an area of 3,000 square miles. It dies down towards the north-west, but reaches its highest elevation in the east and in the south. This great upland district had to be crossed before the peoples dwelling north and south of it could be fused into one. The plateau extends through the old provinces of Marche and Limousin, Auvergne, Forez, the Velay, the Vivarais, Rouergue, and the Gévaudan. But it was disturbed, broken up, and overlaid by volcanic eruptions at a comparatively recent date, pouring forth floods of lava and clouds of ash in Auvergne, le Velay, and le Vivarais. In its upheaval, moreover, the granite turned up, snapped, and exposed the superposed beds, and left them as bristling ridges to the east and south. It is this fringe that constitutes the Cévennes. These describe a half-moon, with its convexity towards the basin of the Rhône. Locally, indeed, the name Cévennes is limited to a tangle of schist ridges and deep-cleft ravines, constituting that portion of the arc which is between the Coiron and the limestone plateau of Larzac. But such is not the original limitation. The Romans undoubtedly, looking from the basin of the Rhône on the long purple chain, behind which set the sun in a glow of amber, as they passed up and down between Arles and Vienne—designated that range Cebennæ, and geographers still are disposed to so name the entire series, as constituting an orological entity, although the several portions have received distinguishing appellations.
They all belong to the same system, were all in their main lines thrown up at the same time, though not by any means all of the same geological formation; and they are all peopled by the same race, all speaking the Langue d'Oc.
The Cyclopses, Mourèze
It seems therefore reasonable to take the entire curve as forming the Cévennes from the depression of the Jarrêt, through which runs the line from Lyons to the coalfields of S. Etienne, as the northern limit, and the Montagne Noire, east of the gap of Revel, by which the road by which Castelnaudary and Castres are linked, as the western termination.
"The Cévennes," says Onésime Reclus, "have this striking feature, that they separate two climates, two vegetations, two natures. To the north and to the west are rain, snow, light fog silvered by the moon, and dense vapours which the sun cannot pierce; and the streams that water the smallest valleys nourish rich green meadows; to the south and east is a blazing sun, are glare, heat, drought, barrenness, dust, the vine, the olive, springs of water few and far between, but where they do issue, copious and clear; here—contrasts of colour, sharp-cut horizons, more beautiful than those of the north. What a contrast within a few leagues' distance between the verdure of Mezamet and the vari-coloured marbles of Cannes, between the Agout and the Salvetat d'Angles ... between the valley of the Dourbie at Nant and the Hérault at Ganges, between the Tarn at Pont-de-Montvert and the embattled gorges of the Gardons, between the Allier at La Bastide and the ravines down which rushes the Cèze, between the young Loire and the terrible rapids of the Ardèche ... on one side a French Siberia, on the other an Africa where the sirocco does not parch up the harvests, but where the mistral shrieks, itself producing a brief winter." [1]
The chain of the Cévennes, of which Mézenc may be regarded as the hinge, forms a ridge on the right bank of the Rhône, running for a while parallel to the French Alps upon the left bank. But whereas these latter turn and curve to the east, forming the Maritime Alps, the Cévennes have bent in exactly the opposite direction.
Geographically and historically the Cévennes divide into two great sections—the Cévennes Méridionales and the Cévennes Septentrionales. This continuous mountain ridge, in fact, forms a line of separation of waters very distinct, without solution of continuity, and which, in spite of the variety of its geological structure, has been determined by the same fold in the earth's crust, by one and the same act of pressure.