Page:A book of the Cevennes (-1907-).djvu/237



PASS now from the east to the west by direct flight from the Vivarais over the plateau of Le Puy to where the Allier descends into the plains from the lofty ridge of the southern Cevennes.

Almost from its source the Allier has met with difficulties. It has had to contend with granite, schist, and finally with basalt, and it has had to form for itself a ravine that widens into a valley below Langeac where are coal-beds.

That ravine is peculiarly tantalising, because it is difficult to explore satisfactorily. From Langeac a road runs up the riverside only till it encounters that from Sauges to S. Privat. Beyond that there is none. The line, indeed, does follow the stream, and it is of all French lines the most remarkable for the engineering