The train toiled up, snorting and turning round and round like a top; then, going into a tunnel, was swallowed by the earth; it seemed to be pushing the light of day away in front, till it suddenly came out into a clearing full of sunshine; presently, as if it were retracing its road, it rushed into another burrow, and emerged with the strident yell of a steam whistle and deafening clatter of wheels, to fly up the winding ribbon of road cut in the living rock.

Suddenly the peaks parted, a wide opening brought the train out into broad daylight; the scene lay clear before them, terrible on all sides.

“Le Drac!” exclaimed the Abbe Gevresin, pointing to a sort of liquid serpent at the bottom of the precipice, writhing and tossing between rocks in the very jaws of the pit.

For now and again the reptile flung itself up on points of stone that rent it as it passed; the waters changed as though poisoned by these fangs; they lost their steely hue, and whitened with foam like a bran bath; then the Drac hurried on faster, faster, flinging itself into the shadowy gorge; lingered again on gravelly reaches, wallowing in the sun; presently it gathered up its scattered rivulets and went on its way, scaly with scum like the iridescent dross on boiling lead, till, far away, the rippling rings spread and vanished, skinned and leaving behind them on the banks a white granulated cuticle of pebbles, a hide of dry sand.

Durtal, as he leaned out of the carriage window, looked straight down into the gulf; on this narrow way with only one line of rails, the train on one side was close to the towering hewn rock, and on the other was the void.  Great God! if it should run off the rails!  “What a hash!” thought he.

And what was not less overwhelming than the appalling depth of the abyss was, as he looked up, the sight of the furious, frenzied assault of the peaks.  Thus, in that carriage, he was literally between the earth and sky, and the ground over which it was moving was invisible, being covered for its whole width by the body of the train.

On they went, suspended in mid-air at a giddy height, along interminable balconies without parapets; and below, the cliffs dropped avalanche-like, fell straight, bare, without a patch of vegetation or a tree.  In places they looked as if they had been split down by the blows of an axe—­huge growths of petrified wood; in others they seemed sawn through shaley layers of slate.

And all round lay a wide amphitheatre of endless mountains, hiding the heavens, piled one above another, barring the way to the travelling clouds, stopping the onward march of the sky.