tablelands lie sequestered valleys fertile fields and flowery gardens,
oases of the Lozerien Sahara.

Above, not a rill, not a beck, refreshes the spongy, crumbling earth;
we must travel far, penetrate the openings just indicated by the dark-
blue shadows in the distance, and descend the lofty walls of the
Causses to find silvery cascades, impetuous rivers, and fountains
gushing from mossy clefts. The showers of spring, the torrential rains
of autumn, the snows of winter, have filtered to a depth of several
thousand feet.

We are not within sight of the grand Causse Mejean, nor of the Black
Causse, or Causse Noir, and only on the threshold of Sauveterre, yet
some idea may be gathered here of what M. E. Reclus calls a 'Jurassic
archipelago,' once a vast Jurassic island. Imagine, then, a group of
promontories, their area equal to that of Salisbury Plain, Dartmoor and
Exmoor combined, with the varying altitudes of the loftiest Devonshire
tor and Cumberland hill.

Such a comparison may convey some feeble notion of the three Causses
just named, two of which belong to the Lozere. The Causse Noir is
partly in the Aveyron. Their extraordinary conformation must be seen
and studied by all who would familiarize themselves with this
geological phenomenon.

No solitude can be more complete than these wastes, except when a
leaden sky replaces the warm sunshine of to-day, and a deep,
impenetrable mantle of snow covers the plateau from end to end. Then
the little life that animates it is hushed, and none from the outer
world penetrates the fastnesses of the Causses.