The universal geography : earth and its inhabitants

92 PEANCE.
many of which have been discovered. Elsewhere, however, they are steep, and
on the west the hike is commanded by the Semnoz (5,572 feet), or Rigi of Savoy.
The existing emissary of this lake appears to be of artificial formation. The old
outlet took its course farther east through a swampy plain.
At Seyssel the Rhone becomes navigable, and soon afterwards spreads out in
numerous channels enclosing sand-banks and willow-covered islands. It crosses, in
fact, the bed of an ancient lake, of which the Lac du Bourget is the last remnant.
Anciently the great glaciers of the Rhone and the Isere met in this depression,
which subsequently was converted into a huge lake, fed by the Drac, the
Romanche, the Isere, and the Rhone, The glacial drift and erratic blocks, which
cover the mountain slopes to a height of 1,600 feet, sufficiently prove this. The
Lake of Bourget has been immortalised by Lamartine's verse, and although its
shores are comparatively barren, the bold grey wall of Mont du Chat reflected in
its blue waters when the sun is about to set, and its wooded peninsulas, afford
superb contrasts.
On leaving the swampy plain of Chautagne and Lavours, with its sluggish
ditches and coveys of wild ducks, the Rhone for the last time takes its course
through a narrow gorge, overlooked in the north by the old Chartreuse of Pierre-
Chatel, perched on the summit of an isolated limestone rock. Having received
the Guiers from the south, the river turns abruptly to the north-west, and as far as
the jDlain of the Ain flows along the western foot of the Jura. Throughout this
portion of its course the Rhone has frequently changed its bed, and there is reason
to believe that it formerly flowed west across the shingles and gravels deposited by
ancient glaciers, and joined the Saone to the south of Lyons. The relief of
this portion of France has undergone a rapid transformation ever since these
glaciers retired from the vicinity of Lyons. In the valley of the Drac erratic
blocks are scattered over the hillsides to a height of 4,260 feet above the river,
and near Lyons up to 1,150 feet. Rock-groovings, locally known as marcs, or
mud terraces, abound throughout these hiUs.
Below its junction with the Ain the Rhone spreads out and forms innumerable
islands, its bed near the hills of Miribel being no less than 2 miles wide. But
soon after it loses its lacustrine character ; its waters are confined to a single bed
and at Lyons it joins the Saone, and thence flows majestically southwards towards
the Mediterranean.
A sail down the Rhone from Lyons is a source of great delight to the traveller.
Swiftly carried along,* he passes ever-varj'Lng scenes of beauty. Without much
swerving to the left or right, the Rhone, overcoming every obstacle, flows due
south, and ]\Iichelet aptly likens it to a " furious bull rushing from the Alps to
the sea." Rapidly do we pass black rocks and willow-clad islands, woods, crum-
bling ruins perched upon bold jDromontories, and populous towns. Looking up the
tributary valleys, we now and then get a peep at the distant mountains, the white
summits of the Alps on the left, the burnt- out volcanoes of Central France on the
* Length of the Rhone, from the confluence with the Saone to the sea, 201 miles ; total fall, 532 feet,
or 32 inches per mile.
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