ren Thal, down the Rhine Valley to Chur, along the Inn nearly to
Kufstein, and for some distance along the Enns. Thus, then, five great
rivers have taken advantage of this main fold, each of them eventually
breaking through into a transverse valley.

The Pusterthal in the Tyrol offers us an interesting case of what is
obviously a single valley, which has, however, been slightly raised in
the centre, near Toblach, so that from this point the water flows in
opposite directions--the Drau eastward, and the Rienz westward. In this
case the elevation is single and slight: in the main valley there are
several, and they are much loftier, still we may, I think, regard that
of the Isere from Chambery to Albertville, of the Rhone from Martigny to
its source, of the Urseren Thal, of the Vorder Rhine from its source to
Chur, of the Inn from Landeck to below Innsbruck, even perhaps of the
Enns from Radstadt to Hieflau as in one sense a single valley, due to
one of these longitudinal folds, but interrupted by bosses of gneiss and
granite,--one culminating in Mont Blanc, and another in the St.
Gotthard,--which have separated the waters of the Isere, the Rhone, the
Vorder Rhine, the Inn, and the Enns. That the valley of Chamouni, the
Valais, the Urseren Thal, and that of the Vorder Rhine really form part
of one great fold is further shown by the presence of a belt of Jurassic
strata nipped in, as it were, between the crystalline rocks.

This seems to throw light on the remarkable turns taken by the Rhone at
Martigny and the Vorder Rhine at Chur, where they respectively quit the
great longitudinal fold, and fall into secondary transverse valleys. The
Rhone for the upper part of its course, as far as Martigny, runs in the
great longitudinal fold of the Valais; at Martigny it falls into and
adopts the transverse valley, which properly belongs to the Dranse; for
the Dranse is probably an older river and ran in the present course even
before the great fold of the Valais. This would seem to indicate that
the Oberland range is not so old as the Pennine, and that its elevation
was so gradual that the Dranse was able to wear away a passage as the
ridge gradually rose. After leaving the Lake of Geneva the Rhone follows
a course curving gradually to the south, until it reaches St. Genix,
where it falls into and adopts a transverse valley which properly
belongs to the little river Guiers; it subsequently joins the Ain and
finally falls into the Sao