Alone among French rivers, the Rhne, itself Alpine in character in its upper course, is partly fed by Alpine rivers (the Arve, the Isre and the Durance) which have their floodsin spring at the melting of the snow, and are maintained by glacierwater in summer.
Outside the southern circle lie on the west the Mesozoic and Tertiary beds of the basin of the Garonne, with the Pyrenees beyond, and on the east the Mesozoic and Tertiary beds of the valley of the Rhne, with the Alps beyond.
During the Tertiary period arms of the sea spread into France in the Paris basin from the north, in the basins of the Loire and the Garonne from the west, and in the Rhne area from the south.
Rhne - - - 1,104 772,912 839,329
The value per acre of land, which exceeds 48 in the departments of Seine, Rhne and those fringing the north-west coast from Nord to Manche inclusive, is on the average about 29, though it drops to 16 and less in Morbihan, Landes, Basses-Pyrnes, and parts of the Alps and the central plateau.