In the south the Orb, the Herault and the Vidourle are independent rivers flowing to the Golfe du Lion; farther north, the Gard - formed by the union of several streams named Gardon - the Ceze and the Ardeche flow to the Rhone.
Forbes was also interested in geology, and published memoirs on the thermal springs of the Pyrenees, on the extinct volcanoes of the Vivarais (Ardeche), on the geology of the Cuchullin and Eildon hills, &c. In addition to about 150 scientific papers, he wrote Travels through the Alps of Savoy and Other Parts of the Pennine Chain, with Observations on the Phenomena of Glaciers (1843); Norway and its Glaciers (1853); Occasional Papers on the Theory of Glaciers (1859); A Tour of Mont Blanc and Monte Rosa (1855).
The Ardeche is the only considerable affluent from the right.
Between Lyons and the sea, the Rhone divides four departments on its right bank (Rhone, Loire, Ardeche and Gard) from as many on its left bank (Isere, Drome, Vaucluse and Bouches du Rhone).
The most typical hydraulic lime is that known as Chaux du Theil, made from a limestone found at Ardeche in France.
ANNONAY, a town of south-eastern France, in the north of the department of Ardeche, 50 m.