Note 1 — Chapter VI · EXTINCT VOLCANOES OF CENTRAL FRANCE.

The literature referring to this region is very extensive. Guettard in 1775, afterwards Faujas, published descriptions of the rocks of the Vivarais and Velay; and Desmarest's geological map, published in 1779, is a work of great merit. The district was afterwards described by Daubeny, Lyell, Von Buch, and others; but by far the most complete work is that of Scrope, entitled Volcanoes of Central France, containing maps and numerous illustrations, published in 1826, and republished in a more extended form in 1858; to this I am largely indebted.