2 
POPULAR SCIENCE REVIEW. 
Again, in tlie Chain of “Puys” near Clermont Ferrand, or 
the Monts Dome , as also in those near the picturesque town of 
Le Puy in the Haute Loire, and near Vais, Montpezat, and 
Aubenas, in the Ardeche, we have examples of cones of 
igneous eruption which are of very recent date compared with 
the miocene volcanos of Mont Dore and the Cantal. Like 
the Vatna Jokull in Iceland, as described by Mr. Watts, the 
Monts Dome must have formerly been a nest of volcanos, and 
the region around 4 a country mourning in ashes and howling 
with desolation.’ But comparatively recent as have been the 
volcanic outbursts of the Puys de Dome, compared with those 
of Mont Dore and the Cantal, sufficient time has elapsed for 
streams to cut deeply into their most modern lava currents ; 
vineyards cluster on their hill-slopes, beautiful woods grow 
in the rock gorges, and very old churches are built of the lava 
rock which once flowed in molten streams from their craters; 
while the fig tree bears its fruit where the ashes of the volcanos 
must have once darkened the air. 
Before the geologist directs his attention to the district round 
Clermont Ferrand we recommend him to examine first the envi- 
rons of Moulins , where are displayed the most northerly exten- 
sions of the sediments of that great freshwater lake of La Li- 
magne d’ Auvergne, whose waters once extended from Moulins in 
the north to Brioude, near Le Puy, in the south. Moulins itself 
is a quaint old place, through which the Allier flows wide and 
free, a very different stream from what we behold it when rushing 
among the hills of the Haute Loire. The great plain of the 
ancient fresh-water lake widens out as we proceed southwards, 
and in the summer-time green vineyards cover the lower slopes 
of the hills which rise above it. Gannat also requires especial 
attention on the part of the geologist, for both here and at 
Moulins there are indications of tertiary beds older than those in 
the Clermont Ferrand country. The Gannat beds furnish vast 
numbers of the thin shells or valves of Cyprides, small crus- 
taceans which lived in millions in the waters of the ancient lake. 
Mammalian relics, too, are found in the basement strata at 
Gannat, Moulins, and Le Puy en Velay, which belong to eocene 
genera, for among them are those true eocene animals, the 
Palaeotherium and Hysenodon, which occur also in the eocene 
strata of Hampshire and the Isle of Wight. Again, we have to 
account, as Mr. Scrope has pointed out, for the difference of 
level in the freshwater beds towards the north at Moulins, and 
southward near Issoire, where they attain a height of 2,700 ft., 
while the elevation north of Moulins is below 1,000 ft. 
I imagine that the Moulins country was depressed, and that 
the miocene beds above the eocene have there been denuded. 
At Aigueperse a higher series of strata overlies the Gannat 
