254 
POPULAR SCIENCE REVIEW. 
the blocks left stranded. This may be seen in the neighbourhood 
of the Dent du Marais. Up the Allier from Issoire is Brassac. 
This Carboniferous outlier is separated by a great tract of 
elevated granitoid gneiss from the coalfield of St. Etienne miles 
away to the eastward on the right bank of the Loire. It lies 
in a hollow of granitoid gneiss, and is overlain on the west by the 
tertiary freshwater marls, which near Ardes to the westward are 
themselves overlain by basalt. Volcanic outbursts of compara- 
tively late date, have penetrated through Carboniferous rocks, 
tertiary marls, and granite in this district, and are seen in masses 
of scorise and peperino. Le Vernet, famous for its amethysts, lies 
to the north-east of Brassac, and is situated on granitoid gneiss- 
Brioude is not quite half-way between Issoire and Le Puy. It 
was once a Roman settlement, and in later centuries suffered from 
the ravages of many armies which from time to time desolated 
France, and from the proscriptions, wars, and massacres which 
accompanied the suppression of the Huguenots and their love 
of civil and religious freedom in Haute Auvergne. Brioude 
is now an old rambling town, quaint, odoriferous, and dirty r 
with houses which once saw better days, and apparently belonged 
to wealthier inhabitants. The site of the church is believed 
to have been occupied by a Roman temple, and the Christian 
forms of worship to have been established here in the old home 
of paganism. The portal is very fine, and the revolutions which 
time has wrought have not been able altogether to efface the 
ecclesiastical monument of bygone centuries. Here we have 
the southward prolongation of the tertiary freshwater strata of 
the Limagne and of the valley of the Allier, and here the granitic- 
gneiss, through which the river flows so many miles from it& 
source, abuts against the stream, and rises to the south in the 
Montagnes de la Margeride, and the mountains of the Haute 
Loire. In this elevated region rise, not only the Allier and 
the Loire which flow northwards, but the Ardeche, Erioux, and 
many streams which flow to the Rhone. At Vielle Brioude we 
cross the Allier by a fine bridge, but the river is subject to such 
violent floods that its bridge and railway are exposed to con- 
siderable danger. In 1824 the old bridge of Vielle Brioude fell 
wholesale into the Allier. A little west of the village of Vielle 
Brioude is the village of Sempole. This place and the ruined 
Castle of Massiac are built on outliers of a current of basalt which 
flowed from the great Etna-like volcano of the Cantal on the 
south-west. In fact, the stream divides the volcanic outbhrsts 
of the Cantal from those of Langeac and Le Puy. 
In the fifth century, in the days of Clovis and Childebert^ 
Brioude was considered a place of importance, and Auvergne a 
rich and tempting land. Gibbon says that 64 the sides of the 
hills were clothed with vines, and each eminence was crowned 
