Ch. XIV.J 
VOLCANOS OF CATALONIA. 
187 
very regular form, and has a circular depression or crater at 
the summit. It is chiefly made up of red scoria?, undistinguish- 
able from that of the minor cones of Etna. The neighbouring 
hills of Olivet and Garrinada, also figured in the frontispiece, 
are of similar composition and shape. The largest crater of 
the whole district occurs farther to the east of Olot, and is called 
Santa Margarita. It is 455 feet deep, and about a mile in 
circumference. Like Astroni, near Naples, it is richly covered 
with wood, wherein game of various kinds abound. 
Although the volcanos of Catalonia have broken out through 
sandstone, shale, and limestone, as have those of the Eifel, in 
Germany, to be described in the sequel, there is a remarkable 
difference in the natui-e of the ejections composing the cones in 
these two regions. In the Eifel, the quantity of pieces of sand- 
stone and shale thrown out from the vents, is often so immense 
as far to exceed in volume the scoria?, pumice, and lava ; but I 
sought in vain in the cones near Olot for a single fragment of 
any extraneous rock, and Don Francisco Bolos informs me 
that he has never been able to detect any. Volcanic sand and 
ashes are not confined to the cones, but have been sometimes 
scattered by the wind over the country, and drifted into narrow 
valleys, as is seen between Olot and Cellent, where the annexed 
section is exposed. The light cindery volcanic matter rests in 
thin regular layers, just as it alighted on the slope formed by 
the solid conglomerate. No flood could have passed through 
No. 44. 
a, Secondary conglomerate. £>, Thin seams of volcanic sand and scorise. 
the valley since the scorise fell, or these would have been for 
the most part removed. 
The currents of lava in Catalonia, like those of Auvergne, 
the Vivarais, Iceland, and all mountainous countries, are of 
considerable depth in narrow defiles, but spread out into com- 
