162 Reviews — Br. Tempest Anderson — Volcanic Studies. 



away from the centre of the cavity. As a mere artistic study this 

 picture is specially worthy of commendation. Well-defined extinct 

 craters are by no means rare in the world ; there are plenty in the 

 Auvergne. Yet in some cases the interest is enhanced by their 

 enclosing a lake, such as the Pulvermaar in the Eifel or the Lac 

 d'Issarles in Central France. But the queen of crater lakes is to be 

 found in the Cascade Eange of Oregon (pi. Ixxxiii). This, again, is 

 a most telling picture, though the outward dip of the beds is not so 

 obvious, owing partly to a considerable accumulation of talus. The 

 dimensions are very great, as the following statement will show ; — 

 " An explosive eruption of enormous magnitude has removed several 

 thousand feet of the summit and distributed the material over the 

 surrounding country. The result is a crater about 8 miles by 6 in 

 size, the rim of which reaches a height of about 8,000 feet above the 

 sea. The cliffs rise about 2,000 feet above the surface of the lake, 

 which is in places 2,000 feet deep." An island in this marvellous 

 lake shows a crater within a crater, and had this been still larger it 

 would have been comparable, he observes, to the Peak of Teneriffe, 

 which is surrounded by an old crater-ring of about the same size. 



It will scarcely be necessary for us to follow the author through 

 the Lipari Islands and the Canaries, in both of which groups most 

 interesting volcanic phenomena are faithfully delineated by his 

 camera. But the extinct volcanic region of Central France calls for 

 special attention on the part of geologists, and to this region about 

 a dozen plates are devoted. The first of these plates (No. xxviii) is 

 a remarkable piece of topography, being a sort of general view of 

 the chain of the Buys, looking south from near the summit of the 

 Puy de Dome. Notwithstanding the difficulties of dealing with 

 such an extended landscape, the outlines are clear even to the most 

 distant hills, and the effective side screen of domite in the fore- 

 ground, besides reminding us of that peculiar rock, gives an artistic 

 touch to the entire composition. The companion picture, looking 

 north, if less artistic, is even more important from a topographical 

 point of view, as we almost look down into the crater of the 

 Puy de Pariou, while the positions of the Grand Sarcoui, the 

 Puy Chopine, and other noteworthy puys are indicated with great 

 distinctness. In the succeeding plates we are introduced to the 

 Puy Chopine and Grand Sarcoui at close quarters. The peculiar 

 elongated dome shape of the latter is well brought out, and it is 

 possible to believe that it was extravasated as a pasty mass in the 

 position it now occupies between two scoria-cones on either side of it. 



Having dealt with the phenomena of the acid rocks in Central 

 France, Dr. Anderson presents us with some very striking pictures 

 of the effects of basalt in that region, and he has in many cases 

 selected basalt necks for illustration. In some instances these necks, 

 by resisting denudation, have given rise to most singular isolated 

 pinnacles of rock, often crowned with a building like the Eocher de 

 St. Michel. In this case he considers that the material forming 

 the pinnacle originally accumulated in a volcanic chimney as an 

 agglomerate ; the scoria-cone, which once probably surrounded or 



