414 REACTION OF THE INTERIOR OF THE EARTH 



and of the Eifel (Kosmos, Bd. iv. S. 275282, pre- 

 sent volume, pp. 229236) from 132 to 152 miles; 

 those of Auvergne, the Velay, and the Vivarais ( 566 ), 

 according to a division into three distinct groups (group 

 of the Puy de Dome near Clermont and the Mont- 

 Dore; group of the Cantal; and group of the Puy 

 and Mezenc), are respectively 148, 116, and 84 miles 

 from the nearest sea. South of the Pyrenees, the ex- 

 tinct volcanoes of Olot, to the west of Grerona, with 

 their very distinct, sometimes divided, lava-streams, are 

 only twenty-eight miles from the Catalonian coast of 

 the Mediterranean ; on the other hand, the undoubted, 

 and, according to all appearance only very recently ex- 

 tinguished, volcanoes in the long chain of the Rocky 

 Mountains in North-west America are from 600 to 680 

 miles from the coast of the Pacific. 



A very abnormal phenomenon in the geographical 

 distribution of volcanoes is the existence of some which 

 have been active within historic times, and some of 

 which may perhaps be even still burning, in the chain 

 of the Thian-schan (the Celestial Mountains) in Central 

 Asia, between the two parallel chains of the Altai and 

 the Kuen-lun. Their existence was first made known 

 in Europe by Abel Eemusat and Klaproth ; and by the 

 aid of the sagacious and laborious sinological investiga- 

 tions of Stanislas Julien, I have been enabled to treat 

 of them more fully in my Asie Centrale. ( 567 ) The 

 distances of the volcano Pe-schan (Mont Blanc) with 

 its lava-streams, and the still burning Mount (Ho-tscheu) 

 of Turfan, from the shores of the Polar Sea and of the 

 Indian Ocean, are almost equal ; being about 1480 and 

 1520 miles. On the other hand, the volcano of Pe- 



