TRUE VOLCANOES. 339 



point of height, these mountains sland between Cotopaxi and 

 Mont Blanc. The great Ararat (Agri-dagh), ascended for 

 the first time on the 27th of September, 1829, by Friedrich 

 von Parrot, several times during 1844 and 1845 by Abich, 

 and lastly, in 1850, by Colonel Chodzko, is dome-shaped, 

 like Chimborazo, with two' extremely small elevations on the 

 border of the summit, but without any crater at the apex. 

 The most extensive and probably the latest pre-historical 

 lava eruptions of Ararat have all issued below the limit of 

 perpetual snow. The nature of these eruptions is two-fold ; 

 they are sometimes trachytic with glassy feldspar, inter- 

 spersed with pyrites which readily weather, and sometimes 

 doleritic, composed of labradorite and augite, like the lavas 

 of ^tna. The doleritic lavas of Ararat are considered by 

 Abich to be more recent than the trachytic. The points of 

 emission of the lava streams, which are all beneath the limit 

 of perpetual snow, are frequently indicated (as, for example, 

 in the extensive grassy plain of Kip-ghioU, on the northwest- 

 em slope) by eruptive cones and by small craters encircled 

 by scorise. Although the deep valley of St. James, which 

 extends to the very summit of Ararat, and gives a peculiar 

 character to its form, even when seen at a distance, exhibits 

 much resemblance to the Val del Bove on ^tna, and dis- 

 plays the internal structure of the dome, yet there ik this 

 striking difference between them, that in the valley of St. 

 James massive trachytic rock alone is found, and no streams 

 of lava, beds of scorise or rapilli.* The Great and Little 

 Ararat, the first of which is shown by the geodetic labors of 

 Wasili Fedorow, to be 3^ 4^^ more northerly, and 6^ 42^^ 

 more westerly than the other, rise on the southern edge of 

 the great plain through which the Araxes flows in a large 

 bend. They both stand on an elliptic volcanic plateau, whose 

 major axis runs southeast and northwest. The Kasbegk 

 and the Tshegem have likewise no summit crater, although 

 the former has thrown out vast eruptions toward the north, 

 in the direction of Wladikaukas. The greatest of all these 

 extinct volcanoes, the trachytic cone of the Elburuz, which 

 has risen out of the talc and dioritic schistous mountains, 



sources on which I have drawn, I would here explain that every thing 

 in the geological section of Cosmos relating to the important Caucasian 

 isthmus is borrowed from manuscript essays o^the years 1852 and 1 855, 

 communicated to me by Abich in the kindest and friendliest manner 

 for my unrestricted use. 



* Abich, Notice Eplicative cfune Vue de V Ararat, in the Bulletin de 

 la Soc. de Geographic de France, 4eme serie, t. i., p. sIg. 



