284 k COSMOS. 



(calculation gives 2540 against 2428 geog. miles) is occupied 

 , by volcanoes. If we examine the distribution of the space 



the Orizaba to the Colima, for a distance of 392 geog. miles, be- 

 tween latitudes 19 and 19 20'. The Volcano of Tuxtla lies 

 isolated 128 miles to the east of Orizaba, near the coast of 

 the Gulf of Mexico, and in a parallel (18 28') which is half a 

 degree further south. 



II. Distance of the Mexican group from the next group, that of 

 Central America (from the volcano of Orizaba to the volcano of 

 Soconusco, in the direction E.S.E. W.N.W.) 300 miles. 



III. Group of the Volcanoes of Central America : Its length from S.E. 

 to N.W., from the volcano of Soconusco to Turrialva, in Costa 

 Rica, more than 680 miles. 



IV. Distance of the group of Central America from the series of 

 volcanoes of New Granada and Quito, 628 miles. 



V. Group of the Volcanoes of New Granada and Quito : Its length 

 from the eruption in the Paramo de Ruiz to the north of the 

 Volcan de Tolima, to the volcano of Sangay, 472 miles. The 

 portion of the chain of the Andes between the volcano of Purac6, 

 near Popayan, and the southern part of the volcanic mountain 

 group of Pasto is directed N.N.E. S.S.W. Far to the eastward 

 from the volcanoes of Popayan, at the sources of the Rio Fragua, 

 there is a very isolated volcano, which I have inserted upon my 

 general map of the mountain group of the South American 

 Cordilleras, from the statements of missionaries from Timana, 

 which were communicated to me : distance from the sea-shore, 

 152 miles. 



VI. Distance of the volcanic group of New Granada and Quito, from 

 the group of Peru and Bolivia, 960 miles, the greatest length 

 destitute of volcanoes. 



VII. Group of the Series of Volcanoes of Peru and Bolivia, from the 

 Volcan de Chacani and Arequipa to the volcano of Atacama 

 (16i 21-1) 420 miles. 



VIII. Distance of the group of Peru and Bolivia from the volcanic 

 group of Chili, 540 geog. miles. From the portion of the desert of 

 Atacama, on the border of which the volcano of San Pedro rises, 

 to far beyond Copiapo, even to the volcano of Coquimbo (30 5'), 

 in the long Cordillera to the west of the two provinces Catamarca 

 and Rioja,there is no volcanic cone. 



IX. Group of Chili, from the volcano of Coquimbo to the volcano 

 San Clemente, 968 miles. 



These estimates of the length of the Cordilleras, with the curvature 

 which results from the change in the direction of the axis, from the pa- 

 rallel of the Mexican volcanoes in 1 9^ of north latitude, to the volcano of 

 San Clemente in Chili (46 8' S. lat.), give for a distance of 4968 miles, 

 a space of 2540 miles which is covered by five linear groups of volcanoes 



