TRtTE VOLCANOES. 



285 



free from volcanoes between the five volcanic groups, we 

 find the maximum distance of two groups from one another 

 between the volcanic series of Quito and Peru. This is 

 fully 960 miles, whilst the most closely approximated 

 groups are the first and second, those of Mexico and Cen- 

 tral America. The four interspaces between the five groups 

 are severally 300, 628, 960, and 540 miles. The great dis- 

 tance of the southernmost volcano of Quito from the most 

 northern of Peru, is, at the first glance, the more remark- 

 able, because, according to old custom, we usually term the 

 measurement of degrees upon the high land of Quito, the 

 Peruvian measure-meat. Only a small southern portion of 

 the Peruvian chain of the Andes is volcanic. The number 

 of volcanoes, according to the lists which I have prepared 

 after a careful criticism or the newest materials, is as fol- 

 lows : 



(Mexico, Central America, New Granada with Quito, Peru with Bolivia, 

 and Chili); and a space probably quite free from volcanoes of 2428 

 miles. The two spaces are nearly equal. I have given very definite 

 numerical relations, as obtained by the careful criticism of my own 

 maps and those of others, in order to give rise to a greater desire to 

 improve them. The longest portion of the Cordilleras free from vol- 

 canoes is that between the groups of New Granada with Quito and 

 Peru with Bolivia. It is accidentally equal to that occupied by the 

 volcanoes of Chili. 



71 The group of volcanoes of Mexico includes the volcanoes of 

 Orizaba,* Popocatepetl,* Toluca (or Cerro de San Miguel de Tutucuitla- 

 pilco), Jorullo,* Coliina,* and Tuxtla.* Here, as in similar lists, the 

 still active volcanoes are indicated by asterisks. 



