148 The Andes and the Amazon. 



hurled down by an eruption on the very day Atahuallpa 

 was murdered by Pizarro. The last great eruption oc- 

 curred in 1803, though so late as 1855 it tossed out stones, 

 water, and sand. Heaps of ruins, piled up during the lapse 

 of ages, are scattered for miles around the mountain, 

 among them great boulders twenty feet square. In one 

 place (Quinchevar) the accumulation is 600 feet deep. 

 Between Cotopaxi and Sincholagua are numerous conical 

 hills covering the paramo, reminding one of the mud vol- 

 canoes of Jorullo. 



Pumice and trachyte are the most common rocks around 

 this mountain, and these are augitic or porphyroid. Ob- 

 sidian also occurs, though not on the immediate flank, but 

 farther down near Chillo. In plowing, thousands of pieces 

 as large as " flints" are turned up. The natives know noth- 

 ing about their origin or use ; the large specimens were an- 

 ciently polished and used for mirrors. But Cotopaxi is the 

 great pumice-producing volcano. The new road up the 

 valley cuts through a lofty hill formed by the successive 

 eruptions ; the section, presenting alternate layers of mud, 

 ashes, and pumice, is a written history of the volcano." 

 The cone itself is evidently composed of similar beds su- 

 perimposed, and holding fragments of porphyry and tra- 

 chyte. What is Vesuvius, four thousand feet high, to Co- 

 topaxi, belching forth fire fi-oni a crater fifteen thousand 

 feet higher, and shooting its contents three thousand feet 



* Compare the following sections : 



Cotopaxi (near TiupuUo). 



Soil 1 ft. Oin. 



Fine yellow pumice 5 " " 



Compact black ashes, with 



seams of pumice 10 " " 



Fine yellow pumice 1 " 6 " 



Compact black ashes 12 " " 



Fine yellow pumice 2 " " 



Compact black ashes, with seams of 



pumice. 



Vesuvius (at Pompeii). 



Soil 3ft. Oin. 



Brown incoherent tuff 1 " G " 



Small scorijB and white la- 



pilli " 3 " 



BroAvn earthy tuif 4 " 9 " 



Whitish lapilH " 1 " 



Gray solid tuff " 3 " 



Pumice and white lapilli... " 3 " 



