THE CORDILLERAS 



was one of grandeur and desolation: mountain after 

 mountain, separated by immense chasms, to the depth 

 of thousands of feet, and the sides broken in the most 

 fantastic forms imaginable. In these higher parts of the 

 Cordilleras they found a large admixture of the jaspery 

 aluminous rock which forms the base of the finest por- 

 phyries; also chlorite in abundance. The rock likewise 

 contains fine white chalcedony in irregular straggling 

 masses. Trachytic breccia was observed in various places. 

 The porphyry is of a dull purple color rather lighter than 

 the red sandstone of the United States. No traces of 

 cellular lava were seen, nor of other more recent volcanic 

 productions. No limestone was seen in the region 

 traversed by our parties, all the lime used at Santiago is 

 obtained from sea-shells; nor were any proper sedimen- 

 tary rocks seen. 



Nothing could be more striking than the complete 

 silence that reigned everywhere; not a living thing ap- 

 peared to their view. After spending some time on the 

 top, they began their descent ; and after two hours' hard 

 travelling they reached the snow-line, and passed the 

 night very comfortably in the open air, with their blankets 

 and pillions or saddle-cloths. Fuel for a fire they unex- 

 pectedly found in abundance; the Alpinia umbellifera 

 answering admirably for that purpose, because of the 

 quantity of resinous matter it contains. Near their camp 

 was the bank of snow from which the city has been sup- 

 plied with water for many years. It covers several acres. 



Dana and Couthouy made another trip, to the copper- 

 mines of San Felipe, one hundred miles north of Valpa- 

 raiso. There they were rewarded with a nearer and finer 

 view of the peak of Tupongato. 



Next, the squadron anchored in Callao, the harbor of 

 Lima and chief port of Peru, which Wilkes had visited 

 eighteen years before. There was a saying, El que bebe 

 de la pila sequenda in Lima, " He that drinks of the 



