130 PERU. 



impure clay, together with some giavel, and the 

 surface, to the depth of from three to six feet, of a 

 reddish loam, containing a few scattered sea-shells 

 and numerous small fragments of coarse red earth- 

 enware, more abundant at certain spots than at 

 others. At first I was inclined to believe that this 

 superficial bed, from its wide extent and smooth- 

 ness, must have been deposited beneath the sea ; 

 but I afterwards found in one spot that it lay on an 

 artificial floor of round stones. It seems, there- 

 fore, most probable, that at a period when the land 

 stood at a lower level, there was a plain very sim- 

 ilar to that now surrounding Callao, which, being 

 protected by a shingle beach, is raised but very 

 little above the level of the sea. On this plain, 

 with its underlying red-clay beds, I imagine that 

 the Indians manufactured their eai'then vessels, and 

 that during some violent earthquake the sea broke 

 over the beach, and converted the plain into a tem- 

 porary lake, as happened round Callao in 1713 

 and 1746. The water would then have deposited 

 mud, containing fragments of pottery from the 

 kilns, more abundant at some spots than at others, 

 and shells from the sea. This bed with fossil 

 earthenware stands at about the same height with 

 the shells on the lower terrace of San Lorenzo, in 

 which the cotton thread and other relics were em- 

 bedded. Hence we may safely conclude that 

 within the Indo-human period there has been an 

 elevation, as before alluded to, of more than eighty- 

 five feet ; for some little elevation must have been 

 lost by the coast having subsided since the old maps 

 were engraved. At Valparaiso, although in the 

 220 years before our visit the elevation cannot 

 have exceeded nineteen feet, yet subsequently to 

 1817 there has been a rise, partly insensible and 

 partlv by a start during the shock of 1822. of ten 



