392 CHARLES DARWIN 



floor of round stones. It seems, therefore, most probable 

 that at a period when the land stood at a lower level there 

 was a plain very similar 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 un- 

 derlying red-clay beds, I imagine that the Indians manu- 

 factured their earthen vessels ; and that, during some violent 

 earthquake, the sea broke over the beach, and converted the 

 plain into a temporary lake, as happened round Callao in 

 1713 and 1746. The water would then have deposited mud, 

 containing fragments of pottery from the kilns, more abun- 

 dant 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 

 embedded. 



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 partly by a start during the shock of 

 1822, of ten or eleven feet. The antiquity of the Indo-human 

 race here, judging by the eighty-five feet rise of the land 

 since the relics were embedded, is the more remarkable, as on 

 the coast of Patagonia, when the land stood about the same 

 number of feet lower, the Macrauchenia was a living beast ; 

 but as the Patagonian coast is some way distant from the 

 Cordillera, the rising there may have been, slower than here. 

 At Bahia Blanca, the elevation has been only a few feet 

 since the numerous gigantic quadrupeds were there en- 

 tombed; and, according to the generally received opinion, 

 when these extinct animals were living, man did not exist. 

 But the rising of that part of the coast of Patagonia, is per- 

 haps no way connected with the Cordillera, but rather with 

 a line of old volcanic rocks in Banda Oriental, so that it 

 may have been infinitely slower than on the shores of Peru. 

 All these speculations, however, must be vague ; for who will 



