July, 1835. RUINS op callao. 451 



brickwork appear to have been whirled about by the retiring 

 waves hke pebbles. It has been stated that the land sub- 

 sided during this memorable shock: I could not discover 

 any proof of this ; yet it seems far from improbable, for the 

 form of the coast must certainly have undergone some 

 change since the foundation of the old town ; as no people 

 in their senses would willingly have chosen for their building 

 place the narrow spit of shingle on which the ruins now stand. 

 On the island of San Lorenzo, there are very satisfactory 

 proofs of elevation within the recent period : this of course 

 would not contravene the belief of a small subsidence, if any 

 signs of such movement could be discovered. The side of 

 the mountain fronting the bay on that island, is worn into 

 three obscure terraces, which are covered by masses of 

 shells many hundred tons in weight, of species now exist- 

 ing on the beach. Several of the univalves had serpulee 

 and small balani attached on their insides; proving that they 

 must have remained some time, after the animal had died, at 

 the bottom of the sea. In such cases we may feel sure that 

 they had not been carried up, as has sometimes been be- 

 lieved, either by birds or men for food. 



When examining the beds of shells, which have been 

 raised above the level of the sea, on other parts of the coast, 

 I often felt curious to trace their final disappearance from 

 decay. On the island of San Lorenzo, this could be done 

 in the most satisfactory manner : at a small height the shells 

 were quite perfect ; on a terrace, eighty-five feet above the 

 sea, they were partially decomposed and coated by a soft scaly 

 substance ; at double this altitude a thin layer of calcareous 

 powder beneath the soil, without a trace of organic structure, 

 was all that could be discovered. This highly curious and 

 satisfactory gradation of change, it is evident could be traced 

 only under the peculiar conditions of this climate, where rain 

 never falls so as to wash away the particles of shells in their 

 last stage of decomposition. I was much interested by find- 

 ing embedded, together with pieces of sea-weed in the mass 

 of shells, in the eighty-five foot bed, a bit of cotton-thread, 



2 G 2 



