hey were detached from
the coast I have not been able to ascertain authentically; but there
appears reason to suppose that the separation took place during the
violent earthquake of 1586. Attentive investigations to the north of
Callao--at Chancay, Huacho, Baranca, &c., would probably bring to light
further evidence on this subject.

Between the facts stated by Mr. Darwin and those here adduced, there
is considerable discrepancy. On the one hand they denote a rising, and
on the other a sinking. But it may be asked, might not both these
phenomena have occurred at different times?[3] Mr. Darwin's opinion
respecting the still-continued rising of the coast does not appear to
me to rest on satisfactory evidence. The relics of human industry
which he found embedded among shells, at the height of eighty-five
feet above the sea, only prove that the elevation has taken place
after the land was inhabited by the human race, but do not mark the
period at which that elevation occurred. Pieces of cotton thread and
plaited rush are no proofs of a very refined degree of civilisation,
such as the Spaniards brought with them to Peru, and cannot therefore
be taken as evidence that the elevation took place at any period
subsequent to the conquest. Garcilaso de la Vega traces the dynasty of
the Incas down to the year 1021, a period when the inhabitants of the
coast of Peru were tolerably well advanced in civilisation. Fernando
Montesinos furnishes facts connected with the history of Peru, of
several thousand years' earlier date; and, judging from the number of
dynasties, the nature of the laws, &c., it may be inferred that
civilisation existed at a period of even more remote antiquity. It
cannot therefore be determined with any accuracy at what time the
deposit at San Lorenzo, now eighty-five feet high, was level with the
sea, or whether the rise suddenly followed one of those frightful
catastrophes which have so often visited the western coast of South
America. Then, again, the different degrees of decay presented by the
beds of shells seem to indicate that the rising has been gradual; and
it may have been going on for thousands of years. Had the coast risen
eighty-five feet since the Spanish conquest--that is to say, within
the space of three hundred and sixty-two years--the Camotal would long
since have again risen above the surface of the sea; for it is very
improbable that it sank to a depth exceeding ninety or ninety-five
feet. It is