Narrative of the surveying voyages of his majesty's ships Adventure and Beagle (vol.2): between the years 1826 and 1836 : describing their examination of the southern shores of South America, and the Beagles's circumnavigation of the globe

420 VERTICAL MOVEMENT OF LAND. April ' Penquistos,'''^ as cordially as if their nerves and minds had endured no strain. Although it was indisputably proved to the satisfaction of every person in the neighbourhood, that elevations of land had occurred to the extent mentioned in the previous chapter, I strongly suspect that a sinking down has taken place since that period, to a very considerable amount, if not quite enough to counterbalance former elevation. This idea is suggested by the fact that when I was last at Talcahuano, in July 1835, only four months after the great convulsion, the shores of Concepcion Bay had regained their former position with respect to the level of the sea :-|- — by what the people of Tubul told me, when I rode by, of the sea having returned to its centre,| (meaning that it had regained its usual height), and by what the inhabitants of Santa Maria said, when they told me that for three or four weeks immediately following the earthquake, their little port was much shallower than it was when I went there seven weeks afterwards. Wliether this conjecture be well founded a short time may show : if it should be, an explanation might thus arise of the differences of opinion respecting the permanent elevation of land near Valparaiso, where some say it has been raised seve- ral feet during the last twenty years, while others deny that it has been raised at all. It may have been elevated, or upheaved as geologists say, for a time, but since then it may have settled or sunk down again gradually to its old position. In a place like Valparaiso Bay, where dust is so much blown from the land to the water''s edge, and even out to sea ; and where many streams bring detritus from ravines, no decisive judgment can be formed as to the rise of land, because of the beach increasing gradually, and the water diminishing in depth. * Natives of Concepcion: so called because they formerly lived at Pence : before that city was overwhelmed in 1730. t Close to the landing place at Concepcion is a rock that was usually covered at high-water, previous to the earthquake (of 1835), but which was two feet above the highest tides of the next few weeks. In July, 1835, that rock was covered at ordinary high-water, as in 1834. X ' Esta ahora el mar a su centre'