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

1832. VENTANA — DELIBERATIONS. 109 possible that those substances might have been thrown out of a volcano in the Galapagos Islands, and drifted on the surface of the sea by currents, which near there run from twenty to eighty miles in twenty-four hours, towards the north-west, one cannot, with certainty, rely upon that fact as evidence of a distance to which pumice has been carried by wind. Captain Eden informed me, that the Conway was sur- rounded by ashes and pumice-stone for a day and a half (on the 5th and 6th of May 1835), and that they were supposed to have been ejected from a volcano near Realejo, at the time of the great earthquake ; and an eruption which darkened the air during three days. The aborigines of these regions attach considerable impor- tance to the Ventana,* chiefly on account of its use as a land- mark ; for, rising abruptly to the height of 3,340 feet in a flat country, where there is not another hill of consequence, it is of no small use to them in their wanderings. I was told by Mr. Darwin, that he found it to be chiefly of quartz forma- tion ; but I need not risk causing a mistake, by repeating here the information which he gave me, when it is given fully in his own words in the accompanying volume. After a few days' examination of Port Belgrano, and making inquiries of Harris, as well as those persons at Argentina who knew something of the neighbouring waters and shores, I was convinced that the Beagle alone could not explore them, so far as to make her survey of any real use, unless she were to sacrifice a great deal more time than would be admissible, considering the other objects of her expedition. What then was to be done ? Open boats could not explore the seaward limits of those numerous shoals which lie between Blanco Bay and the river Negro, because there are dange- rous ' races,'t and often heavy seas. The Beagle herself, no doubt, could do so, and her boats might explore the inlets but, the time that such a proceeding would occupy was • The Puel Indians called the Ventana Casu-hati (high hill); and the Molu-che, Vuta-calel (great bulk.) — Falkner, p. 74. t Tide-races, or ripples.