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

482 ISLAY — WHITE POWDEK. AuffUSt o seen. Of these and other ports along the coasts of Northern Chile and Peru, nautical information will be found in the Ap- pendix. I will only delay the general reader with one or two obsex'vations. From near Iquique to Arica the precipitous coast is so lofty, and approaches so much to the character of enormous cliffs, about a thousand feet high, that it is really sublime. Near Islay, the land is in several places covered with a whitish powder, or dust, which lies many inches thick in hollows or sheltered places, but is not found abundantly in localities exposed to wind. Much difference of opinion has arisen about this powder. People who live there say it was thrown out of a volcano near Arequipa a great many years ago : other persons assert that it is not a volcanic production, and appertains to, or had its origin, where it is found. My own idea was, before I heard any thing of the controversy, that there could be no doubt of its having fallen upon the ground within some hundred years, for it was drifted like snow, and where any quantity lay together, had become consolidated about as much as flour which has got damp in a damaged barrel. In one of the old voyages there is a passage which seems to throw some light upon this subject : " As they (of Van Noort's ship) sailed near Arequipa, they had a dry fog, or rather the air was obscured by a white sandy dust, with which their clothes and the ship's rigging became entirely covered. These fogs the Spaniards called ' arenales.' " — Voyage of Van Noort, in 1660, from Burney, vol. ii. p. 223. On the 9th of August, the Blonde anchored in Callao Bay, and I enjoyed the satisfaction of finding all well on board the Beagle. She had touched at Copiapo and Iquique, for Mr. Darwin, in her way to Callao, where she arrived on the 19th of July. Lieutenant Sulivan brought his little vessel safely to an anchor near the Beagle on the 30th, having accomplished his survey in a very satisfactory manner. So well did he speak of the Constitucion, as a handy craft and good sea boat, and so correctly did his own work in her appear to have been executed, that after some days' consideration I decided to buy