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

312 KKMARKABLE RIPPLES AND RACES. May totally lost, though she was lying in a land-locked bay, or rather gulf. On the 6th of May, while returning from San Jose to the River Negro, our little vessels got into a ripple, which did not break, but had almost the appearance of a whirlpool. There was a hollow short swell, and an irregular motion in every direction, exactly like the boiling of a pot, on a great scale. Here again they could touch no bottom with fifty fathoms of line and a heavy lead. These races and ripplings in such deep water, about the peninsula of San Jose, are very remarkable ; chiefly because there are none such on any other part of the coast. They will be recurred to in a future page of this volume. May 7th. The Paz and Liebre returned to the Negro, but could not reach an anchorage off" Carmen until late the next day, owing to the ' freshes.' * The next occupation for our party was examining and sounding the entrance and bar of the Negro, a task purposely deferred, as being of minor conse- quence. The mouth of a rapid river like this, subject to floods, and disemboguing at a place exposed to the full force of such a heavy sea as is raised on that coast by a south-east gale, must be frequently changed, as to the detail of its shoals and channels ; therefore no plan, however exact at one time, can be depended upon after the lapse of a few years ; and no vessel larger than a boat would be justified in attempting to enter without a local pilot, if one can be obtained. In one spot, near Main Point, where a small battery stood in 1826, there were two fathoms water in 1833 ; and within the same period the deepest water for a few miles within the entrance, changed gra- dually from the south side to the north. Mr. Darwin was told that the river was called Negro after a cacique of that name but Falkner asserts that it was so called by the Spaniards, be- cause the aborigines knew it by the name of ' Cusu Leuvu,"* which means black river. -}* * There are two floods annually : one about December or January, caused by snow melted on the Cordillera; and the other about May or June, occasioned by heavy rains in the interior country. These inun- dations are very variable. t Falkner, p. 79.