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

EFFECTS ON THE PLATA. 89 Singular fluctuations occur in the river Plata before and after these pamperoes.* For some days previously the river rises, and it is always higher than usual when the south-west wind begins : but, after a few hours, the water falls rapidly, and ves- sels are left aground : indeed instances have been known of the upper parts of the river, near Buenos Ayres, being so much emptied by strong south-westerly, or westerly winds, that men have rode several miles into its bed, to places where ships usually anchor. I have myself known the water fall, in the outer road, off Buenos Ayres, from six to two fathoms, in less than twelve hours, in a place where the usual depth was four fathoms. Such a change as this would not be thought remark- able where tides usually rise several fathoms ; but in the river Plata, where there is very little, if any, tide, where the width of the channel is so great in proportion to its depth, and the confin- ing boundaries are so low, and in many places easily overflowed, a variation of four fathoms cannot take place without causing great difficulties and destruction. In this particular instance,-|- a heavy gale from the eastward dammed up the river for some days ; and then changing, by the south, to the west- ward, emptied it again proportionably. Small craft were left literally scattered about the low country bordering on the river near Buenos Ayres, and many vessels never floated again. By that gale, which blew directly up the river, and raised a heavy sea, every vessel was driven ashore from the inner road of Buenos Ayres, except a schooner. Fourteen English mer- chant vessels lay high and dry upon the shore next day, most of them totally lost. The Owen Glendower, bearing the broad pendant of Sir Thomas Hardy, the Icarus brig, and two or three merchant vessels, anchored in the outer road, weathered it out with topmasts struck ; but all drove considerably, except the frigate, and she brought both anchors ahead, backed by • Although generally considered by strangers to refer solely to a squall, or storra, the term pampero is applied by the natives of the country to every south-westerly wind, whether moderate or a hurricane. t In the year 1820. •