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

242 TIDES — CUURENTS. feet at spring tides. The principal swell of the ocean, which causes the tidal streams about these islands, comes from the south-east. Scarcely any stream is perceptible on the south-east coast of East Falkland ; but along the north, south, and west shores it increases in strength, until among the Jason Islands it runs six miles an hour, causing heavy and dangerous races. Off Berkeley Sound, across the entrance, and near Cape Carysfort, the tide runs about two knots, at its greatest strength ; and thence westward it increases gradually. Into Falkland Sound the tide flows from both openings, and meets near the Swan Islands ; shewing, I apprehend, that the principal wave or swell impinges upon the coast considerably eastward of south. The tidal currents are stronger along the northern shores of the archipelago than they are along the south coasts ; and the stream of flood is stronger than the ebb. At Port William, the easternmost harbour, the time of high water at full moon is five ; and thence westward, the times increase gradually to half-past eight, at New Island, which is nearly the western- most of the group. Generally speaking, the sea is much deeper near the south- ern and western shores than it is near those of the north ; and to those local differences I attribute the varying velocity of the minor tide streams. Besides these movements of the surrounding waters, there is a current setting past the islands from south-west to north- east : a current which continually brings drift wood to their southern coasts, and has brought Fuegian canoes. On all parts of the southern shores that are open to the south-west, the beaches or rocks are covered with trees, which have drifted from Staten Land or Tierra del Fuego. Great quantities of this driftwood may be found between Cape Orford and Cape Mere- dith ; upon the Arch, Speedwell, George, and Barren Islands indeed, there are few places between Cape Orford and Choi- seul Bay where a vessel may not find a good supply of fuel. On Long Island, and in the bay behind the Sea-Lion Islands, portions of Fuegian canoes have often been found ; one con- sisted of an entire side (pieces of bark sewed together), which