Narrative of the surveying voyages of his majesty's ships Adventure and Beagle (vol.1): between the years 1826 and 1836 : describing their examination of the southern shores of South America, and the Beagles's circumnavigation of the globe

Feb. 1827. ADMIKALTY SOUND. 59 being shoal, — from the very slight tide-stream, — and from the information of the Natives ; who evidently intended to tell us we could not get out to sea, — that we did not consider it Avorth while to make another examination. I have before observed that the strata of the slate rocks, in the Strait, dip to the S.E. ; and I found that they dip similarly all the way to the bottom of this inlet, which I named Admiralty Sound. The north side, like that of the Gabriel Channel, is steep, without indentations, excepting where there is a break in the hills ; but on the south shore there are many coves, and bights, the cause of which is shown in tlie accompanying imaginary section of the Gabriel Channel. The same cause operates on the outline of the north shore of the reach of Cape Froward, westward as far as Cape Holland, where the rock assumes a still more primitive form. Its general character, however, is micaceous slate, with broad veins of quartz ; the latter being particularly conspicuous at Port Gallant. The following slight sketch, intended to represent an ima- ginary section of such an opening as the Gabriel Channel, may also serve to give a general idea of many Fuegian ancho- rages ; — of deep water passages existing between the almost innumerable islands of Tierra del Fuego ; — and of the effects of those sudden, and violent gusts of wind, — so frequent and dangerous, — commonly called hurricane-squalls,* orwilliwaws. • No canvas could withstand some of these squalls, which carry spray, leaves, and dirt before them, in a dense cloud, reaching from the water to the height of a ship's lower yards, or even lower mast-heads. Happily their duration is so short, that the cable of a vessel, at anchor, is scarcely strained to the utmost, before the furious blast is over. Persons who have been some time in Tierra del Fuego, but fortunate enough not to have experienced the extreme violence of such squalls, may incline to think their force exaggerated in this description : but it ought to be considered, that their utmost fury is only felt during unusually heavy gales, and in particular situations ; so that a ship might pass through the Strait of Magalhaens many times, without encountering one such blast as has occasionally been witnessed there. — R.F.