Narrative of the surveying voyages of his majesty's ships Adventure and Beagle (vol.2- Appendix): between the years 1826 and 1836 : describing their examination of the southern shores of South America, and the Beagles's circumnavigation of the globe

I APPENDIX. 313 and of a grey or white appearance ; whereas the latter are generall)^ covered with vegetation, are dark-coloured, and have smoother out- lines. The slate liills shew some sharp peaks, except which, the only- bare places are those exposed to wind or sea. Soundings extend about thirty miles from the coast. Between ten and twenty miles from the land, the depth of water varies from sixty to two hundred fathoms ; the bottom almost every where being white or speckled sand. From ten to five miles distant, the average depth is fifty fathoms ; it varies in general from thirty to one hundred, but in some places there is no ground with two hundred fathoms of line. Less than five miles from the shore the soundings are very irregular indeed, generally less than forty fathoms, though in some places deepening suddenly to one hundred or more ; while in others a rock rises nearly to, or above the surface of the water. After carrying fifty, forty, thirty, or twenty fathoms, towards an inlet, which you are desirous of entering, you will perhaps find the water deepen to sixty or one hundred fathoms as soon as you enter the opening : and in the large sounds, behind the seaward islands, the water is often considerably deeper than on the outside. There Is a bank of soundings along the whole coast, extending from twenty to thirty miles from it, which appears to have been formed by the continued action of the sea upon the shore, wearing It away, and forming a bank with its remains. Between the islands, where there is no swell or surf worth notice, the water is deep, and the bottom very irregular. A small ship may run among the islands In many places, and find good anchorage ; but she will enter a labyrinth, from which her retreat may be difficult, and in thick weather very dangerous. Fogs are extremely rare on this coast ; but thick, rainy weather, and strong winds prevail. The sun shews himself but little; the sky, even in fine weather, being generally overcast and cloudy. A clear day is a rare occuiTence. Gales of wind succeed each other at short intervals, and last several days. At times the weather is comparatively fine and settled for perhaps a fortnight, but those periods of quiet are few. Westerly winds prevail during the greater part of the year. The easterly wind blows occasionally in the winter months, and at times very hard, but it seldom blows in summer. Winds from the eastern quarter invariably rise light, with fine dd