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

184 APPENDIX. winds are prevalent, almost always. They are frequently strong in the afternoon, and sometimes during a part of the night. Towards morning, and during the early part of the day, moderate winds, light breezes, or calms, are to be expected. Near the land, it is generally calm at night, excepting about once or twice in a month, when the wind blows strongly from the south- ward until about midnight. Occasional northerly winds are expe- rienced, it is true, duriag the summer ; but they are usually so mode- rate, during that season, that they pass almost unheeded. About the end of March, the ' northers,' as they are called, begin to remind one that fogs, heavy and frequent rains, thick gloomy weather, and strong winds, often trouble the southern coasts of ChUe. During a part of March, and throughout April, May, and June, foggy weather is frequent ; and although it is not often that a thick fog lasts longer than a few hours, a day, even two days, of continued thick fog, is not an unknown occiu-rence. With northerly and north-west winds the sky is overcast, the weather unsettled, damp, and disagreeable. These winds are always accompanied by clouds, and usually by thick rainy weather. From the north-west the wind in general shifts to the south-west, and thence to the southward. Sometimes it flies round in a violent squall, accompanied by rain, thunder, and lightning. At other times it draws gradually round. Directly the wind is southward of west, the clouds begin to disperse, and as a steady southerly wind ap- proaches, the sky becomes clear and the weather healthily pleasant. A turn of fresh southerly wind is usually followed by a moderate breeze from the south-east, with very fine weather. Light variable breezes foUow, clouds gradually overspread the sky, and another round turn is generally begun by light or moderate north-easterly breezes, with cloudy weather, and often rain. This is the general order of change. When the vrind shifts against this order, or backs round, bad weather with strong wind may be expected. Lightning is always a sign of bad weather. It accompanies or pre- cedes a change for the worse ; which, howesv^er, is usually a prelude to clearing up. Squalls are rare, excepting at the shift from north-west to south-west, already mentioned. From the westward (south-west by west to north-west by west) the wind does not usually, if ever.