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

228 APPENDIX. nearly as much as in the ports of this coast, where the nights are generally calm, till a land breeze from the eastward springs up. This light message from the Cordillera is never troublesome, neither does it last manyhours. "With these winds the sky is almost always clear ; indeed, when the sky becomes cloudy it is a sure sign of little or no sea breeze in summer, and probably a fall of rain : in the winter it foretels an approaching northerly wind, with rain. In summer, ships anchor close to the land, to avoid being driven out to sea by strong southerly winds ; but as the winter approaches a more roomy berth is advisable, though not too far out, because near the shore there is always an undertow, and the wind is less powerful. Seamen should bear in mind that the course of the winds on this coast, as in all the southern hemisphere, is from north to south, by the west : that the hardest northerly blow, with most sea, comes from the westward of north, and that, therefore, they should get as much as possible under the shelter of rocks or land to the westward of them, rather than of those which only defend from north winds, ' Northers,' as they are called, give good warning : an overcast sky ; little or no wind unless easterly ; a swell from the northward; water higher than usual; distant land remar- kably visible, besides being raised by refraction ; and a falling baro- meter ; are their sure indications : but all northers are not gales : some years pass without one that can be so termed ; though few years pass in succession without ships being driven ashore on Valparaiso beach. Thunder and lightning are rare : wind of any disagreeable strength from the east is unknown. West winds are only felt while a ' norther ' is shifting round, previous to the sky clearing and the wind moderating. The violence of southerly winds lasts but a few hours : that of a northerly gale seldom continues beyond a day and a night, generally, indeed, not so long. Some persons say that the strength of northerly winds is not felt to the northward of Coquimbo, but I have evidence of gales, with heavy seas, at Copiapo : and Captain Eden informed me that he had a very heavy gale of wind in H. M.S. ' Conway,' in latitude 25° S., and longitude 90° W., where such an interruption to the usual southerly winds was little expected. How to make passages is easy to tell, for there are but two ways. When going northward, steer direct to the place, or as nearly so as is consistent with making use of the steady winds which j)revail in