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

APPENDIX. 315 west, are preceded, and therefore foretold, by hea^'y banks of large white clouds rising in those quarters, having hard edges, and appearing very rounded and solid. Winds from the northward and "north-westward are preceded and accompanied by low scud clouds, with a thickly overcast sky, in which other clouds appear to be at a great height. The sun shews dimly through them, and has a reddish appearance. For some hours, or a day before a gale from the north, or west, it is not possible to take an altitude of the sun, although he is visible ; the haziness of the atmosphere in the upper regions causing his limbs to be quite indistinct. Sometimes, but very rarely, with the wind light between N.N.W. and N.N.E. there are a few days of beautiful weather but they are sure to be succeeded by gales from the southward, with much rain. It may be useful to say a few words regarding the seasons in the neighbourhood of Cape Horn, as much question has arisen respecting the propriety of making a passage round the Cape in winter rather than in summer. The equinoctial months are the worst in the year, generally speak- ing, as in most parts of the world. Heavy gales prevail about those times, though not perhaps exactly at the equinoxes. In August, September, and October, there is usually very bad weather ; strong vvdnds, snow, hail, and cold, then prevail. December, January, and February, are the warmest months ; the days are long, and there is some fine weather ; but westerly winds, at times very strong gales, with much rain, prevail throughout this season, which carries with it less of summer than in almost any part of the globe. March, as I said, is stormy, and perhaps the worst month in the year, with respect to violent winds, though not so rainy as the sum- mer months. In April, May, and June, the finest weather is experienced ; and though the days are short, it is more Uke summer than any other time of the year. Easterly winds are frequent, with fine, clear, settled weather. But bad weather occurs during these months, though not so often as at other times. During this period there is some chance of obtaining a few successive and corresponding obser- vations. To try to rate chronometers by equal altitudes would l^e a fruitless waste of time at other seasons. dd2