METEOROLOGY. - 215 



the former. The lower clouds of the valleys showed plainly a motion 

 from east to west, as seen against the dark background of the south- 

 ern mountains. The high southern current was not indicated by 

 clouds in those places where it was vertically over the lowest parts of 

 the valley ; but when drawing nearer to the Cordilleras, on which I 

 stood, the vapors which it contained condensed rapidly, and became 

 visible as drifting, incoherent clouds sweeping by, and which could 

 still be seen on the sea-side as long as they floated over the dense 

 primeval forest, which extends here from the mountains' tops to the 

 ver}' margin of the sea. 



Here I rnay also remark that the great amount of cloudiness, which 

 in some respects may be regarded as a disadvantage to observation, 

 offers, with regard to the currents of the atmosphere, great advan- 

 tages, the condensed vapors indicating the various motions and direc- 

 tions of these currents, and I have had, therefore, opportunities to 

 observe them in most of their various forms. Sometimes I have seen 

 the air ascend and descend vertically with considerable velocity, at 

 other times pushed up the inclined planes of mountain flanks on one 

 side until reaching the crest, and then gliding or flowing down on 

 the other side somewhat like a liquid, following in its course the most 

 depressed localities and ravines in all their windings. Sometimes the 

 eastern currents may be seen in their gradually ascending but nearly 

 horizontal course to meet the higher southern current at right angles, 

 and, without mixing, to be deflected by the latter in a horizontal semi- 

 circle, or downward or upward, as the case may be. I have also seen 

 two opposite currents meet, when each endeavored to force its antago- 

 nist back with alternate success and failure^ until one got the better 

 over the other, and at last kept undisputed sway. 



At certain seasons of the year we may see extensive sheets of cloudy 

 masses press closely over the northern or the southern range of the 

 colony valley, and gliding down the declivity for a short distance 

 become invisible and disappear in crossing the cultivated part of the 

 valley, but reappear again on drawing near the opposite ridge. Fre- 

 quently I have seen immense masses of clouds leaning against the 

 northern side of the crest of the mountains, and as if stuck to them, for 

 whole days, and while the base was gently sliding upwards towards 

 the south, the top of the cloud, which was towering above the moun- 

 tains, was bent back and moving slowly in an opposite direction. 



When standing on some high mountain, esjjecially early in the 

 morning, I have seen dazzling white coherent masses of clouds filling 

 up far below me whole valleys, the surface of these clouds representing 

 immense and level snow fields, from which, in a most lovely and 

 striking contrast, the green summits of the smaller mountains pro- 

 truded as so many islets, or higher and lesser promontories of a frozen 

 arm of the ocean. The delusion is sometimes most complete, and 

 cannot be viewed without feelings of pleasure and surprise. The ele- 

 vation oi the upper surlace of these clouds was between 5,000 and 6,000 

 feet above the level of the sea. 



A striking feature in table No. 4 may be found in the prevalence of 

 northern currents from November till February, inclusive, while they 

 are much rarer or entirely wanting in March, April, and May. 



