THE ATMOSPHERE AND ITS CURRENTS. 441 



originated, it lags behind it in its easterly course. This is the exact path of the trade 

 w i n( | s breezes, with few exceptions, uniform in their direction, perpetual in their motion, 

 and steady in their force which wafted Columbus across the Atlantic, impelled the 

 Portuguese from their southerly course and bore them to the Brazils, and have since been 

 important auxiliaries to the communication of the eastern with the western continent. 



The existence of a current in the upper regions of the atmosphere counter to that 

 below, assumed by the preceding theory, is not mere hypothesis. Clouds, though of rare 

 occurrence in the district of the trade winds, have been observed to take a direction 

 contrary to that which the surface breezes would have given them. A circumstance 

 remarkably in favour of the counter-current inferred from theory, occurred in the year 

 1812. There was then an eruption of the volcano of St. Vincent, one of the West India 

 islands, which covered the island of Barbadoes with a quantity of the ashes and volcanic 

 matter ejected. The trade wind here blows with great power, and it is certain that the 

 volcanic ashes would have been conveyed in a direction from Barbadoes, instead of 

 towards it, by its action. To account for their transportation thither, it is necessary to 

 suppose, that the volcano ejected them to an elevation within reach of a superior stratum 

 of air blowing contrary to the course of the inferior current. When Humboldt was 

 upon the Peak of Teneriffe the west wind blew with such violence that he could scarcely 

 stand, though the island below was under the influence of the ordinary north-east trade 

 wind ; and the remark has often been made, that in the elevated parts of the Canary 

 Islands a contrary wind has been experienced to that which has been prevailing over the 

 general surface. 



All mariners and passengers have spoken with delight of the region of the trade winds, 

 not only on account of the favouring gale, but its genial influence, the transparent atmo 

 sphere, the splendid sunsets, and the brilliancy of the unclouded heavens, day and night. 

 Columbus, in recording his first voyage into their territory, compares the air, soft and 

 refreshing without being cool, to that of the pure and balmy April mornings he had 

 experienced in Andalusia, wanting but the song of the nightingale and the sight of the 

 groves, to complete the fancy that he was sailing along the Guadalquivir. " It is 

 marvellous," observes Las Casas, "the suavity which we experience when half way 

 towards these Indies ; and the more the ships approach the lands so much more do they 

 perceive the temperance and softness of the air, the clearness of the sky, and the amenity 

 and fragrance sent forth from the groves and forests ; much more certainly than in April 

 in Andalusia." Humboldt lingers with pleasure, upon his first acquaintance with the 

 tropical regions at sea, upon the mildness of the climate and the beauty of the southern 

 sky, gradually opening new constellations to the view, stars contemplated from infancy 

 progressively sinking and finally disappearing below the horizon, an unknown firmament 

 unfolding its aspect, and scattered nebulae rivalling in splendour the milky way. " A 

 traveller," he states, "has no need of being a botanist, to recognise the torrid zone, on the 

 mere aspect of its vegetation ; and without having acquired any notions of astronomy, 

 without any acquaintance with the celestial charts of Flamstead and De la Caille, he feels 

 he is not in Europe, when he sees the immense constellation of the Ship, or the 

 phosphorescent clouds of Magellan, arise on the horizon. We pass those latitudes, as if 

 we were descending a river, and we might deem it no hazardous undertaking, if we made 

 the voyage in an open boat. " Mr. Bailey, in his Four Years in the West Indies, relates 

 an adventure, nearly answering to that here referred to. The master of one of the small 

 fishing smacks that ply along the coasts of Scotland, who had no other knowledge of 

 navigation than that which enabled him to keep his dead reckoning, and to take the sun 

 with his quadrant at noon-day, having heard that sugar was a very profitable cargo, 

 determined, by way of speculation, upon a trip to St. Vincent, to bring a few hogsheads 



