Hence, what would simply be a north or south wind but for the earth’s rotatory motion, becomes a north-east and south-east wind as it approaches those regions where, the velocity of the globe being so much greater than where it originated, it lags behind it in its easterly course. This is the exact path of the trade winds—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 favor 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 toward 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.