America, for which various causes have been assigned. The following is the opinion of the late learned Dr Robertson on this subject:— “Though the utmost extent of America towards the north be not yet discovered, we know that it advances nearer to the pole than either Europe or Asia. The latter have large seas to the north, which are open during part of the year; and, even when covered with ice, the wind that blows over them is less intensely cold than that which blows over land in the same latitudes. But, in America, the land stretches from the river St Lawrence towards the pole, and spreads out immensely to the west. A chain of enormous mountains, covered with snow and ice, runs through all this dreary region The wind, passing over such an extent of high and frozen land, becomes so impregnated with cold, that it acquires a piercing keenness, which it retains in its progress through warmer climates; and is not entirely mitigated, until it reaches the Gulf of Mexico. Over all the continent of North America, a north-westerly wind and excessive cold are synonymous terms.—Even in the most sultry weather, the moment that the wind veers to that quarter, its penetrating influence is felt in a transition from heat to cold no less violent than sudden. To this powerful cause we may ascribe the extraordinary dominion of cold, and its violent inroads into the southern provinces in that part of the globe. Other causes, no less remarkable, diminish the active power of heat in those parts of the American continent which lie between the tropics. In all that portion of the globe, the wind blows in an invariable direction from E. to W. As this wind
