168 rnYSICAL GEOGHAPHY op the sea, and its METEOnOLOGT. 



economy of the country would deri^^o by the systematic extension 

 of our meteorological observations from the sea to the land. 

 These lines show how much we err when we reckon climates 

 according to parallels of latitude. The space that these two 

 isotherms of 45° and G5° comprehend between the Mississippi 

 and the Eock}^ Mountains, owing to the singular effect of those 

 mountains upon the climate, is larger than the space they 

 comprehend between the Mississippi and the Atlantic. Hyeto- 

 graphically it is also diiferent, being dryer, and possessing a 

 purer atmosphere. In this grand range of climate between the 

 meridians of 100° and 110° W., the amount of precipitation is 

 just about one-half of what it is between those two isotheims 

 east of the Mississippi. In this new country west of it, winter 

 is the dry, and spring the rainy season. It includes the climates 

 of the Caspian Sea, which Humboldt regards as the most salu- 

 brious in the world, and where he found the most delicious 

 fruits that he saw during his travels. Such was the purity of 

 the air there, that polished steel would not tarnish even by night 

 exposure. These two isotherms, with the remarkable loop 

 which they make to the north-west, beyond the Mississippi, 

 embrace the most choice climates for the olive, the vine, and 

 the poppy ; for the melon, the peach, and almond. The finest 

 of wool may be grown there; and the potato, with hemp, 

 tobacco, maize, and all the cereals, may be cultivated there in 

 great perfection. No climate of the temperate zone will be 

 found to surpass in salubrity that of this Piedmont trans-Mis- 

 sissippi country. The calm zone of Capricorn is the duplicate 

 of that of Cancer, and the winds flow from it as they do from 

 that, both north and south, but with this difierence : that on 

 the polar side of the Capricorn belt they prevail from the north- 

 west instead of the south-west, and on the equatorial side from 

 the south-east instead of the north-east. Now if it be true that 

 the vapour of the north-east trade-winds is condensed in the 

 extra-tropical regions of the southern hemisphere, the following 

 path, on account of the effect of diurnal rotation of the earth 

 upon the course of the winds, would represent the mean circuit 

 of a portion of the atmosphere moving according to the general 

 system of its circulation over the Pacific Ocean, viz. : coming^ 

 down from the north as an upper current, and appearing on the 

 surface of the earth in about longitude 120° west, and near the 

 tropic of Cancer, it would here commence to blow the north-east 



