52 



INTRODUCTION 



waters. During floods, the elevated sides are sometimes burst through, and tlie waters which 

 escape stagnate in temporary lakes, or return into the main stream lower down, or travel to the 

 sea by a separate mouth 



VI. CLIMATE, WINDS, &c. 



1. Climate. The term climate expresses the particular combination of temperature and 

 moisture which characterizes the atmosphere of any particular place. We may distinguish in 

 general six different combinations or climates, which, however, are infinitely diversified in 

 degree ; thus we have warm and moist, warm and dry, temperat-e and moist, temperate and 

 dry, cold and moist, and cold and dry climates. 



2. Causes of Climate. There are nine circumstances which determine the character of 

 climate : 1. The sun's action upon the atmosphere ; 2. the temperature of the earth ; 3. the 

 elevation of the ground above the level of the ocean ; 4. the general slope of the ground and 

 'ts particular exposure ; 5. the position and direction of mountains ; 6. the neighborhood and 

 relative situation of great bodies of water ; 7. the nature of the soil ; 8. the degree of cultiva- 

 tion and density of population ; and 9 the prevailing winds. 



3. JVIodijications of Climate. The whole of America, north of latitude 55'^, may be con- 

 sidered a frozen region. In Greenland, and 

 around Hudson's Bay, brandy freezes during 

 the winter. The ice and snow accumulate on 

 the land and water, and cover a great part of 

 the country throughout the year. The winter 

 begins in August and continues for 9 months. 

 In summer the heat is as great as in New 

 England. It continues, however, for too short 

 a period to bring grain to maturity, and the 

 cultivation of the soil is very little practised. 

 Vegetation is too scanty to supply the inhabi- 

 tants with any considerable part of their food ; 

 they therefore live chiefly on seals, and other' 

 productions of the sea. 



Between .55° and 45°, the climate of North 

 America is still severe. In winter, the cold is intense ; and the snow, which begins to fall in 

 November, remains till May. The summer advances with such rapidity, that the season of 

 spring is scarcely known. In June the fields and forests are covered with luxuriant verdure. 

 Grass is abundant, and in some parts grain is cultivated with success. 



The temperate portions of North America may be considered as extending from 45° to 

 37° north latitude. These • regions are prolific in grass, grain, and various kinds of fruit, as 

 apples, pears, peaches, &c. From 37° north to the latitude of 40° south, the climate is hot, 

 and the products are tobacco, indigo, cotton, rice, and various fruits, and plants called tropical, 

 as oranges, lemons, figs, pine apples, sugar cane, coffee, &c. Beyond latitude 40° south, the 

 climate again becomes cold, and at Terra del Fuego, it is severe. At the Georgian Isles in 

 latitude 54° south, the climate appears to be frigid. 



It seems, therefore, that the temperature in general becomes cold or w-arm as we approach 

 or recede from the equator. Here, beneath a vertical sun, reigns perpetual summer, and na- 

 ture puts on a magnificent array of vegetation. As if enchanted by these regions, birds of 

 beautiful plumage are seen in flocks amid the ever-verdant groves ; monkeys are sporting on the 

 trees, and lurking amid marshes and thickets, are Jaguars, Cougars, and the Jacumana. As we 

 eave these countries and proceed to the north or south, there is a gradual change ; not only 

 does vegetation assume a less and less exuberant character, but the trees and plants are ex- 

 changed for others. The orange gives place to the peach and vine ; these disappear, and the 

 hardier fruits, such as apples and pears, are suspended from the trees. These disappear again, 

 and forests of dark pine cover the land with gloom. These dwindle by degrees, until only 

 here and there a stunted birch, or willow, the hardiest of trees, is found to endure the inhospi- 

 table climate. 



But while the climate of a country thus chiefly depends upon its nearness to the equator 



Icebergs of the Polar regions 



