164 SOUTH AMERICA— THE ANDES REGIONS. 



from the uplands and the hot winds ascending from the plains are constantly in 

 collision, producing a state of permanent instability. 



Being intercepted or obstructed by the Cordilleras, the trade winds blow 

 regularly only on the shores of the Caribbean Sea, where their fury is intensified 

 by the rarefaction of the air, caused by the high temperature prevailing on 

 these coastlands. Although hurricanes, properly so called, never range quite so 

 far south, the east and north east gales often assume the aspect of raging storms, 

 driving the surf with tremendous violence against the exposed parts of the sea- 

 board. On the other hand, the rare north winds never acquire the fury of the 

 corresponding nortes in the Gulf of Mexico. The so-called vendavales, or western 

 breezes, often set steadily along the coast from July to November ; but on the 

 high seas they are powerless to resist the force of the trade winds from the 

 opposite quarter. These vendavales are accompanied by a marine current, 

 moving in the same direction, at times with a velocity of over four miles an hour. 



On the other hand, the atmosphere often remains perfectly still in the hot 

 inland regions, such as the Rio Cesar basin and the plains watered by the 

 middle Magdalena. But the shores of the Pacific, running north and south 

 between the trade winds of both hemispheres, are often swept by the northern 

 gales, which blow with great regularity during the dry season. 



As in other equatorial regions, the seasons are determined by the rains, 

 which in their turn follow the movement of the sun. When it reaches the 

 zenith moisture is precipitated, while clear skies coincide with the solstices on 

 either side of the equator. Thus twice a year Colombia is visited by rain-bearing 

 clouds, and every province has its alternating rerfnws and inrienws, wet summers 

 and dry winters. The heaviest showers occur on the seaward slopes of the 

 mountains ; but the mean rainfall is far greater than in the temperate regions 

 of Europe. On the Bogota plateau it exceeds 40 inches, rising to 100 on the 

 Atlantic, and much higher on the Pacific slope, as well as in the Atrato and 

 San Juan valleys. Apart from the loss caused by evaporation and plant life, the 

 discharge of the Atrato represents a yearly rainfall of no less than 200 inches. 

 These moist and marshy regions are extremely unhealthy for the white man, the 

 Indian half-breeds, and even for the negroes. They not only remain nearly 

 uninhabited, but they arrest the progress of explorers, and delay the settlement 

 of the breezy and fertile upland terraces, which they separate from the sea- 

 board.* 



ri,ORA OF Colombia. 



The Colombian flora rivals that of Brazil both in the variety of its plant?» 

 and the splendour of their flowers and foliage. All the Venezuelan and Brazilian 



* Climate of some Coloinbiaii towns : — 



Honda . 

 Ibagué . 

 Medellin 

 Bogota . 

 Tuquerres 



