THE TROPICAL WORLD. 



'''^-^'/ 



avati:rspout. 



CHAPTER I. 



THE OCEAN AND ATMOSPHERE OF THE TROPICAL WORLD. 



Characteristics of tlie Polar and Tropical Worlds— Geograpliical and Climatic Limits of the 

 Zones— Distribution of Land and Water— Climatic Importance of the Ocean— Currents of 

 the Ocean— The Gulf Stream— Influence of the Gulf Stream upon the Climate of Europe— 

 Tlie Sargasso Sea— Columbus and the Gulf Stream— The Pacific and Indian Currents- 

 Heat and Force— Relative Positions of Hot and Cold Currents— Currents of the Air— The 

 Trade Winds— Atmospheric Currents and Climate— The Calm Belt near tlie Equator- 

 Rainfall of Different Regions— Rainy and Dry Seasons within the Tropics— The Monsoons 

 —Winds as Regulators of Rains— Annual Rainfall— Whirlwinds— Their Rotary Motion- 

 Tropical Islands— Volcanic Islands— Coralline Islands— Atolls and Reefs— Influence of the 

 Ocean upon Life in the Tropical Islands. 



FROM a wide survey of the Polar World, we now turn to the tropical regions, 

 where nature assumes aspects of an entirely different character. In the Polar 

 World there is a constant struggle between all sorts of life and cold. As we approach 

 the poles, cold gains more and more the mastery ; life nearly ceases upon tlie land. 



