WINDS AND WEATHER 



73 



Vessels were delayed by calms for a long time, fresh water would give out and 

 the sailors would be forced to throw the horses overboard. 



Belts of Calms. At the equator warm air is continually rising 

 and cold air falling. There is no current of air blowing horizontally. 





FIG. 58. A place on the Earth's surface where Air is rising. 



Such a condition causes a region of calms about 100 miles on each 

 side of the equator. Why ( was this so troublesome to sailors years 

 ago? Why are not sea 

 captains annoyed with the 

 belt of calms to-day? 



Trade Winds. The air 

 flowing toward the equator 

 causes very steady winds, 

 called trade winds. Winds 

 blowing from the equator 

 are called anti-trade winds. 

 As air approaches the 

 equator, it becomes 

 warmer and, of course, 

 holds more moisture. For 

 this reason the trade wind 

 area is known as the clear- 

 weather belt. 



The Prevailing Wester- FIG. 59. The wind belts on the rotating earth. 

 lies. Between the horse 

 latitudes and the equator the winds take a westerly direction because 



