EASTING OF THE TRADE- WINDS, ETC. 



155 



353. Thus, when, after so classing them, we come to examine 

 The medial bands, thosc movements in the band between 5^ and 10^ 

 south, and to contrast them with the movements in the band 

 between 55° and 60° south, for example, we find the general move- 

 ments to be exactly in opposite du^ections. Observations show 

 that dming the year the winds in the former blow toivards the 

 equator 283, and from it 73 days ; and in the latter they blow 

 toward the j^ole for 224, and from it 132 days. These facts show 

 that there must be a place of rarefaction — of low barometer, an in- 

 draught towards the poles as well as the equator ; — and that conse- 

 quently, also, there must be a medial line or band somev>^here be- 

 tween the parallels of 10° and 65^ south, on one side of which the 

 prevailing direction of the wind is towards the equator, on the 

 other towards the j^ole. So, in the northern hemisphere, the same 

 series of observations point this medial band out to us. They show 

 that one is near the calm belt of Capricorn, the other near the 

 calm belt of Cancer, and that they both probably lie between the 

 parallels of 35° and 40°, where the winds north and south are 

 equal, as per table. 



Winds loith Northing and Wi7ids loith Southing in each Hemisphere, expressed bp 

 Average Number of Days for lohich they blow annually. 



_ The wind ciuwes (Plate XY. and the table) afford a very striking 

 viev/ of these medial bands, as the parallels in either hemisphere 

 between which the winds with northinsf and the winds with south- 



