206 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 51 



portion, that is to say, to go from a point at the distance r to a point 

 at the distance r w is found by the formula 



t = 



1 



U cos </' U r cos </> c 



d r = 



2 U cos 4> r \ \ r< 



- 1 



By the aid of the preceding formulas we have calculated the fol- 

 lowing tables.. In the sixth column h is expressed in kilometers and 

 w Q in meters. We compute the value of U by successive trials. 

 Cyclone of the temperate zone 



= 60° K = 0.00004 </-„ = 72.4° 



30 



*0 



Cyclone of the temperate zone 

 = 30° K = 0.00002 </<„ = 74.7 C 



