MOVEMENTS OF ATMOSPHERE GULDBERG AND MOHN 



145 



and we find the following values for the latitude 45 : 



where 



v = velocity in meters per second, 



G = gradient in millimeters of mercury per degree of a great 

 circle on the earth's surface. 



Supposing the temperature to be 20 and the pressure 74o mm the 



v 

 value of — will be increased in the ratio of 1 to 1.102. Supposingthe 



G v 



temperature to be — io° and the pressure 770™™ the value of -~ 



will be diminished in the ratio of 1 to 0.951. 



By the aid of the last table we have calculated the following table 

 for the latitude of 45 , the velocities being always expressed in 

 meters per second. The scale of wind force is that hitherto employed 

 in several meteorological systems of Europe; the numbers have 

 the following signification: 



o = calm; 1 = feeble; 2 = moderate; 3 = quite strong; 4 = 

 strong; 5 = very strong or storm; 6 = a hurricane. The values 

 of the coefficient of friction are the extreme limits which we have 

 found by preliminary calculations, for the ocean and for the irregu- 

 lar surface of the earth. 



