METEOROLOGY AND ALLIED SUBJECTS. 



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relation between isobars and winds during the great hurricane that 

 marked this month. The angle between the wind and isobar in each 

 quadrant of the hurricane is as follows, on the average of three maps : 



At different distances from the storm-center the angle varied as fol- 

 lows: 



Since these relate to the region beyond the maximum of wind force 

 they can, according to Guldberg and Mohn, be considered as approxi- 

 mations to the normals values of the angle of deviation, and in their 

 notation the average values for the three maps are as follows; 



This angle is, therefore, nearly the same on the Atlantic Ocean, and 

 in latitude 42°, as it is in Denmark and Great Britain. By the formula 

 given by Guldberg and Mohn we can now compute the coefficient of 

 friction and derive the value A;=0.00005409. With this we may compare 

 the value Jc = 0.00007265, computed by Hoffmyer, for Denmark, latitude 

 56°, from the deviation angle a = 59°, and we iind it higher than would 

 have been expected from the ocean (Guldberg and Mohn assume for the 

 open sea Tc = 0.00004). The value 7; = 0.00002582, computed by Clement 

 Ley for tp = 77° for five British coast stations is apparently much too 

 small. {Z. 0. G. M., XY, 1880, p. 201.) 



Friesenhof concludes from the study of the paths of storm centers 

 that the most important factor in determining both the velocity and 

 direction of the progression is the unequal evaporation in the different 



