168 THE MECHANICS OF THE EARTH'S ATMOSPHERE. 



I have also executed the further complete computation for the first 

 case where c=h ; the results of this work are given in Table 2. In this 



D 



computation the equations (29) and (30) were used for the determina- 

 tion of the velocities gd and the deviations s of the directiou of the wiud 

 from the radial gradient. Furthermore, the differences of pressure 

 (?— Po) witu r esP ect to tuat at tne ceuter > iu tDe circles of radius r, were 

 computed according to equations (31), (32), (33) and (34). These latter 

 are however, converted from tbe units ordinarily used in hydro- 

 dynamics into differences of barometric pressure (b— b ). This latter 



is easilv done if we recall that for fc=760 millimetres the ratio -is 



equal to the square of the Newtonian velocity of sound ; therefore we 

 have the proportion 



[b-b ): 160=1 (p-p ); (279.9) 2 



The gradients y are in our present case tbe differences of barometric 

 pressure for a horizontal distance of 100 kilcmetres. 



Table II. 



From this table we see that the cyclone includes a broad storm 

 region from r=200 to r=500 kilometres, of which » portion is in the 

 inner region and another portion in the outer region. Of course the 

 gradients are greatest in the inner region ; therefore there the isobars 

 are most crowded together. 



From those values of the constant c that' are any way possible, it fol- 

 lows that the velocity of the ascending current of air is extraordinarily 

 small ; for the present example c equals 0.000096. If we assume that 

 the formula w=cz holds good to an altitude of 1,000 metres, then the 

 vertical velocity would at that height first attain the value of about 0.1 

 metre per second. 



Hitherto the discussion has exclusively dealt with regions of ascend- 



