EXAMPLES OF ATMOSPHERIC MOTIONS. 1 75 



succeeded in reconstructing the true horizontal motions. We shall therefore use 

 them only to illustrate the formal methods of a complete kinematic diagnosis of 

 atmospheric motions. 



From the charts B we then derive auxiliary charts representing the contribution 

 of each sheet to the vertical component of the specific momentum. These auxiliary 

 charts have not been reproduced. But the method of drawing them is that devel- 

 oped in section 187 (C), and for the incomplete parts of the sheets in section 189. 



As soon as these auxiliary charts are drawn we find the true vertical specific 

 momenta at different standard isobaric surfaces by successive graphical additions 



By graphical addition of the vertical specific momentum at the ground (plate 

 LVI) to that produced in the incomplete sheet X we get the chart LVII c, which 

 gives the vertical specific momentum at the isobaric surface of 900 m-bar pressure. 



By graphical addition of this vertical specific momentum to that produced in 

 the sheet IX we get the chart LVI 1 1 c, which represents vertical specific momentum 

 at the standard isobaric surface of 800 m-bar pressure. 



By graphical addition of this vertical specific momentum to that produced in 

 sheet VIII we get in the same manner the chart LIX c, representing the vertical 

 specific momentum at the standard isobaric surface of 700 m-bar pressure. 



By graphical addition of this vertical specific momentum and that produced in 

 sheet VII we get the chart LX c, which represents the vertical specific momentum 

 at the standard isobaric surface of 600 m-bar pressure. 



The plates LVII to LX thus give the complete result of the static and the 

 kinematic diagnosis of atmospheric conditions on July 25, 1907, about 7 a.m., 

 Greenwich time, on the basis of the aerological soundings performed about this time. 

 The charts LVII a to LX a give the field of pressure and of mass as the result of 

 the static diagnosis ; the charts LVII b to LX b give the horizontal motion within 

 each of the four isobaric sheets defined by the charts LVII a to LX a. The charts 

 LVII c to LX c represent the vertical transfer of mass from one to the other of 

 these isobaric sheets. 



We have exemplified the diagnosis by taking the four lowest atmospheric sheets. 

 Some of the observations on the day under consideration go much higher. But it 

 will have no interest to extend the diagnostic work further before the observations 

 have attained the completeness required for working out diagnoses which have an 

 unquestionable objective value . Till then we can only exemplify the formal methods. 



If the observations were performed according to the plan which we have devel- 

 oped in Chapter I, we should be able to work out complete diagnoses at epochs which 

 were sufficiently near each other to allow us to derive also the fields of acceleration 

 within all atmospheric sheets. This would be the first step in opening the way for 

 serious investigations in atmospheric dynamics. 



