THE HYDROSTATIC PROBLEM FOR THE ATMOSPHERE. 



8l 



Example 3. Observed time, pressure (millimeters of mercury), temperature (C), and 

 humidity {per cent). (Table N.) From the observed pressures and temperatures (columns 2 

 and 3) the curve of true temperature is drawn (the curve to the left in fig. 8). The curve of virtual 

 temperature for saturated air (curve to the right) is drawn by means of table 1 1 a of the Appendix. 



Table N (Example 3). 



Observing the percentages of humidity in column 4, the curve of virtual temperature is drawn between 

 the two other curves. Then the horizontal lines representing the standard pressures are drawn 

 according to the following table of the values of the standard pressures in millimeters of mercury : 



m-bars 1000 900 Soo 700 600 500 400 300 200 100 



Millimeters of mercury 750 675 600 525 450 375 300 225 150 75 



The standard isobaric sheets being thus marked in the diagram, their average virtual temperature is 

 determined by drawing the vertical segments of line in the usual way. Then the determination of the 

 thickness of the standard sheets and the height of the standard surfaces follow as before (columns 5 to 

 8), as well as the determination of the virtual temperature and the specific volume of the air at the 

 standard surfaces (columns 9 and 10). 



