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SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOL. 51 



are determined, first, from the final condition p, t, either step by 

 step from the equation (14) or from the adiabatic formula (18), 

 in which case x must first be computed for each final condition. 

 In table 7 the altitudes are computed for the adiabats of saturated 

 air, whence we find by interpolation the conditions at any other 

 definite altitude such as 1000 or 2000 meters as given in table K. 



These data of table "K are marked on the individual adiabats and 

 the points of equal altitude are connected with each other; we thus 



find that the altitude 

 lines are also represent- 

 ed as straight lines as 

 shown in fig. 7 ; at least 

 the departures there- 

 from are so slight that 

 they a r e n o t shown 

 graphically. 



By comparison of the 

 level lines for the two 

 stages in figs. 6 and 7 we 

 find a slight departure 

 only at great altitudes; 

 thus on the temperature 

 line — 30 for the line 6000 meters the departures are only 60 

 meters. 



Therefore both tables can be united in a single one which can 

 also contain the curves of saturation, and in doing this we either 

 smooth out the differences between the two systems of altitudes 

 and choose an average system or we decide to use either one of 



fig. 7. 



ALTITUDE LINES FOR THE CONDENSA- 

 TION STAGE 



