308 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 51 



(/) "The curve of condition for temperature must consequently 

 in the highest strata asymptotically approach a straight line that 

 cuts the axes at an angle of 45 ." 



(3.) THE OBSERVED MEAN ANNUAL AND SEASONAL VERTICAL 

 DISTRIBUTION OF THE METEOROLOGICAL ELEMENTS 



Now that we have in the second section endeavored to explain the 

 mean distribution of temperature in a vertical column of air at least 

 as to its principal features, we will exhibit both numerically and 

 graphically the mean temperature and moisture as deduced by 

 Besson and Suring (from observations in balloons). These quanti- 

 ties are indicated by t m and y m \ and then for completeness are added 

 under /? m barometric readings corresponding to the different altitudes 

 when the atmospheric pressure at sea-level is 762 mm and the 

 temperatures are such as given by Besson's computation: on the 

 other hand under /? a are given the pressures that would correspond 

 to dry air adiabatically rising or falling, and leaving the sea-level or 

 arriving there from above with the temperature io°.4. 



The numbers under /? m give the average vertical distribution of 

 pressure for the North German plains just as these under t m give the 

 average temperature distribution. Of course these numbers do not 

 represent any greater degree of accuracy than can be expected from 

 the relatively small number of observations submitted in the "Er- 

 gebnisse" 8 but still they afford a very instructive picture. 



As representative of the moisture I have chosen the specific mois- 

 ture for a reason that will be explained immediately. The appropri- 

 ate numbers are found in the column y m . Moreover, under y s are 

 found the values of the specific moisture that represent the condition 

 of saturation for the corresponding pressures ft m and temperature 

 t m . The quotient y m / y 8 , whose value can be at once approxi- 

 mately seen from the graphic diagram, fig. 43, when multiplied by 

 100 gives the relative humidity in per cent. 



Finally the numbers given under Y m represent the total quantity 

 of water in kilograms corresponding to the % observed values of 

 y m and contained in a vertical column of air 1 meter square extend- 

 ing from the ground up to the respective altitudes. On account 

 of the slight accuracy naturally attaching to these numbers they 

 are only given for each full thousand meters. 



With these remarks the following table needs no further explana- 

 tions: 



8 The Ergebnisse: Results of Scientific Balloon Ascensions. 



