XIII 

 ON THE THERMODYNAMICS OF THE ATMOSPHERE 



BY PROF. DR. WM. VON BEZOLD 



Fifth Communication 1 



(Sitzb. Berlin Academy igoo, pp. 356-372. Translated from the Gesammelte 

 Abhandlungen von Wm. v. Bezold, Braunschweig igo6, pp. 216-220) 



THE CLIMATOLOGICAL IMPORTANCE OF THE THEORY OF ASCENDING 

 AND DESCENDING CURRENTS OF AIR 



In the second of this series of memoirs 3 I have submitted to more 

 precise consideration the idea of "potential temperature" first 

 introduced by H. von Helmholtz under the designation "thermal 

 content," and have therein deduced a theorem that has great simi- 

 larity with the second fundamental theorem of the mechanical 

 theory of heat. 



From the circumstance demonstrated in the first article of this 

 series, that the changes of saturated moist air, when heat is neither 

 added nor abstracted and when the precipitated water or ice falls 

 from it, are not as a whole reversible but only in their smallest por- 

 tions, it resulted that in such changes of condition the potential 

 temperatures never diminish but can only increase. 



I then drew various consequences from this theorem that are of 

 fundamental importance not only in the consideration of individual 

 processes but also in understanding the most important prominent 

 facts in the general averages. 



Thus, in the first place the average diminution of temperature 

 with altitude finds its explanation in this theorem, and secondly in 

 studying the average temperatures for whole circles of latitude, 

 the results deduced from this theorem stand clearly forth. 



1 The substance of the present memoir (which could only be established 

 by correct observations after the conclusion of the work then being done on 

 the "Results of the Scientific Balloon Ascensions from Berlin") had been 

 previously communicated to the Berlin Academy at its session of the 5th 

 of May, 1898. (Note added in 1905. W. v. B.) 



2 See Mechanics of the Earth's Atmosphere, 1891, p. 243. Smithsonian 

 Miscellaneous Collections Vol. XXXIV. — C. A. 



280 



