XVI 



ON THE CHANGES OF TEMPERATURE IN ASCENDING 

 AND DESCENDING CURRENTS OF AIR 



BY PROF. DR. WM. VON BEZOLD 



[Meteorologische Zeitschrift, 1898, XV, 441— 4.48. Translated from Gesammelte 

 Abhandhingen, W. von Bezold, iqo6, pp. 2J^.-28^\ 



When I published my first memoir "On the Thermodynamics of 

 the Atmosphere" 1 I expressed the hope that by the elucidations 

 therein given we had finally set aside the view that slipped into the 

 excellent work of Guldberg and Mohn, according to which the cooling 

 of ascending air depends on the work done in lifting it. But since A. 

 Schmidt of Stuttgart, not only in the year 1890 2 but also more 

 recently 3 has come forward again as defender of the idea that the 

 work done in lifting plays a part in the cooling of ascending currents 

 of air, therefore I think that I ought not to delay to repeat and 

 supplement in more thorough manner my earlier explanation of this 

 matter. I will, however, pursue a course directly opposite to that 

 adopted by Schmidt. 



Whereas Schmidt takes the kinetic theory of gases into considera- 

 tion and thereby unnecessarily obscures such a simple question, I 

 will attempt to treat it in a manner as elementary as possible. 



This course seems to me so much the more advisable since in fact 

 the principle of Archimedes as also the theorems based on experience 

 relative to the thermal behavior of gases suffice for the investiga- 

 tion, whereas the introduction of the kinetic theory of gases has only 

 the result of causing an unnecessary and therefore injurious com- 

 plication of the present question. 



If we are to consider the subject of the work done in the ascent 

 of a mass of air, we must first clearly understand the conditions 

 attending a given volume of air within the atmosphere. Let us 

 assume that the volume under consideration encloses the mass m 



1 Sitzb. Berlin Akad., 1S88. [See pp. 212-242 of the previous collection of 

 translations. — C. A.] 



2 On the cause of the diminution of temperature with altitude. Tubingen, 

 1890. 



3 Illustrierte Aeronautische Mittheilungen, 1898, II, pp. 12-15. 



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