132 MR. J. BAXENDELL : RELATIONS BETWEEN 



XII. — On the Relations between the Decrement of Tempe- 

 rature on ascending in the Atmosphere, and other Me- 

 teorological Elements. By Joseph Baxendell, Esq., 

 F.R.A.S. 



Read before the Physical and Mathematical Section, February 27th, 1862. 



According to the theory which attributes the production 

 of winds and storms to upward currents of air caused by 

 the heat liberated during the condensation of aqueous va- 

 pour into clouds and rain, the rate of decrease of tempe- 

 rature on ascending in the atmosphere ought to be less 

 in rainy than in fair weather; and the reasonings and 

 calculations of Dr. Wm. Thomson, in his valuable paper 

 " On the Convective Equilibrium of Temperature in the 

 Atmosphere/^ lately read to the Society, point to the same 

 conclusion; but in a paper entitled '^Remarks on the 

 Theory of Bain," read to this Section on the 29th of March, 

 i860, I gave some results derived from a discussion of the 

 Greenwich and Oxford observations, which seemed to mi- 

 litate against this theory ; and reference was made to the 

 fact, stated by Kaemtz and others, that the diminution 

 of temperature on ascending in the atmosphere is more 

 rapid in rainy than in fine weather. It appears, however, 

 that this fact is not generally admitted by meteorologists, 

 as the observations from which it is derived were mostly 

 of a desultory nature, and continued for only short periods 

 of time. I have therefore thought that a discussion of the 

 monthly results of the observations made during the years 

 1 848-1 858 at Geneva and on the Great St. Bernard, given by 

 Mr. Vernon in his valuable paper " On the irregular Baro- 

 metric Oscillations " at those places, might throw some 

 light on the subject, and, at the same time, serve to indicate 

 the relations which exist between the decrement of tern- 



