PAPER BY PROF. OBERBECK. 189 



are there given in detail. In tliat memoir the pressures were not ex- 

 plained ; this is done in the present treatise. I have arrived thus at 

 the result that the distribution of pressure just described finds its ex- 

 planation completely in the currents of the atmosphere, and that from 

 the observed values of the pressure a conclusion can be drawn as to 

 the intensity of the atmospheric currents.* 



II. 



In conformity with the notation of my first memoir the temperature 

 of the atmosphere will be expressed by 



r = To -f Ti 



where To depends only upon r. the distance of the point in question 

 from the center of the earth, while Ti is a function of r and of 6, the 

 polar distance. 



Let the pressure at the given point be 



In this expression ^>o also depends ou\yupou r, while ^is a function of 

 r and 6. So far as the observations of atmospheric pressure show, ^^can 

 be considered as a small numerical quantity in comparison with unity. 

 For determining po the following equation holds good : 



c2 log i>o= constant +GR-lj. + aj J'^dr\ 



from which the diminution of pressure as a function of tlie altitude 

 above the earth's surface can be computed when the law of the diminu- 

 tion of temperature with the altitude, that is to say, the value of To as a 

 function of r is known. 

 Let us further put 



in which 



GRhxT^ 



while J^i, vt^ 1^3 shall indicate the values determined in the previous me- 

 moir (pages 180 and 181). 



The first two terms of this summation vo+f'x gi^'e those changes in 

 pressure which result directly from tiie ditierences of temperature on 

 the earth's surface; that is to say, without considering the rotation of 

 the earth. 



If the temperature diminishes uniformly on both hemispheres from 

 the equator toward the poles; or, in other words, if the temperature 



* [Ferrel had pnblisbed similar conclusions in 1859 but Oberbeck's independent con- 

 firmation is none tlie less valuable. — C. A.'] 



