THE RATE OF DECREASE OF TEMPERATURE, ETC. 91 



Alagir and Alexandropol. 

 Difference of altitude =2 740 feet. 



Winter. Summer. 



o o 



Alagir 27*0 66*i 



Alexandropol i8'8 64*3 



8-a 1-8 



The results thus given for stations in the Caucasian and 

 Transcaucasian provinces show in a very marked manner 

 that in this region the diminution of temperature for a 

 given ascent in the atmosphere is greater in the winter 

 than in the summer months. 



We now proceed to three stations in Southern Siberia. 



o / o / 



Irkoutzk 52 17 N. 104 11 E. 1 2 5 3 feet above sea-level. 



Werchne-TJdinsk 51 30 107 44 '97© „ „ 



Nertchinsk 51 18 119 21 2230 ,, „ 



Irkoutzk and TVerchne-Udinsk. 

 Difference of altitude=7i7 feet. 



o o 



Irkoutzk —I '3 61*4 



Werchne-Udinsk — 2*2 65*0 



0-9 -36 



Irkoutzk and Nertchinsk. 

 Difference of altitude =977 feet. 



o o 



Irkoutzk — 1*3 6i'4 



Nertchinsk — 166 6o'8 



15-3 0-6 



With respect to the latter result, it must be remarked 

 that a great portion of the difference belongs undoubtedly 

 to the difference of longitude, and not to the difference of 

 elevation between the two stations. In this part of Asia, 

 the differences between summer and winter temperatures 

 increase rapidly with increase of longitude, and tend to 

 complicate the inquiry into the influence of difference of 

 elevation. 



