8 John Eliot — On the occasional Inversion of the Temperature [No. 1, 



or 35 miles from Darjeeling. The first line of snows is at a 

 distance of at least 45 or 50 miles from Simla and Murree and at 

 a distance of about 40 miles from Chakrata. The neighbouring 

 areas of perpetual snow are of greater elevation and of con- 

 siderably less extent in the case of all these stations than of 

 Darjeeling and hence exercise a much smaller influence. 

 As the meteorological conditions of Darjeeling are thus essentially 

 different from those of the hill stations of Upper India, it will be ex- 

 cluded from the final discussion, although data for it are given in the 

 tables for the preliminary comparisons. 



The following table gives the average minimum temperature data 

 for the same pair of stations for the month of January. 









1 



Mean minimum tem- 



Difference of mini- 

 mum tempera- 

 ture of plain and 

 hill stations. 



2 fts^o 



Names of pairs 



of 



g.2 

 p 



1 



M 



P 



perature for January. 



rate o 

 of tem 

 tthec 

 iod of 

 erlOO 



stations. 



Hill 



station. 



Plain 



station. 



Average 

 crease 

 ature a 

 est per 

 night p 



Quetta 

 Jacobabad 



...) 



5300 



163 



29-2° 



42-8° 



13-6° 



2-6<> 



Murree 

 Rawalpindi 



:::! 



4700 



30 



35-5° 



37-9° 



2-4*' 



0-5° 



Simla 

 Ludhiana 





6200 



80 



36-4° 



43-5° 



7-1° 



ir 



Chakrata 

 Eoorkee 





6200 



58 



35-7° 



44-2° 



8-5° 



r4« 



Ranikhet 

 Bareilly 



;:;} 



5500 



90 



39-5° 



45-9° 



6-4° 



1-2° 



Dhubri 

 Darjeeling 





7300 



116 



34-6° 



53 5° 



18-9° 



2-6° 



Deesa 

 Mount Abu 



::•} 



3500 



40 



509° 



BM° 



0'2° 







Pachmarhi 

 Hoshangabad 





2500 



48 



47-2° 



52-5° 



5-3° 



21" 



This table shews that at all these stations the average difference 

 of temperature at night is much smaller than by day. The rate of 

 difference is greatest in the cases of Quetta and Jacobabad, Pach- 

 marhi, and Hoshangabad, and Darjeeling and Dhubri, for which it 

 averao-es about 2° or less than half of the rate of difference for the 

 maximum temperature. The result for Deesa and Mount Abu is so 

 anomalous as to point to peculiar local conditions, the nature of which 

 have, however, not yet been determined.* In the case of the pairs of 

 stations in Upper India the average rate of change of temperature with 



* I have recently (January 1890) visited these two stations : the temperature 

 observations are carefully recorded, and are taken under the same conditions of ex- 



