12 Jolin Eliot — On the occasional Inversion of the Temperature [No. 1, 



This shews that in Upper India the average daily range of tem- 

 perature in January is very nearly twice as great in the plains as at the 

 adjacent hill stations at elevations of 6000 to 7000 feet. The ratio is 

 even greater in the Eastern Himalayas, the daily range of temperature 

 probably varying from 2 J to 3 times as mucb in Assam and 'North 

 Bengal as it is in the adjacent Himalayas at an elevation of 7000 feet. 

 In the bills of Upper India this diminished range of temperature 

 cannot be ascribed to any deficiency of radiating power, either of the 

 sun or of the earth at this period of the year, for the air is much clearer 

 (free from dust, smoke, etc.) and drier in the hills than the plains in Up- 

 per India, and, as shewn in the following tables, solar heat is absorbed more 

 largely by day and terrestrial heat given out more rapidly by night in the 

 hills than in the adjacent plain districts. The only measure for the radi- 

 ating power in either case that we at present possess is the average daily 

 difference between the readings of the solar radiation thermometer 

 and maximum thermometer in the one case and between the readings of 

 the grass radiation thermometer and minimum thermometer in the 

 other. The following two tables give these differences for the pair of 

 stations selected. 



Names of pairs of stations. 





Average difference be- 

 tween readings of solar 

 radiation and maximum 

 thermometer in shade. 

 January. 



Ratio of differ- 

 ence for hill 

 station to that 

 for plain sta- 





Hill 

 stations. 



A. 



Plain 

 station. 



B. 



tion, 



A. 

 B. 



Quetta 



Jacobabad . . . 



Murree 



Rawalpindi ... 



Simla 



Ludliiana 



Chakrata 



Roorkee 



Ranikhet 



Bareilly 



Darjeeling ... 



Dhubri 



Mount Abu . . . 



Deesa 



Pachmarhi . . . 



Hoshangabad 





;} 



■) 



:;) 



] 



62-9° 

 60-4° 

 62-7° 

 67-0° 

 60-7° 

 54-4° 

 62-2° 

 618° 



59-9° 

 50-6° 

 51-5° 

 54-3° 



48 0° 



50- r 



53-4° 



55-8° 



11° 

 1-2° 

 1-2° 

 1-2" 



1-2° 



