12 John 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\ to 3 times as much in Assam and North 

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

 In the hills 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. 







Average difference be- 

 tween readings oi solar 









radiation and maximum 



Ratio of differ- 







thermometer in shade. 



ence for hill 







January. 



station to that 



Names of pairs of stations. 







for plain sta- 









tion. 







Hill 



Plain 









stations. 



station. 



A. 







A. 



B. 



B. 



Quetta 



Jacobabad ... ... 



::] 



629° 



599° 



11° 



Murree 



.J 



60-4° 



50-6° 



1-2° 



Rawalpindi ... 









Simla ... 

 Ludhiana 



::) 



62-7° 



51-5° 



1-2° 



Chakrata 

 Roorkee 



::} 



67-0° 



543° 



1-2° 



Ranikliet 

 Bareilly 



::] 



60-7° 



480° 



1-3° 



Darjeeling ... 

 Dhubri 



::) 



54'4° 



50-1° 



1-1° 



Mount Abu ... 

 Deesa 



::} 



62-2° 



53-4° 



1-2° 



Pachniarhi ... ... 



Hoshangabad 



::) 



61 '8° 



55-8° 



11° 



