1890.] Relations between the Sills and Plains of Northern India, 9 



elevation at night in January varies from 0'5° for Murree and Rawal- 

 pindi to l - 4° for Chakrata and Roorkee, and averages 1°, that is, little more 

 than one third of the day rate of decrease of temperature vertically. 



These two tables may hence be summarized as follows : — 



(a). The rate of decrease of temperature with elevation at the 

 time of maximum day temperature in the month of January averages 

 3° per 1,000 feet in the Western Himalayas and 4° per 1,000 feet in the 

 Eastern Himalayas up to 7,000 feet and in the Aravalli and Vindliya 

 Hills and perhaps also in Beluchistan. 



(b). The rate of decrease of temperature with elevation at night 

 or at the time of minimum temperature averages 1° per 1,000 feet in the 

 Western Himalayas, 2° per ],000 feet in the Eastern Himalayas and 

 Vindhyas, and 2|° per 1,000 feet in Beluchistan. 



An interesting point in connection with the night temperature in 

 the plains of Upper India is shewn by the data of the following table. 

 The first column gives the average minimum temperature of the month 

 of January at stations nearest to the hills and the second that of stations 

 at a greater distance than those of the first column. 





S § 





B S 



ze between 



tempera- 



f the two 



s for each 



-B. 



o "o 





s © 



Plain stations 





GO "JS 



Plain stations near 



.5 



at consider- 



'3 5 



ts a 



hills. 



"S| £ 



able distance 



S £ £» 



=5 d »; 





8 £3 



£ a a 

 a & B 



from hills. 



d 5? & 



§ S g 



« ° a <j 



CD d O ^ 

 J< c« <B '43 U 



zonf 

 wee 

 tion 





O) ra 





cd cd m 



,<B CD '■* c3 "2 



•j-* ■ 4 - 3 c3 





S~^ 





feS •+= Hs 

 3 



a a^la 







(A. 





(B.) 



p 



M 



Eawalpindi 



379° 



Peshawar 



39 r 



— 1-2° 



100 miles 



Sialkot 



42 9° 



Lahore 



42-4° 



05° 



75 , 





Ludhiana 



43-5° 



Sirsa 



42-4° 



1-1° 



100 , 





Roorkee 



442° 



Meerut 

 C Delhi 



44-4° 



— 0-2° 



60 , 

 90 , 





Bare illy 



45-9° 



< Agra 







120 , 









(. Lucknow 



45-9° 



0° 



125 , 









I Allahabad 



47-5° 



1-1° 



125 , 





Gorakhpur 



48'6 



1 Benares 



47-9° 



07° 



100 , 





Dhubri 



535° 



Berhampore 



532° 



03° 



150 , 





The geographical relations between Rawalpindi and Peshawar are 

 quite different from those of the other pairs of stations, which are all 

 situated in the great plain of Northern India stretching along the foot 

 of the Himalayas from the North Punjab to East Bengal. 



posure as at other stations in India. Several series of hourly observations of tem- 

 perature during the night have been recently taken, and, as they confirm the con- 

 clusions of the present paper, I hope to discuss them in a brief paper to be 

 submitted to the Society shortly. 

 2 



