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



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

 pindi to 1-4° 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 Vindiiya 

 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 1,000 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. 





13 qn 





u 



^ ill 



O o 





.§£ 



Plain stations 



.§2 



1 s.^ <« 



-2 .ii 



Plain stations near 



S 



at consider- 



a B 



36 be 



ten 



f th 



s for 



-B. 



1 A 



hills. 



'^la" 



able distance 



"^1^ 



1 a '^ 





c! S « 



from hills. 



^11 



P fl .2 . 



C^ c3 <D ^ ^< 



Ifl 





1^^ 





^^4 



a ^ -S P. 



•ri -u 73 

 O o ts 





(A. 





1:b.) 



Q 



a 



Eawalpindi 



37-9° 



Peshawar 



39- 1° 



-1-2° 



100 miles 



Sialkot 



42-9° 



Lahore 



42-4° 



0-5° 



75 „ 



Ludhiana 



43-5° 



8irsa 



42-4° 



1-1° 



100 „ 



Roorkee 



44-2° 



Meerut 

 r Delhi 



44-4° 



— 0-2° 



60 „ 

 90 „ 



Bareilly 



45-9° 



] Agra 







120 „ 







C Lacknow 



45-9° 



0° 



125 „ 



Gorakhpnr 



48-6° 



1 Allahabad 

 ( Benares 



47-5° 

 47-9° 



11° 



07° 



125 „ 

 100 „ 



Dhubri 



53-5° 



Berhampore 



53-2° 



0-3° 



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. 



