PPENDIX G. 



HUMIDITY OF AIR AT DORJILING. 



429 



No. of 

 Obs. 



102 

 97 

 40 

 23 



48 



40 



176 



167 



185 



74 



46 



998 



Comparison of Dorjiling and Calcutta. 



Month. 



HUMIDITY. 



January 



February 



March 



April 



May 



Juue 



July 



August 



September 



October 



Nov. and Dec 



Mean 



Dorjiling. 



Calcutta. 



-•795 



•571 



•828 



•590 



•940 



-•438 



•684 



•523 



•926 



•698 



•895 



•800 



•929 



•800 



+ -955 



+ -818 



•932 



•760 



•950 



•658 



•798 



•640 



0-876 



0-663 



Diff. 



Dorjiling. 



+ -224 



+ -238 

 + -502 

 + -161 

 + -228 

 +■ -095 

 + -129 

 + -136 

 + -172 

 + -292 

 + -158 



+ -212 



WEIGHT OF VAPOUR IN CUBIC 

 FOOT OF AIR. 



Dorjiling. 



+ 



2-68 

 2-75 

 3-42 

 3-98 

 5-22 

 5-39 

 6-06 

 6-25 

 5-72 

 4-74 

 340 



4-51 



Calcutta. 



-4-80 



5-40 



5-72 



7-65 



9-90 



10-17 



1005 



+ 10-35 



9-88 



8-55 



6-27 



Diff. 



Calcutta. 



8-07 



2-12 

 2-65 

 2-30 

 3-67 

 4-62 

 4-78 

 399 

 4-10 

 4-16 

 3-81 

 2-87 



+ 3-55 



It is hence evident, from nearly 1,000 comparative observations, 

 that the atmosphere is relatively more humid at Dorjiling than at 

 Calcutta, throughout the year. As the southerly current, to which 

 alone is due all the moisture of Sikkim, traverses 200 miles of land, 

 and discharges from sixty to eighty inches of rain before arriving at 

 Dorjiling, it follows that the whole atmospheric column is relatively 

 drier over the Himalaya than over Calcutta ; that the absolute 

 amount of vapour, in short, is less than it would otherwise be at the 

 elevation of Dorjiling, though the relative humidity is so great. A 

 glance at the table at the end of this section appears to confirm this ; 

 for it is there shown that, at the base of the Himalaya, at an 

 elevation of only 250 feet higher than Calcutta, the absolute 

 amount of vapour is less, and of relative humidity greater, than at 

 Calcutta. 



