ME. H. F. BLANFOED ON THE WINDS OF NOETHEEN INDIA. 
599 
Chuckrata, in the North-west Himalaya, the humidity of the air is from 10 to 12 per 
cent, (of saturation) lower than atRoorkee in the months of the cold weather (November 
to February), and from 3 to 16 per cent, higher from March to September. The 
general form of the curve of annual variation is the same at both stations (see fig. 3, 
p. 591), but both the winter and summer maxima occur a month later at the hill-station, 
and the spring minimum a month earlier. Next, comparing Darjeeling with Goalpara, 
it appears that it is only in the last three months of the year that the humidity of the 
hill-station ranges below that of Goalpara, and then only to the extent of from 4 to 1 
per cent, of saturation. In May they are equal, and in all the other months Darjeeling 
is the higher. This is especially the case in February, when there is a difference of 
16 per cent, of saturation between the two stations. Darjeeling exhibits in a very 
marked degree the subordinate winter maximum already described in the Upper Pro- 
vinces, but it falls later, the secondary minimum being in December and the maximum 
in February. The cause is doubtless the same in both cases, Darjeeling, as we have 
seen, being brought by its elevation within the influence of the anti-monsoon current. 
At Shillong, however, no such phenomenon is to be observed, and the cause is again 
obvious. The north-east current from Assam, flowing down the valley and across the 
Khasia plateau, must drive the compensating equatorial current into a higher region of 
the atmosphere, and the registers of the station show that in the cold-weather months 
the preponderating winds at this station are from the north. 
The Shillong registers show further that, as compared with Goalpara, the humidity of 
the station is low. Except in February and December and from July to October, when 
it is equal to that of Goalpara (in the last month somewhat higher), the mean humidity 
of the hill-station is from 1 to 5 per cent, less than that of the Assam valley. A similar 
relation is shown, but far more decidedly, by Hazareebagh, which from October to May 
has a drier atmosphere, not only than Calcutta and Cuttack, but even than Patna, 120 
miles further inland : from October to April its humidity ranges below that of Jubbul- 
pore, although it is less than 700 feet higher. I should not indeed venture to infer 
from this fact that in a vertical column of the atmosphere over the plains the relative 
humidity of the atmosphere would be found in the cold and early hot-weather months 
lower than near the land-surface, to any thing like the extent shown by the Hazareebagh 
registers. The situation of this station on the highest part of a dry plateau, freely 
absorbing and emitting the solar heat, while it affords little evaporation, presents condi- 
tions very different from those of the free atmosphere ; and probably by raising the tempe- 
rature raises the tension of saturation, while it raises that of the vapour actually in the 
air only in about the same ratio as that of dry air. But I have already noticed this 
subject in a previous part of this paper. 
In a paper published in 1870 in the 39th volume of the Journal of the Asiatic Society 
of Bengal, I gave Tables of the average monthly rainfall at 47 stations in Bengal, Behar, 
Orissa, Assam, and on the Arakan coast. In Table VI. (at end) these have been corrected 
and supplemented by the registers of subsequent years and data drawn from other 
sources ; and I have added similar Tables for 41 stations in the Central Provinces, the 
