1884.] Rains of Noftliefn India. 11 



of the country. I do not think, therefore, that, on the average of a 

 long period of years, the November rainfall of Rajpatana would be 

 found to follow a different law of distribution from that of other pro* 

 vinces around. In Centml India, including those portions of the Central 

 Provinces and the N. Wv Provinces that extend between the Jamna and 

 the Satpura range, the total fall is again higher, with a maximum in 

 January and February ; and, still further east, in Mirzapore^ South 

 Behar, and Chutia Nagpur, it is again greater, with the maximum in 

 February ; but this apparent retardation of the maximum is evidently 

 due to the inclasion of the early spring storms which in Chutia Nagpur 

 become of relatively greater importance ; and this is rendered further 

 evident in the table for Lower Bengal. 



The conditions which determine the storm precipitation of the 

 spring months will be noticed elsewhercv Meanwhile, it results from 

 the above analysis that the cold woather rainfall, as hefl^e considered, is 

 that which takes place chiefly on the north and east of the barometric 

 depressions, which are occasionally formed, in the winter months, in 

 North-Western India. It is most copious where normally the winter 

 temperature is lowest, vvz.^ on the N". W. Himalaya. It decreases rapidly 

 to the south, and less rapidly to the south-east, and, in this latter direc- 

 tion, it blends into and becomes with difficulty distinguishable from the 

 rainfall of the spring storms, which are, however, a phenomenon of a 

 different order. 



Having thus defined the area and noticed the general characteristics 

 of the winter rainfall of North- Western India, I will return to the 

 question of the origin of those barometric depressions which have been 

 shewn to be the immediate precursors of the precipitation, or perhaps 

 rather of simultaneous formation. The area above defined as that of 

 the winter rains, is identical with that in which, as has long been 

 known, the relative humidity of the air, instead of diminishing towards 

 the interior of the country, increases with the increasing distance from 

 the sea-coast» On page 203 of the Indian Meteorologist s Vade Mecam 

 (Part II, para. 109), I described this phenomenon as follows : " In the 

 maritime provinces (of India) there are but one (annual) period of 

 maximum and one of minimum humidity ; in the Punjab and in Central 

 India and the North- Western Provinces, there are two annual maxima 

 and two minima ; and in the drier part of the first named province, the 

 winter is the dampest season of the year # # * # . Stations on the coast 

 line have, at all times of the year, a higher degree of relative humidity 

 than those on the plains of the interior. But the rate of increase is 

 very different at different seasons ; and in consequence of the greater 

 cold of Upper and extra-tropical India, in the first three months of the 



