216 Mr. H. F. Blanford on the [Feb. 26, 



of Bengal the driest month is January, the period being later as \ve go 

 inland up the Gangetic valley, till it is found in May or June in the 

 Punjab and North-west Provinces. 



In the western part of the Gangetic valley and the Punjab there is a 

 secondary minimum of dryness, which follows a converse rule to that of 

 the principal minimum ; that is, it falls earlier the greater the distance 

 from the sea in the sense before explained. In the Punjab this minimum 

 is as early as September or October, shortly after the cessation of the 

 rains, gradually advancing till November at Benares, east of which it is 

 not appreciable. Intermediate between the two minimum periods is a 

 secondary or winter maximum, evidently related to the winter rains of 

 the Upper Provinces, and, like the corresponding winter maximum and 

 rains of Europe, traceable to the descent of the equatorial (here the anti- 

 monsoon) current, and the low winter temperature. 



The relative humidity of the air remains pretty constant at all eleva- 

 tions on the Himalaya, as already pointed out by Dr. Hooker and other 

 writers, but not including Tibet, the conditions of which are very 

 different. There are, however, considerable exceptions to the general 

 rule ; and the local law of variation depends much on local conditions. 



The rainfall is next discussed. The author points out that there are 

 three principal seasons of rain calling for notice. The summer and early 

 autumn rains (that is, those of the south-west monsoon, or of the rainy 

 season commonly so called) are the most important. In Bengal they 

 begin on an average about the middle of June, with a fall of from 9 to 15 

 inches in that month. In the Upper Provinces they are later, and in 

 B/ajpootana there is little rain till July. Everywhere they have their 

 maximum in July. In the Upper Provinces and E-ajpootana very little 

 rain falls in October, and the rains may be said to end in the last week 

 of September. In Bengal and Central India the fall is still considerable 

 in October ; and the rains there end about the middle of this last-named 

 month. 



The spring rains prevail in the region over which the sea winds blow 

 from the Bay of Bengal early in the year. In Assam and Eastern 

 Bengal showers are frequent in March, and in April the fall is copious, 

 amounting, in those districts to windward of the eastern mountains, to 12 

 or 14 inches in the latter month. In Western Bengal the fall is less, 

 and takes place with occasional thunder-storms, locally known as north- 

 westers, which extend as far inland as Nagpoor and Benares. 



The winter rains are received most regularly and copiously in the Punjab 

 and Upper Provinces, Assam, and Cachar. In Bengal and the lower 

 part of the Gangetic valley they are less regular and lighter. They begin 

 at the end of December, continuing till March in the North-west Pro- 

 vinces, and till April in the Punjab. The fall in these districts amounts 

 to about 4 or 5 inches during the whole season. The author considers 

 that, as they do not coincide either with the period of greatest cold or 



