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



valleys of the Indus, the Nerbudda, and Taptee, carrying a west or 

 south-west current over Central India, and from the Bay of Bengal 

 pouring up the funnel-shaped opening occupied by the Gangetic delta, 

 whence turning westward it passes up the Gangetic valley towards the 

 Punjab, which seems to be the limit of the south-easterly winds, in 

 Afghanistan the dominant winds being westerly even during the summer 

 months. This is the period of the rainy season of Northern India. 



In October, as the south-west monsoon ceases, the southerly current is 

 recurved towards the heated region along the Coromandel coast (on 

 which the rainfall is till this season of the year comparatively small), and, 

 blowing as a south-east wind, causes the autumn rains on that coast, 

 which some writers have erroneously attributed to the north-east mon- 

 soon. "With the gradual cessation of the southerly winds the westerly 

 winds of Northern India again begin, and the cycle of the year is thus 

 completed. 



PABT II. Relation of Winds to other Elements of Climate. 



1. Temperature. The seasons of Northern India present three distinct 

 phases : the cold season, from the end of the rains in September to February 

 or March ; the hot season, characterized by a dry atmosphere and great 

 diurnal range of temperature ; and the rainy season, in which the tem- 

 perature is moderately high and equable, and the air very humid. At 

 the close of the rains (the end of September) the temperature of Northern 

 India from the Punjab to the sea is nearly uniform at about 81 or 82. 

 But evaporation and radiation to a cloudless sky soon reduce the tem- 

 perature of the interior below that of the maritime regions ; and in 

 January the Punjab is about 11 colder than Bengal, the plains of the 

 North-west Provinces being about midway in temperature between the 

 two. In March the advance of temperature in Central India has brought 

 out two thermal foci one on the west in Rajpootana, and the other on 

 the east in the hilly tracts of "Western Bengal. In April the Central- 

 Indian thermal focus is well developed. The mean temperature of 

 Nagpore is 7 above that of Bombay, 13 above the northern Punjab, 

 and 6 above the coast of the Gangetic delta. The hottest region has a 

 mean temperature between 85 and 90, the Upper-Punjab and Upper- 

 Assam being from 75 to 77. In May the thermal focus has gone 

 further to the north-west, and lies in the northern part of the Eajpootana 

 plateau. In June it has reached the Punjab, the temperature of which 

 continues to increase, rising to 95 and more ; while that of the south of 

 India begins to fall, consequent on the rains, which commence about the 

 middle of the month. In July the Punjab ranges above 90, while the 

 greater part of Central India is below 85. After July the temperature 

 again falls, so that by the end of September it is nearly equalized all over 

 Northern India. 



To sum up briefly. In the cold weather there are two foci of mini- 



