1874.] Winds of Northern India. 213 



winds, forming, as it does, an open passage for the monsoons to pass to 

 and from the region north of the Himalaya. The winter monsoon begins 

 in October, when north and north-east winds blow with great steadiness 

 till January, after which westerly winds are felt, chiefly blowing from 

 the south-west, till in June they predominate and continue till Septem- 

 ber, when they in turn give way to the easterly winds. On the whole 

 the characteristic of Assam is the prevalence of easterly winds, which is 

 here as conspicuous as that of the westerly winds over the G-angetic 

 plain and Punjab. 



8. Aralcan Coast. The observations in this region are limited to 

 places on the coast. The northerly winds begin in October, with occa- 

 sional north-west wind, continue till March, or a month later than in the 

 Gaugetic delta, after which they work round to the southward, and at 

 length to south-east by south, which is the normal mean direction of the 

 wind along this coast during the south-west monsoon. This mean 

 direction is varied at all times of the year by the land and sea breezes. 

 The changes of the monsoons occur sensibly later on the southern parts 

 of the coast than on the northern ; also the southerly winds attain less 

 easting, and the northerly winds less westing, in the south than in the 

 north. In August a sudden drawing of the wind towards the west is 

 observable on this coast (and is also discernible in Bengal and the North- 

 west Provinces of India), followed by a return to the eastward, due 

 apparently to the influence of the true south-west monsoon of the 

 Arabian Sea, then at its height. 



Summary. From the foregoing it will be seen that the winds of 

 Northern India are very different from those of the adjacent seas. In- 

 stead of two monsoons from the north-east and south-west alternately 

 prevailing during about equal periods of the year, we find rather three 

 distinct seasons in which spe'cial winds prevail, the directions of which 

 mainly depend on the directions and relative positions of the mountain- 

 ranges and plains. 



During the cold-weather months, November to January, light westerly 

 and northerly winds blow from the plains of Upper India down the 

 valleys of the Ganges and Indus, and across the tableland of Central 

 India, and join into the north-east monsoon of the Peninsula. The 

 easterly winds of the valley of Assam add to this current. 



In April and May, as the hot weather comes on, the winds of Northern 

 India become more westerly and powerful, and take the form of the hot 

 winds, which are not continuous but diurnal, blowing till sun-down and 

 then followed by calms, and prevailing to the eastern limits of the 

 Grangetic delta. At the same time southerly winds are commencing on 

 the coast, and are felt from Sindh across to Bengal, but only at intervals, 

 and feebly except near the sea. 



In June the south-west monsoon, being established in the equatorial 

 ocean, sets in round both coasts of the peninsula, penetrates up the 



