

1884.] Himalaya Snowfall with Drought in India. 17 



The barometric features of the season may then be summed up as 

 follows : With local and more or less temporary exceptions the 

 pressure of the atmosphere over India was below the average 

 throughout the first eight months of the year, the greatest de- 

 pression being in May, when it was universal in India. But this was 

 only the general average of a series of oscillations of pressure (some- 

 what greater than usual at most stations in May, June, and July), 

 which succeeded each other throughout the period. These oscilla- 

 tions were closely connected with great variations of temperature, 

 and were to some extent an effect of the latter, each fall of rain 

 (or snow on the hills) being accompanied with a rise of pressure and 

 a temporary excess which speedily diminished, and was followed by 

 a fall below the average, with the return of dry, fine weather. 



Meteorology of the Land Winds. 



Tlie Westerly Winds of the Winter and Spring. The land winds 

 from west and north-west are the characteristic winds of the winter, 

 spring, and early summer throughout the greater portion of Northern 

 India, and of Western India from February to May. In the Punjab 

 indeed, the atmosphere is most frequently calm, or agitated only by 

 light movements of very variable direction,* and especially so in the 

 winter months. But down the Gangetic plain (save in the neigh- 

 bourhood of the hills), and on the plateau of Rajputana and Central 

 India, light and steady winds from between north-west and west are 

 those most characteristic of the whole of the dry season. During the 

 winter months these winds are cooler, from March onwards warmer, 

 than those from the opposite quarters ; and in April and May they 

 constitute the well-known hot winds of Northern India. At both 

 seasons they are dry winds, and the striking change in their tempe- 

 rature is due, as was long ago pointed out by Sir Joseph Hooker, to 

 that of the land surface swept by them. Pari passu with the rise of 

 temperature they undergo certain partial changes of direction, and 

 also in the region of their prevalence. From November to February, 

 when, as a rule, an axis of maximum pressure runs from the Punjab 

 and Sind across Rajputana, Central India, and the Central Provinces 

 towards Orissa, with lower pressures over the Gangetic valley and 

 Bengal on the one hand, and over the peninsula, and especially on 

 its south-west coast, on the other, the current of which they form 

 part tends to circulate anticyclonically around the ridge of high 

 pressure above defined, and thus the directions are northerly on the 

 eastern portion of the Central India plateau and easterly to the 

 south of the Satpura chain in Nagpur, the Deccan and Hyderabad. 

 But when in March a barometric minimum is established over the 



* See " Winds of Northern India," " Phil. Trans." for 1874, vol. 164, p. 563. 

 VOL. XXXVII. C 



