344 MR. S. A. HILL ON THE WINDS OF NORTHERN INDIA, AND THEIR 
country, the most important exceptions being at Agra, Jeypore, and Multan, where 
the winds have a northerly component, whereas a southerly one is indicated by the 
distribution of pressure. At the Himalayan stations on the outermost range, as at 
Darjiling, Naini Tal, and Mussoorie, there is usually an easterly component in the 
resultant wind ; while at others, more in the interior, as at Ranikhet, Chakrata, Murree, 
and Leh, the resultant is westerly. 
In October the pressure differences are very small, and the winds as a rule are light 
and irregular. I he resultant directions, however, conform in most places to Burs 
Ballot’s law; but the anticyclonic circulation of the air over South-eastern Rajputana 
and Central India States is apparently more regular and uniform than might be 
expected from the irregularly-shaped isobar of 29'85". 
Over Bengal also, from the Himalayas to the head of the Bay, the wind blows 
almost exactly at right angles to the isobars, instead of more or less inclined to them- 
From the charts on Plate 19 it will, therefore, be seen that, when the air is moist, 
the sky cloudy, and the diurnal range of temperature small, the usual relation obtains 
between the distribution of pressure and the resultant direction of the wind, These 
conditions obtain over most parts of the country in July, and at many of the coast 
stations in the other months. 
In January there are exceptions to the rule, the most important being in Bengal, 
which, at that season, is a region of moderately high temperature, clear skies, and a 
large daily range of the thermometer. 
This will be evident from the following Table, in which certain meteorological con¬ 
ditions for January and July at several Bengal stations are contrasted :— 
Table IV.—Contrast of Bengal Climates in January and July. 
Station. 
January. 
July. 
Mean 
Temperature. 
Daily 
Range. 
Cloud 
Proportion. 
Mean 
Temperature. 
Daily 
Range. 
Cloud 
Proportion. 
O 
O 
O 
O 
Purneali .... 
61-9 
27'9 
1-2 
84-0 
12-9 
7-1 
Berliarapur. 
64-5 
25-3 
2'2 
83-2 
107 
S'S 
Burdwan .... 
66-0 
24A 
1-7 
83'5 
10-9 
8-1 
Jessore . 
65T 
26T 
1-6 
82-5 
10-7 
8-3 
Dacca. 
66-6 
229 
1-6 
83-7 
9-5 
80 
Calcutta .... 
67-3 
22-4 
1-3 
83T 
9-6 
8-0 
Chittagong.... 
66-6 
21-0 
1-3 
807 
93 
7-4 
The skies in this region are usually almost cloudless in January, and the daily range 
of temperature is between 20 and 30 degrees ; while in July the average cloud pro¬ 
portion is high, and the daily range of the thermometer only about 10 degrees. The 
disturbances of thermal equilibrium by the daily transit of the sun must, therefore, 
presumably be nearly three times as great in January as in July, and if the distribu- 
