ME. H. F. BLANFOED ON THE WINDS OF NOETHEEN INDIA. 
615 
they what Dr. Muhry supposes, they would probably be felt by night as well as by day ; 
but we have seen that in the hot weather in Upper India the nights are generally calm, 
and the temperature falls lower than in Bengal. 
The effect of the winds in tending to equalize the temperature along their path is very 
distinctly exhibited in the charts for the cold-weather months, more especially that of 
November. The cool current from the North-western Provinces flows most steadily 
down the Gangetic valley, across Western Bengal and the tract intervening between this 
province and Nagpore; and it is here that the isothermals make their great southerly 
bend. Their northerly curvature opposite to the Gulf of Cambay and in Eastern Bengal, 
shown more or less distinctly in all the cold-weather months, I can attribute only to the 
influence of the anti-monsoon currents flowing at lower levels in those regions. The 
evidence on this head afforded by the tabulated observations of the surface-winds is, of 
course, not very distinct, but is not altogether wanting, and, as far as it goes, lends 
support to this view. I have noticed, in Part I. (pages 581 & 585) of this paper, that 
southerly winds blow on the Arakan coast a full month after they have ceased on the 
opposite coast of India, and at Dacca calms are very common in the cold-weather months, 
which is not the case normally at Calcutta*. Moreover the diurnal movement of the 
wind in the four months of the cold weather averages 46 ’6 miles only at Dacca, while 
at Calcutta it is 98 T miles per day. At Ajmere, again, southerly winds are in excess 
both in October and February, and they are very common both in December and 
January ; and here, too, as in the North-western Provinces (but not in the Central Pro- 
vinces), calms are very common throughout the cold weather. 
The isobars afford evidence to a similar effect. In all the cold-weather months there 
is a lower mean pressure over Eastern Bengal, and, as far as evidence goes, apparently 
opposite the Gulf of Cambay (certainly on the Bombay coast), than in the region 
between Nagpore and the Gangetic delta. I conclude, then, that while the anti-monsoon 
currents exist probably over the whole of Northern India, they flow in greater volume 
and at lower levels in Eastern Bengal and opposite the Gulf of Cambay than else- 
where. 
In the hot weather the course of the isothermals is evidently determined chiefly by 
the form of the land ; but in July the cooling influence of the monsoon currents, setting 
in from both coasts, is very distinctly shown in the chart ; and up to September the 
hottest region is that most remote from the coast, as measured along the course of the 
rain-bearing winds. 
With respect to the influence of the winds on rainfall, little is to be added to what 
has already been said. The winter rains are, I conclude, dependent upon the descent 
of the anti-monsoon current, and to the cooling which it undergoes by radiation either 
of the air directly, or of the land-surface with which it comes in contact. In December 
and January the isotherm of 68° or 64° coincides approximately with the limit of the 
* At both of these stations calms have been recorded regularly throughout the period represented in the 
Tables. 
