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mountains on the face turned towards the sea, the rainfall is 

 generally heavy, as condensation of vapour takes place most 

 readily on these mountains. A table-land surrounded by 

 mountains receives very little rain, since the winds which 

 reach it have already parted with their moisture in ascending 

 the hill-sides. Differences of temperature in different regions 

 of the globe stimulate currents of air, and when into a very 

 hot and dry region a current of air flows from the sea or from 

 cold and moist hill-tracts, cyclonic disturbances accompanied 

 by rain follow. In February and March, when the sun is still 

 southerly in direction, there remains a tendency for north 

 winds to blow, though south winds are the rule, at this time. 

 The south winds charged with vapour from the Bay get cooled 

 down when they move up the sides of the Himalayas, and if 

 at this time, a southern direction is given to this wind at the 

 higher regions, they recede in their course, and the particles 

 of condensed or congealed vapour come down in the form 

 of rain or hail. If later on in their downward and south- 

 ward march these receding winds come in contact with a 

 strong well established current of wind from south to north 

 west, a gale, or a cyclone, is the result. Thus in February 

 and March we may have hail due to certain local currents 

 and in April generally rain accompanied by north-westers, 

 also due to local currents. But it is the continuous heat of 

 April, May and June which tends to rarify the air and make 

 the atmospheric pressure light, that establishes zones of 

 low pressure, which take more or less a definite shape, and 

 continuous currents of air laden with moisture thereafter 

 flow into these zones, in definite directions. Thus in Bombay 

 the monsoon current is from the South-west, i. e. the Arabian 

 sea, while we have it from South-east, i. e. the South-west 

 current from the Bay is deflected by the Chittagong and 

 Assam hills which accounts for the easterly direction of the 

 wind in Bengal during the monsoon. The establishment of 

 these non-local currents of air, immediately precedes the 



