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bare or is overgrown only by short grass, must not be ignored. 

 The finer particles of clay getting washed out, the soil has a 

 tendency to get lighter, which is an advantage only for soils 

 which are too stiff. High winds, however, bring back some 

 amount of fine dust and tend to keep up a balance. High winds 

 which prevail on the sea-side districts are therefore not to be 

 regarded as absolutely inimical to agricultural pursuits. In 

 course of time they help to make sandy tracts loamy and fit 

 for cultivation. On the whole, however, boisterous winds are 

 not helpful to the proper growth of crops unless they are 

 very short crops. An occasional gale may lay low and spoil 

 a crop nearly ready for the sickle and where high winds are 

 the rule, very few crops can be grown and the landscape is 

 generally found quite bare of trees in such localities, 

 and how helpful trees are to agriculture in various ways, we 

 will see later on. 



108. What proportion of rain evaporates, what proportion 

 sinks into the soil and feeds wells and springs, and what 

 proportion finds its way by means of drains, streams and 

 rivers, into the sea, depend upon the climate of the place, the 

 season of the year, the porosity of the soil, the nature of 

 the strata below, and the contour of the surface of the whole 

 district or locality. 



109. Hail. The cause of hailstorms is not definitely 

 known. They occur in Lower Bengal at the change of season 

 from winter to summer, when southern breeze brings winds 

 laden with moisture from the sea, and occasionally northern 

 wind brings the clouds back towards the south from the 

 Himalayas. These clouds are formed high up in the air (z>., 

 Cirrus clouds) and not low down as in the case of Nimbus 

 of the rainy season, and the colder regions of the atmos- 

 phere sometimes congeal the rain drops before they come 

 down in the form of hail. Hailstones are larger or smaller 

 in size as they come down from a greater or smaller height. 

 The destruction caused by hailstones, though local, is often 



