[ 8? 1 



105. The rainfall of some parts of Assam is higher even 

 than that of Darjiling. The average annual rainfall of Chera- 

 punji is as much as 475 inches. In some years it runs up to 

 600 inches. In Sylhet the averages for the several months can 

 be seen from the following figures: January 0*39" ; Febru- 

 ary 1-59"; March 5-74" ; April 13-73" ; May 2164"; 

 June -32-02"; July 25-48"; August 25*69"; September 

 20-05"; October 8-31" 5 November ri8" -, December 

 0*30"; Annual average 156-12". In Chittagong the annual 

 average rainfall is 104". It should be noted that even rice of 

 the ordinary varieties grows better in the plains with a monthly 

 rainfall of 5" or 6" at the germinating and ripening periods 

 and 10" or 11" at the growing period. The rainfall of 20" 

 or 25" per month is suitable only for hill tracts where the 

 excess water can be easily drained away. Excess is often 

 as injurious as deficiency for most varieties of rice. Some 

 varieties of rice, however, can stand a rainfall of 20" to 30" 

 per month. A monthly rainfall of 2 to 6 inches is the most 

 favourable for ordinary vegetation, the lower figure being 

 more suited for the early and late periods of the growth of 

 Kharif crops, and also for the cold weather crops, as evapora- 

 tion does not go on so rapidly in the cold weather as it does 

 in the hot weather. 



1 06. In selecting site for a farm the average monthly rain- 

 fall registered in the nearest meteorological station should be 

 consulted. If the average rainfall in any locality in April 

 May and June, and September, October and November is less 

 than i" to 2", or very precarious, and that in July and August 

 over 12" and in some years as much as 20" or 30" or more, 

 such a locality should be avoided as naturally unfavourable 

 for general farming unless it is a cool hill tract. Of course, 

 the presence of canals or other special facilities for irrigation 

 alters the question entirely. 



107. The effect of rainfall slowly but surely in changing 

 the physical character of the surface soil, where such soil lies 



