CONDITIONS INFLUENCING PEE VALENCE 189 



on the average, about 20 feet from the surface, water-logging 

 is not Hkely to occur until a lapse of forty-seven years and 

 probably not even then. 



"(c) There has been on the whole, during the last ten 

 years a general rise of spring level on the other canals of 

 the division but water-logging need not be apprehended 

 even in the remote future." 



The departmental literature on this subject, would alone 

 more than fill the present book, and indisputably establish 

 that everywhere the introduction of canal irrigation has 

 brought about a serious raising of the spring level, but the 

 above quotation shows sufficiently for our purpose the 

 amount and considerable variation in extent of the changes 

 within a given small area. 



The European engineer endeavours as far as possible, 

 to take his canals along the lines of the water-sheds, but 

 the reverse plan was followed as a rule by our native pre- 

 decessors, and when the old canals made by them have 

 been utilised the results on the health of the population 

 have often been so serious as to necessitate heavy expendi- 

 ture in altering their alignment ; as the untoward effects, of 

 canal irrigation in intensifying malarial diseases, has been 

 thoroughly recognised by the Indian Government for many 

 years, and the prevention of water-logging has been the 

 subject of anxious consideration by their canal engineers. 



As regards the direct production of puddles, I suspect 

 that most of the 25 per cent, of waste " in various ways" is 

 spent in their production, as a very large proportion of this 

 item results from leakages due to carelessness on the part of 

 the cultivators. The water is allowed to flow on to the land 

 from the ultimate distribution channels by simply breaching 

 the bank, and is stopped by repairing the opening by means 

 of a few handfuls of mud. Although when carefully done 

 the plan is much more efficient than one would expect, 

 leakages, which necessarily result in the production of 

 puddles are certainly very common, and owing to the 

 water-logged condition of the soil resulting from the high 

 spring level, such puddles are likely to last for a consider- 

 able time. 



