54 
Indian Agriculture in Us Physical Aspects, 
simply breaking down tlie dividing partition. Thus, by letting 
the water flow slowly, first into one compartment which is 
blocked off from the others, then breaking the partition and 
allowing the water to run into the next, the whole crop is 
gradually watered in turn, the cultivators meantime keeping up 
a regular flow along the main channel, be it from well, canal 
branch, or other source. This work, more especially in the case 
of irrigation from wells, is most admirably done, and the 
" garden land," as in the latter case it is called, presents some 
of the most splendid features of careful and high-class culti- 
vation that one can possibly see in any part of the world. 
It must not be supposed, however, that irrigation from wells 
is possible everywhere, for it is often the case that the water- 
level is too low to repay the labour of well construction, or, 
again, hard rock may intervene, or the water be brackish. This 
depends entirely upon the geological character of the district in 
question. It is quite possible, as e.g. in the case of the North- 
West Provinces, to find a successive series of zones running 
across the country, each one differing in respect of adaptability 
to this or that means of water-supply. First, there may be the 
zone where rainfall is abundant and neither canal nor well be 
needed ; then one where the water-level is high and irrigation 
from wells may be a useful supplement ; next a region where no 
canal comes and cultivation with wells is the only kind to depend 
upon ; after that another where both canals and wells are present, 
and where both are needed, one to supplement the other ; lastly, 
there may be a district whei'e the water-level is so low that the 
digging of wells is impracticable, and dependence must be 
placed entirely upon a canal supjoly. It is to the extension of 
canals in districts such as the last named that the attention of 
Government and of the Irrigation Department in particular is 
rightly directed, inasmuch as the cultivation alters, and differeVit 
crops are often grown according as canal or well irrigation is 
used. 
This explanation shows the great variations that may be 
observed in the agi-iculture even within a moderate range, and 
that no one description can be made general h\ its application. 
In the alluvial Indo-Gangctic plain, as we pass from west to 
east we cross three tracts with quite distinct general features as 
regards iiTigation : first, the Punjab, the country jmr excellence 
of canals ; then the North-West Provinces and Oudh, where, as 
shown above, both wells and canals have their place ; then 
Bengal, where for the most part both are unnecessary, and 
storage of rainfall takes place in surface reservoirs which dry up 
each year. On the black cotton-soil of Central India irrigation 
