1HE 1RRIGA 7 10 N A GE. 361 



most years by means of the rainfall alone, or with the assistance of 

 wells, ordinary grain and fodder crops being grown. But whenever 

 the rainfall is deficient much of this land takes canal water in order 

 that crops may be sown or matured. The people have only to send in 

 a written request to the engineer in charge of the canal for water for 

 their land, and arrangements are at once made to supply the water, as 

 much more being taken into the canal at its head from the river as 

 may be required, up to the full carrying capacity of the canal, or* the 

 quantity available in the river if this is less. In such years, the area 

 irrigated by a canal and the revenue received from the water rates 

 assessed thereon, are largely increased above the average; and the 

 canal returns a satisfactory income to the Government besides avert- 

 ing the loss that would be caused by the land being thrown out of cul- 

 tivation for a time. 



The great rivers, from which the canals of North India are sup- 

 plied, have their sources far back among the high snowclad ranges of 

 the Himalaya Mountains. During the generally constant and often 

 heavy rains of the rainy season, from the middle of June to the middle 

 of September, these rivers are in flood. After the cessation of the 

 rains they are at their lowest level and with their least volume of 

 water. The cold weather rains from December to February cause 

 them to rise a little for a time and sometimes produce freshets in them 

 for a day or two; but they fall again very soon when those rains have 

 ceased. At the same time more or less heavy falls of snow take place 

 in the higher mountains. In the beginning of March, when the power 

 of the sun appreciably increases, these snows begin to melt and cause 

 the rivers to rise gradually. As the season advances and the beat 

 increases, the snows melt faster, so that the continual rise of the riv- 

 ers is steadily maintained until the rainy season begins, by which 

 time the snows are largely exhausted. This rise is at the rate of 

 from 1 to 2 or 3 feet a month during March, April and May; and by 

 the time the rains begin the rivers are from 3 to 6 feet higher than 

 their cold weather level. During the rainy season heavy falls of rain 

 in the hills cause floods to come down suddenly, making a river to 

 rise sometimes several feet further in one day. These fluctuations 

 are frequent throughout the rainy season. The greatest floods pro- 

 duce a rise in a river of from 10 to 16 feet above its cold weather level, 

 in its course through the plains, while its width is increased from less 

 than a quarter of a mile to as much as 4 or 5 miles in the case of the 

 largest rivers, and the volume of 'water is increased nearly one hun- 

 dred fold. 



These rivers are peculiarly well adapted for feeding irrigation 

 canals. They are high throughout the hot weather months, when 

 water is most in demand, and give then a practically unlimited supply, 



