308 IRRIGATION CANALS. Book II. 
stantly into the river, and, instead of fertilizing the adjacent 
valley, only spread devastation over it. As soon as the 
time of high-water is past, the river falls much below the 
level of the valley, and the banks appear like perpendicular 
declivities of sand or clay. In this point, as well as in the 
muddy colour of its waters, the Rio Grande resembles the 
Missouri, Arkansas, Ohio, Lower Mississippi, California!! 
Colorado, and many other rivers of North America. On 
the Rio Grande, likewise, the banks — undermined by the 
stream — fall in from time to time ; the poplars and willows 
bordering them fall into the river : whilst on the opposite 
side new banks are formed, and covered with young wood. 
Here and there the stream forces for itself a new channel, 
and the old one remains a stagnant water among the poplar 
groves of the valley. Owing to the steep banks, the river 
is often inaccessible for many miles ; so that a caravan may 
suffer from want of water for its animals, in the immediate 
vicinity of the river. If the beasts suffer greatly from 
thirst, there is a danger of their discovering some access to 
the water, getting down into the river, and being unable to 
get out again. If possible, therefore, the caravan encamps 
near some irrigation canal, as we did at Joyita. 
Much as the valley of the Rio Grande has suffered from 
the continual irruptions of the wild Indians, especially the 
Apaches, it is not uncommon to see two or three irrigation 
canals, each capable of driving a mill, running through the 
valley for miles, at different levels, in order to convey the 
water to fields further distant from the river and lying 
higher. This system of agriculture is foreign to the inhabi- 
tants of the United States, and opposed to their spirit of 
personal independence ; as a system of irrigation on a 
larger scale presupposes express legislative interference, 
and a restriction of the free disposal of his land by each 
