22-2. utr 
AGRICULTURAL CAPACITIES. 
We have attempted to give a sketch of the external features and spontaneous vegetation of | 
the region of country along the United States and Mexican boundary line. It now remains to. 
notice its adaptation to agriculture, and our remarks regarding this may all be embraced in one 
general conclusion. 
Wherever the supply of water is constant, and sufficient fcr the purposes of irrigation, ог 
wherever the regular overflow of the rivers can be relied upon to supply the amount of moisture 
required for the growth of crops, independently of the rains, in those places, and in those only, 
can agriculture be pursued with success. 
The portions of the country best suited to cultivation are those which are capable of irrigation. 
For these the supply of water is obtained, not only from the larger rivers, as the Rio Grande 
and Gila, in which the head of water is increased by the construction of dams, but springs and 
small water courses, these often lving in mountainous situations, are laid under tribute. 
In the course of the preceding sketch we have noticed’ the fact that the lower portions of the 
numerous valleys are of a sterile and unproductive character, for the reason that the water of 
the streams is absorbed before it reaches the portions which lie farther below, where, instead of - 
a running stream, we only find a sandy bed, with the adjoining region unfit for the purposes of 
cultivation. 
Those places which are supplied with the necessary moisture by the overflow of the rivers 
have a still more precarious dependence than those where irrigation is practiced. In these the 
quantity of water cannot be regulated, and they are exposed to the two extremes of scarcity or ; 
superabundance. One of the best examples of this system of cultivation is seen at Presidio 
del Norte, where the Concho unites with the Rio Grande. As these two rivers have different 
periods of high water the inhabitants are enabled to frequently secure two crops from the same 
"INTRODUCTION. т 
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fields in one season. In order to accomplish this the first crop, depending upon the overflow of | 
the Rio Grande, must be sown and harvested in time to admit of the planting of the second 
crop, depending upon the later rise of the Concho. All this depends upon so many contingent 
circumstances that it is oftener attended by disappointment than by success, and, between the ` 
extremes of flood and drought, the people frequently suffer for want of food. 
We have already noticed that a large extent of country, though destitute of streams to supply - 
the water required in cultivation, receives from the atmosphere and clouds, in the form of dew | « 
and rain, sufficient moisture to permit the growth of the richest pasturage, and we have large 
districts of unequalled grazing lands, so broad and so abounding in herbage as to compensate 
for their deficiencies in other respects. Here the buffalo and antelope have already given place | 
to wild cattle and horses, and we look for the time when these shall yield in their turn 49 | 
domesticated flocks and herds, denoting that nomadic barbarism has been — by oe 
civilization, with its ameliorating influences. a ee 
Many large tracts of this country must ever remain as deserts, being alike destitute of Boe 2 
vegetable and mineral resources ; but even these otherwise valueless regions are the very portions 0 2 
which present the fewest impediments to travelling, and, indeed, form natural highways to 0 - 
с 
otherwise inaccessible parts of е country. e 
, Other facts connected zih this part of the бө, as regards character of climate and gerer ы 
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