43 
a ground so level, that in the rainy season it becomes inundated, 
for which reason this plain has been called the lake of Tarila. 
Sr. Moro took advantage of this circumstance to save the trou¬ 
ble of a new levelling between the latter place and the Por¬ 
tillo, or opening of the road to the Yenta, since the line left by 
the waters on subsiding clearly shows that the two points are 
nearly on a level; thus, with a cut a foot or so deep in the 
edge of the Portillo, the waters to the south of Tarifa would 
proceed towards the Pacific, whilst those on the northern side 
naturally run towards the other sea. 
All that now was wanting was to find the manner of increas¬ 
ing the volume of available waters, and to avoid having re¬ 
course to the expensive means of constructing great reservoirs. 
The waters of the Almoloya, Citune, and other streams on 
the side of the Chivela were calculated, but their distance from 
Tarifa, and the difficulties of the ground they would have to 
cross, would make their conveyance somewhat expensive; and 
therefore Sr. Moro resolved to examine the great river Os tuta. 
At Zanatepec he experienced some difficulty in fording the 
river, which was rather swollen, notwithstanding which its 
waters continued to be perfectly clear as far as that spot. The 
documents deposited in the archives of the village, were ex¬ 
amined, amongst which he found a few fragments of a map 
of the land comprised in its jurisdiction. This interesting 
document, almost entirely destroyed, may be inferred to have 
been executed during the first period of the Conquest; for 
whilst^it is painted on paper, made of Maguey (agave Ameri¬ 
cana), and preserves all the characteristic signs of the Aztec 
works of this kind, there is on it a figure of a Spaniard by whose 
order the map was probably drawn; but that which most par¬ 
ticularly attracted attention w r as to find noted down the tra¬ 
ditional opinion that the river Ostuta takes its source in a lake. 
It was with the greatest difficulty that he found any one 
able to accompany him in the exploration of the river. Amongst 
the inhabitants of the town, there were only two old men who 
remembered having visited a small portion of its course, and 
pictured with the blackest colours the dangers and difficulties 
of the undertaking. It would be tedious to enumerate those 
