52 ENGINEERING REPORTS. 
the Gulf. From Mina-titlan to a point on the Arroyo de los 
Urgells, about seven miles above its confluence with the ITs- 
panapa, we availed ourselves of canoe navigation. Leaving 
this point, our route thence to the Hacienda of San Jose, a dis- 
tance of 7 miles, lay over a gently undulating country beauti- 
fully diversified with w T oods and prairie. The timber bordering 
the arroyo, and extending some distance easterly, is very fine, 
comprising many valuable woods. 
About a mile westward of the Hacienda we crossed a high, 
rolling prairie, elevated 150 or 200 feet above the level of the 
Tancochapa River. From this point the ground descends very 
gradually to the south and west, but towards the Tancochapa it 
falls rapidly to the level of the river-bottom. On this eleva- 
tion, which commands an extensive view of the country, we 
measured off two base-lines — one of half a mile, and the other 
of a mile in length — from which we determined by tri angulation 
the relative position of all the principal mountain ranges, as 
w r ell as numerous other points. The location of our base-lines 
with reference to the line of survey to the west of the Coatza- 
coalcos, was obtained by measuring the angle subtended by 
a line joining Mts. Tecuanapa and San Martin, the position of 
which was afterwards accurately determined by observations 
made at Cosuliacaque, Jaltipan, and Tesistepec. 
The following are some of the results of observations made 
from this point (designated on the map as Station " A"). The 
nearest highland in a southeasterly direction we -found to be 
distant from 22 to 30 miles, the mountain ranges being limited 
on the left by a line bearing about S. 60° E. from Station " A." 
To the left of this line, and east of the Tancochapa and To- 
nala rivers, the country presents the appearance of a vast level 
plain. We could distinctly trace, meandering through this plain, 
the courses of the Tancochapa and Sanapa rivers, by the peculiar 
foliage of the trees on their banks ; the former from the Hacienda 
of San Jose to its confluence with the Tonala, and the latter from 
the town of San Francisco to the same point. The country bor- 
dering the Sanapa River on the south is gently undulating, and 
well adapted for cultivation ; on the north it is more level, but 
extremely rich and fertile, and generally above overflow. There 
