40 
ENGINEERING REPORTS. 
and terminated on the west by a sharp conical peak, elevated 
some ten or twelve hundred feet above the surrounding plains. 
Between this range and the Coatzacoalcos is a smooth,* level 
plain, having an average breadth of two or three miles ; be- 
ing limited on the south by the Malatengo River, and on the 
north by an elevated, broken ridge, or chain of highlands, 
which, terminating at Mai Paso on the east, separate the 
waters of the Malatengo and Sarabia rivers. This plain country 
alternates with woods and prairie ; the latter furnishing abun- 
dance of excellent pasturage. 
The first crossing of the Malatengo will require a bridge of 
175 feet span, with an elevation at grade of thirty or thirty-five 
feet above the bed of the stream ; the foundations will rest on 
coarse gravel. The left bank of the river at this point is bor- 
dered by rich alluvial bottoms, which extend to within half a 
mile of the confluence of the Pachine River, and vary in width 
from one-fourth to three-fourths of a mile : these are covered 
with a dense growth of tangled vines and underbrush, which 
it is impossible to penetrate without the use of a machete / and 
are limited on the east by elevated ground, the summit of which 
forms a continuous ridge, running nearly parallel with the 
Malatengo, and joining the hills of Xochiapa to the south. 
The rock formation to the east of the Malatengo, and opposite 
the confluence of the Pachine River, is a compact limestone of 
a slaty structure, and traversed by numerous veins of calcareous 
spar. This stone would constitute a good building material, 
and also burn to quicklime. It extends a distance of about one 
mile on the line of survey. 
There is a considerable interval of bottom-land on the west 
of the Malatengo, extending as far south as the Pachine River, 
beyond which the ground becomes much more elevated, form- 
ing rocky, precipitous banks on either side of the Malatengo for 
a distance of six miles. The excavations for this distance will 
be wholly in rock. The formation at the surface is sandstone 
of a loose friable texture, which, as we descend, gradually be- 
comes more close and fine-grained, and in the bed of the river 
is found very compact : the lower beds have generally a dark 
purple color, probably due to the presence of a small quantity 
