"HYDRQGRAPHIC REPORTS. 
89 
channel as laid down upon the accompanying chart will seldom 
be found at aD y season of the year. 
The Jaltepec Kiver affords the same depth (two feet) as far 
up as you directed the survey to be carried, and though nar- 
row, and in some parts very crooked, containing several rapids, 
too, at extreme low water, I have no doubt it could be rendered 
serviceable for light-draught steamers to within three-quarters 
of a mile of the limits of our survey, by simply clearing it of 
snags. Should it be decided, however, to connect the railroad 
with shoal-water navigation by means of this river, it might be- 
come advisable, by reason of its inferior width., to construct 
steamers of a smaller size than could be used if the connection 
were at or near its junction with the Coatzacoalcos or at 
Suchil. 
The strength of the current varies in the upper portion of the 
river from two to three miles per hour, and decreases gradually 
in its average towards the mouth, till at length it becomes lost in 
the tides. During the rainy season of course it increases at the 
same place with the increase of the volume of water. 
The traces of overflow indicate an extreme rise of twenty-two 
feet at the mouth of the J altepec, and fourteen at La Plorqueta. 
The influence of the tides is perceptible as far as the junction 
of the Brazos Apotzongo and Mistan, and becomes lost in mak- 
ing the circuit of the Island of Tacamichapa. Northers, too, 
affect the height of the river very sensibly as far as tide- water 
extends ; but above that, any increase in depth of water is at- 
tributable entirely to the state of the weather in the moun- 
tains. 
If the final decision of the company be that the railroad shall 
connect with sea navigation, there will exist no physical objec- 
tion to a temporary arrangement by which they will be enabled 
to throw the whole force at their command upon that portion of 
the work embraced between the head of shoal-water navigation 
and the Pacific, thus making the entire connection by steam in 
a much shorter time than could otherwise be done. After 
which the road can be extended more at leisure, if, in the 
mean time, it be not demonstrated that such an arrangement 
will satisfy all the permanent demands upon the route. For this 
