PREFACE. 
In presenting this account of the Isthmvis of Tehuantepec to 
the Public, the Editors deem it necessary to premise that it 
has been principally compiled from two reports published in 
London, in the year 1844, by Sr. Gaetano Moro, the Engi- 
neer, under whose superintendence the Survey was executed ; 
and it has been their endeavom", in all statements of facts, to 
give them as near as possible, in the words of Sr. Moro, as 
found in his publications. 
They have, however, thought it advisable to re-arrangc *.he 
materials in their present order, diifering in this respect from 
the work of Sr. Moro. They have omitted such parts as 
purely described the scientific methods adopted by the engi- 
neers, but the results are carefully preserved in the Appendix, 
in a tabular form, as given by themselves. 
The Comparison of the various proposed lines of Commu- 
nication across the American Isthmus has been stated, with 
some additions, not given by Sr. Moro, but which are ren- 
dered necessary in consequence of a Report by M. Garella, 
on the Isthmus of Panama, having appeared in the Journal 
des Debats iu Paris, on the 15th January, 1846, while this 
work was still in the press. 
The chapter of Estimates of Returns did not appear in Sr. 
Morp's first work. The materials he collected in his addi- 
tional Report have, however, been made use of by the present 
Editors, with some modifications. 
