PREFACE. ix 
specimens, may be authorized to present them to the 
scientific world in such a style and form as their value 
and interest merit. 
From the peculiar geological features of the coun- 
try passed over, a valuable report on that subject 
might be expected; but I regret that, as Congress 
denied me an appropriation for the purpose, I was 
unable to secure the services of any geologist compe- 
tent to make such investigations as were desirable. 
Several gentlemen who filled responsible places, par- 
ticularly Dr. Webb, Secretary of the Joint Commission, 
contributed their services in collecting such minera- 
logical specimens as circumstances would allow. It 
was highly desirable to institute a continuous series 
of geological and mineralogical researches, and to form 
a cabinet illustrative of the structure and mineral 
resources of the region along the whole course of the 
survey; but both the scientific corps, and the number of 
soldiers at my disposal for the purpose of escort, were 
too small to admit of this being done. Nothwithstand- 
ing, however, every drawback, a large collection of 
minerals was made by Dr. Webb, including silver ores 
from New Mexico and Chihuahua, and other ores from 
various places along the line, which have reached home 
‘in safety. Among these mineralogical treasures is a 
fine specimen of bituminous coal. In connection with 
this subject I may add, that we visited and explored 
many of the mines in New Mexico, Sonora, Chihuahua, 
