198 
EL PASO 
Yet, with these prospects before us, I had every reason 
to believe, if the officers we were waiting for should 
soon present themselves, that by letting the surveying 
parties at once take the field in various sections of the 
work, we should be able to complete the survey of the 
line which constitutes the southern boundary of New 
Mexico, as well as of the Eiver Gila to its junction 
with the Colorado, and return to El Paso before win- 
ter set in. 
Our first stop was for an hour or two, at the astro- 
nomical observatory at Frontera; soon after leaving 
which, one of my mules was attacked with colic, 
probably from eating green grass. This delayed us 
for some time. Various inward remedies were resorted 
to, without apparent effect, when the poor creature 
was rolled and pounded by the merciless teamsters, 
until I thought there was no life in him ; nevertheless, 
this rude treatment seemed to answer : for at length 
we were enabled to drive him along. We continued 
our journey, and encamped in the Alamos, or cotton 
woods, twenty-eight miles from El Paso. After leaving 
that town, the road winds over a wild, rugged, and 
hilly country, for nearly eight miles. These hills are 
the spurs of the mountain ranges, through which the 
Eio Grande forces its passage. They consist chiefly of 
limestone, which often appears above the surface, or 
projects from the hill sides. Many organic remains 
are here found. There is no bottom land for the entire 
distance ; nor is there sufficient space by the river’s 
bank even for a road or mule path : consequently the 
way is very difficult and tortuous until the hills are 
passed. The bottom land does not appear for some 
