92 
FREDERICKSBURG 
between rocky walls, so close together as to render 
it impassable for two wagons abreast. These walls 
were covered with immense cacti wherever the almost 
perpendicular surface would afford them a foothold. 
As we entered the pass, we found among the debris 
of the limestone rock numerous fossil shells. It became 
necessary here to lock the wagon wheels and advance 
with great care. We had not proceeded far, when, 
at an abrupt turn, one of the wagon tongues snapped 
off. Two hours were lost in repairing this injury, 
which was effected by lashing two tent-poles to the 
broken tongue. I took advantage of the delay, and 
strolled about on the summit of the mountain. Por- 
tions of this pass are so narrow, that a few Indians 
well armed could keep off a large body of men. In 
exploring some of the recesses of this wild and roman- 
tic spot I noticed many caverns, which, from the quan- 
tity of bones within, were evidently the habitations or 
resort of wild beasts. 
On emerging from these mountains, on the western 
side, several moving objects were discovered. They 
were at first supposed to be Indians ; but on applying 
my telescope, they were discovered to be cattle. 
Several of the men set off in pursuit, and, soon com- 
ing up with them, drove them to our train. They 
proved to be quite fat, and had evidently strayed from 
some herd or train which had preceded us. 
The road here was so excessively sandy, that our 
nearly exhausted animals could scarcely draw the 
wagons through it. The sun beat down with fiery 
force upon us, and we had not a drop of water to 
relieve our thirst, or that of the poor beasts, who 
