TOWN THE URIQUE BARRANCA. 271 
canon-like sides of the former, with their 
bristling, perpendicular fronts of thou¬ 
sands of feet in height, were now rounded 
off along the ridges with their vertical 
descents, and _ only their sides were 
straight up and down. In fact it was 
down these steep ridges that we must 
make our descent by zigzag trails that 
gave us a grade on which a mule could 
stand. Every time we came to the side 
of a ridge the trail hung over a precipice 
with a sickening dizziness to the rider 
until the mule could make the turn and 
get back on the descending trail. Occa¬ 
sionally it was necessary to leave one 
ridge for another far away that gave a 
better grade, and then we might have to 
skirt some cumbra, or crest, with walls 
practically vertical on either side, where, 
if we ever started to fall, we could guar- 
