356 
USPALL AT A PASS 
CHAP. 
The scenery thus far was very uninteresting, compared with 
that of the Portillo pass. Little can be seen beyond the bare 
walls of the one grand, flat-bottomed valley, which the road 
follows up to the highest crest. The valley and the huge rocky 
mountains are extremely barren : during the two previous nights 
the poor mules had absolutely nothing to eat, for excepting a 
few low resinous bushes, scarcely a plant can be seen. In the 
course of this day we crossed some of the worst passes in the 
Cordillera, but their danger has been much exaggerated. I was 
told that if I attempted to pass on foot, my head would turn 
giddy, and that there was no room to dismount ; but I did not 
see a place where any one might not have walked over back¬ 
wards, or got off his mule on either side. One of the bad 
passes, called las Animas (the Souls), I had crossed, and did 
not find out till a day afterwards that it was one of the awful 
dangers. No doubt there are many parts in which, if the 
mule should stumble, the rider would be hurled down a great 
precipice ; but of this there is little chance. I daresay, in the 
spring, the “ laderas,” or roads', which each year are formed anew 
across the piles of fallen detritus, are very bad ; but from what 
I saw, I suspect the real danger is nothing. With cargo-mules 
the case is rather different, for the loads project so far, that the 
animals, occasionally running against each other, or against a 
point of rock, lose their balance, and are thrown down the 
precipices. In crossing the rivers I can well believe that the 
difficulty may be very great: at this season there was little 
trouble, but in the summer they must be very hazardous. I can 
quite imagine, as Sir F. Head describes, the different expressions 
of those who have passed the gulf, and those who are passing. 
I never heard of any man being drowned, but with loaded mules 
it frequently happens. The arriero tells you to show your 
mule the best line, and then allow her to cross as she likes : 
the cargo-mule takes a bad line, and is often lost. 
April 4, th .—From the Rio de las Vacas to the Puente del 
Incas, half a day’s journey. As there was pasture for the mules 
and geology for me, we bivouacked here for the night. When 
one hears of a natural Bridge, one pictures to oneself some deep 
and narrow ravine, across which a bold mass of rock has fallen; 
or a great arch hollowed out like the vault of a cavern. Instead 
of this, the Incas Bridge consists of a crust of stratified shingle, 
