193 
in the midst of frost and snow, and is seldom known to sleep, 
or neglect his charge. In this instance, a dense mist had 
filled the valley, and no blame could attach to the watchman; 
but from the abuse that was lavished upon him, one would 
have thought that he had been taken in the act of stealing 
all our mules, instead of merely not having seen one or two 
_ of them through the mist on a dark night. 
Mr. M continued very ill, and although I felt tolerably 
well when I rose, we had not travelled half a league when 
the headache returned with increased violence, and it was 
greatly aggravated by the motion of the mule. Some of our 
companions, too, were similarly affected in the course of this 
day's ride. 
The valley, and even the slopes of the hills, were so 
swampy, that we travelled very slowly for about a league and 
a half, when we left the valley, and crossed over some high 
land that brought us to the small river of Palcamayo, three 
leagues from Casa-cancha. Red sandstone, breccia, and 
conglomerate prevail as far as Palcamayo, where I observed 
whitish stratified limestone, and Cale-tuff, with blocks of 
Lydian-stone, that appeared to have fallen from the hills 
above; afterwards, the sandstone and conglomerate, containing 
large quartzose pebbles, were the only rocks that occurred 
near the road. From Palcamayo, we passed over a succession 
of low hills, covered with short grass; the intervening 
hollows were very swampy, and we were frequently obliged 
to make a long circuit to avoid them. In such places, there 
Was sometimes a considerable depth of peat, an occasional 
Tupture exposing a thickness of several feet of the decayed 
roots of the grass, which, mixed with mosses and Lycopodiacee, 
Continues to grow on the surface of the spongy mass. The 
Whole of the district through which we were travelling, 
including the plain of Bourbon, whither we were bound, 
and the country for many leagues to the north and south, 
. May be considered as forming an immense basin between two 
distant Cordilleras; and from the quantity of rain and snow 
that falls in winter, and the thawing of the latter on the 
summits of the hills and sides of the mountains during 
VOL. II. o 
