a a 
[26] . 68 
the right of on road, or east, at the distance of from three to five miles 58 ep 
and. untain chain o: stone rises; and another chain to 
‘ett, distant | oom 10 to 15 miles. Both chains gradually Ei bait = 
y the eastern, which seems to. run towards the northeast, and to 
“mp2 thence. to s the southwest, at an angle, leaning a large cul de 
or pouch, Pe the sonata, ft an which form the country has probably 
Sa its name,.as Bolson means. pouch, or pocket. ‘The barometrical 
profile will rant it » better Ss a description, this pouch-like slope of the 
country, which extends most kkely as far a ee the north as the » 
Grande. . Passing over a ridge, on our road, I enjoyed me ais distant 
present travelling. All around us was.an immense ¢ aa lain and in 
the distance of from 15 to 20 miles ahead of us the Rie Nasas, which runs 
ae north, into the abovementioned pouch, and forms there the 
large . Suna lagualila, (on maps generally called lake Cayman.) 
Neither the lake nor the northern end of the Bolson. was to be seen from 
the place of my observation; but the outlines of the mea toead oe moun- 
tains, disappearing in the most distant horizon, , seemed to extend towards 
the north to about 80 miles in length, and towards east and west to an 
average breadth of 30 miles. The limits of the Bolson have never been 
clearly defined, either in. geographical or political regard. The northern 
part, Rs it belongs to. the State of Chihuahua; the southern, to that of Du- 
rango; but no certain boundary line seems to exist. As to the physical 
properties of the Bolson, the general impression is, that it represents a low, 
flat, swampy country, and.a mere desert, which is but posiy: Ke The 
two terminating points of our march through the Bolson are Mapimi, 
where we entered it, and el Pozo, or rather a point eae Pozo, and 
Parras, where we. left it.. At Mapimi, the elevation above the sea was 
4,487 feet; in oy valley of the Nasas, at San Sebastian, 3,755; at San 
Lorengo, 3 815; at San Juan, 3,775; eo towards the eastern edge of 
the Bolson, I found el Pozo 3, ,990, and Parras 4,987 feet above the sea. 
We perceive, therefore, that the valley of the Nasas river, which may 
the vein and centre of the Bolson, has a mean elevation of 3,80 
feet; and. though from 500 to 1,000 feet lower than the surrounding coun- 
try, it occupies. nevertheless a considerable absolute elevation above the 
sea. The soilin the Bolson is less sandy and better than in the higher 
country; in the valley of the Nasas, especially, is a black rich soil, and 
_most luxuriant, vegetation, as we shall see hereafter. 
From the ridge, from whence I overlooked the valley, the road descends 
_ slightly aboutfive miles to q hacienda, where formerly sil ores used tobe _ 
smelted. They have a large and deep well here, from which the water is 
drawn by a mule, and in peaceable times sold 12 the fe eal we 
~ of course refreshed ourselves, gratis. Some miles further, two more 
ranchos lie on the road, where, also, wells have beensunk. Although the 
Pea Hh dgoks everywhere “dry, and the nearest. water-course is the distant 
a Water is got everywhere i in this valley by digging to a certain 
opt en Near these ranchos the road forks, and. a Tagre northern or south- 
ern route pen taken from here. The northern To leads by Alamito, 
San Lorenzo, and San Juan, (all settlements on the aes . el Pozo; 
@hile me southern goes to San on the Nasas,) and by Mata- 
de si 1. Th route is considered the 
shortest; we selected it, fiat 4 nare 
d on the nig hand zoad as 
