103 



tus, agaves, and a few otlier kinds of plants whose bark serves the purpo- 

 aes of leaves, except in places where the roots can reach water. The pro- 

 kxnged drought dñes up all the rivulets in the low land or "tierra calien- 

 te" as it is called locally, but the immeuse rock masses of the platean — 

 rjghtly named Sierra Madre, mother of moiintains — store up and give out 

 a perennial stream, never falling below 64,000 cubic feet per minute. 



The Fuerte is 275 miles long from source to mouth, and the united 

 river for a third of the whole length flows through the low plain the re- 

 maining part and all the chief tributañes pass through rugged foot hills 

 and in deep cañons worn in the SieiTa itself. 



This country was traversed by the author in 1897 from west to east, 

 but it wUl be more convenient for the puipose of description to startuear 

 the watershed. 



Proceediug therefore from the town of Chihuahua on the Mexican 

 Central Railway, one traverses the central plain, gradually rising from 

 east to west towards the wave crest of the gi-eat slope; for the first 70 mi- 

 les the road or track goes over a rugged country composed of weathered 

 dark volcanic rocks, and studded with abrupt hills which i-ise like islands 

 in a stormy sea of lava. Thers is little surface soil, and, except a few sha- 

 Uow valleys like that of Sta. Isabel, the región, owi% to drought, is a de- 

 sert. After reaching Cosihuiriachic, a town depending on very ancient 

 and rich silvfer and lead mines, the llanos are seen stretching upward to- 

 ward the watershed of the continent; they are very smooth, broken by 

 few aiToyos, and covered with gi-ass formiug a good cattle country where- 

 ver water is obtainable. Thirty miles to the N. W. of the town is a group 

 of rocky hills whence streams flow in three directions— south-east tothe 

 Rio Conchos, which joins the Rio Grande del Norte, and discharges into 

 the Gulf of México — north to the Rio de Sta Maña, an inland sytem of 

 drainage ending in a salt lagoon near the United States frontier — and west 

 through the mountains to the Gulf of California. 



The llanos preserve the original slope and surface of the oíd lava 

 flows, and are protected from denudation by their lof ty elevation, the small 

 rainfall on thé inland side of ^he mountains, and by a coating of soil with 

 permanent gras. (1) Travelling over them, is a pleasing contrast to pro- 

 gress over the stony plain, and the antique-looking; leather-slung coa- 

 ches drawn by teams of eight or ten, well-matched, closely-clipped, whi- 

 te mules go at a fast canter over the smooth surface. Towards the summit 

 of the slope rounded hills studded with dwarf oaks appear, and the ground 

 ÍH broken; but some attempt at grading the tracks enables wheeled vehi- 



(1) There are alBO íiUnvial depotits In tLis región, contaiuiDg boneremaiiis ofQua- 

 ternary age. 



