ALONG THE RIO GRANDE VALLEY.
the "National" system at Saltillo, whence is a straight course to San Luis Potosi and Mexico City.
This system, then, when perfected, will control a rich agricultural region, and will draw to itself, by branches and independent lines, the products of the valuable mines of the sierras. Mining operations in Coahuila are not now active, but were formerly, in districts now deserted, and which may revive with the coming of the railroad. Iron, in a pure state and in great masses, is found in the Sierra del Valle, and at other points, and copper, lead, amianthus, nitre, and sulphur, in various districts. A great furor was created, a few years ago, about the mineral deposits of the Sierra Mojada, which lie in a desert country, one hundred miles distant from the nearest centre of population. In the Government Report (Mexican) one hundred and forty mines are enumerated, showing nearly every mineral found in Mexico. It is supposed that this region will be profitably opened again when entered by the railroad, and hidden mines brought to light that the wild nature of the country has hitherto kept secret.
At the construction camp, where I was given a bunk by the physician in charge, and dined with the well-known contractors, the Monroe Brothers of California, I had an excellent opportunity of witnessing the wonderful operation of track-laying. At half-past six next morning, the advance engine blew its whistle for all hands to report for duty, and started for the front, pushing ahead of it a long line of platform cars laden with ties and rails. Each car contained thirty rails, fifteen on a side, sufficient for four hundred and fifty feet of track. A mule pulled it to the end of the rails laid the day preceding, when four men, armed with powerful tongs, seized a rail, two on each side, and ran it out, before the car had well come to a halt. "Steady," says the foreman; "drop," and it falls with a clang on the sleepers, while the other side does the same; the old mule draws the car ahead, and the process is repeated. Sharp after them come the spikers, two sinewy negroes in advance, who drive so rapidly that their strokes keep up a running clatter, and who do all the heavy work, the Mexicans not being up to it. Four gangs then
