OPENING A NEW MINE.
From the mine our friends went to one of the reduction haciendas, where they saw the process of extracting silver from the ore, which has been described on previous pages. There are about fifty reduction-mills at Guanajuato, some worked by horse or mule power, others by water, and others by steam. Three kinds of crushers are in use, the Mexican arastra, the Chilian mill, and the American stamp-mill, all of which have their advocates, who prefer them to the others. The patio process is employed here as well as elsewhere, and hundreds of horses and mules are annually worn out in treading the ores. An American named Parkman made an improvement on this system by rolling a loaded barrel over and through the mixture by means of horses or mules walking in a circle, as in an old-fashioned cider-mill. The barrel mingles the ore and the chemicals as well as the horses' feet could do it, and the injury to the hoofs of the animals is prevented, as they do not come in contact with the mass. Sometimes heavy wheels are used instead of the barrels, and they are arranged on a graduated scale, so that they move slowly from centre to circumference of the torta, or pulp heap, as they revolve, and from circumference back to the centre again. In this way the entire surface is gone over; the reduction of the mass takes from twenty to thirty days, and is thoroughly done.
ENTRANCE OF A MINE NOT IN OPERATION.
From the hacienda they were taken to the mint, where silver coins are made in the same manner as in mints in other parts of the world. The machinery of the mint is of English construction, and several Englishmen are or were connected with the establishment to superintend the more delicate parts of the apparatus. From the mint they went to a hill called the Cerro de San Miguel, which gave them an excellent view of the city and the hills that surround it. The number of elegant residences in sight convinced them that there is yet a great deal of wealth in Guanajuato, notwithstanding the decline in the yield of silver from the mines.
The next stop in the journey towards the capital was made at Queretaro, eighty-five miles from Silao, or one hundred from Guanajuato. It is a city of from fifty to sixty thousand inhabitants; it has no mines on which to base its prosperity, but is devoted to manufacturing, having been famous for 200 years and more for its production of cotton goods. The largest cotton-mill in Mexico is at Queretaro; it is known as the Hercules, and stands in a ravine, about two miles from the city. It was built by Señor Rubio, is enclosed by a high wall loop-holed for musketry, and could stand an ordinary siege very fairly, provided the besiegers brought no cannon. A defensive force of forty soldiers is maintained at the mills, and they are armed with rifles and howitzers.