installing steam-driven Cornish pumps, the new owners were able to operate them with considerable success until work was greatly curtailed in 1893 by the drop in the price of silver. Later, American capital joined with British in working these mines and the American engineers, by introducing the cyanide process of treating the ores, and cheap power for operating the pumps and mining machinery from hydroelectric developments in the vicinity, again brought prosperity to this section, so that shortly before the revolution of 1910, Pachuca production of pure metallic silver was about 1.5 tons per day, making it the leading producer of silver in Mexico and one of the most important in the world. But this result was achieved with low-grade ores which could never have been mined or reduced at a profit by Mexican methods.
Guanajuato, State of Guanajuato. The history of this section corresponds closely to that of Pachuca, although the ores are of a somewhat lower grade. After work under Mexican methods of mining had been suspended for a period, Americans undertook to apply modern processes of mining and ore-reduction and, in doing so, invested large sums. They applied cheap electric power, supplied by the Central Mexico Light and Power Company owned by capitalists of Colorado Springs, Colorado. Much of the ore treated came
