modern machinery, and the construction of a railway from the smelter to the mines, the output gradually increased until in 1911 it amounted to about 700 tons of ore per day and gave employment to some 2,000 people. Again hydroelectric power, supplied by American capital, was a factor in the successful operation of these low-grade properties where the product was made up exclusively of material rejected by the Spaniards and Mexicans, who gutted the best part and allowed the rest to cave and become mixed with valueless country rock.
COPPER MINES
With a few unimportant exceptions, the Spaniards were never able to exploit copper ores in Mexico successfully; therefore, all of the copper mines which have been operated in the recent past were developed by foreign capital. In the order of their importance, these copper properties are located and owned, as follows:
Cananea, State of Sonora. Owned by American capital.
Boleo, Lower California. Owned by French capital.
Tetziutlan, State of Pueblo. Owned by American and Italian capital.
Matehuala, State of San Luis Potosi. Owned by American capital.
