234 Mexican Mines. 



only lOSi feet above the level of the lake of Zumpango; but 

 the ores which they extracted did not compensate the expense 

 of the process, and the mine was again abandoned in 1801. 



" It is surprising that they never thought ^substituting for 

 this wretched plan of drawing off the water by bags proper 

 pump apparatus, put in motion by horse whims, by hydraulic 

 wheels, or by machines moved by a column of water {colonne 

 d'eau). A level begun at Pachuca, or lower down towards 

 Gazave in the valley of Mexico, would have exhausted the 

 mine of Biscaina at the pit of San Ramon, for a depth of 202 

 fathoms. The same object could be attained at less expense 

 by following the project of M. D'Elhuyar, in placing the 

 mouth of a new level near Omitlan, in the rond which leads 

 from Moran to the place of amalgamation at Regla. I'his last 

 level, before reaching 12,466 feet in length, would cut the vein 

 of Biscaina. 



" The very wise plan which the Count de Regla at present 

 follows is, to leave off the clearing of the old works, and to in- 

 vestigate the mineral repository in points where it has never 

 yet been worked {in unverfahrene^n felde). In studying at Real 

 del Monte the surface and undulations of the ground, we ob- 

 serve that the vein of Biscaina has furnished for three centu- 

 ries its greatest riches from a single spot ; that is to say, from 

 a natural hollow {enfoncement) contained between the shafts of 

 Dolores, Joya, San Cayetano, Santa Teresa, and Guadalupe. 

 The shaft from which the greatest quantity of silver ores has 

 been extracted is that of Santa Teresa. To the east and west 

 of this central point the vein is contracted for a distance of 

 more than 1300 feet. It preserves its primitive direction, but 

 becomes destitute of metals, and reduced to an almost imper- 

 ceptibte vein. For a long time it was believed that the vein 

 of Biscaina was insensibly lost in the rock ; but they discover- 

 ed in 1798 very rich metals, at a distance of more than 1640 

 feet, to the east and west of the centre of the old works. They 

 then sunk the shafts San Ramon and San Pedro, and dis- 

 covered that the vein resumed its old power, and that an im- 

 mense field was opened to new undertakings. When I visited 

 the mines in the month of May 1803, the San Ramon shaft 

 was then only 16 fathoms in depth ; and it will be nearly 131 

 fathoms to the bottom of the level of Moran, which is itself 

 still distant 147 feet from the point which corresponds to the 

 intersection of the new shaft, and the roof of the level. In its 

 present state, the mine of the Count de Regla annually yields 

 more than from 30,000 to 40,000lbs. troy of silver. 



" The vein of Biscaina contains in the points of the principal 

 mines milk-quartz, which frequently passes into splintery 



horn- 



