March 6, 1863: New Almaden

Rotary furnace, Almaden Quicksilver County Park

San Cristobal Mine, Almaden Quicksilver County Park; by Tom Hilton, on Flickr

[Today] we visited [the Guadalupe Mine]. As I have told you before, three quicksilver mines lie within a distance of six miles, the Guadalupe, the Enriquita, and the New Almaden. Of these, only the last has proved very valuable. We saw Doctor Mayhew, the superintendent and engineer of the Guadalupe; he said that the company had spent upward of $400,000 in prospecting. This mine is a good illustration of the uncertainty of mining quicksilver. The ore is found in three different conditions: as fine threads of the brilliant red cinnabar in the harder rock, called jilo; or as a red looking earth, known as terres; or in great chambers of solid ore, called labors. Now, of course, the occurrence of these last is the most desirable, but they are very capricious, following no regular law in their distribution. A year and a half ago a large labor was discovered in the mine, which is not yet exhausted, although they have taken out over 100,000 pounds of metal from it; yet, until the discovery, its presence had not been suspected, although one drift had passed within eleven feet of it and another had been worked to within four inches of it and then stopped. Years later this labor was discovered by accident in cutting an air passage from one part of the mine to another.

English Camp, Almaden Quicksilver County Park; by Tom Hilton, on Flickr

We visited the Enriquita Mine. It, too, is doing but little. The Dutch superintendent and his Irish wife received us kindly and treated us to lager beer. We pushed on our way and stopped at New Almaden, a mine of real value. Here we remained from Friday until the next Tuesday, exploring the region. We had intended to work south of New Almaden, but the very broken country and dense chaparral prevented us. A large region is thrown into high ridges and very deep canyons, the ridges from 1,500 to 3,700 feet high, but mostly about 1,800 or 2,000 feet, covered with a dense growth of almost impenetrable chaparral. We reached a few elevated points, from which we could map out the topography of the country.