THE TECHNOLOGIST. [Nov. 1, 1864. 



172 QUICKSILVER MINES OF I 



The first thing which strikes the observer, on entering the mine, is 

 the liberal scale of its exploration. Everything indicates a liberal and 

 judicious use of capital ^in the development of a property which, upon 

 any other principle of exploration, would probably have been unremu- 

 nerative. We note also the absence of the usual galleries or levels, cut 

 at regular distances of ten fathoms, common in the exploration, for 

 example, of copper mines, and of other metallic deposits in which the 

 ore is confined to well-characterised veins. 



In order to reach the lower workings of the mine, the observer may 

 employ the bucket as a means of descent, or he may, in a more satisfac- 

 tory manner, descend by a series of ladders and steps, not in the shaft, 

 but placed in various large and irregular openings, dipping, for the most 

 part, in the direction of the magnetic north, and at an angle of 30 deg. 

 to 35 deg. These cavities have been produced by the miner in 

 extracting the metal, and are often of vast proportions ; one of them 

 measures 150 feet in length, 70 feet in breadth, and 40 feet in height — 

 others are of smaller dimensions ; and they communicate with each 

 other sometimes by narrow passages, and at others by arched galleries 

 cut through the unproductive serpentine. 



Some portions of the mine are heavily timbered to sustain the roof 

 from crushing, while in other places arches or columns are left in the 

 rock for the same purpose. 



The principal minerals associated with the cinnabar are quartz and 

 calcareous spar, which usually occur together in sheets or strings, and, 

 in a majority of cases, penetrate or subdivide the masses of cinnabar. 

 Sometimes narrow threads of these minerals, accompanied by a minute 

 coloration of cinnabar, serve as the only guide to the miner in re- 

 discovering the metal when it has been lost in a former working. 



Veins or plates of white massive magnesian rock and sheets of yellow 

 ochre also accompany the metal. Iron pyrites are rarely found, and no 

 mispickel was detected in any portion of the mine ; running mercury is 

 also rarely, almost never, seen. 



The cinnabar occurs chiefly in two forms, a massive and a sub- 

 crystalline. The first is fine granular, or pulverulent, soft, and easily 

 reduced to the condition of vermilion ; the other is hard, more distinctly 

 crystalline, compact, and difficult to break ; but in neither of these 

 forms does it show any tendency to develop well-formed crystals. 

 It is occasionally seen veining the substance of greenish white or brown 

 compact steatite or serpentine. 



The ores are extracted by contract, the miners receiving a price 

 dependent upon the greater or less facility with which the ore can be 

 broken. By far the larger portion of the workpeople in the mines are 

 Mexicans, who are found to be more adventurous than Cornishmen, and 

 willing oftentimes to undertake jobs which the latter have abandoned. 

 The price paid for the harder ores in the poorer portions of the mine is 

 from 3 dols. to 5 dols. per cargo of 300 lbs. This weight is obtained 



