130 



as have running water for a considerable distance, which can be 

 conducted in canals for irrigation. 



Arizona forms a link in the great chain of mining regions that 

 stretches along the western side of the continent. Though but a 

 small portion of the country has been explored ; yet, between the 

 Rio Grande and the Colorado, numerous districts of great mineral 

 wealth have been discovered, and on some of them more or less 

 labor expended. The Mexicans have, at various times since the 

 middle of the last century, commenced workings on a great number 

 of veins, but owing to the continued inroads of the Apaches, but 

 little was accomplished by them. 



After the conclusion of the Gadsden treaty, Messrs. Poston and 

 Ehrenberg, with a small party, entered the country, and after pro- 

 specting a large number of localities found the Heintzelman vein. 



The results of an examination of this proved so satisfactory, that 

 considerable attention was drawn towards that part of New Mexico. 

 Joint stock companies, with little ready capital and immense ex- 

 pectations, were formed. Speculators bought in stock for ten per 

 cent, of its nominal value, and sold out at from fifty per cent, to 

 ninety per cent, to tradesmen and widows, too poor to meet assess- 

 ments, when means for working were absolutely necessary. Men 

 were put in charge who had never seen a mine, and usually with 

 no professional assistance. The results of enterprises conducted in 

 a similar manner are Avell known. Eetween the absence of avail- 

 able funds on the one hand, and of protection to life and property, 

 on the other, enterprise was already beginning to stagnate, when 

 the withdrawal of the troops made the abandonment of the country 

 absolutely necessary. 



The most important of the mines already known and worked is 

 the Heintzelman, or Cerro color-ado, belonging to the Sonora Mining 

 Company. It is situated west of Tubac, about twenty-four miles 

 by road. The vein runs north and south, has a nearly vertical 

 dip, and is enclosed in a broAvn por^jhyry, free from quartz, and con- 

 taining ill-defined crystals of feldspar. The thickness of the lode is 

 from twelve to twenty inches. A vertical main shaft has been com- 

 menced, with the expectation of intersecting the vein at a depth of 

 two hundred feet, but it is only completed to about one hundred 

 and twenty feet. This shaft communicates by cross-cuts, at sixty 

 and one hundred feet, with two galleries. 



The ore is separated by hand into two classes, rendered neces- 

 sary by the difference in their chemical character and in their rich- 

 ness in silver. The first class consists of the more massive and 

 richer ore, composed of Stromeyerite, tetrahedrite, blende and ga- 

 lena, with native silver ; the gangue is quartz, with some barytes 

 and the carbonates of magnesia and lime. The blende and galena 



