Bisbee daily review., 1908-09-13
.PILARES MINE 1T NACOzAR|
 BELIEVED BY ENGINEERS TO
 BE THE EQUAL OF RID T|NTO

store supplies all the wants, rom check for their money to everything in clothing. food or drink. The sur face showing here is in what is called by the Mexican miners "caiiche,
 meaning a very soft andesite dyke This has a tendency to cave and sur
 face water percolates through It 10 some extent, this being the only source of water in the mine. The "slickensides" are noticeable in many places This "caliche IS the hanging wall in some places, but on the south and west of the ore body is well de fined andesite wall dipping slightly. The ore bodies on the inside of the pear-named the Guadaloupe and the Don Juan stopes-are the same ih character as those on the outer rim Of the pear, but they are perfectly dry. and in fact the dust in these stopes is sometimes very annoying. Between the inner and outer bodies the mater ial is barren
 The ore is found around the entire pear or horseshoe, the narrowest point carrying Is feet of ore and up to 300 feet. There are two of these ore bodies around the pear, one carrying an average width of 40 feet and the other an average of more than 100 feet. The lowest stope is on the sixth level, 500 feet below the surface. The ground below has been prospected with diamond drills and the ore takes great depth, increasing in value with depth. The drilling showed that there were good ore bodies for at least 300 feet deeper than the present lowest X1, r,F sulphides are found, from chalcopyrIte workings. No native copper is found up to glance, and occasionally some bornite.
 They are mining about 2500 tons day, working 200 miners and so car men, with 75 contractors on the faces. The work is done by contract, prices ranging from s7 to $1I per foot, ac- cording to the nature of the ground. Mr. Douglas states that there is no comparison between this method and days labor, and 50 per cent of the ordinary mucking and all tramming is done by contract. All miners work by contract and get so much for each foot of, holes drilled.
 There are two methods of stoping now in use here. One style they break ore continuously for 100 to 200 feet at a stretch, reaching the roof by stand ing or the broken ore and drawing off the surface. When this has been done to the limit of the strength of the walls, they draw of all the ore and fill from the surface, and then re- peat the process. The other method is to take short cuts, 10 to 15 feet high, draw out all the ore and fill to within a few feet of the roof, then making another cut and proceeding as before.
 The country rock is andesite and the rhyolite comes in as a volcanic outflow. A large part of the rhyolite is brecciated The ore is found both in the andesite and in the rhyolite breccia, but the andesite is the origi-' nal source of the ore. It is expected that all found in the lower workings will be in andesite.
 They find some high grade, which is shipped direct to the Copper Queen smelter at Douglas, owned by the same corporation Just recently they have opened up a new body of very rich sulphides in the "Y' shaft coun- try, and when this is opened up it is expected they will be able to ship a fair tonnage from this. It is in this section particularly that MT. Douglas has decided on the 50-foot stope and 50-foot pillar system of mining, as we'll as in other portions in the skin of the pear
 A great advantage in this mine is that all ore is chuted from every level to the 700-the main traction level-I and loaded direct onto the cars as they go to the mill. No ore whatever is hoisted Another economy is that no waste is hoisted, but it is left in the mine to fill stcpes No water is hoisted-it all runs out through the waterway in the traction tunnel. The timber costs aggregate but few cents Mex, per ton of ore mined, as the hardness of the ground makes timber ing generally unnecessary.
 The miners here are all Mexicans, and yet they do fine work, the drill men being among the pest in the world All drilling is single hand work They drive to S-foot holes, l breaking to Is tons of material to a hole
 It takes six hours, travelling four miles an ho.r, and with no stops. 10 go through this mine One will, in l making the trip for investigative pur- poses, take about twice as long. and in his journeyings he will use up at i least twelve candles. No portion of 1 the mine is without tracks, and about 1 g per cent is equipped with electric l lights.
 The power is electricity transmitted from Nacozari main power station At | the Pilares plant, however there is a | reserve of many thousand cords of | wood for use in case of necessity. | There are two boilers here and steam | can be connected with the hoists and i thus the work would progress were there a shutdown of the electric plant l for any reason. A new compressor has just been installed. for carrying | air to those portions of the property | needing it. It is expected that work | of sinking at the .'Y" shaft will be re- sumed in about another month, and | forwarded to the tenth level. Then 1t | Is proposed to drive a traction level | on the 1000 and do all hoisting be- tween the tenth and seventh by means | of an automatic skip. The skip sta ton has been cut out and all prepara- tions are made for this new work and | the shaft is ready for sinking opera lions. and they are now only waiting f for the close of the rainy season There Is a winze 40 feet below the 700 fin to IA per cent ore.
 An extremely conservative estimate | places the ore in sight as sufficient i for five years continuous work at z-i DO tons d day. But SO per cent ori the ground above the seventh lever