Arizona republican., 1915-04-18

low the third level in order to com
 plete the ore pockets, stump, etc,
 prepI atory to mining on that level.
 In the future development will pro
 gress at more moderate rate than
 in the past, as the mine is now so thoroughly opened up as to easily
 fulfill all production requirements.
 In the prosecution of development
 as well as in actual stoping practi- cally all of the fringe ore forming the margins of the principal ore bodies has either been explored or stopped, and in the light of the ad- Gitional information obtained during the past four years it has been deem
 ed advisable to recalculate the ore reserves of the property. This has
 been done and the reserves so cal
 culated as of Dec. 31st. 1914, amount to 74,765,789 tons, averaging 2.214
 per cent copper and underlie an area of 205.2 acres.
 This recalculated tonnage shows a
 variation of only about l 1-2 per cent as compared to the total ton mage previously reported as calcu- lated from churn drill developments, and after deducting the :, eel, ,821 tons Of ore that have been mined up to the end of 1914. As an offset to this difference in tonnage, call
 Culated to some extent on the basis of more perfect data, the increase in percentage of copper content amounts to about one per cent of the former grade. so that in net result the two sets of calculations are substantially identical. There is practically no difference at all between the original and new estimates as pertaining to the main portions of the principal ore bodies. Such differences as these are apply entirely to smaller outlying areas containing thin ore bodies or irregular shape, concerning which the data serving as a basis of original calculations was not so complete IS that subsequently, derived from more thorough underground development It must be remembered in this con nectlon that certain of the deeper iylng ore bodies, occupying areas Of considerable extent, have not been drilled to their full depth and it is certain. therefore, as has been stated Tn connection with previous esti- mates. that the tonnage intimately available will be substantially great CT than the fully developed reserves heretofore or now stated.
 It has not been necessary during the year to make any additions or unusual betterments to the plants at the mlne or mill and their physical condition is excellent. No new con- struction is contemplated, but some improvements are being inaugurated in mill practice as briefly referred to previously in this report These, however. will only require incidental changes so far as mechanical ar engagement is concerned
 The mine is fully developed and capable of maintaining the output re- quired or 1t in such a manner that the proper proportions of ore can be produced from reserve drawing thus maintaining uniform costs. With the area tributary to the No. , shaft 1 fully developed and ready to produce, | as 1t now is, to the extent of it's l full proportion of the total tonnage. there should, during the next year. | be a further improvement in the | grade or ore treated compared to ] that or the past The curtailment of 1 output which became necessary dur Ing that period, caused a serious break in earnings, butt from an oper- | ating standpoint, the experience | served as a demonstration and lesson l which will be lasting in their benefits | through having pointed out the way | to economies and measures towards | break In earnings, but from an oper- | alton on a normal scale, will make | Tor costs of producing copper much | lower than have been predicted or even thought possible heretofore by | those most optimistic concerning the | property's capabilities for low cost production.