Arizona republican., 1899-12-02
Mines and MininQ

FeStINS upon the strength Of 1t. EOeS it bear the earmarks of business doe
 ument, or is it a pseudo-scientific doc ument that starts with the nebular hy- pothesis and ends with the latest geo
 logical theory. with an incidental ref erence to the property in question. In the latter case, beware.
 "The experienced, reliable engineer or expert. if some prefer that term, takes as little for granted as possible and does very little prophesying. while he uses with great caution such terms as true Assure veins increasing rich ness and width with depth. nearness to a rich property, vein crossings etc. The inexperienced expert gives full range to his imagination. He uses these terms indiscriminately and reads the horoscope of a mining property with the assurance given only by that
 wonderful searching glass invented by MT. Frank Stockton in his story of the
 Great Stone of Sardis'
 We would not pretend to say in de- tail what a mining expert should be and should not be. but the following suggestions. given by Mir. Walter Me
 Dermott. before the London Institute of Mining and Metallurgy some years ago will give the investor some of the
 earmarks by which q good report can
 be judged.
 "A report need not be long-winded to
 justify the fee paid for it. but should
 be so full in actual description as to enable a reader inexperienced in min ing to draw his own conclusions from the facts given, without having to trust entirely to the deductions of the writ CT. The important details to be set forth clearly are those relating to po- sition and facility of access of the property; local conditions as to fuel and water and timber supply: extent and forms of openings; variations in i thickness of deposit; character and value and form of occurrence of ore. It
 is important in giving a clear idea Of
 the property that the distribution of
 the payable ore in the deposit should
 be described. It makes a great differ ence sometimes in the conclusions to
 be drawn, whether the value consists in a uniform value throughout the rock On account of the necessity for this description it is not always sutfl- cient to state that an average width or vein contains an average of so mIc1 value per ton, as this may be in the nature of a conclusion, not or a lact, and so may need to be justified by the detailed facts of the report. The eX- tent and character of the dump piles
 at a worked mine often afford valuable confrmatory evidence as to the char acter and value of the property. l have seen reports i1 which piles of rich ore were stated to be on hand in the mine in certain quantity and value;
 but on figuring out the experts own statements as to width of pay ore and extent of openings, it was clear that
 the hole in the ground could never hold the ore said to have come out of it. The configuration of stopes in
 worked mine often gives very sugges- tive ideas as to the run of pay ore. and as to the probable character of the ground still standing.
 Geology and mineralOgy should nat
 urally be used with discretion. but only for purposes actually bearing on the description and conclusions to be drawn, not for mere padding, nor for the airing of theories better t.eated n
 purely scientific paper