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By Luckie. Peter T., Deurbouck. A. W., Harold L. Lovell, E. R. Palowitch, James K. Kindig

PART 1: DENSE MEDIUM SEPARATION by E. R. PALOWITCH and A. W. DEURBROUK INTRODUCTION During 1974, 43.9% of the 603,406,000 tons (549,099,000 mt) of bituminous coal and lignite produced was cleaned mechanically, of which 82,280,000 tons (74,875,000 mt) was cleaned by dense medium processes.l The percentage of bituminous coal and lignite cleaned mechanically by dense medium processes increased from 7 to 31 % between 1938 and 1974. Dense medium separations include those coal preparation processes which clean raw coal by immersing it in a fluid having a density inter- mediate between clean coal and reject. As there is a general correlation between ash content and specific gravity, it is possible to achieve the required degree of removal of ash-forming impurities from a raw coal by regulating the specific gravity of the separating fluid. Dense medium processes offer the following advantages over other coal cleaning processes: 1) Ability to make sharp separations at any specific gravity within the range normally required even in the presence of high percentages of the feed in the range of 2 0.1 sp gr units. 2) Ability to maintain a separating gravity that can be controlled with ± 0.005 sp gr units.

Jan 1, 1979

By John L. Burns

The object of this chapter is to present data concerning the effect of the introduction of relatively slight amounts of carbon and nitrogen into supersaturated solution in iron. The study is confined to the alpha temperature range of both the Fe-C and Fe-N systems. The age-hardening characteristics of these two systems are considered. These data are compared to those of other age-hardening alloy systems and a "classification" is essayed. A.—Relation of Lattice Parameter and Electrical Conductivity to Changes in Physical Properties Due to Aging of Fe-C Alloys Since Whiteleyl in 1927 showed that some of the iron carbide that is normally present in slowly cooled low carbon-iron alloys disappears on rapid cooling from just below the A, point, interest has been manifested in the possibilities of age-hardening in these alloys. Masing and Koch,~ and at the same time and independently, W. Koster,~ proved these alloys to be age-hardenable. A. A. Bates4 a little later also published an interesting paper on changes in physical properties due to the aging of low-carbon steels. Many other papers have appeared showing changes in physical properties in specific instances due to this same phenomenon.

Jan 1, 1934

By J. M. Camp

In conforniity with the design of the oficials of the United States Steel Corporation for the standardization of the methods employed in the sampling and analysis of all materials encountered in their various lines of manufacture, the Chemists' Committee presents this compilatioti of standard methods for the sampling and subsequent analysis of molten pig-iron. In selecting the methods, the Committee employed the same line of procedure as in former cases, viz., the careful consideration of all the methods employed in each laboratory of the Corporation, evolving therefrom the several methods herein described, the immediate adoption of which is desired. The services of Messrs. W. B. N. Hawk, William Brady, and C. H. Rich, a sub-committee appointed for the preparation of the present paper, are gratefully acknowledged. II. Introduction. A quite obvious cause of nonconformity of results of comparative analyses in the various laboratories of the Corporation has been an apparent lack of uniformity of method in the sampling and analysis of molten iron. This condition is particularly apparent with regard to the determination of the sulphur, numerous discrepancies in which would appear t.o indicate the absence of, and the necessity for, some uniform method of procedure. The estimation of the

Jan 1, 1913

By E. S. Grumell

THE correct sampling of coal and coke is becoming important to an ever increasing number of producers and consumers. This, therefore, may be an opportune moment to examine where we stand with regard to existing and proposed methods. In this paper an attempt will be made to review, as briefly as possible, some of the considerable amount of painstaking research which has been done in the last 10 years, and which has unquestionably led to a much better understanding of the subject. In so doing we shall try, on the one hand, to make clear where substantial progress has been made, and on the other hand, to draw attention to points that require further investigation. The paper is divided into sections in order to emphasize the major divisions of the subject; further, in order to retain this emphasis, detailed consideration of some of the points has been relegated to appendixes. No attempt has been made to give a complete survey of the literature, as this has already been done by L. A. Bushell.2 The following abbrevia-tions will be used: A.E., average error; P.E., probable error; S.W.R., size-weight ratio; B.S.I., British Standards Institution.

Jan 1, 1939

By A. B. Parsons

Not so many years ago the interest of the average mining engineer in money matters-aside from his pay check or his consulting fees-was confined to the per-ton cost of mining and beneficiating ore and to the amount of capital that would be required to erect the plant necessary to carry out such operations on a prescribed scale. The so-called "business men" assumed that questions of marketing the products, of profits, and of dividends were in their exclusive sphere-matters too intricate or, perhaps, too practical for the mere engineer! In the case of a new enterprise, the promoter shouldered the entire responsibility for raising the necessary funds, and incidentally he got the lion's share of profits. In fact, he frequently profited handsomely even though the mine earned little or nothing. Occasionally the engineer turned promoter or entrepreneur--conspicuous examples are Herbert Hoover, D. C. Jackling, William Braden and F. W. Bradley- but by and large he remained in a sphere of his own. To what extent this condition of affairs has changed is difficult to say. It might be argued that it were better that it be not changed; and yet I cannot help feeling that in mine promotion lies a distinct opportunity for the

Jan 1, 1932

By Louis D. Huntoon

The Hammond Mining and Metallurgical Laboratory is the gift of Prof. John Hays Hammond to the Sheffield Scientific School of Yale University. Professor Hammond was graduated from this school in the class of 1876, and has always shown great Merest in its welfare and progress. In 1903, he offered to build and equip for it a mining and metallurgical laboratory. This offer was gratefully accepted by the trustees; and in October of the same year the architect, W. Gedney Beatty, and I were employed to draw up plans for the building, which is the largest of its kind in this country. The Treasurer's report shows the total gift of Professor Hammond, including land, building, and equipment, to have been $128,741.53. This does not include $5,000 given by Professor Hammond to defray incidental expenses. The detailed cost of the machinery and installation, included in the above sum, is as follows: Macbinery,.......$9,846.00 Pipe and fittings,......925.05 Hangers, shafting, pulleys, belts, etc.,.. Steel-work, tanks, launders, etc.,...272.19 Screens for sizing ore,.....411.37 Lumber,.......1,896.36 General Supplies : Hardware,......$135.96 Tools,.......263.66 Paints,.......204.63 Electric and incidental,.... 439.57 ----------1,043.82 Machine-shop material, . 259.44 Labor,.. 722.29 ----------981.73

Jan 1, 1910

I. C. WHITE, Morgantown, W. Va. (written discussion *).-The writer's conclusions with reference to the possibility of finding commercial deposits of petroleum in Brazil were published in 1908 in the Final Report of the Coal Commission of Brazil.1 Since this volume is not generally accessible, and the author has nothing to acid thereto, the following quotation found on pages 243-7 may prove of interest: The Possibility of Petroleum Deposits in Brazil "The writer has often been asked to express an opinion as to the possibility of finding petroleum in commercial quantity in Brazil. "The question is one that does not admit of an adequate answer except for the regions visited by the writer, which as already stated, include only, a portion of that great territory, and only the southern portion of Brazil; namely, the states of Rio Grande do Sul, Santa Catharina, Paraná, and a few rapid excursions across São Paulo, and Minas Geraes, as well as the brief visit to Marahú in Bahia. "That the sedimentary beds of the Brazilian Permian once held some petroleum is attested by the evidence of the Iraty black shale which gives off the characteristic odor of this substance from São Paulo to Rio Grande do Sul.

Jan 1, 1918

By M. J. McPherson, R. Venkataramani

R. Venkataramani (Assistant Professor of Mining Engineering, Dept. of Mining, The Pennsylvania State University, University Park, Pa.)-Y. J. Wang and L. W. Saperstein are to be congratulated for their paper on the computer solution of ventilation problems. The limitations on the problem size to be solved by the program (Appendix II) has been outlined in the paper. I would like to add the following additional limitations of this computer program: The dimensions of the variable J1and J2 should be changed to J, (550) and J2 (550) to handle problems containing more than 400 branches, and up to 550 branches. If there are a large number of branches common to the various meshes, another limitation on the problem size will be the dimension of the variable NA. While a higher-order polynomial fitting for the fan characteristic data points is more rigorous, a quadratic relation, if linear interpolation between the points is inadequate, will result in saving computing time without much loss of accuracy. Of course, this can be handled by minor modifications to the existing polynomial fitting routine in the program. M. J. McPherson (Dept. of Mining Engineering, University of Nottingham, Nottingham, England)-The

Jan 1, 1972

By F. E. Turton

THE town of Rancagua, at the junction of the state and Braden Copper Co. railroads, is located 82 km south of Santiago, the capital of Chile. From Rancagua 70 km to the east, situated in the Andes at an elevation of 7000 ft, is the town of Sewell, the location of a millsite. Two and one half km east of Sewell by underground railroad at an elevation of 7500 to 10,000 ft is the Teniente orbody. The history of El Teniente dates from the eighteenth century, when according to legend a Spanish lieutenant, or teniente, a fugitive from justice, escaped to the Andes and camped at what afterwards became known as the Mineral El Teniente. This man reputedly discovered a vein of high grade copper ore. The first official records date from 1819, when some exploitation was begun, and continue until 1870. The orebody was large and of relatively low grade and was beyond the capabilities of the small groups attempting to operate it. No effort was made to erect a concentrator until William Braden became interested in the property. In 1901 Mr. Braden promoted the necessary capital for the first practical exploitation of the orebody. Barton Sewell and E. W. Nash, both of the

Jan 1, 1952

By E. S. Bardwell

TWENTY years ago, W. T. Burns, in his paper presented at the Butte Meeting of the Institute, discussed the general scheme then in use in the electrolytic copper refinery of the Anaconda Copper Mining. Co. at Great Falls, Mont., for removing impurities from tank-room electrolyte and controlling its acid content. Since then marked changes have taken place in copper-refinery practice at Great Falls. The electrolytic copper refinery in use in 1913 has been replaced by a new and entirely modern plant capable of producing up to 27,000,000 lb. of cathode copper per month. With the building of the new plant in 1916, the treatment of converter anodes was discontinued. At first the substitution of refined anodes for converter anodes resulted in a decrease in the impurity content of the anodes, but as time went on, changes in metallurgical practices at the smelter resulted in substantial increases in the impurity content of the anodes. The leaching of the silver slime to remove copper before shipment to Raritan for treatment further added to the purification problem. The fact that the scheme of purifying electrolyte which Mr. Burns described in his paper' has proved adequate for our needs under a wide variation of conditions speaks well for its essential soundness.

Jan 1, 1933

By J. A. Fulton

GOLD was discovered in the Sierra Nevada by J. W. Marshall on Jan. 2, 1848. The town: of Grass Valley soon sprang up and contained several stores in 1849; but the population of the town has always reflected the fluctuations in quartz mining. Gold-bearing quartz was found on Gold Hill in September 1850, and in the next two years most of the quartz bearing veins in the vicinity were located. At first, the quartz was crushed in mortars with spring poles; the Huff Co. took out $20,000 in this manner during the winter and spring of 1851. The first mill was put up in January, 1851. In 1866, there .were in Grass Valley 248 stamps, crushing 71,420 tons of ore with an average yield of $30 to $35; in Nevada City, there were 142 stamps, crushing 14,200, tons, with an average value of $25. But in 1918, only two properties in. this region, the Empire and the North Star, were producing. Since then, there has. been a revival of mining in the district and the following properties are being opened up: The Golden Center, Grass Valley Gold. Mines CO , Idaho-Maryland Mines Co., while the Sultana is kept unwatered and work is going on in a half dozen small properties.

Jan 2, 1926

By D. H. Newland

CERTAIN observations from the field and laboratory suggest the need for recasting some of our ideas about gypsum as a rock-forming mineral and in relation to supplies for industrial use. Until about 25 years ago, the use of gypsum was confined almost entirely to agriculture. During the past quarter century, though, its usefulness has been greatly developed, particularly in the building trades, which now absorb most of the gypsum produced. In 1919, according to the U.S. Geological Survey, the output of crude gypsum was 2,240,163 tons, a gain of 912 per cent. in 25 years. About one-half of this production was mined in New York, Ohio, and Michigan, where the proved supplies can hardly be regarded as over-large when viewed in relation to the rapid expansion of industrial requirements. The occurrence of gypsum in the United States is treated by R. W. Stone and others.1 The deposits of Canada are described by L. H. Cole.2 Several states, including Kansas, Oklahoma, Iowa, Michigan, and New York, have had special surveys made their of gypsum deposits, but the reports, as a rule, refer to conditions as they existed from 15 to 20 years ago.

Jan 9, 1921

By Richard Moldenke

In crowding the recent mass of work on the physics of cast-iron into the compass of a short review, I cannot do better than to follow the lines of Mr. W. R. Webster's suggestion, made at the Florida meeting of the Institute, March, 1895.' The classification of the properties of the metal, and the influences to which it is subjected during the various processes it undergoes, is quite complete; and as Mr. Webster gives it again in full in another paper at the present meeting, a simple reference to it now will be sufficient. I. Correspondence Between Chemical Composition, and Melting-Point, Fluidity, Shrinkage, Fracture,Chill, Micro-Structure, and Other Physical Properties. Melting-Point.—The melting-point of cast-iron had long been a subject of controversy among foundrymen. They knew that a hard iron melted faster than a soft one, but this effect was occasionally disputed, and the reasons given were unsatisfactory; but could not be well controverted. It was my good fortune to take the actual melting-temperatures of some 70 pig-irons and castings; the Le Chatelier pyrometer, suitably protected, being introduced into the interior, and the iron melted off in a specially-constructed cupola. The irons had been previously analyzed by taking the borings at the point of the intro-

Jan 1, 1905

By E. W. Felegy

THE need for improved mine communication to increase efficiency and to insure greater safety has long been recognized. General and unrestricted communication between all points underground, and between the surface and all points underground, is probably the least advanced phase of the mining industry. An ideal system of mine communication must require no fixed wire installations. The equipment must be small, lightweight, and readily portable, and the power requirements low. A system that can be used not only under normal circumstances but also in an emergency, when the continuity of wires, tracks, and pipelines may be disrupted, must function independently of any aid furnished by standard installations. Radio communication offers possibilities of meeting all the requirements necessary for an ideal communication system in underground mines. Transmission of signals must be achieved through one or both of two mediums, through the air in mine openings or through the strata. The results or lack of results obtained by early investigators showed conclusively that radio communication by space transmission cannot be accomplished effectively beyond line-of-sight distances in underground passageways. A radio system underground therefore must depend solely upon transmission through soil and strata. The application of radio to underground mine communication was investigated by many individuals and agencies at different times in the last several decades, but little success was achieved before World war 11.2-0, The results of experiments during the war, and further knowledge gained in experiments with vastly improved communication methods and equipment after the war provided the background for additional research in radio communication in underground mines. During 1950 to 1.952 the University of Minnesota sponsored an investigation to determine the possibility of developing: a system of radio communication universally applicable in underground metal mines in the Lake Superior district. The possibility of using radio equipment to determine the imminence of rock bursts in deep copper mines in that district also was investigated. The investigation supplemented previous and concurrent emergency mine communication studies of the U. S. Bureau of Mines. Testing equipment and laboratory facilities maintained by the Bureau of Mines at Duluth, Minnesota, were used in the research program, which was conducted as a mining engineering graduate research problem by the present writer under the direction of T. L. Joseph and E. P. Pfleider. The radio units used in the research program were designed and built to specification solely to conduct tests of radio communication in mines. Two identical units were used in all tests. Each unit contained a transmitter section, a receiver section, and a power-supply section, mounted on a single chassis. The entire unit was enclosed in a single 10x12x18-in. metal case provided with a leather-strap handle for carrying purposes. The front of the case was hinged to open upward and provide easy access to the single control panel on which all controls were mounted. Storage batteries supplied the operating power for all tests. Standard 6-v automobile batteries were utilized to provide adequate capacity to conduct tests for a full day without exhausting the battery. A frequency range from 30 to 200 kc was covered in eight pre-fixed steps on each unit. The carrier frequencies were crystal-controlled and amplitude-modulated. The receiver employed an essentially standard superheterodyne circuit and was sufficiently sensitive to detect signal strengths of 5 micro v. A heterodyne circuit was employed in the transmitter to obtain the low-carrier frequencies used in the units. Power output of the transmitter, usually less than 2 w, rarely exceeded 3 w in any test. Tests were conducted in mines on the Vermillion iron range in Minnesota, the Gogebic iron range in Wisconsin, the Menominee and Marquette iron ranges in Michigan, and a copper mine in the upper Michigan peninsula. All tests were conducted when the mines were operating normally, and usual mining, maintenance, and transportation activities were in progress, so that any interference caused by normal production activities could be evaluated during the tests. Tests were made between different points underground in each mine, and between underground and surface points at some mines. Test readings obtained at any one mine were calibrated in the laboratory before another series of tests were begun at the next mine. The transmitter and receiver were separated by one or more levels in each test, and generally there was no other means of communication between test points. Two 100-ft lengths of rubber-covered wire were used for antenna wires on each unit in both transmission and reception. The ends of the wires were connected to ground points in one of several methods, depending upon physical conditions at each test site. The wires were clipped to metal rods about 200 ft apart in the back, side, or bottom of the mine opening where the character of the rock permitted driving rods. Both wires were clipped to points about

Jan 1, 1954

Abel, Charles Edwin, Student, Univ. of California Los Angeles, Cal. '31 Adams, Horace M.5148 Benton Ave., Downers Grove, Ill. '31 Ahlskog, Harold A., Student, Washington State College Pullman, Wash. '30 Aldridge, John, Student, New Mexico School of Mines Sbcorro,, N. M. '30 Allen, Hugo K., The Univ. of Texas 104 W. 33rd St., Austin, Tex. '31 Ames, Marshall B., Student, Washington State College Pullman, Wash. '31 Ancell, Virgil F., Student,. Missouri School of Mines Rolla, Mo. '30 Anderson, Norman John, Student, South Dakota School of Mines Rapid City, S. D. '32 Annett, Norman T., Student, Mackay School of Mines, Univ. of Nevad Reno, Nev. '32 Apablasa, Salvador C., Student, Univ. of California Los Angeles, Cal. '31 Armstrong, James Arthur, Jr., Student, Michigan College of Min. & Tech., Houghton, Mich. '31 Armstrong, John R. Box 274, Neosho, Mo. '31 Armstrong, Robert H., Student, Lafayette College Easton, Pa. '31 Armstrong, Thomas E., Student, Univ. of California Los Angeles, Cal. '31 Arnot,. Paul H 2617 Haste St., Berkeley, Cal. '31 Ashby: Harve I., Willow Creek Mines Wasilla, Alaska. '31 Aud, Robert A., Student, Lafayette College Easton, Pa. '30 Augenthaler, Robert L., Student, New Mexico School of Mines Socorro, N. M. '32 Augustine, Grant, Jr., Instrument man, Min. Dept., Fairbanks Exploration Co., Fairbanks, Alaska. '31

Jan 1, 1932

The banquet Wednesday evening was attended by about 700. The list of speakers was unusually brilliant and each one proved to be so interesting that it was nearly midnight before the dancing began. Capt. Robert W. Hunt was toastmaster. Captain Hunt is about to celebrate his eighty-first birthday but is blest with unusual vigor and it was a great pleasure to all his friends to honor him at this time. His selection is toastmaster was a happy one. The guest of the evening, if among so many stars one could be selected from the rest, was Charles M. Schwab, who said nothing but the urgent telegram from his dear old friend, Captain Hunt, could have drawn him away from his seclusion on his Pennsylvania farm to attend the meeting in Chicago. Mr. Schwab's address was, as usual, scintillating with wit and humor; and while lie did not directly or indirectly allude to the steel strike lie did at the end of his talk discuss serious things and gave it as his opinion that any effort to legislate or control the high cost of living would be futile until this country got down to a basis of an honest day's work for an honest day's wage.

Jan 11, 1919

By J. C. Wilhoit, J. B. Cheatham

Although an oil well is a long cylindrical hole with an irregular bottom, it appears likely that the nature of the stress concentration at the bottom of the hole can be ascertained from an analysis of the stresses around a short cylindrical cavity with rounded comers and smooth bottom. Such a cavity is studied primarily because it leads more readily to a solution to the problem by the use of stress functions. In this paper the stress distribution around a short cylindrical cavity subjected to bit loading, overburden and drilling-fluid pressures is determined by means of an analytical solution which approximately satisfies the boundary conditions of the problem. From this solution the stresses at the corner of the hole are calculated to be about 35 per cent lower than comparable results obtained by photoelastic and relaxation analyses. This difference is apparently due to the large radius of curvature at the corner of the cavity in the present analysis. Since good agreement is obtained between the results of this analysis and the stresses calculated for a similar loading on a semi-infinite elastic solid, it is concluded that the bit action in the region near the center of the hole is not appreciably affected by the presence of the sides of the hole. INTRODUCTION Much has been written concerning drilling "under down-hole conditions" and pertaining to the stress distribution in the rock at the bottom of an oil well.1-5 For example, it is known that identical rocks can be drilled more rapidly at the surface than under subsurface conditions of pressure and stress.6 Information on the behavior of rocks under loading can be obtained from triaxial test data.7-9 From such tests it is found that rocks exhibit brittle failure when the confining pressure and pore pressure are equal, but the mode of failure may change to ductile as the difference between the confining pressure and the pore pressure is increased. Brittle failure implies that there is very little permanent deformation before fracture, whereas ductile failure indicates that permanent deformation takes place before fracture. Some rocks are ductile at differential pressures of 5,000 psi , but other rocks are brittle even at differential pressures of more than 50,000 psi. Cuttings embedded in mud at the bottom of the hole may act as a plastic mass which the bit teeth must penetrate in order to attack the virgin rock below. 10 During drilling, the mud pressure acts as the confing pressure, and in many cases the difference between the mud pressure and the formation pore pressure IS sufficiently low so that the rock most likely falls in a brittle manner. Very little penetratiori by the bit teeth may be required for brittle failure of the rock. For these brittle materials, the elastic stress distribution is of practical interest in determicing the possible effects of a given loading on failure. The penetration of bit teeth into ductile or plastic rock has been analyzed previously ll,12 and will not be considered further in the present work. During actual drilling, many teeth act at various points ovel an irregular hole bottom. In the present analysis a solution is obtained for an idealized problem of determining the elastic stress distribution caused by only one tooth acting alone at the center of a smooth hole bottom. It obviously is not proposed that any driller should put a special one-tooth bit on bottom, but it is hoped that extensions of the simpler problems can eventually lead to a better understanding of more complex actual drilling phenomena. To obtain a solution by the use of stress functions, a short cylindrical cavity with rounded corners and smooth bottom is studied. The solution to this problem should give an insight into the nature of the stress concentration at the bottom of an oil well which is in reality a long cylindrical hole with an irregularr bottom. After selection of the proper curvilinear co-ordinate system, the stress functions are expressed as series of Legendre polynomials. The coefficient of each term in the series is then determined to satisfy the boundary conditions at a finite number of discrete points on the boundary of the cavity with least square error. Results are compared with bottom-hole stresses obtained by photoelastic and relaxation analyses.

A permanent exhibition of mining machinery has just been opened in the Grand Central Palace, New York City. The exhibits include: Aerial tramways, amalgamation, assaying and laboratory appliances and supplies, blast furnaces, coal, coal-breaker plant, coal excavation, coal products, compressed-air plant, concentrating, crushing, cyanidation, distillation, drainage and pumping, drilling, earth excavation, electrical supplies, explosives, fire prevention, flotation, general supplies, hoisting, hygiene, welfare, iron products, leaching, mechanical conveyors, metal products, natural gas, petroleum, petroleum products, electric, steam, hydraulic, gas, air, and internal-combustion engines, power machinery, preparation of coal, pumping, refining, roasting, rock excavation, rotary drilling; boring, safety appliance, screening and washing, sizing and classifying, smelting, storage of coal, storage of petroleum, surface transportation, surveying, underground timbering, underground trans-port, ventilation, mine. This exposition is operated by the Merchants and Manufacturers Exchange of New York for the purpose of showing under one roof all lines of machinery and mechanical appliances. As for as possible, the exhibits will be shown in operation. The Advisory Committee is as follows: General Howard R. Ward and H. C. Parmelee. Coal and Coke.-Prof. H. H. Stoek, Samuel A. Taylor, Edwin Ludlow. Petroleum and Gas.-Frederick G. Clapp, Ralph Arnold.¬ Extraction of Metals.-Charles W. Merrill, E. Gybbon Spilsbury. Refractories.-Kenneth Seaver.

Jan 12, 1919

WILLIAM YOUNG WESTERVELT, Chairman, Representing A. T. M. E. and M. and M. Soc. of Am. ALFRED G. WHITE, Secretary, Representing U. S. Bureau of Mines. W. 0. HOTCHKISS, Representing Association of American State Geologists. DAVID WHITE, Representing U. S. Geological Survey. The organization and purpose of the War Minerals Committee was explained in a special war notice in the-August Bulletin. The first work of this Committee is to secure and condense information as to the relative importance of different properties from the standpoint of domestic mineral production. When the possibilities of ore deposits are known, involving, in some cases, further examination through the voluntary services of, Engineers and Geologists, then the necessary policy required to stimulate such development can be determined. Proper recommendation has been and will be made to .the various agencies controlling the situation during the war. This will insure a complete presentation of the needs of the situation. Every legitimate effort will be made to stimulate the production of domestic minerals and to put the industries on a permanent basis. The following information forms indicate the type of information required by the Committee. Engineers and Geologists can assist in one of several ways in furnishing information to the War Minerals Committee:

Jan 10, 1917

By F. E Turton

THE town of Rancagua, at the junction of the state and Braden Copper Co. railroads, is located 82 km south of Santiago, the capital of Chile. From Rancagua 70 km to the east, situated in the Andes at an elevation of 7000 ft, is the town of Sewell, the location of a millsite. Two and one half km east of Sewell by underground railroad at an elevation of 7500 to 10,000 ft is the Teniente ore-body. The history of El Teniente dates from the eighteenth century, when according to legend a Spanish lieutenant, or teniente, a fugitive from justice, escaped to the Andes and camped at what afterwards became known as the Mineral El Teniente. This man reputedly discovered a vein of high grade copper ore. The first official records date from 1819, when some exploitation was begun, and continue until 1870. The orebody was large and of relatively low grade and was beyond the capabilities of the small groups attempting to operate it. No effort was made to erect a concentrator until William Braden became interested in the property. In 1901 Mr. Braden promoted the necessary capital for the first practical exploitation of the ore-body. Barton Sewell and E. W. Nash, both of the

Jan 1, 1953