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By M. L. Requa

This paper is abstracted from the report of the Appraisement Committee of the Independent Oil Producers' Agency, of which the writer was Chairman. The other members of the committee were M. V. McQuigg and R. S. Haseltine. To Thomas Cox, engineer in charge of the investigation, and to his efficient staff of assistants, is due the credit for the detail work necessary in carrying out the plan of the Committee. It treats only of the valuation of the lands, wells, and piping, without going into details of equipment and other features. It was recognized, early in the operation, that the value of oil lands was the value of oil to be extracted, and marketed, less the costs attendant thereon. Referring this back to the costs in cents per barrel, it became obvious that surface improvements, absolutely necessary in the production of oil, from wells then drilled; had no separate and independent value aside from the value of the land, but that any excess equipment, not necessary for the production of oil from present wells, such as drilling tools, well casing, etc., should be given a present condition value. In valuing the properties of the Independent Oil Producers' Agency, the Committee has considered the following facts: 1. That from each property there will ultimately be. produced a certain total quantity of oil. 2. That in the production of that oil a certain total quantity of money will be expended. 3. That a certain total amount of money will be received from the oil. 4. That the total net receipts will be the total gross receipts less the cost of development and production. 5. That the present value of the net receipts must be such an amount that when invested by a purchaser it will be returned with 8 per cent. interest additional during the life of the property.

Jan 2, 1918

By F. C. Miller

THE metallurgical fuel of Colorado, Utah, and New Mexico has been a very tardy member in the caravan of western industrial progress. The history of western coke has naturally been closely related to the development of the metallurgy of iron and steel and the precious metals, in the State of Colorado. It was at Leadville, with a population of 300 in 1877, that the Sentinel was published by Richard S. Allen. The Sentinel gave very full accounts of the various mineral discoveries at the new town of Leadville, which found their, way to the more widely circulated journals of the East, and attracted the attention of many people. At the close of 1878, a census showed a total of 5040 persons. The first smelter was established in 1877, at Malta, two miles from Leadville, by A. R. Meyer, but was not successful. It was succeeded by the Harrison Reduction Works, in 1878. The La Plata began with one furnace in June, 1878, and in 1879 had four furnaces in active operation. These furnaces used charcoal for fuel, and, because of hot tops, suffered a tremendous loss in lead and silver. This difficulty was overcome by the erection of 50 single-bank 10-ft. beehive ovens at Crested Butte, Colo., in 1880. The slack coal sent to these ovens was very pure, and yielded a coke carrying as little as 4.5 per cent. ash. Among the pioneers in the Leadville district were Grant, Eddy, James, Billings, Eiler, and Dickson. To these men the West owes the present expansion of its mining industry, and the erection of metallurgical processes for the treatment of precious metals.

Jan 8, 1918

TWO hundred enthusiastic engineers and coal, op-erators attended a joint meeting of the A. I. M. E., the National Coal Association, and the American So-ciety of Mechanical Engineers in the auditorium of the Alabama Power Co. building at Birmingham, Ala., on Jan. 21. S. W. Farnham, mining engineer of the Goodman Manufacturing Co., Chicago, in his paper on mechanical loading of coal discussed the feasibility of scraper and machine loading. A. R. Anderson of the Jeffrey Manufacturing Co., in a paper on loading coal with conveyors covered their adaptation for long-wall mining and for loading into cars. Discussion of these papers was hampered because the cheap labor costs prevailing in the district have handicapped gen-eral mechanization of the mines. The Bureau of Mines film, "The Story of a Rock-dusted Mine," showing the New Orient mine, West Frankfort, Ill., was also shown at the meeting. F. H. Crockard, president of the Wood-ward Iron Co., represented the A. I. M. E., S. L. Yerkes, vice-president of the Grider Coal Sales Agency, and J. L. Davidson, secretary of the Alabama Mining Institute, represented the National Coal Association, and Paul Wright represented the American Society of Mechan-ical Engineers.

Jan 2, 1927

Jan 3, 1953

By Robert B. Smith

The South Texas Mineral Trend is now estimated to contain uranium reserves of 150 million pounds U308 . Within the past year, an estimated 10 million pounds U308 have been added to this gross reserve. It is probable that a similar amount has been identified in previously unknown orebodies that, as yet, have not been delimited or announced. Exploration that was limited in the past to a narrow band containing only the known trend has now expanded into older sediments updip and into younger units towards the coast. Uranium host formations are also now being explored at a considerable depth and distance eastward from known deposits. Only about 30 percent of the potential uranium host rocks in South Texas have been adequately explored. Geology The South Texas uranium deposits are confined mainly to sediments of the Tertiary system. Reserves are divided almost equally between the Whitsett Formation of the Jackson Group, the Catahoula Formation, and the Oakville Formation. A minor amount of the reserves occurs in sands of the Goliad Formation which may be either in the Tertiary or Quaternary Epoch. Figure 1 is a geologic column of the South Texas uranium host formations. These producing formations are marked with a mine symbol but there are also several prospect symbols that denote potentially favorable uranium host formations both younger and older from the producing formations. It is generally accepted by most workers in South Texas that the source for the uranium is the volcanic ash that is abundant within several of the formations. Likewise, the required reductant is considered to be hydrogen sulfide gas, derived from deeper seated hydrocarbon accumulations, that emanate upward along fault zones into favorable host-rock sand units. Within this basic framework of source, host, structure and hydrocarbons is where most of the reserves have been discovered and where most of the current exploration is either concentrating or expanding. Structure in South Texas is predominantly faults. Swarms of faults exist in zones paralleling the coast and running from the Rio Grande to the Sabine River. These faults are usually growth faults with the down-dropped block on the coastward side. Displacement may range from a few feet to a few hundred feet. Dips are near vertical in the younger rocks at the surface but become flatter as the fault cuts older beds in the subsurface. A map of the oil and gas fields in South Texas indicates a correlation between these fault swarms and accumulations of hydrocarbons. It is not coincidental that the known uranium trends closely follow the hydrocarbon accumulations and the faults swarms, all of which supports the theory of uranium concentration by groundwater movement through volcanic ash-rich beds into favorable host rocks impregnated with reducing hydrogen sulfide gases that migrate upward along fault planes from hydrocarbon accumulations. History Newcomers to South Texas are often amazed that active entry is possible in a district that has produced uranium for over 20 years. Understanding the conditions and occurrences of the past would explain why the opportunity still exists for companies not now active in South Texas to become active. Uranium was discovered in the middle 1950's in sandstone units of the Jackson Group at Tordillo Hill in Karnes County. This discovery was followed by a rush involving most of the major uranium exploration companies as well as several of the not-so-major. Those western prospectors who were used to numerous outcrops and neat land subdivisions were further discouraged by the small size and low grade of the deposits. Then after a brief blast, they left South Texas as they found it and returned to the richer diggings of New Mexico and Wyoming. Susquehanna Western was the only one to stay and develop mines in the area. Eventually they discovered enough ore along the Jackson outcrop to warrant constructing a small mill. They managed, with limited budget and diligent effort, to find enough ore to keep the mill going and eventually expanded into exploration in other formations. By the late 1960's, Susquehanna was mining from both the Jackson and Oakville deposits. About this time, the oil companies began to enter the uranium industry and found, that because of sound forward planning, they controlled the uranium on vast tracts of acreage. At this time, which was more than ten years after discovery, there was so little literature on South Texas uranium deposits that the oil companies began following the known trends and off-setting known orebodies. This, and a few kicks on some well gammaray logs, lead to the discovery of new areas in formations that previously had n o uranium discoveries. Still, the following of the trend as it crossed from one formation to another was the main geologic guide. Nowadays, we in South Texas feel that science has entered into the quest to discover new orebodies. The work of Galloway has indicated new pathways to explore. The understanding of multiple stages of oxidation and reduction has created some doubt about areas drilled in the past and abandoned. The expanded use of oil well logs and geochemical prospecting has lured the more progressive exploration companies off the mineral trend and into unexplored areas. Prognostication The fact that uranium exploration in South Texas has been active for only the past ten years is not an indication that South Texas is not a major uranium district. The geology of the South Texas uranium deposits as described here serves only to indicate that similar geology extends in all directions from the known mineral trend as can be seen on Figure 2.

Jan 1, 1979

By Simon D. Strauss

INTRODUCTION The changes in ownership, management, and operation of the non-fuel minerals industry since the Second World War have been dramatic. World-leading enterprises have lost their identity; host countries have taken over operations from multi-national firms; marketing practices have been drastically altered - and yet the world industry is supplying minerals on a scale far greater than had been anticipated in projections made at mid-century. The world's known mineral resources have been enormously expanded, despite the doom sayers who for decades have been predicting that depletion of non-renewable resources would impose limits to growth. PALEY REPORT One can set the stage by reviewing how the minerals outlook was regarded in a thoughtful and comprehensive analysis made in the years 1950 and 1951. During the War years, President Harry Truman of the United States had come to appreciate the decisive role played by minerals resources through his chairmanship as a U.S Senator of a committee that investigated the procurement and allocation of natural resources. In 1950, in the Cold War era that resulted in actual military conflict in Korea, he appointed a prestigious five-man commission to study the problems of Materials Policy over the following quarter century. Their findings, published in five impressive volumes in early 1952, became known as the Paley report. The text was prepared by expert scientists and economists who spent 18 months assembling statistics, making projections of future demand, and interviewing leaders in industry, academia, and government. [ ] The Commission had correctly foreseen that aluminum would replace copper as the largest volume non-ferrous metal, but it had fallen short of reality by a wide margin indeed for all three materials. Even though the Commission's expectations for growth proved to be extremely understated, it had concluded its report with grave foreboding about the effect of its estimates of demand in relation to supply, as follows: "Consumption of almost all materials is expanding at compound rates and is thus pressing harder and harder against resources which, whatever else they may be doing, are not similarly expanding. This materials problem is thus not the kind of 'shortage' problem, local and transient, which in the past has found its solution in price changes which have brought supply and demand back into balance. The terms of the materials problem we face today are larger and more pervasive." With respect to some minerals, the Paley Report expressed scepticism that, in fact, supplies would be forthcoming regardless of price. Because the Paley demand forecasts understated the actual growth in demand for virtually every mineral, one could logically have expected frequent and protracted shortages in the years since 1950.

Jan 1, 1985

By AIME AIME

MIING Engineer. Metallurgist, Economist-in any of those three capacities Paul Tyler should be able to make a living. Further- more, he has proved his ability as an operating man teacher, researcher. and prolific writer. For the last three years he has been chief engineer of the non-metal Economics Division of the. U. S. Bureau of Mines.

Jan 1, 1941

The first practical and successful use of a laser-beam guidance system for a tunnel machine drilling to a remote target has been achieved at the Bureau of Reclamation's Navajo Indian Irrigation Project near Farmington, N. Mex. Using such a guidance system, the Hughes Tool Co.'s "Betti I" drilled a 10,000-ft long tunnel in eight months and 18 days to within 5/8-in, of established line and grade. The electronic system which guided the "Betti I" features a gas laser whose beam is aimed at two light-sensitive targets on the boring machine. From these targets, the operator of the machine receives electric signals on a read-out panel which tell him the machine's precise location within the tunnel. The operator can then make any adjustments necessary to maintain line and grade while drilling ahead.

Jan 6, 1966

By J. W. Hickman

Most of the electron diffraction studies of oxide films which form on metals and alloys have been carried out by oxidizing the specimens in an auxiliary furnace, cooling down to room temperature and then inserting the sample in the camera and taking a diffraction photograph. Prior to the investigations at the Westinghouse Research Laboratories, no systematic study of the oxidation of any metal or alloy had been made over a wide temperature range with photographs taken at elevated temperatures except the investigation of iron by Jackson and Quarrell.' In order to interpret the electron diffraction patterns of the oxides which may form on alloys, it seemed advisable to make a comprehensive study of the oxidation of the purest metals available in the bulk form. Thus far studies have been completed on iron,2 cobalt,~ nickel,= chromium,= copper,z tungsten,s molybdenum,3 beryllium,' uranium,' thorium,' titanium6 and zirconium6 while investigations are in progress on tantalum and columbium. The next step in the study is concerned with the investigation of the oxides which form on binary alloys. Some of the alloys consist of a single phase while others contain more than one phase. The identification of the oxides on the surface of a binary alloy may be more difficult than on the metals since oxides containing both metals as well as those of each metal separately may form. Furthermore, it is possible that solid solutions of the various oxides may occur. In these cases the electron diffraction method may not be able to identify the oxidation products unequivocally. Examples of solid solutions which may present difficulties are MOO* and WOp, Fe304 and FeO.CrnOa since the diffraction patterns are so similar. Since electron diffraction can determine only the structure of the oxide, the chemical composition must be inferred from the diffraction data based upon X ray diffraction investigations of specimens of known composition. It is possible in some cases to decide whether a given solid phase reaction can occur on the surface of an alloy by a study of available thermodynamic data. Table I lists the equations for the formation of most of the oxides from the elements together with values of loglo Kg for the several temperatures. AF"B = -RT In KR AF°R and KR are the free energy and equilibrium constant of the reaction. Calculations may be made using the the given in I 1 to determine whether a given solid phase reaction is possible thermodynamically. For example, a solid phase reaction should occur between aluminum and chromium oxide to form

Jan 1, 1949

By Peter H. Fletcher

THE ECONOMIC THEORY It will assist in the understanding of the Resource Rent Tax ("RRT") proposals in Australia if the economic theory behind the tax is briefly explained. The idea goes back to the concept of rent put forward by the nineteenth century economist David Ricardo. His analysis was broadly as follows: A tenant who farms land which is just on the margin of economic viability cannot afford to pay his landlord any rent, because the value of the crop produced by such marginal land is equal to the cost of producing the crop, plus the cost of keeping the tenant alive. There is nothing left out of which to pay rent to landlord. A tenant who farms good land can afford to pay his landlord rent -- but the maximum amount of rent that he can be asked to pay is the excess of the value of the crop produced by the good land over the cost of producing the crop and of keeping the tenant alive. Adapting this theory to the taxation of mining projects, modern economists who favour this system of taxation say that a profitable mining (or resource) project produces rent in the Ricardian sense. The amount of the rent is the excess of the profits by the project over the amount of profit which is required to attract the taxpayer to invest in the project in the first place. This explains why the tax is called "Resource Rent Tax". PAPUA NEW GUINEA PRECEDENT Although Papua New Guinea ("PNG") is now independent of Australia, there are still close links between the two countries, and strong similarities between their respective tax regimes. PNG introduced an Additional Profits Tax ("APT") in 1978. In many respects, Australia's RRT proposals follow the precedent set by PNG1s APT. However, in practical terms, not a great deal can be learned at this stage from PNG's experiences since, according to the writer's understanding, no PNG mining project has yet paid any APT. The Bougainville mine is not liable to APT, being subject to tax under its own separate Act, which contains a different formula. Outline of PNG Additional Profits Tax. PNG has two versions of Additional Profits Tax ("APT) - one applying to general mining, the other to petroleum mining. The two versions are very similar. The general mining version is described below. The tax applies on a licence by licence basis. This means that losses on Licence A cannot be offset against profits on Licence B. Expenditure relating to two or more licences, is apportioned "in such manner as the Chief Controller thinks reasonable". Tax is levied on the "accumulated value of net cash receipts" at the rate of (70 - n)% where n=the rate of income tax. The accumulated value of net cash receipts ("av") is calculated as follows: Calculations commence from the first year in which substantial expenditure was incurred on the construction of facilities for the carrying out of mining operations on the licence. For that year the av consists of the total allowable expenditure to date on that lease. For the second year, the av is the av at the end of year one indexed in accordance with the statutory formula set out below, plus the total allowable expenditure in year 2. For year 3, the av is the av at the end of year 2 adjusted by the index factors, plus the total allowable expenditure in year 3. This process is repeated year after year. When the licence starts to earn revenue, the revenue is deducted from total allowable expenditure for that year. If revenue exceeds total allowable

Jan 1, 1985

By R. J. Brown

Design of a submarine pipeline system is governed by many factors, one of which is the effect of transverse horizontal currents on the pipeline structure itself Although this feature alone can be of utmost importance to the life span and stability of the underwater pipeline, it is usually the least recognized, with these hydro-dynamic forces being either completely overlooked or grossly underestimated. In an attempt to supply the methods and means for stabilization of sub-marine pipelines, much capital has been spent by pipeline companies. Design criteria incorporated by these organizations extend over a broad spectrum of engineering with bases varying from pure theory to cut and dry methods. A history of numerous failures has substantiated the postulate that many of these submarine pipelines have been underdesigned from the stability standpoint. By the same token, equally as many have been excessively overdesigned with resultant excess expenditures. An attempt has been made in this paper to establish the magnitudes of these hydrodynamic forces by measuring the lateral current-induced differential pressure distribution around the periphery of the submarine pipeline. INTRODUCTION The expenditure of money for research by corporations obviously requires beneficial results to justify the investment. One of the functions of the engineer is first to make the problem known and then to provide a means of solution at the least possible cost. The initial procedure is to investigate all pertinent published technical articles on the subject to determine if this problem has been previously solved. If resolution of this problem is not obtainable, the next course of action is to evaluate through experiments these forces and their magnitudes. On the specific subject of drag and lift, the accumulation of data is provided from three separate and distinct sources: from experience, from theoreticians and through experimental observations. The experience source has proved costly with money wasted either because of underdesign and failure or excessive expenditures for overdesign, and has not been sufficient to form a definite conclusion on these hydrodynamic forces. The pure theoretician is often not completely cognizant of the situation and his works bear little adaptation to the real problem. The experimentalist has his own problems with regard to obtaining results from small-scaled models and successfully adapting them to the larger prototypes. Each method has its own advocates who diligently adhere to their own separate routes as being the only means of resolving this problem. However, a review of the various methods of analysis leads one to the conclusion that if the advantages of all three are combined, a reasonable solution to this problem can be reached. Briefly then, the problem is to obtain the magnitudes of the forces on the submarine pipeline subjected to a lateral current by investigations of previous design considerations, by a study of existing theoretica1 data and by appropriate experimentation. This paper deals mainly with obtaining experimental data and the interweaving of theoretical and experience factors for resolution of these forces. APPARATUS AND PROCEDURE These tests were performed in 1961 at Collins Construction Co.'s main office near Port Lavaca, Tex. Test equipment consisted of a steel tank 3 ft high by 4 ft wide by 40 ft long, with several pumps circulating the water through the tank via suction lines from the downstream portion of the tank and discharging from the pumps directly into the upstream end of the tank. For reduction of turbulence, a wire section was constmcted in the upstream portion and straightening vanes in the form of pipes, screens, etc., were used to reduce the vortex and eddy action in the tank (Fig. 1). A venturi was built at the test specimen for obtaining velocity sufficient to simulate actual conditions. This full-scale test was initiated to eliminate the error introduced in modeling and obtain a truer picture of forces actually encountered. Six- and 10-in. specimens were prepared by

Jan 1, 1967

By Frank H. Kneeland

Safety First is a popular motto—most mining companies have adopted it. It is probable, however, that in the majority of cases it is only a motto and gets no further than the office stationery or the bulletin board at the mine's entrance. In but few industries is there employed a greater diversity of machinery and mechanical devices than in coal mining. The list ranges all the tray from mechanical stokers to wood-working machinery and undercutters. Many of these devices, particularly those employed in wood working, are extremely dangerous. In 1913,23 per cent. of all fatalities occurring in coal mining in the U. S. were caused by machinery of some sort or other. Although the forms of accidents occurring with mining machinery are legion, they generally arise from one or more of five causes: (a) Falls from ladders, platforms, etc.; (b) coming in contact with moving machines or parts thereof; (c) electric shocks; (d) failure of some machine part; (e) mismanipulation of valves, levers, switches or other hand-operated controlling devices. The steps which may be taken to prevent accidents from the above causes are almost as numerous as the accidents themselves. There is, and can be, no panacea for all mishaps, nor for any one class of accidents. There is no mathematical or other formula that will bring immunity under any set of conditions. Common sense is the only guide. The remedy for the first-named class of accidents is simple and generally effective—namely, make the staging, ladder, platform, or other support, abundantly strong to carry any possible weight that it may be called upon to bear; provide ample railings on platforms or runways, and non-slipping feet on movable ladders. Coming in contact with moving machine parts is one of the greatest dangers met with in the operation and maintenance of mining machinery. Unfortunately, machine manufacturers have not as a class adopted the idea of thoroughly protecting and incasing the dangerous parts of their product. No one has, or should have, a better or more thorough knowledge of what the dangerous parts or elements of a machine may be than its builder. The desire to construct a piece of mechanism as cheaply as

Jan 1, 1915

SEVERAL distinctions can rightfully be accorded the Bagdad enterprise. For one thing, it has the most romantic name among the Porphyry Coppers and this is said with all due deference to Copper Queen and Inspiration! Bagdad was one of the richest and most magnificent cities of the glamorous world of the Arabian Nights. The record does not say who was responsible for applying the name Bagdad to the company that in 191 1 took over the property of the Arizona-Nevada Copper Company; but whoever it was must have had visions (or at least hopes) of a fabulously profitable mine. So far as I know, Bagdad is the only Porphyry whose owners, or officials, ran afoul of the law because of alleged sins of omission or commission in vending shares of the company's stock. E. B. Bronson, of New York, had been interested in Bagdad since 1909; and, during the lean period of the 1930's he had, as president of the corporation, endeavored to raise needed funds by the sale of 140,000 shares of treasury stock. Some legal questions arose as to the need for registration under the Securities and Exchange Act; but, when Mr. Bronson finally filed a registration statement, the New York office of the Securities and Exchange Commission found 155 "deficiencies" in the document. According to the judge who later heard the criminal case against Bronson, no evidence was introduced to show that he had personally benefited "to the extent of one dollar." However, it was charged that the setup was such that he was in position to profit if he had wanted to! A somewhat quixotic position, it would seem. In any event, he was convicted, on highly technical

Jan 1, 1957

By W. H. Lewis, J. C. Yingling, M. H. Leon

This paper describes the present state-of-the-art and status of longwall lighting in the U.S.A. Specific subtopics discussed are as follows: review of MSHA lighting regulations and requirements for longwalls; overview of available lighting hardware; installation procedures and costs; analysis of installations to date, including operator and management acceptance, complaints, benefits, and maintenance considerations.

Jan 1, 1981

EASTERN VENEZUELA PETROLEUM Established December 15, 1954 Meets fourth Thursday each month at Chepa's Ice House in Anaco Glenn N Murchey, Chairman Jerome C Kearby, First Vice-Chairman J L Thompson, Second Vice-Chairman Thomas G Wall, Treasurer G J Clarke, Secretary Mene Grande Oil Co Apartado 3974 Caracas, Venezuela S K Wilkie, '58, Section Delegate

Jan 1, 1957

By M. R. J. Wyllie, Walter D. Rose

The use of electrical well logs for the quantitative determination of such reservoir parameters as connate water saturation, formation permeability and connate water salinity has recently been attracting the attention of a number of workers1,2,3,4,5. While the theory of the determination of connate water salinity from the self potential S.P. log has received rather detailed treatment, relatively little attention has been paid to the theoretical aspects involved in the quantitative interpretation of resistivity data. It is clear that if electrical well logs can be used for the quantitative evaluation of physical characteristics of reservoir rock, they will provide a valuable tool to supplement cheaply information obtained by more laborious core analysis. In certain cases it is conceivable that the coring program could be considerably curtailed if the electric log could be relied upon to give reasonably accurate quantitative information. It is our object in this paper to examine the theoretical basis of quantitative log interpretation as expressed in such well-established logging concepts as formation factor and cementation factor. It is also our object to investigate the physical aspects of the rela- tionship which is presumed to exist between resistivity index and brine saturation in reservoir rock. In particular, we will endeavor to draw attention to the fact that it is possible to express these logging concepts in terms of capillary pressure-saturation relationships, permeability and tortuosity, parameters which we will consider in this paper to be fundamentally indicative of rock texture. The probability of being able to obtain from log recordings alone the data theoretically essential to permit quantitative log interpretatiou will be examined, and consideration will also be given to the problem of formulating simple semi-empirical relationships for use in the field. THEORETICAL CONSIDERATIONS The concept of formation resistivity factor, or as it is now commonly called, formation factor, appears to have been introduced by G. E. Archie",". Formation resistivity factor as defined by Archie is the resistivity of a rock 100 per cent brine-saturated divided by the resistivity of the brine. This relationship had previously been used by physical chemists and the concept is, for example, implicit in an early treatment by Fricke7 of the conductivity of aqueous slurries. Archie was able to establish the fact that although the relationship between formation factor and porosity did not change too greatly for different rock textures, the relationship between formation factor and permeability was markedly dependent on rock texture. The relationship found by Archie between formation factor and porosity was expanded by H. Guyod8. Archie had suggested that the formation factor, F, could be expressed in terms of the porosity, F, as follows: F =F-m .... (11 where, F = effective porosity fraction of the sand, and, m = an exponent greater than about 1.3. Guyod introduced the term cementation factor for the exponent, m, since it may be qualitatively shown that formation factor for any given porosity tends to increase as the sand becomes more cemented. It would appear that the concept of m as an exponent representing the cementation in a sand is strictly only of qualitative value, since the quantitative estimation of m by means other than the determination of F and F has not been possible. Guyod suggests that m can be estimated from a visual examination of a sample of rock, but this method appears to be both arbitrary and unreliable. It can be said, however, that in intergranular reservoirs of practical interest, the range of m is from about 1.4 to 3.0. A possible explanation for the fact that m is found to lie between these limits will be offered below. The determination of formation factor is an essential preliminary to the

Jan 1, 1950

By William Braden

This paper is presented in the hope that it will be instructive in view of the future large expansion of the mining industry in the west-coast countries of South America. There is a more or less general impression that the Spanish-American workman is inferior to the American, but after some years of experience and observation I doubt the correctne~s of this view. Taking into consideration all the elements which make for efficiency of labor, it has been found, particularly in Chile, that under proper organization native labor yields as much, man for man, and more, dollar for dollar, than in the Western United States. If a manager is willing to accept unreservedly the costum-bres del pais, without combating intelligently and patiently the ones tending to inefficiency, he should expect no better results than he deserves. He must conscientiously insist that a " square deal" be given and exacted; that liquor be excluded from camp as far as possible; that comfortable quarters and other uplifting elements of life be provided; and that past and existing methods and customs shall not be over-ridden rough-

Jan 1, 1910

By H. C. Doepken

Wrought Hadfield steel was tested in axial tension at from 100° to —196°C, to determine flow and fracture stresses as well as conventional properties. Ductility and related properties, such as fracture stress, decreased continuously with temperature. Peculiarities during straining indicated possible martensite formation or mechanical twinning. THE mechanical properties of austenitic manganese steel have been summarized by Avery and Day,' including the low temperature tensile properties reported by Hadfield and coworkers2,3 " These data show the material to be brittle at both liquid oxygen and liquid 'hydrogen temperatures. Avery and Day report considerable ductility measured by Charpy V-notch tests at —100°F (-73°C). Since the review of low temperature properties by Seigle and Brick' show face-centered cubic structures, other than Hadfield steel, to be ductile at low temperatures, it was felt that a study of tensile properties, between the reported intervals, should show whether the decrease in ductility was a gradual decline or an abrupt drop beginning at some intermediate point. X-ray examinations were made in an attempt to shed further light on the mechanism of work hardening of austenitic manganese steel. The presence of a magnetic constituent has been found by Hall" and by Avery, Homerberg, and Cook." Krivobok7 demonstrated the growth of magnetic constituents on reheating cold-worked specimens. Hadfield2,3 ' and Goss found no a iron. The steel from which the specimens were taken was commercial hot rolled % in. diam rod of electric furnace steel. The ladle analysis was as follows: C, 1.40 pct: Mn, 12.11; P, 0.060; S, 0.012; Si, 0.120; Ni, 0.080; and Cr, 0.090. Fifteen specimens, 6 in. long, were cut from a

Jan 1, 1953

The first meeting of the Naval Consulting Board was held at the office of the Secretary of the Navy, Washington, D. C., on Oct. 6, 1915. The Board organized by electing Thomas A. Edison, Chairman, Peter Cooper Hewitt, First Vice-Chairman, William L. Saunders, Second Vice-Chairman, and Thomas. Robins, Secretary. All of these officers are members of the American Institute of Mining Engineers. The other members of the Board are given below, and those who are members of the Institute are marked with an asterisk: *W. R. WHITNEY MATTHEW B. SELLERS. L. H. BAEKELAND. HUDSON MAXIM. FRANK JULIAN SPRAGUE. HOWARD T. COFFIN. BENJAMIN C. LAMME. ANDREW J. RIKER. R. S. WOODWARD. HENRY A. WISE WOOD ARTHUR GORDON WEBSTER. ELMER A. SPERRY. A. M. HUNT. *BENJAMIN B. THAYER. ALFRED CRAVEN. *J. W. RICHARDS. *SPENCER MILLER. *LAWRENCE ADDICKS. WILLIAM LE Roy EMMETT.

Jan 12, 1915

By F. W. Osterwald, C. R. Dunrud

Coal mine bumps are a serious hazard to life and property in the mines of east-central Utah. Research into geologic factors associated with these bumps indicates that the bumps are spatially and genetically related to structural and stratigraphic features. Some bumps are directly related to stress accumulation along faults, either from natural causes or as a result of mining. Frictional properties of bedding planes between coal and roof rock, and between some rock units within the roof, directly affect the deformation of coal ribs, and hence the incidence of bumps. These frictional properties are related to the lithology of the roof rocks as well as to the sedimentary structures within the rocks. Commonly a sequence consisting of 1/3 ft of carbonaceous silt-stone, about 2/3 ft of rider coal, and several ft of massive siltstone or sandstone overlies the main seam. The sequence causes difficult roof conditions in the mines, difficult mining conditions and, directly or indirectly, many bumps. The U. S. Geological Survey has studied the relationships between geological features and coal mine bumps at Sunnyside, Utah, for about six years. The work, which was originally undertaken at the request of and in cooperation with the U.S. Bureau of

Jan 1, 1965