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By Milton H. Fies

Although pig iron from iron ore and red cedar charcoal preceded the mining of coal by many years, for tradition says that Alabama iron was used to shoe the horses of Andrew Jackson's soldiers, coal was not produced until 1830. In that year, coal was mined in Tuscaloosa County, in the vicinity of what is now the University of Alabama, and shipped on flat boats (obviously during the wet season, for there were many shoals) down the Warrior River to Mobile. About that time, the first railroad, the Decatur & Tecumseh, was being constructed in northern Alabama to overcome the obstructions to freight traffic caused by the now well-known Muscle Shoals in the Tennessee River. This railroad was patterned after a railroad at Mauch Chunk, Pa., which was used for hauling anthracite from the Panther Creek valley. The Alabama railroad, which required about four years to complete, was 46 miles long and was used solely for the transportation of cotton. Although it was a failure, it demonstrated the practicability of the undertaking, and the succeeding railroads, which were begun in 1834, 1848, 1852, and 1853, added immeasurably to the development of the coal resources of the state. Between the years 1830 and 1860, practically all the coal mined in the state was dug from the outcrop near the river or from the river beds, and shipped by boat to Mobile. Transporting coal down the Warrior River was an undertaking of great risk, required much skill, and frequently had heavy losses. It is recorded that this coal was sold to the gas company in Mobile in 1844; it was most likely mined from the Black Creek Seam. In 1914, on the completion of Lock 17, the Warrior River became a navigable stream from 9 miles above Cordova, Ala., to Mobile and offers a great opportunity for the future development of the coal resources of the state. Coke for foundry use was first made in Alabama in 1855. It was 21 years later, however, in 1876, that pig iron was made from Alabama ore with Alabama coal.

Jan 1, 1925

By Keijiro Nishio

At a time of great antiquity when our Yomato tribe had not yet found its way throughout the country, there lived in Japan barbarous tribes of the stone age, whose dwellings were vertical caves covered with roof's of twigs and weeds. In a cave lately discovered at the village of Morita, 10 miles west from the port of Aomori, there were found pieces of micaceous iron-ore and psilomelane, with oval holes pierced from both sides. Apparently these objects were regarded as ornaments or curios, without being applied to any practical use. Among the traditions given in the Nihonshoki, an ancient history of Japan, there is one relating to the mining industry. According to this tradition, in the mythological age Izanami-no-Mikoto gave birth to Kanayamahiko-no-Mikoto, god of mines, and Amaterasu-Okami (the sun-goddess) was armed with swords. It came to pass at one time that she concealed herself in Ama-no-Iwato ("Heavenly Cave"), and several gods made contrivances to entice her out. Among them, Ishikori-dome, a smith, made a mirror with copper obtained from the Ama-no-Kagoyama, by means of a pair of bellows known as the Ama-no-habuki, which was made of a deer-skin. It is recorded also that Susanb-no-Mikoto, her younger brother, observed the abundance of gold and silver in Korea, where his descendants were to reign, and urged them to provide themselves with boats to convey them across the Sea of Japan. In the course of time he accomplished his object, proceeding to Korea with his son, Isotakeru-no-Mikoto. These accounts

Jan 1, 1913

By B. H. Sage, R. T. Carter, W. N. Lacey

The phase behavior of a number of binary systems consisting of parafin hydro-carbons has been determined in recent years. In addition, the composition of the coexisting phases of mixtures of crude oil and natural gas has been investigated.~ However, the latter study did not include information concerning the influence of the concentration of a component upon its distribution between two coexisting phases. Owing to the paucity of such information it was considered desirable to investigate in some detail the composition of the coexisting phases in the methane-propane-n-pentane system throughout the greater part of the two-phase region at a tempera-ture of 100°F. Information of this nature also permits the establishment of the critical behavior of this ternary system. Method The compositions of the coexisting phases in this ternary system at 100°F. were deter-mined by withdrawing samples from a pres-sure vessel containing a heterogeneous mixture of the three components that had been brought 10 equilibrium by mechanical agitation at the desired pressure and tem-perature. The samples were withdrawn under such conditions that the equilibrium was not disturbed and the composition of each of the phases was ascertained by means of the conventional low-temperature fractionation procedure. The apparatus employed in this investi-gation was nearly the same as that utilized in an earlier study of the methane-pentane system.~ Several minor modifica-tions in the arrangement of the apparatus were made in the interest of simplifying the procedure and avoiding the possibility of condensation in the tubing connecting the equilibrium apparatus with the analyti-cal equipment. The pressures were meas-ured by means of a pressure balance with a precision of 0.5 lb. per sq. in. It is believed that the equilibrium pressure was ascer-tained with an uncertainty of not more than 2 lb. per sq. in., even though small varia-tions in pressure obtained during the withdrawal of the samples. The tempera-ture of the equilibrium equipment was maintained by use of an automatically controlled oil bath. The bath temperature was determined by means of a copper-constantan thermocouple, the electromo-tive force being determined by means of a potentiometric circuit of such a nature as to reduce the uncertainty of the tempera ture to less than O.I f. The fractionating column employed in the determination of the composition of the gas phase had a diameter of 0.12 in. and was approximately 4 ft. long, while the column employed in the analysis of the liquid phase was 0.18 in. in diameter and about 5 ft. long. Each column was equipped with the conventional constant-volume receivers, which were maintained at a constant temperature by means of an automatically controlled oil bath. In nearly every case the distillation in thr neighborhood of the transition between

Jan 1, 1941

By W. N. Lacey, R. T. Carter, B. H. Sage

The phase behavior of a number of binary systems consisting of parafin hydro-carbons has been determined in recent years. In addition, the composition of the coexisting phases of mixtures of crude oil and natural gas has been investigated.~ However, the latter study did not include information concerning the influence of the concentration of a component upon its distribution between two coexisting phases. Owing to the paucity of such information it was considered desirable to investigate in some detail the composition of the coexisting phases in the methane-propane-n-pentane system throughout the greater part of the two-phase region at a tempera-ture of 100°F. Information of this nature also permits the establishment of the critical behavior of this ternary system. Method The compositions of the coexisting phases in this ternary system at 100°F. were deter-mined by withdrawing samples from a pres-sure vessel containing a heterogeneous mixture of the three components that had been brought 10 equilibrium by mechanical agitation at the desired pressure and tem-perature. The samples were withdrawn under such conditions that the equilibrium was not disturbed and the composition of each of the phases was ascertained by means of the conventional low-temperature fractionation procedure. The apparatus employed in this investi-gation was nearly the same as that utilized in an earlier study of the methane-pentane system.~ Several minor modifica-tions in the arrangement of the apparatus were made in the interest of simplifying the procedure and avoiding the possibility of condensation in the tubing connecting the equilibrium apparatus with the analyti-cal equipment. The pressures were meas-ured by means of a pressure balance with a precision of 0.5 lb. per sq. in. It is believed that the equilibrium pressure was ascer-tained with an uncertainty of not more than 2 lb. per sq. in., even though small varia-tions in pressure obtained during the withdrawal of the samples. The tempera-ture of the equilibrium equipment was maintained by use of an automatically controlled oil bath. The bath temperature was determined by means of a copper-constantan thermocouple, the electromo-tive force being determined by means of a potentiometric circuit of such a nature as to reduce the uncertainty of the tempera ture to less than O.I f. The fractionating column employed in the determination of the composition of the gas phase had a diameter of 0.12 in. and was approximately 4 ft. long, while the column employed in the analysis of the liquid phase was 0.18 in. in diameter and about 5 ft. long. Each column was equipped with the conventional constant-volume receivers, which were maintained at a constant temperature by means of an automatically controlled oil bath. In nearly every case the distillation in thr neighborhood of the transition between

Jan 1, 1941

By J. Q. Ehrgott

INTRODUCTION The U. S. Army Engineer Waterways Experiment Station (WES), under sponsorship of the Defense Atomic Support Agency, has recently developed a unique dynamic high-pressure triaxial testing device (DHT). The device permits acquisition of both axial and lateral deformation data while undisturbed soil and/or rock specimens are subjected to various states of controlled impulsive-type stresses produced by varying both the axial stress and the radial stress rapidly with time. The device is used to develop controlled dynamic pressure pulses within the triaxial chamber fluid on soil or rock test specimens to 3 inches in diameter. Controlled dynamic axial pulse loads are delivered to the specimen by a piston driven by an existing pneumatic ram loader (SECO). The DHT consists of a triaxial cell and a pressure supply and decay system which permits the chamber pressure to be varied with time. Together the DHT and SECO operate in a testing program so as to provide time varying confining pressures and axial loads to test specimens at independently controlled but synchronized programmed rise, hold, and decay times. Rise time is defined as the time from zero load or pressure to peak load or pressure; hold time is the time of constant peak load or pressure; and the decay time is the time from peak load or pressure to zero load or pressure. The maximum dynamic confining pressure attainable is approximately 15,000 psi and the fastest rise and decay times are 3 millisecond (msec) and 20 msec, respectively. This paper presents a description of the DHT, the necessary support equipment, and details of the measurement system. Performance evaluation tests conducted on clay siltstone and a Cretaceous sandstone are presented since the results demonstrate some of the capabilities of the device and show some of its characteristics.

Jan 1, 1971

By Clarence Zener

IT is customary to regard the stress-strain relation as consisting of two parts, the elastic region and the plastic region. The essential attribute of the plastic region is the presence of a permanent set, which remains upon removal of all stresses. The essential attribute of the elastic region is the absence of such a permanent set. Absence of a permanent set does not imply a linear relation between stress and strain, nor even a single valued relation. In fact, in no real metal is stress a single valued function of strain in the elastic region. The property of a solid in virtue of which stress and strain are not uniquely related in the elastic range will be called "anelasticity." The purpose of the present article is to review and correlate the past work upon the anelasticity of metals. The following paper by W. A. West124 describes investigations upon anelastic properties of iron. Many manifestations of anelasticity have been observed, the first as early as 1835 by Weber.1,2 In his experiments Weber subjected a specimen to a constant load (or deformation) for a given time, and then suddenly removed the load. He observed that most of the deformation suddenly disappeared, but that there remained a residual deformation, which disappeared only gradually with time, as is illustrated in Fig. I. The occurrence of a residual deformation which only gradually disappeared, Weber called the elastic after-effect (Elastische Nackwirkung). An extensive review of the early work upon elastic after-effects has been given by Auerbach.3 Another manifestation of anelasticity is the dependence of the elastic constants-e.g., Young's modulus upon the method of measurement. Thus, if dynamic methods are used, the measured value will depend upon the frequency of oscillation. Still another manifestation is dissipation of energy attending vibration, called damping or internal friction. One objective of metallurgical science is the understanding of the plastic and fracture properties of metals in terms of their microstructure. Through such an understanding will come the ability to design microstructure to give the desired mechanical properties. A study of an elasticity will furnish an invaluable aid in the attainment of this objective. Such studies, when properly guided, yield information regarding the relation between stress and strain in the individual components of the microstructure. In order, however, that this type of information may be obtained, it is necessary that the experimental studies of anelasticity be interpreted by the appropriate mathematical analysis. This article, therefore, starts with the mathematical formulation of anelasticity.

Jan 1, 1946

(Members are urged to send in for this column any notes of interest concerning themselves or their fellow-members.) Members and guests who called at Institute headquarters during the period Feb. 10, 1916 to Mar. 10, 1916: D. A. S. Bell, Ottawa, Can. E. B. Latham, Santa Maria, Cal.. John Cooper, Exeter, Devonshire, Eng. H. N. Lawrie, Portland, Ore. I. Dally, Seattle, `Wash. L. A. Levensaler, Tacoma, Wash. George W. Evans, Seattle, Wash. George J. Lyon, Schenectady N. Y. Alexander Fyfe, London, Eng. Fred MacCoy, Antofagasta, Chile. F. C. Greene, Seattle, «rash. J. Mitchell-Roberts, London, Eng. I. Ishikawa, Tokio, Japan. Chas. W. A. Sultan, Yonkers, N. Y. William Kelly, Vulcan, Mich. R. B. Tinsley, Big Stone Gap, Va. Paul S. King, Wilmington, Del. Walter E. Trent, Reno Nev. Oscar Lachmund, Greenwood, B. C. Alfred W. G. Wilson, Ottawa, Can. J. S. Lane, New York City. Nelson Dickerman has resigned as general Manager of the Pato Mines (Colombia), Ltd., and The Nechi Mines (Colombia), Ltd., and will return from Colombia to San Francisco, Cal., the latter part of April. W. A. Prichard has been appointed as his successor.

Jan 4, 1916

J. M. Wadsworth,' Okmulgee, Okla. (written discussion).—It seems to me that thc young man must first be absolutely sure that the work he has taken up is to his liking and then I would advise that he get into the practical end of it and learn as much about it as he can as fast as he can. For instance, in the refinery business the college man, graduated in chemical engineering, should ground himself by going through the various departments in a refinery and working in them until he is thoroughly familiar with the operating problems. In a short time he would be able to apply many things which appear in the abstract form in his college work and this would opcn up an opportunity for him to capitalize on them, promoting his own interest. I do not criticize the present-day college men as a class, but I have found that many of them come into your plant with the idea that mere possession of a diploma should insure rapid promotion; in a short time they are impatient and usually leave. We have found in employing men that the single attribute most difficult to find in them is a lot of energy and whole-hearted interest in the work at hand, and it seems to me that if a man combines these with a careful technical training he should be fairly well equipped to gamble on his future. They must learn that the biggest satisfaction to be gained in life is in their work. Procedure for Attaining Objective of Young Petroleum Engineer H. B. Fell,+ Ardmore, Okla. (written discussion).—Of course, the first thing to be ronsidered in any proposition is the ultimate objective that is desired to be attained. 1 presume that the desired objective of most of the young men graduating in petroleum engineering will be that of chief executive of one of the companies in the petroleum industry, or one of the allied industries, or to become an independent oil producer, or oil refiner, or possibly an oil distributor. The next phase then to be considered is the procedure which should most logically be followed to attain the objeckive of the indivitlual, since in these cases these young men will have been trained in a course in petroleum engineering and it would logically be presumed that the attainment of their objective should be through the operating end of the branch of the business with which they are connected. The operating end is, of course, the department of each branch of the business that develops the resources, or refines the products, or distributes the products, from which the profits are derived, and is a part of any business which is filled with enough interesting work to appease the desires of the most ambitious young men. In order to get the best possible training it would appear to me that the place for a young man to start after graduation would be at the bottom of that branch of the industry which he expects to follow. For example, if he is going in the producing end he can gct no better training than is secured by starting as a roustabout in the ficltl, where he romes in constant rontact with the character of work that is necessary

Jan 1, 1928

By Allan J. Clark

It is nearly three years since the metallurgy of the Homestake ore was discussed with considerable thoroughness, in a paper1 read before the Institution of .Mining and Metallurgy. Certain changes have been made in this period which are perhaps of sufficient interest to justify a brief description, and it is chiefly with such details and miscellanies that this paper will deal. In the circumstances, a certain amount of repetition is inevitable, but matter treated of in the former paper will be referred to here only when it is necessary for the sake of coherency. For full descriptions of equipment and technique, the former paper should be consulted. The mineralized slates and schists which constitute the ore vary considerably in composition, but the unoxidized ore, perhaps constituting the major part of the reserves, contains either chlorite or hornblende (cummingtonite), with quartz, carbonates of lime, magnesia and iron, and arsenopyrite, pyrite, and pyrrhotite. Ferrous minerals predominate, and this fact has been an important factor in determining the metallurgical treatment. With one or two exceptions the minerals noted are of relatively high specific gravity, and the ore as a whole is exceptionally heavy, many determinations giving an average specific gravity of 3.00. This high specific gravity presents one decided advantage, when the cost of treatment is compared with operations elsewhere, in that the ton, almost universally the basic unit, represents a volume probably less by 10 per cent. than that of many gold ores. On the other hand, this high gravity renders more difficult the discharge of pulp from mortars, its distribution on amalgam tables, and its transportation in launders. In the same way, as attesting the usual balance of such variations of different ores, it may be noted that the needle-like fibers of hornblende (cummingtonite), interlacing throughout the mass, render the ore more difficult to crush than would be anticipated, but on the other hand assist

Jan 1, 1916

By W. E. D. Jr. Stokes

THE application of aviation to mining and petroleum operations, on the basis of economy and attainment, has become a demonstrated fact. According to Dominion Government records, 30. Canadian companies engaged in air transportation with northland mining camps, carried 13,000 tons of freight in 1935, and in 1936 carried 16,000 tons. In addition, many mining companies used planes to transport prospectors with canoes, outboard motors, gasoline drums and supplies to remote locations, and one company maintained a plane to take radium-bearing ore from its mine on Great Bear Lake nearly 1000 miles south to the rail-way at Waterways, Alberta. Heavy pieces of mining machinery weighing 2 tons are being carried by Ford trimotor planes over the Andes, at an altitude of not less than 15,000 feet. At Bulolo, New Guinea, 17,500 tons of disassembled gold-dredging equipment has been flown over inaccessible terrain, while supplies and building materials for a, community of 1000 whites have been transported by airplane. A 3 1/2-ton shaft was carried on one notable trip, while at another time an automobile, 2 tons of rice and a large safe went over the mountains in one plane. Fig. 1 shows an electric generator that was carried by plane to Bulolo.

Jan 1, 1937

By T. P. Harrington, P. G. Doctor, K. A. Prisbrey

Crushing and grinding ore consumes so much energy that it represents a major component of total processing costs. While it has been estimated that only about 0.6% of the total energy expended in grinding is actually used to create new surfaces, accurate measurement of this quantity is difficult. If energy expended in crushing and grinding could be more directly measured, alternatives for increasing efficiency of the processes could be evaluated more effectively. Since the energy intensity associated with rock fracture is related to fracture sonority, it should be possible to use this sound (acoustic emission) to measure the actual energy expended. However, it is difficult to apply this approach because the mill environment is so noisy. To make the approach practical, a method for differentiating acoustic emissions caused by rock fracture from those caused by extraneous noises must be found. Pattern recognition analysis may provide such a method. This paper presents the results of pattern recognition analysis to make two types of differentiations: acoustic emissions caused by crushing two types of minerals (quartz and chrysocolla) and those caused by two extraneous noise sources, and acoustic emissions produced by each mineral.

Jan 1, 1982

By E. Maltby Shipp

YouR committee's secretary submits the following report, or summary, to the members of the committee, in an endeavor to lay before them a general review of the information so far received and also his own knowledge of the work as carried on at a number of plants, this being done in part to secure further information and suggestions from members and lead to a more effective means of furthering the work of the committee. It is suggested that more detailed data be compiled regarding engineering features involved, and that papers be contributed which will deal with the safeguarding of underground electrical installations. There are few operating companies which have not started a more or less systematic campaign to safeguard their employees from accidental injuries and unhealthful surroundings, but a great deal is to be gained by experience. All may welcome the advice and cooperation of those who have been actively engaged in the work and have demonstrated the results obtainable by organized effort, and it is, therefore, exceedingly gratifying to note the ready assistance and hearty cooperation rendered by the companies that may be truly termed pioneers in the movement. No solution of the safety problem is to be found in a skrict standardization of methods, rules or devices, as the various mining, milling and metallurgical practices present too many conditions differing broadly in general principles, but some standard system embodying principles already proven to be efficient should be created, which may be modified or elaborated to meet specific requirements of each individual company, or to fit working conditions as they exist in the various mining camps throughout the country. An industrial plant is primarily a business undertaking, therefore the economic side of a safety or welfare campaign is of importance. Many small operators have been deterred from undertaking the work by their belief that it involved an expense beyond their means, and one that could not be counterbalanced by greater efficiency or saving along other lines. This idea is generally due to a lack of knowledge of the actual costs of such work, and of the results secured by judicious selection of a method commensurate with the size and nature of the opera-

Jan 1, 1918

By P. Pollard

A method has been developed for evaluating acid treatments in fractured limestone fields by breaking down pressure drawdown into three component parts: (I) pressure differcntial across "skin" near the borehole face, (2) pressure differential due to flow resistance in the coarse communicating fissures and (3) pressure differential between the fine voids and the coarse fissures. It is apparent that in most successful acid treatments the first term, skin resistance, has been reduced or eliminated. Further, it is often possible to estimate the volume of coarse fissures associated with the second term, coarse fissure flow resistance. In cases where this volume is comparable with practical acid volumes it seems likely that this resistance also may be attacked with a suitably retarded acid. INTROD UCTION Acid treatment has been successfully applied as a general practice in the limestone wells in the Mara/ Maracaibo districts of Venezuela for some 10 years. At the same time the need has been felt for a more precise method of: (1) evaluating the effect of an acid job and (2) selecting wells which should benefit from an acid treatment. The following method, based on an analysis of build-up curves for wells producing from fractured limestone, provides a means of forecasting the effect acid will have on a well and in many cases the probable order of production rate increase which may be expected. In certain cases it is also possible to calculate the fissure volume through which the acid has to be displaced for best results. Various approximations are introduced in the method, but within the limitations of these the analysis gives an indication of how a well, whether previously acidized or not, may be expected to respond to acid treatment. Suitable build-up curves cannot be obtained on "tight" wells which do not give sustained production and the method is not applicable to such wells. Figs. 1 through 7 illustrate various types of build-up curves obtained from limestone wells in Western Venezuela. Curves are included showing (1) both skin and coarse fissure resistance, (2) skin resistance only, (3 and 4) reduction of skin resistance by acidization, (5) fissure resistance only, (6) reduction of coarse fissure resistance by acidization, and (7) acidization failure. This theory has been successfully applied for over three years during which 22 acid treatments have been carried out specifically to reduce skin resistance and three treatments to reduce coarse fissure resistance. The method has been found to be a useful aid in the selection of wells for acidization.

By Norman Weiss

THE need for more efficient utilization of labor in the metal-mining industry has been the subject of several recent editorials in the mining press, and one attractive possibility for such improvement lies in the designing of future milling plants particularly with economy of man-power in mind. We are accustomed to think of mill design as the selection and coordinated arrangement of process equipment, but if labor is to be efficiently utilized it must be given early consideration in planning the new mill. There are three good reasons for economizing in labor: (I) to reduce costs, not only in the form of wages but also in housing, hospital, welfare, and other obligations that a company accepts when a new man is added to the payroll; (2) to prepare for recurrent periods of manpower shortage, during which a well-designed plant can manage to get along with skeleton crews; (3) because a milling plant that must depend upon an inordinately large labor force for its operation and maintenance is certain to be inefficient in other respects, for many of the shortcomings in design that make necessary the excessive use of labor are generally not corrected merely by having too many men. A simple example of this is a poorly designed ore-feeding system: if this is inadequate to the extent that one man must be constantly unclogging feed chutes, it may help the situation to put two men or three at this task instead of one, but the feed rate will still be inconstant. First of the factors that affect labor saving is the location of the mill. This is often determined by transportation costs alone, and as a result the mill may be placed close to the mine regardless of the nature of the terrain. The designer must then adapt his layout to the conditions, favorable or not. This happens often at small properties, where capital investment may seem more important than operating expense. In most instances, however, a mill site carefully selected for the advantages it gives the designer in laying out the plant is the most economical in the long run, even if it involves a slight increase in cost of ore haulage. Given some freedom of choice, the design engineer may be able to find just the piece of ground that provides the proper gradient for the needs of the flowsheet, permits installation of essential yards and trackage, and perhaps supplies an excellent site for a tailing dam. Further justification for having placed the mill not too close to the mine sometimes emerges only years later as an opportunity to treat ores from other properties. When it is known from the beginning that the new mill will serve a number of scattered mines, a free choice of mill site is naturally stimulated. The most important single factor in limiting the labor requirements of a mill is its materials-handling system for bring-

Jan 1, 1946

By D. Watson, T. J. N. Grainger-Allan

A technique for studying the mechanism of the froth flotation process in which continuous froth removal does not take place but, instead, an equilibrium is reached between froth and pulp is described. A flotation cell, specially designed to facilitate equilibration, and froth and pulp sampling procedures are described. The main advantage of the technique is that the ability to measure the steady-state froth height allows froth-stability effects to be separated from pulp-process effects. In the flotation of hematite front quartz, linear relationships are found between airflow rate and froth height and between airflow rate and the ratio at equilibrium of mass of values in froth to mass of values in the pulp. A simple mechanistic interpretation of these results is given. It is suggested that froth-stability effects may play a more important role than hitherto allowed. In particular, the way in which concentration and size distribution of gangue particles may affect overall flotation rate is shown.

Jan 1, 1975

By Franz Wever

ACCORDING to Tammann,1 the explanation of the effect of mechanical deformation in producing changes in the properties of metals is one of the most important problems of physical metallurgy, taking rank with the study of the constitution of alloy systems; and this problem has long attracted-the attention of practitioner and scientist alike. Its solution was not advanced materially until Tammann2 set up his translation hypothesis with its crystallographic basis, while other hypotheses, such as the amorphous metal hypothesis of Beilby3 and Rosenhain,4 have been shown by more intensive studies to be less and less satisfactory. The principles of the Tammann translation hypothesis have proved to be useful even up to today and in spite of all of the recent accumulation of experimental data, while the differences of opinion which have arisen relate to the extent to which the hypothesis accounts for the observed changes in properties and to what extent further assumptions are necessary. Stimulated by the proposals of Tammann, there soon developed a lively experimental activity which aimed at the elucidation of the structural or crystallographic changes produced by the mechanical deformation of metals. Parallel movements of crystal "blocks" along definite crystal slip planes had already been observed by lowing and Rosenhain5 in 1900, in metals which had been moderately deformed but without shedding light on the crystallographic nature of the processes accompanying more severe deformation. The solution of this important problem was not advanced until a much later date, or until the methods of X-ray crystal analysis had become available. Shortly after the discovery of the diffraction of X-ray by crystals, symmetrical diffraction effects were

Jan 1, 1931

By R. W. Raymond

Under the names of Conservation, Social Justice, the New Nationalism, and Progressive Democracy, many earnest reformers are calling for a new system of Federal government to replace the one which they ascribe to our fathers, and declare to have been outgrown. They are proposing the lease by the United States of certain natural resources on the public domain, for the profit of the U. S. Treasury, instead of the sale of such resources to private citizens or associations of citizens. In the present paper, I shall try to show that this notion is neither new nor good. It is clear that the United States is owner, as well as sovereign, of public lands acquired through conquest or purchase from other nations, as it was owner of the public lands expressly ceded to it by the original thirteen States. Its policy with regard to such lands involves, therefore, two entirely distinct questions: What shall it do as owner ? and, What shall it do as sovereign ? The latter question, it must be confessed, has played but a small part in our history. All the prerogatives of sovereignty which were not explicitly conferred upon the Federal government by the original States were retained by them. The ownership or control of precious or other metals or minerals in the earth, for instance, was thus reserved to the several sovereign States. New York, South Carolina, and other States have passed laws on this subject, without regard to Federal authority. As new States have been successively admitted to the Union, the tacitly accepted theory has been, that they thereby acquired all the reserved rights of the original States. These newer States largely outnumber the first thirteen; and it is inconceivable that they would submit to any deprivation of sovereignty based on historical grounds. One of them—Texas—came into the Union by its own voluntary

Jan 1, 1913

By Robert Linton

Tats paper deals with work that has been carried on for over three years by the management and staff of the North Butte Mining Co. in an effort to standardize mining methods, to eliminate lost motion in the operating organization, and to improve the efficiency of the individual workman. Naturally, much of this work is an adaptation of ideas suggested by other mining operations or by practice in manufacturing and other productive industries. The studies, however, have developed some features that it is believed are new. Both new and adapted features are given in detail. The normal capacity of the North Butte mines is about 2000 tons per. day. Hoisting is done principally through the Granite Mountain shaft, which is 3740 ft. (1140 m.) deep and equipped with an electric hoist capable of hoisting 200 tons per hour from a depth of 4000 ft. (1219 m.). The lowest stoping level is the 3400-ft. The Granite Mountain shaft is connected with the Speculator shaft, about 850 ft. (259 m.) south, and with the Gem, about 1150 ft. (350 m.) east, which are 3000 (914.4 m.) and 2000 ft. (609.6 m.). deep, respectively. These two shafts are equipped with reversible fans for ventilation. The Speculator has a; steam hoist with a capacity of 150 tons per hour from the 3000-ft. level. The Granite Mountain shaft is concrete lined from the 1600-ft. to below the 3000-ft. level and gunited with cement from the 1600-ft. level to the surface. Sections of the Speculator shaft with a total combined length of 500 ft. (152.4 m.) are also concreted. There are approximately 36 miles (58 km.) of drifts and crosscuts in the mine, in which there are 15.2 miles (24.5 km.) of track. At normal capacity, about 75 stoping faces, 20 raises, and 30 sill development faces are working. Stoping is usually by the standard square-set method. Where the size of the oreshoot and character of. the walls permit, the rill (or cut-and-fill) system is employed.

Jan 8, 1920

By Van Dyne Howbert, Fred E. Gray

The Presidio mine of The American Metal Co. of Texas is situated 45 miles south of Marfa, Texas, a town on the Southern Pacific R. R., and lies approximately 20 miles north of the Mexican border. Communication with the railroad is maintained over a state highway. All supplies for mine and mill are hauled in by truck from Marfa and precipitates and concentrates are freighted to the railroad by the same means and shipped to Selby and El Paso, respectively. The mill is at the town of Shafter, 1 mile from the mine and at approximately 350 ft. lower elevation. The ore is conveyed to it by an aerial tramway which requires practically no power on account of the difference in elevation. The mill is a countercurrent decantation cyanide and gravity concentrating plant of 200 tons daily capacity. Coarse and fine crushing are done at the mill. Two neal-by shallow wells in the bed of Cibolo Creek furnish an abundance of water. Power is generated for the mill and town by a Diesel engine plant. Ore Treated The ore is oxidized and siliceous. The greater part contains approximately 16 oz. of silver per ton, but mixed with this are many particles of ore of much higher grade, assaying in many instances 100 oz. or more. In the 16-oz. material there is an almost constant amount of silver which is difficult to recover by cyanidation. The high-grade material contains a much greater proportion of silver which is easily amenable to cyanide treatment. Thus, as the grade of ore becomes higher, the percentage of recovery of silver increases rapidly, under equal milling conditions. The silver minerals contained in the ore are principally argentite and cerargyrite, the former predominating The lead minerals, all of which are argentiferous, are chiefly cerussite and galena, with occasionally a little anglesite. The gold is free; most of the ore contains merely a trace

Jan 1, 1935

By H. K. Work, G. H. Enzian

In the manufacture of steel for commercial purposes, the deoxidation practice used, i.e., the method and degree of deoxidation, is an important factor affecting the structure and mechanical properties of the finished steel. Deoxidation practice exerts a pronounced influence not only on the soundness of the ingots but also on the reaction of the steel to a number of mechanical and thermal treatments. The first mentioned effect of deoxidation is more or less obvious and was first demonstrated, though perhaps not fully appreciated, by Robert Mushet when, in 1856, he added speigeleisen to low-carbon bessemer blown metal. In 1861. Bessemer patented the addition of one pound per ton of silicon to his blown metal to "cause the metal to lie quietly in the mold." The second effect of deoxidation-—that is, the effect on the properties and behavior of the steel—is, one might say, more subtle, and certainly not as well understood as the first, although in many cases it is the more important consideration. This paper is limited to a discussion of only the second effect of deoxidation and: in particular, to the effect on the strain-sensitivity of low-carbon steels. General Discussion Originally it was thought that the function of a deoxidizer was to combine with the oxygen present in the steel as iron oxide and prevent its subsequent evolution as a gas. -More recently it has been realized that a deoxidizer does more than this. Frequent reference has been made to the effect of deoxidizers on the nitrogen in the steel, and some attention has also been paid to hydrogen. As a consequence of the above situation any study of deoxidation must be concerned with the gas content of the steel and the effect of the deoxidizer on the gases involved. The term "gas content" as used here refers to gases extracted from steel during melting in vacuum rather than to elements present in steel in the gaseous state. The extracted gases, at least in the case of oxygen and nitrogen, are generally accepted to be products of decomposition of oxides, nitrides, or other more complex compounds. The manner in which deoxidation affects the gas content of steel and the significance of gases in steel have been and still are subjects of considerable speculation. No attempt will be made here to give a complete discussion of the literature on this subject but a few references will be cited for purposes of illustration. N. Hamilton1 found a correlation between the oxygen content of alloy steel and the behavior of the steel during tube piercing. Davenport, Bain, and others associated oxygen with aging properties of steel while Köster5 and a number of others6-lo made similar claims for nitrogen. Daniloff, Mehl, and Hertyll stated that "deoxidation decreases the susceptibility of steels to aging directly

Jan 1, 1945