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By Leo P. Tarasov

Magnetic torque studies of ferromagnetic single crystals have been carried out in a number of laboratories during the last decade&apos;s2 and some work has been reported on polycrystalline material showing preferred orientation. Goss3 used the method extensively in developing electrical sheet with desirable magnetic properties, but he used it as a control rather than as a means of studying the texture. Bozorth4 made a quantitative correlation of a torque curve he obtained from some cold-rolled iron with the texture as determined from X-rays, but did not extend his studies beyond the one specimen. Other studies, which have been reported from time to time2,5 have also been incomplete in the sense that no effort was made to study a whole series of samples, differing only in degree of cold reduction or in the annealing temperature, in order to ascertain the effect of such treatments on the texture as revealed by torque measurements. It is the purpose of this investigation to make such a study, mainly in order to see how useful the method can be made when used under favorable circumstances and to find what kind of a correlation can be expected between magnetic and X-ray studies of texture. Before proceeding further, it is desirable to say a little about single crystals, so as to make clear the concepts involved in magnetic torque measurements. Magnetic Torque Method It is fairly well known nowadays that single crystals of ferromagnetic substances have directions of easy magnetization and of hard magnetization. In Fig. 1 are reproduced typical magnetization curves for a single crystal of iron, which show that in a < 100 > direction saturation occurs at low fields compared to those required to saturate the same crystal in a <110> or a <111> direction. (The magnetization intensity I is defined by the equation B = H + 4pI.) At fields high enough to

Jan 1, 1939

By Leo P. Tarasov

Magnetic torque studies of ferromagnetic single crystals have been carried out in a number of laboratories during the last decade&apos;s2 and some work has been reported on polycrystalline material showing preferred orientation. Goss3 used the method extensively in developing electrical sheet with desirable magnetic properties, but he used it as a control rather than as a means of studying the texture. Bozorth4 made a quantitative correlation of a torque curve he obtained from some cold-rolled iron with the texture as determined from X-rays, but did not extend his studies beyond the one specimen. Other studies, which have been reported from time to time2,5 have also been incomplete in the sense that no effort was made to study a whole series of samples, differing only in degree of cold reduction or in the annealing temperature, in order to ascertain the effect of such treatments on the texture as revealed by torque measurements. It is the purpose of this investigation to make such a study, mainly in order to see how useful the method can be made when used under favorable circumstances and to find what kind of a correlation can be expected between magnetic and X-ray studies of texture. Before proceeding further, it is desirable to say a little about single crystals, so as to make clear the concepts involved in magnetic torque measurements. Magnetic Torque Method It is fairly well known nowadays that single crystals of ferromagnetic substances have directions of easy magnetization and of hard magnetization. In Fig. 1 are reproduced typical magnetization curves for a single crystal of iron, which show that in a < 100 > direction saturation occurs at low fields compared to those required to saturate the same crystal in a <110> or a <111> direction. (The magnetization intensity I is defined by the equation B = H + 4pI.) At fields high enough to

Jan 1, 1939

By Noel H. Stearn

OF the many instruments devised for the measurement of magnetic anomalies, the ordinary dip needle, by virtue of its superior simplicity of construction, facility of manipulation, and definiteness of interpretation, seems to merit serious attention as the instrument most readily applicable to the detection of magnetic anomalies of the higher order of magnitude. In spite of the fact that it has been used for many years for the discovery of iron ore in Europe and in the Lake Superior region of America, its capabilities as a geological instrument have not yet been thoroughly plumbed. The Wisconsin Geological Survey, under Dr. W. 0. Hotchkiss, E. F. Bean, and H. R. Aldrich, has been most thorough in developing the technique of the instrument, and the results it has obtained have aroused a general interest in a more widespread use of geomagnetics as an exploration method and the dip needle as a geological instrument. The simplicity of the instrument is an especial advantage, as it can be used by anyone, regardless of his technical training; but to insure useful results not only is a knowledge of the background of geomagnetics necessary but also an understanding of the principles of the instrument itself. Principles of the Dip Needle The major feature of the dip needle is an elongated magnet suspended with fixed bearings in such a way that it can move in a single plane. If the point of suspension were exactly at the center of gravity of the magnet, the instrument would be identical with the "dip circle" or "dipping needle" of terrestrial magneticists, and as such could be used to determine variations in the inclination of the earth&apos;s magnetic field when observed in the plane of the magnetic meridian. The dip needle, however, differs from the "dip circle" or "dipping needle" in having an adjustable counterweight affixed to one end of the magnet. This counterweight serves to balance the magnet at an angle to the inclination of the earth&apos;s field when the instrument is oriented in the plane of magnetic

Jan 1, 1929

By J. A. Putnam, A. D. K. Laird

In laboratory research on the behavior of oil, gas and water in porous materials, no direct method has been devised to measure saturation without disturbing the flow. Indirect methods involving various forms of radiation have been developed for measuring one or two components. The X-ray absorption method for two components has been described previously1-3. The possibility of three component measurement has also been mentioned1. Since two component measurement still requires considerable care to insure accuracy, the fact that three components can be measured satisfactorily is not generally appreciated. The fraction of the energy of an X-ray beam of one wavelength transmitted through a material is given by the transmission factor. in which 1 is the beam&apos;s path length through the fluid. p is the fluid density, and 1,. is its mass absorption coefficient. Eq. 1 implies that all parts of the beam pass through equal amounts of the fluid. Practical applications are, therefore, limited to systems in which the fluid is distributed so that I varies negligibly over the cross-section of the beam. Typical variations of the transmission factor with X-ray tube potential arc shown in Fig. 2 from which experimental points have been omitted for clarity. The X-ray absorption of low pressure gases in a core is practically zero so it cannot he distinguished from that a vacuum by instruments that will differentiate between liquids. The transmission factor of a gas in a core is. therefore, unity. Consequently, the saturation of only one gaseous component can be found. If two fluids completely fill a core, their two saturations add to unity and, therefore, only one value of the transmission factor, T, is needed to determine both of them. When two liquids do not completely fill the core, their saturations do not add to unity and transmission factors at two wavelengths must be measured. At one of these wavelengths, 7 for one liquid must be different from T or the other liquid. The change of T for one liquid us the wavelength is changed between the two values must be different from the corresponding change of T in the other liquid. The two values of fluid saturation will also give that of the gas because the three saturations must add to unity. In Fig. 2 it can be seen that there are many large differences of T between various oil solutions and water solutions at any one potential, and between potentials for any one solution. Consequently, conditions for optimum accuracy of measurement of the saturations of a gas and two liquids can be chosen. Once the operating potentials have been selected, however. it is more convenient to cross plot the data from Fig. 2 on transmission factor-solution concentration coordinates for the chosen potentials, as shown in Fig. 3. Fig. 3 was used to plan the experimental procedure for Core N-38-1. Since the voltage control at 45 kv was good, the slopes of the curves in Fig. 2 at this potential would cause little error. At low potentials, however, the voltage control was not good, so 33 kv was chosen because the small slopes of the curves made voltage control less critical. The lowest strength beam that could be measured reasonably at 33 kv corresponded to a minimum T factor of 0.385. Fig. 3 shows that both 4.80 weight per cent of cadmium chloride in water and 24.0 per cent of iodobenzene in crystal oil had this T value, and, consequently, were indistinguishable to the X-rays at 33 kv. Thus, at 33 kv, the liquid saturation was given by the same curve regardless of the relative amounts of oil and water solutions present. This simple calibration curve from which the gas and liquid saturation can be read, is shown in Fig. 4. Fig. 3 also shows that at 45 kv, T for the aqueous solution is 0.610. and that T for the oil solution is 0.220. These values were transferred to Fig. 4 to give the triangular calibration plot from which the brine and oil saturations can be found, after the gas saturation has been determined at 33 kv.

By R. L. Robinson, P. DeFrank, R. F. Hatfield

Production equal to or greater than open-hole completions is possible through perforated completions if the flow paths throughout the perforations are free of obstructions.&apos; Previous investigations have indicated that, in some cases, maximum productivity is not obtained due to plugging of the perforations with debris from the wellbore fluid and/or debris from the perforating process. Control of wellbore fluid and proper well completion techniques are very important in the elimination of perforation plugging.&apos; Selection of properly designed perforating equipment also is quite important for maximum well productivity. Studies made with the use of the perforation flow laboratory, in which perforating tests are run under simulated well conditions, have shown that perforation plugging occasionally occurs. Plugs in perforations result from various causes. One of the contributors to plugging that can be controlled by the perforating device is the slug or carrot resulting from jet perforating. This condition has undergone extensive study, and previous developments have resulted in a decrease in carrot size—but not in complete elimination. It was felt that, if a method of completely eliminating the carrot could be found (with charge performance equal or better than previously obtained), a significant contribution would have been made. Such a charge has been developed and is reviewed in this paper. THEORETICAL CONSIDERATIONS OF CARROT ELIMINATION There are several popular theories of how a shaped charge jet is formed."," One of these is the hydrodynamic theory, wherein the liner is treated as a fluid under the impact of the explosive forces. Another is the spalling theory, where the interaction of shock waves in the liner causes small particles to be torn from the inner surface of the liner and projected at high velocity toward a common focal line to form the jet. It is not unreasonable to assume that both of these theories may be partially correct. For purposes of our discussion, it is simpler to use the second theory. Generally speaking, when a plate of metal is attacked by an explosive shock pulse, the pulse is transmitted through the metal at high velocity, as shown in Fig. 1(A). Pressures at the shock front may be 6 X 10&apos; psi or higher. This shock wave (a compression wave) upon striking a free surface, Fig. 1(B), is partially reflected back as a tension wave. The interaction of the tension wave with the decaying compression wave causes a stress concentration in the metal; when this stress becomes great enough, a failure occurs and a small particle flies off and is projected away from the metal surface, as shown in Fig. 1(C). A new free surface is then presented to the shocks; the process repeats itself until there is no longer enough energy to cause failure, leaving a portion of the metal relativcly untouched. See Fig. 1(D). To apply this theory to a perforating shaped charge, consider the flat plate to be folded into a somewhat conical shape, with a column of explosive placed in intimate contact with the cone (Fig. 2). An explosive initiator detonates the charge, creating a shock wave

By Howard J. Smith

At the meeting of this Institute in February 1933,I presented a paper on potash development in southeastern New Mexico1, which contained a brief review of the Geological Survey&apos;s 20-year search for commercial sources of soluble potash minerals and of the events that led to the discovery, exploration, and first development of the deposits in that state. AS a more comprehensive review of the subject was published in December2, the present paper is intended only to discuss recent developments in the domestic potash industry, particularly in New Mexico. A summary of the findings of potash in the Permian Basin, by G. R. Mansfield and W. B. Lang, geologists of the United States Geological Survey, is now in process of publication by the University of Texas and will be omitted from this paper. In New Mexico prospecting for potassium salts during the past two years has increased materially the known area of commercial deposits; development has resulted in an increase from one to three in the number of shafts and the starting of a fourth; an increase of annual productive capacity to 1,000,000 tons of crude salts, or 250,000 tons of K2O; and an increase in annual refining capacity to 140,000 tons of muriate of 62.5 per cent grade. Construction has been completed to increase still further the production of high-grade salts. In California the American Potash & Chemical Co., operating on Searles Lake brines, has increased its plant capacity from about 100,000 tons to 180,000 tons of muriate a year and is now producing soda ash and salt cake in addition to potash and borax. Potash production from cement-plant and industrial-alcohol wastes remains unimportant.

Jan 1, 1938

By Howard J. Smith

At the meeting of this Institute in February 1933,I presented a paper on potash development in southeastern New Mexico1, which contained a brief review of the Geological Survey&apos;s 20-year search for commercial sources of soluble potash minerals and of the events that led to the discovery, exploration, and first development of the deposits in that state. AS a more comprehensive review of the subject was published in December2, the present paper is intended only to discuss recent developments in the domestic potash industry, particularly in New Mexico. A summary of the findings of potash in the Permian Basin, by G. R. Mansfield and W. B. Lang, geologists of the United States Geological Survey, is now in process of publication by the University of Texas and will be omitted from this paper. In New Mexico prospecting for potassium salts during the past two years has increased materially the known area of commercial deposits; development has resulted in an increase from one to three in the number of shafts and the starting of a fourth; an increase of annual productive capacity to 1,000,000 tons of crude salts, or 250,000 tons of K2O; and an increase in annual refining capacity to 140,000 tons of muriate of 62.5 per cent grade. Construction has been completed to increase still further the production of high-grade salts. In California the American Potash & Chemical Co., operating on Searles Lake brines, has increased its plant capacity from about 100,000 tons to 180,000 tons of muriate a year and is now producing soda ash and salt cake in addition to potash and borax. Potash production from cement-plant and industrial-alcohol wastes remains unimportant.

Jan 1, 1938

By Stuart E. Buckley, C. R. Hocott

The viscosity of the oil in the reservoir is one of the properties that influence its movement through the sand to producing wells. Measurements of viscosity, therefore, are pertinent to problems associated with well behavior and with the estimation of recoveries, and afford an indirect means for partial evaluation of various methods of controlling reservoir behavior. The effect of dissolved gases on the viscosity of crude oil has been determined,ls2 but no data have been published on the viscosity of representative samples of reservoir oils. This paper describes a simple instrument that has been used to determine the viscosities of a number of subsurface oil samples at the temperatures and pressures existing in the reservoirs, and presents the results of the determinations for typical fields. Construction oF the Apparatus The principal requirements of any instrument used for the examination of subsurface samples are that it be strong and simple both in design and in method of operation. Accuracy beyond that of the degree of reproducibility of subsurface Sam-~les from various wells in a reservoir or exceeding that of the common measure-merits of reservoir temperatures and Pressures is not required. Because of the expense of procuring subsurface samples, it is necessary also that the instrument operate on a relatively small fraction of a sample, leaving the remainder for other tests, and that there be few or no failures of the equipment to cause undue delay or loss of a sample. After preliminary experiments with a falling bullet, the results of which were not satisfactory, a simple viscosimeter was built of the rolling ball type first proposed by Flowers3 and later used by several investiga-tor. 5.8 The apparatus consists essentially of a removable, accurately bored cylindrical barrel of 1/4-in. nominal internal diameter, 8 in. long, in which a closely fitting steel ball rolls through the oil with the barrel inclined at a definite angle. The ball makes contact at one end of the barrel with ail insulated electrode, closing an electrical circuit, which actuates a buzzer. The meas-urements consist essentially in determining the time required for the ball to travel the length of the barrel. The details of the construction are shown in Fig. I. The barrel in which the ball rolls was made from a section of 25-caliber blank rifle barrel, specially bored to an exact uniform diameter and polished. The barrel slides snugly into a hole bored in a solid stainless-steel cylinder, an upper external shoulder of the barrel compressing a small spring, and is held in place by a hollow nut. The spring prevents the barrel from seating against the bottom of the bored hole in the cylinder, while narrow external longitudinal slots in the barrel permit fluid to flow around it and through the bottom. The upper part of the recess in the steel cylinder is enlarged to form a tapered chamber, which acts as a reservoir for the oil and affords space for agitation to ensure

Jan 1, 1941

By C. R. Hocott, Stuart E. Buckley

The viscosity of the oil in the reservoir is one of the properties that influence its movement through the sand to producing wells. Measurements of viscosity, therefore, are pertinent to problems associated with well behavior and with the estimation of recoveries, and afford an indirect means for partial evaluation of various methods of controlling reservoir behavior. The effect of dissolved gases on the viscosity of crude oil has been determined,ls2 but no data have been published on the viscosity of representative samples of reservoir oils. This paper describes a simple instrument that has been used to determine the viscosities of a number of subsurface oil samples at the temperatures and pressures existing in the reservoirs, and presents the results of the determinations for typical fields. Construction oF the Apparatus The principal requirements of any instrument used for the examination of subsurface samples are that it be strong and simple both in design and in method of operation. Accuracy beyond that of the degree of reproducibility of subsurface Sam-~les from various wells in a reservoir or exceeding that of the common measure-merits of reservoir temperatures and Pressures is not required. Because of the expense of procuring subsurface samples, it is necessary also that the instrument operate on a relatively small fraction of a sample, leaving the remainder for other tests, and that there be few or no failures of the equipment to cause undue delay or loss of a sample. After preliminary experiments with a falling bullet, the results of which were not satisfactory, a simple viscosimeter was built of the rolling ball type first proposed by Flowers3 and later used by several investiga-tor. 5.8 The apparatus consists essentially of a removable, accurately bored cylindrical barrel of 1/4-in. nominal internal diameter, 8 in. long, in which a closely fitting steel ball rolls through the oil with the barrel inclined at a definite angle. The ball makes contact at one end of the barrel with ail insulated electrode, closing an electrical circuit, which actuates a buzzer. The meas-urements consist essentially in determining the time required for the ball to travel the length of the barrel. The details of the construction are shown in Fig. I. The barrel in which the ball rolls was made from a section of 25-caliber blank rifle barrel, specially bored to an exact uniform diameter and polished. The barrel slides snugly into a hole bored in a solid stainless-steel cylinder, an upper external shoulder of the barrel compressing a small spring, and is held in place by a hollow nut. The spring prevents the barrel from seating against the bottom of the bored hole in the cylinder, while narrow external longitudinal slots in the barrel permit fluid to flow around it and through the bottom. The upper part of the recess in the steel cylinder is enlarged to form a tapered chamber, which acts as a reservoir for the oil and affords space for agitation to ensure

Jan 1, 1941

By P. Barnes

The sums given in the accompanying table are those actually paid for material and labor up to about August, 1875; but, as some parts of the machinery were not wholly completed at the starting of the works in September, 1875, the statement cannot be taken as an absolutely correct note of the total cost. A complete description, with engravings of the building and machinery, was given in Engineering, April 26th, 1878, in a paper by Messrs. A. L. Holley and Lenox Smith, to which convenient reference may be made. A detailed list of the construction accounts has been given in a paper, by the present writer, in vol. vi, Transactions of the Institute. A summary is given in the table of the items in each class which enter into the total cost, and also a note of the proportion which each of these items forms of the whole. A concise view may thus he obtained of the facts embodied in the statement as a whole, even though it cannot lay claim to completeness in showing the entire or final cost. An urgent suggestion has reached the writer from a distant country that such statements of cost to be really most serviceable should give the details in days of labor, in weight of iron, and in number of brick, and to this an assent is most cordially yielded. It is true, however, that the mere labor of copying arid compiling these details to such a degree of minuteness, would be very great, and, in any event, the probable difference between the plans of an existing establishment and one projected, would be so wide as to render even so complete a statement of cost of little more real service than the approximate notes given herewith.

Jan 1, 1879

By Howard Smith

AT the meeting of this Institute in February 1933, I presented a paper on potash development in southeastern New Mexico1, which contained a brief review of the Geological Survey&apos;s 20-year search for commercial sources of soluble potash minerals and of the events, that led to the discovery, exploration, and first development of the deposits in that state. As a more comprehensive review of the subject was published in December2, the present paper is intended only to discuss recent developments in the domestic potash industry, particularly in New Mexico. A summary of the findings of potash in the Permian Basin, by. G: R. Mansfield and W. B. Lang, geologists of the United States Geological Survey, is now in process of publication by the University of Texas and will be omitted from this paper. In New Mexico prospecting for potassium salts during the past two years has increased materially the known area .of commercial deposits; development has resulted in an increase from one to three in the number of shafts and the starting of a fourth; an increase of annual productive capacity to 1,000,000 tons of crude salts, or 250,000 tons of K20; and an increase in annual refining capacity to 140,000 tons of muriate of 62.5 per cent grade. Construction has been completed to increase still further the production of high-grade salts. In California the American Potash & Chemical Co., operating on Searles Lake brines, has increased its plant capacity from about 100,000 tons to 180,000 tons of muriate a year and is now producing soda ash and salt cake in addition to potash and borax. Potash production from cement-plant and industrial-alcohol wastes remains unimportant.

Jan 1, 1935

By Cyril Smith

SOMEWHAT over ten years ago the author described studies1,2 on the constitution of the copper-silicon system. The copper-rich portion of this diagram is shown in Fig. 1. The experimental points freely dotted about the diagram seemed to justify an otherwise unconvincing diagram and for several years the curious reverse bend in the alpha-phase bound-ary was accepted as substantially correct, even by later investigators3,4 of the system who introduced changes in the high-silicon phases. The binary diagram has been used as a base for several ternary systems" without any suggested changes. Voce10 suspected the existence of another phase from his study of the cast alloys in the copper-manganese¬silicon system, but evidently hesitated to extrapolate this to the binary diagram, particularly in view of the too ingenious explanation that was advanced" to account for the pools of constituent clearly visible in castings; namely, that they were secondary alpha of twinned orientation deposited from beta. Von Schwarz,12 in 1932, called attention to the fact that this micro-constituent in copper-silicon alloy castings was anisotropic under polar-ized light and asserted that a new phase, not cubic, should be placed in the diagram adjacent to alpha. Sautner,13 on the basis of investigations with the polarizing microscope and with X-rays, introduced this phase into the diagram at about 6 per cent Si. The relevant part of his dia-gram is shown in Fig. 2. Sautner called the new phase beta, renaming the old beta phase zeta. To avoid confusion, in redrawing Fig. 2 the phases have been renamed in accordance with the terminology adopted in the present paper, in which the new phase is called kappa and the other phases retain the designation given them by Arrhenius and Westgren.4

Jan 1, 1939

By R. Scot Clark

The reactively sputtered silicon dioxide capacitor -was developed for use in the monolithic integrated circuit, thereby requiring the capacitor to be fabricated on an oxidized silicon slice. The silicon dioxide film is formed by reactively sputtering silicon in a 50 pct Ar-50 pct 0, atmosphere and the physical properties are indistinguishable from silica. A practical upper limit of capacitance per unit area of 0.25 pf per sq mil is reached with the capacitors fabricated from the Si0, film. Methods shown to enhance this value are double stacking the thin-film capacitors and addition of aluminum to the silicon cathode during sputtering to form an aluminosilicate dielectric. A major contribution to the field of diffused integrated circuits would be the addition of auxiliary passive devices for replacement of diffused passive devices which are currently being fabricated for many integrated circuits. This accomplishment would increase the flexibility of the diffusion process in order to concentrate more on transistor parameters rather than on fabricating diffused resistors and capacitors. To pursue this technique, a thin-film SiOz capacitor was developed which has _ proven applicable to many integrated circuits. Although the SiOl capacitor has an application, the major deterrent from extending the integrated circuit into many useful areas such as low-frequency linear application is the low dielectric constant of SiO, and the low usable capacitance in an integrated circuit. This paper will cover the sputtering techniques used for forming the SiO, film, the physical and electrical properties of sputtered SiO,, and yield information concerning the application of these capacitors to integrated circuits. REACTIVE SPUTTERING Reactive sputtering is simply the sputtering of a metal or semiconductor in glow discharge in the presence of a reactive gas. The material to be sputtered is seen in Fig. 1 as the cathode of the system and is bombarded with positively charged ions of the ambient gas. In this investigation, the ambient gas is composed of 50 pct Ar and 50 pct O2 at a pressure of approximately 2.5 X l0-&apos; Torr. The ions are accelerated toward the cathode in the cathode dark space by the electric field and upon striking the cathode effect a momentum energy transfer to the surface atoms. The transferred energy is sufficient to dislodge a surface atom or atoms and these particles diffuse through the glow discharge to the collector or anode. Several mechanisms of oxidation in the reaction chamber can be considered during reactive sputtering. 1) The surface of the cathode is oxidized and the oxide is subsequently sputtered. 2) Oxidation and sputtering occur simultaneously. 3) Sputtering of the cathode material is followed

Jan 1, 1965

THE CHAIRMAN (E. G. SPILSBURY, New York, N. Y.).-The relation of the character of manganese ore to the surrounding rocks was called to my attention very strikingly in a recent investigation in Costa Rica. In the foothills of the main coastal range there is a large deposit of manganese which extends for over 150 miles along the coast. This is in a porphyry district and the occurrences are almost exclusively along the lines of contact between a recent diorite intrusion through the porphyries. Wherever that intrusion appears to have exerted great force, the line of contact is very clear between the porphyries and the diorites. Where the action has been slower and the lifting force of the intrusion more gradual, there has been a zone of fracture of very considerable width. Those ores which occur where the fractured zone has not been very extensive carry a, lower percentage of manganese than where it has been deposited along a wider zone of fracture. In the so-called narrow veins, which are really the predominant ones, the solution carrying the manganese has evidently attacked the silica in the intrusive rock, and the resulting ore is practically a combination of manganese and silica, running froth 20 to 30 per cent. of manganese and from 20 to 40 per cent. of silica: hence those ores are not likely for a long time to become a factor in our manganese supply :for this country. On the other hand, where the disturbance to the porphyritic schist has been more intense; the manganese deposits are not so extensive, but the ore is richer, running from 45 to 51 and 52 per cent. manganese, with a silica content of from 4 to 5 per cent. There seems to be some resemblance in these deposits to those of the Cuyuna range. EDMUND NEWTON, Minneapolis, Minn.-The State Bureau of Mines has been working on the problem of concentrating manganiferous iron ore for two years or more. I should consider hand sorting as the best form of treatment, because it is practised at all of the mines which ship ore for making alloys, but not, however, oil the ore that is being used for pig iron. Hand sorting, assisted by selective mining, is readily applicable to some of this ore because the gangue is practically the original rock and is easily separated. However, it is only in rather limited zones that we find clean patches of rock. Generally the silica exists as a skeleton of the original rock structure, in which the manganese has been precipitated; some of the silica may have been dissolved, but if any of the original rock remains, the silica must be eliminated by ore-dressing processes.

Jan 1, 1918

By T. E. Leontis

ONLY a limited amount of information has been published on the effect of thorium as an alloying ingredient in magnesium. McDonald13&apos;2 showed that the addition of thorium in amounts up to 3 pct increases significantly both the ductility and the strength of rolled magnesium sheet. A recent publication by Sauerwald" indicates that thorium contributes strength and creep resistance at elevated temperatures to magnesium in both the cast and wrought states. The observations of Sauerwald are confirmed in this paper, which presents the results of a systematic study of the effects of compositional variation on the tensile properties, creep resistance, conductivity, density, and metallography of Mg-Th alloys containing up to 50 pct Th both in the sand-cast and in the extruded states. The effect of the addition of cerium to Mg-Th alloys is also reported. Experimental Methods The alloys studied in this investigation were pre.pared in small laboratory melts according to the melting practice described by Nelson4 as the crucible method. Electrolytic magnesium was used as the starting material to which the thorium* was introduced in metallic form. It was observed that the behavior of thorium in molten magnesium with respect to reaction with protective fluxes is similar to that of rare-earth metals. In order to obtain the highest possible alloying efficiency, it is necessary to use non-MgC1, fluxes and to apply all the precautions described by Marande6 for melting, alloying, and casting magnesium-rare-earth alloys. .Under these conditions it is possible to obtain an alloying efficiency in the range of 85 to 95 pct. The Mg-Th-Ce alloys were made with cerium of the highest purity available, not with the commercial product "misch-metal" which contains approximately 50 pct Ce. The total rare-earth content of this material was 97.1 pct, of which 0.3 pct was rare-earth metals other than cerium; the major impurities comprising the balance were iron and magnesium. The thorium and cerium contents of each alloy were determined chemically. Test bars 6% in. long with a 2% in. long reduced section of % in. diam were cast in sand molds using a four-baf pattern. In most cases, a 3 in. diam extrusion billet 10 in. long was cast in a steel mold from the same melt used for making the sand-cast test bars. For the higher thorium alloys, it was necessary to remelt the foundry scrap from the test bars in order to make the extrusion billets. The billets were scalped to a diameter of 2 15/16 in. and the ends faced to a length of 9% in. as limited by the size of the extrusion container. The alloys were extruded into % in. diam rod on a 500-ton direct-extrusion press. The details of the extrusion process are as follows: Billet preheat 925°F (2 to 16 hr) Container temperature 900 °F Die temperature 900°F Extrusion speed 10 ft per min Reduction ratio 36:1 Percent reduction 97.3 Alloys containing up to 10.2 pct Th were preheated at 925°F for 2 hr; all alloys with higher thorium contents were preheated for 16 hr. In order to establish the effect of extrusion temperature, billets of

Jan 1, 1953

The work of the Committee during the year 1914 was especially directed to the securing of a larger representation in the Institute of those engaged in coal mining and coking. While these industries exceed in volume and in monetary importance all other mining industries in the United States, the membership of the Institute representing them has in recent years been relatively small. It was thought that an increase in the membership of the Institute obtained from among those engaged in these industries was desirable in order to increase interest in the work of the Institute, for this result can only be reached by securing the presentation and publication of a larger number of papers relating to these industries. It is evident that the reading of such papers will tend to increase the attendance at the local and general meetings of the Institute. Sessions of the Coal and Coke Committee were held and a number of papers relating to these subjects were presented at the meetings at Butte, Salt Lake, and Pittsburgh, the Pittsburgh meeting especially being planned with this in view. The activities of the Local Section of the Institute organized in the Pennsylvania Anthracite region have reawakened interest in that district and it is hoped that the same object can be obtained in the bituminous coal fields, either through the organization of one or more. local sections, affiliation with some of the local coal-mining societies, or through activities of the Coal and Coke Committee. Referring to the work of the Committee in its efforts to increase the membership of the Institute, the Committee desires to acknowledge the services rendered by many members scattered throughout the various coal-mining districts of the United States, in compiling lists of those qualified for membership in the Institute, but who have not yet become members. The lists so compiled comprised about 1,100 names, which were furnished to the Committee by the co-operation of 40 or 50 members of the Institute.

Jan 3, 1915

By G. M. Ritcey

Sulphuric acid leaching has been up to the present, the most popular of the leaching routes. Oxide ores are usually leached with sulphuric acid directly by dump leaching, as practiced at the Bagdad or Bluebird Mines in Arizona, or by vat leaching as done at Inspiration Mining in Arizona. Upgrading of the low-grade oxide ores by dump leaching followed by cementation of the copper from solution by scrap iron has been replaced by the leaching-solvent extraction-electrowinning route which results in a high purity product at the mill site at reduced production costs compared to previous practice. High-grade oxide ores, vat leached with H2SO4, can contain, for example, 25 g Cu/l and 25 g H2S04/,l, or higher concentrations of both, and are presently fed directly to electrorefining plants. Advantages of coupling solvent extraction-electrowinning with the low cost dump leaching instead of using cementation, are as follows (1): a) the production of high purity electrolytic copper rather than cement copper;

Jan 1, 1978

By M. W. Cox, V. F. Hollister

Exploration for metallic mineral deposits is carried on by those special adaptations of methods which the explorer believes will yield most economically or satisfactorily the particular answer sought. In this project the usual methods of geologic observation, recording, and interpretation, when combined with magnetic geophysical methods and geochemical soil sampling, led to disclosures of appreciable zinc mineralization where none was visible in surface exposure. Since 1945 considerable work has been done with geochemical prospecting methods, chiefly in determining the presence and distribution of various elements existing in minor amounts in rocks, soil, vegetation or waters of mineralized areas. Such work, in which the U. S. Geological Survey has taken the lead, finds a ready place in the field repertoire of the exploration geologist as a supplement, not a substitute, for other methods. The Chollet project was carried out in 1951 by the American Smelting & Refining Co. near its Van Stone mine in northern Stevens County, Wash., in the area shown in Fig. 1

Oct 1, 1955

By W. Griffith

The purpose of this paper is to make public record of new information in regard to the sustaining power of artificial mine-roof supports (not timber props), the result of investigations recently made in the anthracite coal fields of Pennsylvania. First.—By the "Scranton Mine Cave Commission," appointed to investigate the mining conditions under the City of Scranton. Second.—By the "Pennsylvania Mine Cave Commission," appointed by the Governor to investigate the general subject of mine caves in the anthracite region of Pennsylvania. Third.-—By the personal researches and tests made by the author in an effort to secure a better artificial mine-roof or surface support. During the progress of the work of the Scranton Mine Cave Commission, the Engineers for the Commission, Messrs. Conner and Griffith, being aware of the general lack of exact information in the engineering profession as to the strength of the ordinary artificial mine-roof or surface support, and particularly the stronger kinds, such as mine cogs, rock piers, etc., had tests made at the Fritz Engineering Laboratory at Lehigh University, to determine the sustaining power under various compressions of the several kinds of artificial mine supports in use in the anthracite region of Pennsylvania. A report of these tests wasincluded in the report of this Commission, which was published as Bulletin No. 25 of the United States Bureau of Mines, Washington. A similar series of tests, more extensive and more elaborately planned, were subsequently made for the Pennsylvania Minc Cave Commission at the U. S. Government Testing Laboratory at Pittsburgh, Pa. The report of this Commission was made to the Governor, but has not yet been published. The author, during his connection with the Scranton Mine Cave Commission, observed that of all the various devices employed for sustaining the roof of coal mines, the one universally used and the best

Jan 1, 1918

JAN. 17-In what appears to be a general spirit of post-Christmas emotional malaise, most adult Americans have bidden farewell to the Forties and turned with no perceptible enthusiasm toward the Fifties. The dying decade had started amid a phoney war which verged on the romantic, stirred the pulse with excitement and seemed far away. A phoney peace dominates the new decade. The romance is no longer there. Nor is the excitement. Nor is the distance. While most of the world preferred to be chronologically correct and hold off for another year before celebrating the demise of the first half of the twentieth century, the United States with true competitive enterprise and a great whirl of words scurried into the second half a year early. This undue haste might perhaps have been dictated unconsciously by a yearning for the pattern of history to be repeated. For many centuries, ever since Roman times, the second half of most centuries tended to be far more tranquil than the first half. In Washington, Mr. Truman got on both sides of the mid-century line with all the aplomb of a good politician. He told Congress early in January that "the state of the Union continues to be good," as it nears "the midpoint of the twentieth century." Later he spoke of moving forward into the second half of the century. He promised an infinitely better life for everyone, whichever side of the mid-century line, and reaffirmed his prescription toward that end: assistance for small businesses; more houses for the middle-income groups; tougher anti-monopoly laws, retention of rent controls; development of natural resources; better insurance against the hazards of old age, idleness and unemployment; better medical care and education, civil rights legislation; new labor relations law and production payments to support farm incomes. All this was to be coupled with suggestions on how to balance the budget. The bloody and confusing 1940&apos;s had brought to most men&apos;s minds a fear of the future such as they had not known for centuries, and Mr. Truman&apos;s objective is to temper that fear. Only time will tell whether the terminal point of such a philosophy would or would not belie the old English proverb citing inability to both eat and have a cake. Brave words to the contrary, the national budget persisted in sliding off into the red. The smell of further inflation was equally persistent. And just to impart a little more zip to the trend, the American Federation of Labor announced its intention of seeking "substantial" and "large" wage increases this year. The AFL forewarns of a business slump after June and a 10¢ an hr wage in¬crease for each worker "will be enough to reverse the prospective downward trend and start a rise." Thus it goes-"the way to halt a drop in demand for labor is to raise the price of labor." Elsewhere in the harassed world, beleagured individualists in New York achieved a local triumph of sorts for one of the freedoms denied by the Soviet and Nazi systems-the right of escape, some escape at least, from the servitude to decibels. Grand Central Station weakened perceptibly at Christmas on its 5-min commercials and bore down heavily on "Hark, The Herald Angels Sing," and on New Year&apos;s Day capitulated entirely by abandoning the broadcasting of canned music and slugs of advertising slogans. In Europe, M. Bidault&apos;s Assembly majority fell away and newspaper accounts of the incredible monstrosities of political trials beyond the iron curtain were supplanted by headlines marking the birth of Princess Yasmin. The latter was surrounded by Byzantine splendor but otherwise showed no apparent deviation from the accepted norm. In Western Germany, Dr. Adenauer began to speak up more boldly, and the whole fabric of Allied policy towards the defeated enemy further dossolved under the impact of rivalry with the Russians. In the Far East both the Americans and British seem somewhat embarrassed by Chiang Kai-shek&apos;s refusal to lie down. Dual thinking regarding the "squalid and useless struggle in the China seas" is such that newspapers give sympathetic accounts to an American ship running supplies to the Communists at Shanghai while calling for help for the recognized Chinese government in Formosa. And with Britain recognizing Communist China they may well have to team up with Russia against the United States to kick the Chinese representative off the UNO Security Council, the Far Eastern Commission and the Allied Council in Tokyo. Far Eastern policy has never been a bipartisan matter and as General Chiang retreated to his final redoubts in Formosa and Hainan, a number of Republicans pecked away at Administration lassitude. Senator Smith advocated the occupation of Formosa and Messrs. Hoover and Taft asked for use of the Navy. Mr. Acheson has stood firm, however, against military aid. None the less, a study will be made of the Generalissimo&apos;s chances. Mr. Truman has a private purse of $75 million for the Far East and some $94 million in frozen ECA funds. Mr. Truman will likely trade some of this money for support of new Marshall plan appropriations, always mindful, of course, of Mr. Acheson&apos;s plan to drive a wedge between the Chinese and Moscow, and his wish to avoid any revival of imperialist nightmares throughout the Orient. Mr. Acheson is very convinced that the victories of Communism in China will be short-lived and South Asia will not fall

Jan 2, 1950