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By Paul A. Beck

IN several recent investigations1 ' considerable evidence was accumulated to show the predominance in various face-centered cubic metals of a certain relative orientation, corresponding to a rotation of 30" to, 40" around a [111] axis, between a matrix with a strong single orientation texture and grains growing in this matrix." This relative orientation was found to occur both in recrystallization and in coarsening, "secondary recrystallization", so that one is inclined to look for an explanation applicable in both cases. The abundance of growing grains in the described orientations proves that suitable "nuclei" are present in the matrix material and that they have the capacity to grow. The scarcity of growing grains in other orientations may be explained in one 'of two ways. Either the number of nuclei or the rate of growth must decrease strongly for orientations deviating from that predominating among the growing grains, Fig. 1. Both the "oriented nucleation" and the "oriented growth" theory found support in the literature. Because the frequency of nuclei as a function of orientation is in most instances not amenable to direct experimental investigation, a definitive decision is difficult to achieve. However, it is now known with great certainty that the rate of boundary migration is strongly dependent on the relative orientation of the two grains meeting at the boundary and that the orientation favored by high boundary mobility closely corresponds to that predominating in most cases of recrystallization and coarsening. Thus, it was found that, in general, the mobility is very low for boundaries between grains of nearly identical orientation, or for coherent twin boundaries. On the other hand, the boundaries between two grains of a relative orientation correspending to a [1111 rotation of 30" to 40" have the highest mobility in face-centered cubic metals. If a large variety of nucleus orientations are produced grow- by means of a highly inhomogeneous local deformation, nuclei close to the above orientation are found to grow fastest.z4 In view of this evidence and of the fact that the preferred orientation relationship is the same in recrystallization and in coarsening, the oriented growth theory appears by far the more promising one. Since the origin of nuclei in primary recrystallization is certainly different from that in coarsening, the occurrence of the same orientation relationship in the two processes would be difficult to explain on the basis of oriented nucleation. other advantages of the oriented growth theory are its capability of accounting for the often observed sharpening of the texture in coarsening, and its suitability for explaining the role in the formation of the ''cube texture,, of the most important variables, such as the degree of rolling, the penultimate grain size, and the time and temperature of the last anneal: No similarly consistent explanation of all these effects has ever been offered in terms of oriented nucleation. An important problem in connection with the oriented growth theory is the following: In the ce-c entered system there are four [111] axes and

Jan 1, 1952

By W. J. Kroll

W. J. Kroll (Belgium)—Those who are acquainted with the metallurgy of our forefathers may have occasionally a good time when glancing at recent publications in which aged discoveries are unconsciously reported as novelties. We know very well, that oxygen blowing of iron has been described by old Bessemer. The author of the present article is, however, not aware of the fact that the process he describes, the fused salts scrubbing, was already used in the middle of the last century by St. Claire Deville in his attempts at making higher-purity aluminum from raw AlCl3 by sodium reduction. The same fact escaped the three investigators to whom the author refers. The technical grade AlC13 produced by St. Claire Deville from impure oxide, chlorine, and carbon (Oersted process) was contaminated with Sic4 and FeC13, which he removed on an industrial scale by various methods.' He sublimed, for instance, his chloride in contact with iron nails, or aluminum chips, or in hydrogen, which reduced the FeC13 to the less volatile FeCl2. He used also alkali-alkaline earth chlorides as a solvent for A1C13 and FeC13 in presence of iron as a reducing agent, and sublimed his purified AlC13 from solvent salts. The successors of Deville used also zinc or lead as a reducing agent. These methods were later used currently for the purification of BeCl2 and for collecting this compound in a salt bath, suitable for fusion electrolysis. More recently, the same Deville process has been described as applied to the purification of ZrCL4, as part of a method of extraction of ZrCL4 from silico zirconium, which later was reacted with FeC12 in a separate part of the equipment. According to the patent referred to3 the ZrCL4 is dissolved as a gas in a carrier salt such as alkali-alkaline earth chloride, from which it can be reclaimed in a purified form by distillation. A bath of NaCl/KCl is recommended in the specifications. The FeC12-FeC13 go in the salt solution in which raw ZrCl4 is introduced by bubbling, while Sic4 and Tic4 pass through the bath and escape in the atmosphere. purification by this salt-solvent method is thus well described. It may be worth while insisting on some minor details about which the author did not bother too much. One of these concerns the material of construction for the container. If iron is used, and if no other reducing agent is added, then it is the iron of the pot that acts as a reagent in the breakdown of FeC13 to FeCl2, and corrosion can be expected. This shows the importance of using extraneous large surface-reducing agents, of which there is a choice. Zir-

Jan 1, 1963

By Benjamin L. Miller

THE essential differences expressed by the different speakers participating in this symposium concern merely the relative emphasis placed on the subjects that are commonly included under the term "geophysics" and the branches of science that form the basis for investigations in this field. In order to appreciate the present situation it may be profitable to briefly refer to a few historical matters. One can find almost countless descriptions of geological phenomena long antedating the introduction of the title of "geology," which has been credited to Richard de Bury in the fourteenth century. Interpretations, when they were offered, were generally pure speculation. Only toward the close of the eighteenth century do we find theories developed as the result of observations and tested by additional observations. It is difficult to select and give proper credit to the individual who was particularly responsible for turning geology into a distinctly observational science. William Smith, who has been called the "Father of English Geology," certainly represents the period when observation was the only method used. As he traveled through the British Isles, "sometimes 10,000 miles in a year," he was continually making notes of his observations. Geikie says: "His plain, solid, matter of fact intellect never branched into theory or speculation, but occupied itself wholly in the observation of facts." William Smith, with others of his time, definitely laid firmly the foundations on which modern geology has been built. Field and laboratory observations can no longer be said to constitute the sole basis for geologic contributions but we have not laid aside the methods of Smith and his followers. It is folly to underestimate the fundamental value of the observational part of geology in the present. The objection to purely observational geology is that it is mainly qualitative and not quantitative, general and not specific. No one can deny this charge and probably there are few who do not welcome every method or process whereby we can put aside generalities for definite established values. Physics is the science that has particularly come to the aid of the geologist in this respect. CONTRIBUTIONS OF PHYSICS It is not the intent of the writer to enumerate or to evaluate all of the contributions to geologic advance in the field of physics. A few only are used for the purpose of illustration. When Clarence King, Director of the United States Geological Exploration of the Fortieth Parallel, invited Ferdinand Zirkel to study 2500 thin sections of rocks collected from the western United States, the use of the microscope came into general use. Zirkel's report was published in 1876. He was not the first to use transmitted light for microscopic rock determination, some work having been done by Henry Clifton Sorby and others some years earlier, but he was the first to put into general use this method. We may well claim that this

Jan 1, 1941

By Morris Muskat

The detailed analogy between flow systems in porous media and the corresponding poten-tiometric model systems is developed under conditions where it may be desirable to take into account variable pay thickness, variable porosity, and permeability, and also the dependence of the fluid density on pressure. It is shown that in such models it is only necessary that the electrolyte thickness be made everywhere proportional to the millidarcy-feet of the formation. In contrast to the iso-vol type model, previously suggested as a basis for the analogy, the porosity does not enter directly in the construction of the model. It is introduced only in translating the electrical voltage gradient measurements into the equivalent fluid travel times. A discussion of this procedure is given. I NTRODUCTION It is now some 50 years since it was pointed out' that on the basis of Darcy's law Laplace's equation must govern the steady state flow of homogeneous fluids through porous media. It is 16 years since the obvious implication of this fact, namely, that such steady state homogeneous flow systems in porous media could be simulated by electrical analogies, was first applied2 to problems of practical interest with respect to oil production. In these initial studies major emphasis was placed on the use of electrolytic models, made of blotting paper, to give a direct and graphic history of the fluid particle motion in regular and infinite well networks. However, it was also noted there that the basic requirement of the model was that it give a potential distribution similar to the pressure distribution in the flow system, and that from the electrical measurement of the potential distribution the fluid particle motion could be graphically or numerically determined. This was demonstrated by application to the five-spot infinite network, for which a conducting metallic sheet was used to establish the equipotential contours. As anticipated, the fluid particle motion computed from these contours agreed well with that given directly by the blotting paper model. For irregular well distributions it was found more convenient to use electrolytic bath analogs rather than metallic sheets. Several investigations,3'4 as applied specifically to cycling well patterns, have been reported with these models, which have become known as "potentiometric models." However, the extremely laborious nature of both the electrical measurements by direct probing and the associated interprctive computations retarded the widespread use of these procedures. The electrical measurements can be accelerated by using a four-probe electrodc,5,6 which provides a means for simultaneously determining the streamline paths along which the fluid particles must move and the voltage gradients along these paths which are proportional to the fluid velocitics. With the increasing frequency of discovery of condensate pools, as drilling depths are becoming greater, the applicability of the potentiometric model to production problems, and especially to the study of well patterns for cycling, has been given a fresh impetus. Although the formal theory for determining the motion of fluid particles in porous

Jan 1, 1949

By W. I. Duvall, D. E. Stephenson

A theoretical solution is given for the energy that is radiated outward when either a cylindrical or spherical cavity located underground in a uniform stress field is suddenly created or enlarged. The method of derivation shows that the stress field in the solid rock surrounding the opening does work on the rock because of elastic displacements that result when the size of the cavity is increased. The amount of this work is sufficient to account for both the increase in the strain energy in the rock surrounding the opening and the seismic energy that radiates outward. Thus, the source of the radiant seismic energy is mainly the gravitational potential energy and not the strain energy stored in the rock. The amount of the radiant seismic energy is directly proportional to the volume of the rock removed from the opening or relieved of stress. Seismic energies from rockbursts are compared with earthquake energies. Also, the amount of gravitational potential energy released by underground explosions is calculated and found to be small compared to the seismic energy generated by the detonation of the explosive. A review of the early literature on rockbursts shows that a number of investigators calculated the amount of energy released by rockbursts. 1-5 However, none of these papers give the formula used to make these calculations or a reference to the derivation of any formulas. The general impression that one obtains from these early papers is that the main source of the seismic energy released by rock-burst is the strain energy stored in the rock before it is fractured. However, a few of the early papers appear to have considered the solid rock at a distance from the mine opening as a possible source of the seismic energy. Recently Black and starfield7 gave a theoretical solution for the strain energy in a stressed plate with and without a circular hole. Also, Press and Archambeau8 gave the theoretical solution for the seismic energy released when a spherical cavity is created in rock subjected to a three-dimensional stress field. Both of the above theoretical papers start with the condition of no opening and calculate the strain energy before and after the opening is suddenly formed. Neither of these papers appear to have calculated the work done by the applied stress field as the cavity is enlarged. The rockburst problem associated with deep mining is concerned with the failure of the solid rock surrounding an underground opening. Therefore, it seems appropriate to consider theoretically the problem of suddenly enlarging the size of an existing opening. The purpose of this paper is to present the theoretical solution for the energy that is available for release as seismic energy when an underground circular tunnel or spherical cavity is suddenly enlarged in diameter. To keep the mathematics as simple as possible, a uniform radial applied stress field is assumed and the rock is assumed to be isotropic, homogeneous and perfectly elastic.

Jan 1, 1965

By Charles Barron McIntosh

BECAUSE of the well known relationship between a low atmospheric pressure and increased amounts of methane in coal mines, attempts have been made to find associations between low pressures and coal mine explosions. An early study by F. Able disclaimed this relationship. He found that half the explosions took place during a rising barometer when methane content in a ventilated mine would be decreasing. A more recent study by C. L. Hosler revealed a close relationship between anthracite mine explosions and low atmospheric pressure. Bituminous coal mine explosions, where coal dust as well as methane can be exploded, were found to be more closely associated with a rising pressure following a low barometer than with the falling or low pressure period. Emphasis on rising pressure periods led the present writer to investigate the effect of the post-frontal or post-cyclonic weather on coal dust. Dust samples of uniform mesh were exposed in an Illinois mine. Analyses of the dust taken before and after the passage of cold fronts and their accompanying low pressure troughs indicated an increase in coal dust moisture prior to a frontal passage and loss of moisture from coal dust following the time of lowest pressure. Thus the warm, moist air (Tropical Maritime)found over the mine during the falling pressure period was cooled in the mine and moisture added to the dust. Cold, dry air (Polar Continental) accompanies' the rising barometer following a frontal passage and the air, being heated in the mine, subtracted moisture from the coal dust. A similar but seasonal phenomenon occurs from summer to winter, the dry dust period in winter being recognized as the more dangerous period. The question arose as to how the short period or daily changes in moisture content of coal dust compared with the seasonal changes. Temperature and humidity statistics were obtained from the surface and mine entry for the months of July andJanuary. The gain and Ioss of mdisture. to the hine were calculated for these two morths as were the gain and loss associated with mT (Tropical Maritime) and cP (Polar Continental),air masses as observed in the investigatiynsl. Temperature and humidity statistics tigatiynsl.taken from [the two air masses represent atimp span of only 34 hr. The redultant changes as presented in the accompanying table verify the supposition that short period changes in coal mine moisture may attain the magnitude of recognized dangerous seasonal changes. Statistics for the mT air and the July air have been placed next each other and those for cP and January air together for easier comparison of the two warm and two cold air units. The last column readily reveals that there is little difference in the amount of moisture being deposited in the mine from the mT air and the July average air. A similar conclusion is reached regarding the loss of moisture from the mine when it is affected by the cP air mass or the average January air. This comparison would be particularly true from late fall through early spring when strongly contrasting air mass changes are a common occurrence. The invasion of cold, dry air following a cold front thus produces a drying period that could well receive more attention as a danger period for coal dust explosions. This drying period would compare with Able's explosion period during a rising barometer. The drying period is also perltinent in Hosler's findings, where it was noted that the average explosion day (for bituminous coal mines) followed the day of lowest atmospheric pressure. Moreover, the author's investigation of some 365 coal mine explosions also indicates that this post-frontal period should receive special attention in connection with mine safety measures. Two comparatively recent major explosions in Illinois (Centralia and West Frapkfort) occurred after the mines had been under the influence of cold-dry air for 25 to 30 hr-following a deep low pressure passage. Dust was the important explosive element in both these explosions.

Jan 1, 1958

By R. Bakish, C. S. Barnett

IN experiments on tantalum strained in tension, Bechtold did not observe deformation-twinning even at a temperature as low as that of liquid air.' This is an unexpected behavior for a metal of body-centered-cubic structure. Therefore, it is desirable to determine whether the lack of twinning is an inherent characteristic of this particular metal, or whether the reluctance to twin can be overcome under suitable conditions. The following experiments were performed under conditions favorable to twinning and cleavage in their competition with slip, namely, with impact loading on large-grained sheet at low temperatures. The crystallography of cleavage in tantalum sheet was also investigated carefully because of the remarkable ductility of tantalum at low temperatures and because recent tests on oxygen-embrittled tantalum had disclosed unusual cleavage behavior for a metal of this structure: cleavage primarily on (110) planes and only occasionally on {100}.2 The tantalum, supplied by Fansteel, was of 99.9 pet purity, with the chief impurities being iron (0.03 pet) and carbon (0.03 pet). Coarse grains were produced by the strain-anneal method, the anneal being 4 hr at 2000°C in a vacuum of 10-3 mm Hg, followed by furnace cooling. Impact deformation was applied in various ways: a) by hammer blows on an anvil, the specimen and anvil being immersed in liquid nitrogen ( —196°C), b) by driving a precooled center-punch into the sheet, and c) by bending around a crystallographically determined axis with a hammer blow. The impact-deformation produced bands and slip lines on the surface, Fig. 1. The bands have every appearance of being deformation twins, a) They are tilted with respect to the untwinned surface. b) They have the appearance of Neumann bands in iron, thin lens shape, some having serrated edges. c) The orientation in each is different from that of the surrounding matrix and uniform within a given band, see slip lines within them in Fig. 1. d) Upon repolishing and etching, the difference in orientation and the resemblance to Neumann bands is again evident, Fig. 2. (In this micrograph the slight bend in the bands as they cross grain boundaries was noted frequently and results from the high degree of preferred orientation in the sheet.) e) The bands persist after annealing treatments that would have removed them had they been a low-temperature martensitic phase, e.g., after an anneal of 1/2 hr at 900°C. When back-reflection Laue data were plotted for single-surface analysis of several grains, every trace of the bands in each grain could be explained by (112) planes. In addition, two of the bands were located in space by traces on two surfaces, and these also were found to lie on (112) planes within the error of the stereographic plot. Since (1 12) is the anticipated composition plane for deformation twins in body-centered-cubic metals it is felt that the observations listed above are conclusive evidence for the identification of the bands as twins. Similar tests with impact at —77° and at 25°C produced no twinning. It is concluded that the critical shear stress for slip at the rates of straining used was always low enough to prevent the applied stress from reaching the value required for twinning at these temperatures. It was noted that the serrations along the edges of the twin bands exhibited parallel crystal facets. Several similarly oriented notches are visible in Fig. 1, and a remarkable set is shown in Fig. 3. It appears from Fig. 1 and similar areas that notches are frequently associated with the intersection of a slip line with a twin, although not all such intersections are at notches. In some instances a slip line appears to enter the twin, cross it, reflect from the opposite side and recross it, producing a pattern resembling a notch but without producing the notch itself, see Fig. 1. It is suggested that the stress concentration at the end of a slip line is responsible for these details. The strain energy associated with the pile-up of dislocations at a twin boundary may be lessened by untwin-ning or failing to twin a portion of the twin band, or

Jan 1, 1959

By J. L. Jorstad

The hypereutectic Al-Si alloys 390 and A390 have wear characteristics superior to any of the more common aluminum casting alloys. This excellent wear resistance, coupled with good mechanical properties, high hardness, and low coefficient of thermal expansion, has made these alloys candidates for the all-aluminum internal combustion engine, the application for which they were primarily developed. A390 alloy is intended for sand and permanent mold casting, and requires a lower iron ccxltent (0.5 pct maximum) than its die casting companion 390 alloy (0.6 to 1.1 pct Fe). The 17 pct nominal silicon in these alloys provides sufficient quantities of the hard primary silicon phase to assure a high degree of wear resistance, yet little enough of this phase, to minimize the casting and m achining problems associated in the past with the hypereutectic alloys. The mechanical and physical properties of 390 and A390 alloys are competitive with the best of the common aluminum casting alloys with the exception of low ductility. This low ductility is not considered a detriment, since in many applications these alloys replace cast iron. Corrosion resistance is similar to the standard alloys 380 and 333. Numerous parts, of varying degrees of complexity, have been cast of alloys 390 and A390, including engine blocks and heads. The deviations from normal good handling and casting practices that are required for the alloys are those associated with the presence of the primary silicon. To obtain optimum strength and machinability, the molten alloys should be treated with phosphorus to refine the primary silicon phase. Care must be exercised to properly control the pouring temperature and rate in order to minimize primary silicon growth and segregation. AUTOMOTIVE engineers have for years recognized the advantages of lighter weight and better heat transfer that aluminum could offer as material of construction for engine blocks. These advantages alone, however, are insufficient justification for acceptance of aluminum engines by the automotive industry. To be acceptable, an aluminum engine first must pass all tests to which cast-iron engines are subjected, and, in addition, must represent no cost penalty in manufacturing. None of the conventional aluminum casting alloys have sufficient wear resistance to withstand the tests to which cast iron is subjected as a cylinder bore material, and recent attempts to manufacture aluminum engines with cast-in-place iron sleeves could not compete costwise with the equivalent cast-iron engine. The prerequisite to an acceptable aluminum engine seemed to be a casting alloy with a high degree of wear resistance that would eliminate the necessity of cast-in iron sleeves or liners. The hypereutectic A1-Si alloys 390 and A390 have met this challenge.' Combined with modified pistons and a patented cylinder bore surface finish,2 the performance of these alloys in more than 1300 cold start and cold scuff tests, over 3500 hr of dynamometer wear and endurance tests, and more than 350,000 miles of road tests leaves no doubt as to the feasibility of running on bare aluminum cylinder bores. ALLOY DEVELOPMENT The desirable characteristics of the hypereutectic A1-Si alloys have been recognized for some time. Their excellent wear resistance and low coefficient of thermal expansions have been used to advantage in the production of diesel-type pistons in Europe and to a limited extent in this country. The major contributor to the good wear resistance of these alloys is the extremely hard primary silicon phase in the microstructure. Although the percent silicon used experimentally has been much higher, most commercial alloys have ranged from about 14 to 25 pct. Generally, as the silicon content is increased, wear resistance increases, and the coefficient of thermal expansion decreases. With increases in silicon, however, machinability and cast-ability tend to suffer. The development of a satisfactory aluminum engine block material at Reynolds involved the testing and evaluation of many alloys, covering a wide range of silicon contents and numerous variations of iron, copper, magnesium, manganese, and other alloying additions. Castability, mechanical and physical prop-

Jan 1, 1969

By R. E. Jenkins

The Bell Canyon member of the Delaware Mountain group has yielded quite a large number of fields in which completion and production problems have been numerous and complex. Reserves are difficult to estimate due to the problem of evaluating the formation water saturation, and the feasibility of water flooding is questionable. Extensive laboratory investigations were undertaken to determine if normally measured rock and contained fluids properties could account for many of the peculiar characteristics of the formation. A statistical study or routine core-analysis data was made. Capillary-pressure data were obtained by several techniques. Fresh-water and brine permeabilities were measured and relative permeabilities of oil, water and gas were determined. Some qualitative wetta-bility tests were performed, and the petrography of a few thin sections was studied. The results of this work are presented, with typical or average data shown for each test. The permeability -to- water characteristic of the Delaware was found to be abnormally poor. Correlations of laboratory and field performance data indicate high water saturations in much of the formation. Pore geometry is highly uniform. INTRODUCTION The Delaware formation has undergone extensive exploration and development in the past few years. This has resulted in the discovery of quite a number of fields—producing oil for the most part. A large percentage of the productive wells have produced water along with the oil. Often there is no apparent pattern for the percentage of water cut experienced. In several instances vertical displacments of over 200 ft have been established between communicating wells in which the formation appears to be about the same, yet the structurally high wells yield a much higher water cut than the lower wells. Drill-stem tests have contributed little to well completion because they nearly always show small amounts of water (usually mud filtrate), regardless of what is produced later in the life of the well. Other formation evaluation methods have had no more than limited success in indicating ultimate productivity. Consequently, predicting the type of fluid productivity of Delaware wells has been very difficult. Hydraulic fracture treatments are almost universal, and unstimulated Delaware wells have not exhibited the productivity that normally would be expected of wells with the specific permeabilities encountered. Some operators have indicated that their Delaware wells need frequent re-stimulation. The uncertainty of reservoir water saturations reported for the Delaware has made difficult the task of evaluating oil in place in the reservoirs and estimating primary recovery. The unreliability of this data also will cause feasibility studies for water flooding or other secondary-recovery methods to be problematical. Several opinions have been voiced to explain why the Delaware performs as it does. Chronically poor well completions, dynamic water and tilted water tables, capillary inequi-libria, peculiar relative permeability characteristics and oil-wetness are among the suggested reasons. The dual purpose of this paper is (1) to describe the principal rock characteristics, and (2) to present an evaluation of those characteristics so that approaches can be made to explain the irrational behavior of wells completed in the Delaware. STUDY OF ROUTINE CORE-ANALYSIS DATA A statistical study of routine core-analysis data has been made to relate fundamental rock properties and characteristics of the formation to well productivity. For the most part, well production data were obtained from operators and augmented by production data from commercial information services. Only data which were available in detail and which were considered to be accurate were used. The core data used were obtained on samples from the perforated or open interval only and, thus, may not always represent the total productive interval in a well. All the core-analysis data included in this study are from the Bell Canyon member of the Delaware and were obtained by "plug-type" techniques, as opposed to whole-core or full-diameter techniques. Porosity values were obtained by the summation-of-fluids technique, permeability values are air permeabilities corrected for slippage to an equivalent liquid permeability, and the oil and water contents were determined by means of a high-temperature downdraft retort. All the procedures used are discussed at length in Ref. I. The core-analysis data were sorted

By D. Hawington

HEALTH and safety in the mining and allied industries of the United States have unquestionably been progressing, particularly during the past three or four years, even though the progress has been anything but great in some branches of these industries. Statistical data to support this statement are readily available as to safety, but similar health data are unfortunately not available. In coal mining the rate of occurrence of fatal accidents per million tons of coal produced for the ten-year period 1911.20 inclusive was 4.27; this rate was 3.84 in 1930, .3.31 in 1931, 3.36 in 1932, and 2.69 (tentative) in 1933. In metal mining, the-rate of occurrence of fatal and- non-fatal injuries per .thousand 300-day workers (calculated) was 224.36 for- the same ten-year period. This fell slowly until after 1929 when it was 203.14, dropping to 170.78 in 1930, to 142.09 in 1931, to 138.46 in 1932, and to 155.13 in 1933. Here, again,-the real progress began in 1931 though the rate in 1930 was not particularly bad. For the same ten-year period, the rate of those killed and injured: in: quarrying per thousand 300-day workers (calculated)

Jan 1, 1935

The Editor, with the full realization of his own forgetfulness of political duties until it is brought to his attention perhaps by some unfavorable election already. consummated, wishes to remind the thinking men who compose the body of the membership of this Institute that never before in the history of the country has it been so important that we should be represented at Washington, and in our State Legislatures, by men of vision, high character, courage, broad experience in the more important affairs of life, and undoubted loyalty. Let us all endeavor to secure the nomination and election of this type of man, and let us, each in his own district (which collectively will represent practically every important locality in the Union) carefully scrutinize all candidates for election and work for the-best one who seems to have any chance of being. successful. Let its place ourselves in communication with political leaders, newspaper men of prominence, and public men generally, strengthening our own appreciation of the importance of the election at this time and cooperating for the purpose of obtaining candidates of the highest character. Upon the men of intellect depends chiefly the burden of wise selections at this time. Congressional elections will occur this Fall in the following states:

Jan 8, 1918

By J. C. Fisher

C. S. Smith has described a method for measuring the relative values of different solid-solid and solid-liquid interfacial tensi0ns. When a polyphase alloy is held at an elevated temperature, individual particles of each phase adjust their shapes and minimize the interfacial energy. Wherever three interfaces meet, the dihedral angles are such that the three interfacial tensions, considered as forces, are in equilibrium. When the angles between three forces in equilibrium at a point are known, it is possible to determine any two in terms of the third. In this way ratios of interfacial tensions have been .obtained. The value of a given interfacial tension ratio was found to be independent of the alloy system from which it was determined. Smith also has employed the method when one of the phases is liquid. When equilibrium is reached with respect to In the course of work on grain growth in high purity aluminum a simple optical method was developed for detecting the presence or absence of preferred orientation in annealed specimens. The specimens were prepared by grinding, polishing and "deep etching." The etching reagent used for high purity aluminum has been described.* The resulting etch pits produced selective

Jan 1, 1949

By O. C. Wheeler

There was a marked increase in the investigation of undeveloped areas in Colombia during 1936. The Shell company commenced geological and geophysical investigations on an intensive scale in the Upper Magdalena Valley and at the end of the year had several geological and geophysical parties working in that area. These investigations were supplemented by aerial photography and it is understood that negotiations are under way for having this work continued. The Shell is reported to have acquired some options and leases on private properties in the Upper Valley region and in the western part of Cundinamarca. The Socony Vacuum was making preparations to begin seismograph work on its property north of the Sogamoso River, acquired in 1934 from Sefior Luciano Restrepo. This company will probably start drilling on the property during 1937. The Richmond Petroleum Co. (Standard of California) is said to have renewed geological investigations in the Upper Magdalena Valley above Honda. Local Colombian interests took an active part in applying for concessions on nationally owned lands in the area between the Carare and Magdalena Rivers. The application of the Sociedad National del Carare for a concession in this area was granted during the year. Subsequently an agreement was reached between this

Jan 1, 1937

POSITIONS VACANT Position as superintendent of all-sliming cyanide plant in Montana will he open in spring. Thoroughly experienced man wanted. No. 6. Position as engineer for iron-mining company in Virginia is open. Single man with experience in underground surveying preferred. No. 7. ENGINEERS AVAILABLE (Under this heading will be published notes sent to the Secretary of the Institute. by members or other persons.) Member, 34 years old, married, nine years responsible position in South America, excellent knowledge of Spanish, Latin-American people and customs, with present employer seven years, six years as manager and legal representative of a mining company, desires to make a change April, 1914. Prefers position requiring energy, executive ability, business tact and practical knowledge dealing with political and legal authorities, rather than strictly technical position. No. 35. Technical graduate, married, with four years' experience in assaying, surveying, sampling,. and mine supervision in Utah and Mexico, open for engagement. No. 37. Member, aged 28, desires opening on engineering or sales force of machinery house, or manufacturing concern. Twelve years' experience, in smelters, cyanide plants, concentrators and gold dredges, steam, gas and electric machinery and mechanical drafting. At present foreman for a silver-lead company. No. 40.

Jan 1, 1914

By Frank C. Greene

Drilling for oil and gas in Missouri continued at a slightly lower rate than has been prevailing. A summary of operations for the past few years as compiled and published by the Missouri Geological Survey and Water Resources is as follows: Two oil pools are being developed in Cass County. Neither area has been drilled completely, and detailed descriptions will not be given at this time. In the Endicott pool in the southern part of T. 44 N., R. 33 W., oil is found in the Warrensburg sand, which is now considered to be the Big Lake sand of eastern Kansas. The top of the sand is about 125 ft. below the Herthalimestone. The best well is reported to have made 14 bbl. per day for the first four days. The oil is 30" to 32' BB. gravity. This is the only pool in the state, aside from the older areas on the east and west edges of Lees Summit, Jackson County, that is producing oil from the Warrensburg sand. Drilling continues in the Knoche pool in the central part of T. 46 N., R. 33 W., where the oil is found in the Squirrel sand. The oil produced by both these pools is sold by truck in Kansas City.

Jan 1, 1937

By A. E. Bellis

The time effect in reheating certain steels below the critical range is very marked. The increased toughness, shock-resisting power, and machinability of steel subjected to a long, high drawing temperature has been thoroughly demonstrated and is of practical importance, particularly in the manufacture of "smokeless" rifle-barrel steel. The time effect in tempering is most important when a maximum drawing effect is desired, in which case the highest physical properties as well as ease of machining are important considerations. These are the conditions in drilling a rifle barrel. A hole, 0.30 in. in diameter and 24 in. long for the Springfield rifle, and 30 in. long for the Russian military rifle, has to be drilled in the heat-treated material. This barrel-drilling operation is probably the most difficult one in rifle manufacture, and anyone who has been connected with rifle manufacture knows how seriously production is affected when "hard" or non-uniform steel for barrels is encountered. The importance of high physical properties (tensile strength, toughness and resilience) in a rifle barrel is obvious. The physical properties of two different lots of barrel steel are given below. The first lot, No. 1, gave serious trouble in the drilling operation; the second gave no trouble at all.

Jan 2, 1918

Frank Owen, El Perú Venezuela (communication to the Secretary): Mr. Cragoe's accurate description of the rich and extensive mines of the Frontino and Bolivia Co. is of much interest to those acquainted with Colombian mining. While the labor in that part of Colombia is, of course, admittedly far inferior to that of white miners, it is,. nevertheless, decidedly superior to that available in other parts of the republic, and in the northern mining regions of South America generally. The Autioquenos have been miners for several generations, and many of those employed at the Frontino Co.'s works have been brought up at the mines, which is a distinct advantage. The ground encountered in the surface-workings of that district being very treacherous, they are skillful timber-men, every miner being able to put in his own timber in tunnels, stopes, etc., so that, except for the main shafts, where sawn timber is used, special timber-men are not required. In the shallow workings it is the custom for a miner to come out of the mine into the thickly-wooded bush and select and cut the timber he requires, which he will then take into the mine and put in

Jan 1, 1899

By C. A. Wert

THE change in mechanical properties accompanying quench aging of carbon in a iron has been known for a number of years. Since the amount of carbon involved is rather small, however, no measurements could be made to correlate the property change with the state of precipitation of the carbide. Indeed, until a few years ago it was not plain which property might be used to indicate the state of the progress of precipitation. Some years ago the internal friction of solid solutions of carbon in a iron was demonstrated, and the use of this phenomenon to ascertain the amount of carbon in solid solution at any given time was developed. Shortly afterward the author made a number of measurements in which changes in electrical resistance, thermoelectric emf, and hardness were determined simultaneously with the internal friction (and hence with the precipitation) ? A little later Dijkstra and Wert measured the change in magnetic coercive force accompanying aging.' The present work was undertaken to inquire into the changes in yield strength accompanying aging. The work was done on specimens made of Puron. These specimens were 0.05 in. in diam and about 6 in. long. Though specimens of this small size are not ideal for yield strength measurements, such specimens are desirable for internal friction meas-

Jan 1, 1952

By E. T. Cox

WHILe engaged, in the year 1856, in determining the oil-bearing properties of some bituminous coals from Western Kentucky, by subjecting them to dry distillation in an iron retort, which held about a pint;, and to the neck of which were attached several bottles, for collecting the carbon oils, and washing and measuring the gas, I observed that there was a very great gain in the weight of coke thus made, over that obtained from the same coal when charred in a platinum crucible, as is usual in the laboratory for making the proximate analysis of coal. It was thought at the time that the increase of coke, by the former mode of treating the coal, was due to the pressure which the retarded gas exerted upon the solid carbon, and the possible fixing of a portion of the carbon from the volatile hydrocarbons. For the purpose of obtaining a more definite idea of the effects of pressure on the coking of coals, a series of experiments were made this spring under my direction, by my assistant, Dr. G. M. Levete. The results are highly instructive and full of interest, since they point out some peculiarities in the nature of bituminous coals which

By Emory J. Douglass

Mining companies are unique in that they extract mineral resources and must therefore deal with ecological disturbances and other special problems. Like most enterprises, however, their primary motive must be to make money. The problem of mining investment starts with the question of what "make money" means. This article proposes an answer consistent with what economists call the theory of the firm and then applies it to two of the common, and perhaps unrecognized, problems connected with min¬ing investment. In essence, the concepts presented here call for thinking to terms of the income change associated with a given change it outlays or operating procedures To illustrate. ABC Distributing Co. has just discovered the power of advertising. It has raised its annual advertising budget from $25,000 to $50,000, and sales have, zoomed from 250.000 to 350,000 units. The company buy, for 50e per unit and sells at $l. This move has produced $50,000 of operating income for $25.000 in additional advertising expense. This looks great, so the next year the advertising budget goes up to $100,000. Sales go to 440,000 units. With 90,000 more units at 50[c] per unit, ABC sales are up by $45.000. Its advertising costs, however, went up $50,000.

Jan 1, 1971