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By F. L. Sizer

SOME old-time views which have recently come into my possession have inspired me to record that part of the early history of Leadville, Color- ado, with which I am familiar, the years 1878 to 1882, in the hope that others will add to what is here mentioned. My first appearance in Leadville was in June, 1878, immediately after graduation from the University of Michigan, and I found a congenial and lively crowd of young men, already there. The old log hotel, at the corner of Pine and State streets, housed some distinguished guests in the summer and fall of 1878. It was my good fortune there to make the acquaintance of James B. Grant, afterwards Governor of Colorado, in July of that year, when we were both glad of the accommodation afforded by cots in the second floor loft of the hostelry presided over by Herman Hibschle. Grant was then building his smelter and our associates were Eddy and James, August R. Meyer, and Berdell and Witherell. The Grand Hotel-Harris and Walsh, pro- prietors-was the first-class hotel of the place; but in a very few months there were many competitors.

Jan 1, 1924

By Walter R. Hibbard, George H. Eichelman, William P. Saunders

INTEREST in the various products of the austenite eutectoid transformation in iron-carbon alloys, particularly as produced by the isothermal sub-critical techniques introduced by Davenport and Bain,1 has resulted in the application of similar heat treatments to other eutectoid transformations. Studies2.3.4 of the beta copper-aluminum alloy eutectoid transformation revealed microstructures very similar to those found in iron-carbon alloys. Investigations5,6 of the kappa phase in the copper-silicon alloy system have established the eutectoid type transformation of this phase into terminal alpha and intermediate gamma phases. This transformation has been reported' as forming a eutectoid type structure in a very sluggish manner by a long time isothermal treatment. The purpose of the present investigation is to study the products of the kappa eutectoid transformation as affected by transformation temperatures by means of microscopic and hardness methods. PREPARATION OF ALLOYS The copper-silicon alloy equilibrium diagram is shown in Fig I. The kappa field converges to a minimum silicon solubility at the eutectoid composition and all other completely kappa alloys are hypereutectoid. Thus, kappa decomposition involves first the proeutectoid precipitation of gamma, followed by the eutectoid transformation of a lower silicon content kappa (5.2 pct). Smith5 has indicated that alloys containing between 5.4 and 5.7 pct silicon could be hot rolled, but that the latter composition was desirable in order to permit a wider kappa temperature range. The alloy was prepared by adding Baker's commercially pure silicon to an ingot of copper-silicon alloy containing 2.34 pct silicon remaining from the investigation of Brick, Martin and Angier.7 Following the casting techniques of Krynitsky, Saunders and Stern,8 the ingot was melted under a heavy layer of dried charcoal in a clay-graphite crucible in a gas-fired pot furnace. Small lumps of silicon were held under the melt surface with a graphite rod. After the silicon had dissolved, the alloy was chill-cast and then remelted without a cover, stirred thoroughly, skimmed and poured into a preheated cast iron mold. The cast microstructure is shown in Fig 2. The casting, 10 X 4 X ¾ in., was annealed at 750°C for 21 brand furnace cooled. About 1/16 in. was milled from all surfaces. The plate was cut in half longitudinally and the bottom half analyzed by A.S.T.M. methods.9 The composition by weight was as follows: copper 94.24 pct, silicon 5.56 pct, iron 0.11 pct.

Jan 1, 1948

The curve of Fig. 3 for pyrite requires modification. There 11% a range of pH values from 6.2 to 7.8 for which no cyanide is required to prevent contact. From 7.8 to 11.3 a small amount of cyanide is required, with a sharp maximum of 20 mg. per liter at pH=9.6. The mistake arose from considering too few solution compositions (17 were considered) in constructing the curve. Subsequent work with other collectors indicates that the corrected curve is typical for such systems; it illustrates the further development of the dip in the pyrite curve of Fig. 5.

Jan 1, 1938

By P. W. Neurath, R. E. Waite

INFORMATION is available on the effect of stress on permeability, coercive force, and hysteresis for a variety of materials' but for the technically important grain-oriented 3 pct Si-Fe' the stress effects are not adequately covered in the literature; in addition, most of the stress data do not permit estimation of what would happen to the 60 cycle watt losses of the material under stress. Direct measurement of these effects therefore has been made and appears to be of considerable theoretical as well as practical interest. Losses were measured on the central 25 cm portion of 40~3~0.035 cm samples which could be stressed in a small tensile machine built for this purpose. Under tension the following effects, illustrated in the figures by a particular example, were observed: 1—"Unstrained" material of commercially acceptable loss level shows no change or a small increase in loss at low elastic stresses. For the sample shown in the figures, this is illustrated during the initial run, where a 7 pct increase is observed (Fig. 1). 2—There is no additional change in loss when the sample is further strained up to the elastic limit (Fig. 1). Within that limit the loss-stress curve is reversible. This is not illustrated in Fig. 1. 3—Even in the plastic range only small increases in loss are observed as long as the sample is kept under stress (Fig. 2, point N); often no increase can be observed (Fig. 1). 4—A large increase in watt losses is observed after removal of the stress subsequent to plastic deformation (Figs. 1 and 2). 5—All, or nearly all, of the foregoing increase in loss due to plastic deformation can be eliminated by a reapplication of tensile stress but returns upon removal of this stress. This is illustrated in the third run (Fig. 3). This run remains within the elastic limit and shows the reversibility of the stress-loss curve under this condition. These findings have been confirmed on large Samples (approximately 200~10~0.035 cm and larger) except that under 1 no initial increase in loss was ever observed on these. The accuracy of the watt loss measurements is of the order of 1 pct. Neither bending of the sample in the tensioning device nor a redistribution of flux along the width of the sample accounts for these results. They therefore must be explained on the basis of either a change in the domain configuration due to stress or a change in the domain wall mobility. Acknowledgment The assistance of Mr. Robert L. TenBroeck with the instrumentation is gratefully acknowledged.

Jan 1, 1956

By P. P. Gregory

Natural petroleum gas occurring in the oil-bearing reservoirs is found to exist either as free gas associated with the oil and/or in solution in the oil. In some virgin fields practically no free gas is encountered under the reservoir conditions of pressure and temperature, although in other fields a considerable section of the "pay" horizon is occupied by free gas. In other words, a given oil field may or may not have a gas cap before the exploitation takes place. However, when the reservoir pressure is reduced to a point below the critical saturation pressure by withdrawals of fluids from the producing formation, the gas dissolved in the oil inevitably begins to come out of solution and becomes free gas. Under the controlled methods of production and drilling, a portion of this gas is produced with the oil to the surface and a portion of it remains within the reservoir to accumulate at higher structural levels toward which it migrates by virtue of its low specific gravity. The rate of growth of a gas cap in a given structure depends primarily upon the rate of decline in the reservoir pressure. If the rate of pressure decline is rapid, the gas cap likewise will grow rapidly. On the other hand, shrinkage in the gas-cap area was noted in some fields in which reservoir pressures wereincreasing. Determination of Gas-oil Contact and Thickness of Gas Cap The gas-oil contact can be conveniently located in the process of drilling a well and by electrical logging. However, very little can be found in the petroleum literature concerning methods of predetermining gas-oil contacts in producing reservoirs. Therefore, the writer feels justified in describing briefly a simple, workable, and inexpensive method of determining gas-oil contacts and outlining the limits of gas-cap areas in a field where such knowledge may be essential for efficient production and development operations. The method involves the determination of the following data: (I) Structural data, such as the depth or elevation of the top' of "pay" horizon; (2) reservoir pressures; (3) tubing and casing pressures at the well head; (4) static oil-pressure gradient; (5) static gas-pressure gradient. These data can be secured with a minimum of expense, inasmuch as the

Jan 1, 1938

By R. S. Sandhu, S. H. Advani, J. K. Lee, B. L. Aboustit

A comprehensive finite element formulation for thermo-elastic consolidation based on a general variational principle is presented Sample one dimensional problems associated with isothermal consolidation, heat conduct ion, and thermo-elastic consolidation are presented. In addition, evaluations of thermo-elastic consolidation for an underground coal conversion field site are conducted.

Jan 1, 1982

By D. L. Passmore, J. D. Bennett

The degree of injury and days lost from work due to an injury are examined for selected electrical sources, occurring in conjunction with falls of the injured miner or with selected machinery, that could have been eliminated by use of diesel equipment. Although the number of preventable electrical source injuries is small relative to the total number of injuries during the period examined, many lost-time injuries could have been precluded and thousands of days lost from work could have been avoided.

Jan 1, 1986

By Richard J. Mainiero

INTRODUCTION Because of the hazards associated with flammable methane gas and coal dust, the shooting of mudcaps (adobes) or other unconfined explosive charges in underground bituminous coal mines is prohibited; all explosives must be fired in stemmed boreholes. However, there are situations where it would be advantageous from a safety standpoint to fire open shots. This would be in the areas of dislodging loose roof slabs, overhangs, rock-fall leveling, slab or boulder breaking, crib removal, and crevice shooting. The Bureau of Mines, U.S. Department of the Interior, has been developing an explosive charge that is non-incendive; that is, detonation of the charge will not ignite a flammable atmosphere. This explosive charge could be applied to the blasting conditions mentioned above. As of this writing, the explosive charge has not yet been certified as "permissible" for use in flammable atmospheres, but the necessary protocol is being finalized with the Mine Safety and Health Administration (MSHA), U.S. Department of Labor. The explosive charge described in this paper is merely a prototype sheathed rock-breaker charge (sheathed permissible explosive rock- breaker charge) demonstrating the feasibility of such a device. Industry may modify the design and composition of the charge in producing a commercial product so long as it is still safe, as defined by a testing schedule being developed by the Bureau of Mines and MSHA.

Jan 1, 1984

By K. M. Myles

The vapor pressure of palladium over a series of Rlz-Pd alloys has been measured by the torsion-effusion method. The thermodynamic properties of the alloy system at 1575=K have been calculated from the vapor pressure data. The activities and the free energies of formation exhibit large positive deviations from ideal behavior. The enthalpies of formation are endother-mic. The entropies of formation are positive and larger than the ideal entropy of mixing. All of the thermodynamic properties suggest that a strong tendency toward phase separation exists in the solid solutions. The possible origin of the phase instability and the various factors that influence the thermodynamic properties are discussed. RECENT studies of the thermodynamic properties of alloys of palladium with nontransition elements have indicated that a significant contribution to the enthalpy of formation is related to the redistribution of the conduction electrons upon alloy formation.'-' The present work was undertaken to ascertain the importance of this contribution in Pd/transition-metal alloys. The Rh-Pd system was chosen for this investigation for several reasons: 1) The thermodynamics of the system were unknown. 2) Rhodium and palladium are completely soluble at high temperatures; below 1118OK the solid solution becomes immiscible.', 3) The difference in magnitude between the vapor pressures of rhodium and palladium permitted the use of an existing effusion apparatus. 4) Additional information was known about the alloy system that would facilitate the interpretation of the thermodynamic results. EXPERIMENTAL PROCEDURE The thermodynamic properties of the Rh-Pd alloy system were calculated from the vapor pressure of palladium over solid palladium and over several solid Rh-Pd alloys. The vapor pressure was measured by means of the torsion-effusion apparatus that has been described previously. In this method, an effusion cell is suspended from a tungsten filament inside a high-temperature furnace. Two orifices are located eccentrically such that the effusion of the vapor creates a rotational torque in the filament. The angle of rotation is directly related to the total vapor pressure within the cell. As the vapor pressures of rhodium and palladium are approximately five orders of magnitude apart," the total vapor pressure was considered to be effectively equal to the equilibrium vapor pressure of palladium. The effusion cells were made from high-purity alumina since auxiliary experiments indicated that essentially no reaction occurs between alumina and solid Rh-Pd alloys. Unfortunately, because the orifices were irregular, an accurate calculation of the Free- man-Searcy correction factors" could not be made. The constants were determined in an independent experiment where the vapor pressure of copper, as measured in the alumina cell, was compared with an accurate value of the vapor pressure, which had been determined previously.4 Depletion of palladium from the surfaces of the specimens was minimal as the deflection of the cell remained constant, for at least 15 minutes, at each of the experimental temperatures. Lattice parameter measurements of the postrun alloys also indicated that no changes in the composition of the surfaces had occurred. The alloys were prepared by arc melting the requisite amounts of the 99.99 pct pure elements. The four most palladium-rich alloys were remelted in a levita-tion furnace since complete melting of the components had not occurred in the arc furnace. All of the alloys were subsequently homogenized at elevated temperatures in sealed alumina thimbles. After heat treatment, the alloys were analyzed chemically and were in essential agreement with the nominal compositions. The thermal histories and nominal compositions of the alloys are given in Table I. Lattice parameters of the heat-treated alloys were computed, by means of the method described by Mueller et a1. ,I2 from X-ray diffraction powder patterns obtained with filtered copper radiation in a 114.6-mm-diam Straumanis-type Debye-Scherrer camera. The results, which are tabulated in Table I, exhibit a slightly greater negative deviation from Vegards' law than the values reported by Raub et al.13 The diffraction lines were sharp and well-resolved and thus indicated that the alloys were homogenous. RESULTS The logarithms of the individual values of the vapor pressure of palladium were fit, by the least-squares method, as a linear function of the reciprocal of the absolute temperatures. The constants of the equations are given in Table I along with the temperature range over which the data was accumulated. The latent heat of vaporization at 298.15"K for pure palladium, calculated by the third-law method,14 showed no systematic temperature dependence. The average value of 88,920 * 20 cal per g-atom agrees favorably with the average of the results obtained in the most reliable previous investigations.15"19 The activities of palladium were computed from the vapor pressure data at 1525', 1575", and 1625OK. Consistent with the mass spectrometric study of the atomicity of palladium vapor,lg the vapor was assumed to be monoatomic. The activities of rhodium were determined by integrating the Gibbs-Duhem equation with the aid of the a function.20 In the calculations, the activities of the pure solid metals were assigned the value of unity. From the activities, the partial and integral free energies, entropies, and enthalpies of formation at 1575° K were computed; they are assembled in Table 11.

Jan 1, 1969

By Anthony Lucas

THE discovery of oil in 1901 on the Spindletop dome, Texas, inaugurated a new industry on the Gulf Coast, an industry which has grown with the discovery of successive fields, until today it engages the services of thousands of workers and employs enormous capital. New fields are being discovered from time to time and doubtless some still remain to be found, though of late years discoveries have become more infrequent. Nowadays several hundred dry holes are drilled each year in a fruitless and blind effort to discover new fields, for as yet geologic science has developed no effectual method of locating the coastal oil deposits in advance of drilling. Moreover, despite the occasional discovery of new fields, the total production of the Gulf Coast is today no greater than it was in 1906, for the added production of the new fields has been offset by the rapid decline and more or less complete exhaustion of some of the older ones. Careful geologic work within the fields has in some cases increased the production temporarily, but has developed no really new supplies. The Gulf Coast oil industry seems to have passed its period of greatest expansion and to be declining at a fairly steady rate, and this condition is naturally viewed with alarm by the more farsighted operators. In my opinion, the time has come for the adoption of radical and aggressive methods of prospecting, and a fraction of the money wasted yearly in drilling shallow wells in hopeless locations might well be devoted to this purpose. Many facts lead me to believe that all the salt-dome oil has had a common origin; that it has migrated up from considerable

Jan 7, 1918

By P. R. Sahm, T. V. Pruss, D. A. Gandolfo

Cb 3 Sn powders were hot-pressed to estahlish densi-fication conditions and assess the possible use of such compacts in multiphase structures with ceramic or magnetic inclusions. Superconducting transition temperatures, Tc, were measured as a function of powder particle size, pressing temperature, and second-phase admixtures. The highest transition temperatures were found in coarse powder (5 to 500 u) compacts and were only weakly depended on pressing temperatures up to 1200°C. Fine powders (below 5 p), however, both single-phase CbsSn and Cb3 Sn-composites, showed a stronger dependence on hot-pressing temperatures. While Al2 O3 phase admixtures did not affect T, much more, a Pronounced T, degradation was observed upon the addition of ferrimagnetic Fe2 Mno. 5 Zno.5 O4 powders. Likewise, critical current densities, Jc, at 4.2° K were lowered appreciably in the ferrite doped samples, whereas the neutral A1203 inclusiow gave slightly improved Jc values. MULTIPHASE structures in electronically active materials have recently gained in interest as pointed out by Galasso in a review article.' In superconductors the most widely reported group are eutectic alloys which have been mostly investigated with respect to the proximity effect.2"4 In addition, "artificial eu-tectics", for example in the form of mercury-vycor glass sponge5 or fine niobium wires imbedded in a copper matrix,= have been prepared to attain higher critical fields and critical current densities. The idea was to enhance flux pinning phenomena by second-phase inclusions or ho1es. 7 Flux pinning should also be possible by the introduction of insulator inclusions into a superconducting matrix. Ceramic-metal combinations are most easily produced by hot pressing (= pressure sintering), as it permits an almost unlimited selection of material combinations. Cb 3 Sn has been prepared by vapor phase growths or in the form of thin films. Large compacts must be sintered,1° however, and normally present difficulties. At temperatures below 1350°C insufficient densities are obtained and at higher temperatures the loss of tin due to dissociation upsets the stoichiometry. Hot pressing is a natural approach to circumvent the problems, since one can obtain satisfactory densities despite low sintering temperatures. This work was mostly concerned with establishing conditions to hot press Cb3 Sn and Cb3 Sn multiphase structures (= composites), because no data are presently available, and to evaluate these with respect to their transition temperatures. However, a few measurements on critical current densities were also carried out, in particular to assess the value of ferrimagnetic inclusions. I) EXPERIMENTAL PROCEDURE The experimental procedure involved the preparation of feed material and powders, hot pressing, and evaluation of the resulting ingots. As no attempts were made to synthesize Cb3Sn from the elements during hot pressing, feed material had to be produced. For this purpose, a stoichiometric Cb-Sn powder mixture was compacted into a 3-cm-diam ingot (80,000 psi) and then inserted into a quartz tube and evacuated. Rf heating was employed. Above the tin melting point (230°C) liquid tin was forced out of the ingot, but was pulled back by capillary action after approximately 0.5 hr of continuous pumping at 700°C. Thus, it appears that evacuation at this temperature caused desorption of impurity gas creating wetting surfaces which, later on, favored alloying at relatively low temperatures. After a presintering period of 17 hr at 800°C, the quartz tube was tipped off and sealed into another such larger-diameter tube which, in turn, was connected to a pump system. This configuration permitted a temperature treatment at 1400°C, carried out for 65 hr, without collapsing of the glass walls or unfavorable chemical interaction of Cb3Sn with the quartz. The resulting material was

Jan 1, 1969

By John V. Beall

Let's start at the beginning, Mr. Turner. Where and when were you born? In Lansing, Mich., on July 31, 1880. And what was your education? I went to the University of Michigan, where I got an A.B. degree in 1902; then to the Michigan College of Mines at Houghton, graduating from there in 1904 with a B.S. and an E.M. What was your first job in the mining industry, Mr. Turner, and what were you paid? In the summer of 1902, 1 was a field assistant for the U. S. Geological Survey in southwestern Idaho and southeastern Oregon, working under Israel C. Russell, professor of geology at the University of Michigan, who incidentally, had just returned from an expedition to study the effects of the eruption of Mt. Pelee, on Martinique. I was paid $60 a month and found; in addition to doing geologic and hydrographic work, I cooked many of the meals for a party of four, and wrangled four horses. I slept for four months under the stars, without a tent.

Jan 1, 1949

By Eugene E. Ayres

The centrifuge has come into general use in the oil fields and in the establishments where lubricating and fuel oils are used. Probably centrifugal machinery will be found more useful in the refinery when the operators are more familiar with'the principles of modern centrifuga-tion and when centrifugal engineers better understand the refinery emulsion problems. It is not generally realized that centrifugal force and gravity have two distinct functions: First, subsidence wherein the suspended globules are brought into contact; second, coalescence (when this is possible) by rupturing the films around the globules. In the case of a water-in-oil emulsion, an exercise of the former function alone would yield: (1) oil, free, or as free as desired, from water; and (2) a concentrated water-in-oil emulsion—concentrated in the sense that it contains a relatively large percentage of the internal phase. An exercise of both functions will yield: (1) water-free oil and (2) oil-free water. Centrifugal force is much better than gravity for subsidence because, in the case of industrial emulsions where the suspended globules are visible under a microscope, subsidence is directly proportional to the force applied. Centrifugal force is only slightly better than gravity for coalescence. A minute trace of a proper reagent will immediately do more to nullify the interfacial surface tension opposing coalescence than an indefinite application of the highest attainable centrifugal force. No mathematical analysis has been made to explain the failure of high centrifugal force to induce a decidedly more rapid and more complete coalescence than is obtained by gravity. The adjustment of the centrifuge rotor depends more on the extent of coalescence that is desired or is possible than on any other factor. One reason for this dependence is to be found in the curious relation between the specific gravity and the hydrostatic pressure of emulsions. The continuous centrifuge works on the U-tube or Florentine flask prin-

Jan 1, 1924

By AIME AIME

THE report of the united. States Steel Corporation for the' year 1928 gives the, following ,figures of raw materials and' finished products . Raw materials, tons :

Jan 1, 1929

By H. R. MacMichael

IN the Chihuahua district of Mexico the first smelting was that inaugurated by the early Spaniards for the production of silver bullion. The ores treated were high in silver and lead. Silver-lead bullion was first produced and the lead then cupelled to waste, with the slag produced running from 5 to 10 per cent in lead and about 25 to 40 per cent silica. The ore was mined by peon labor, often being carried out of the mine on the backs of the men, and then transported by burros. Furnaces were of primitive construction, adobe or rock being used in the earlier period and some iron later when it became available. Blast was originally supplied by bellows manually operated. Such smelting was carried on to a greater or lesser extent until the latter part of the last century, and so extensive was it that many hundred thousand tons of leady slag remained to be treated in modern furnaces. In 1908 a smelter was placed in operation at Chihuahua by the American Smelting & Refining Co. At that time the ore was practically all oxidized and by a little selection, self-fluxing mixtures could be made, but with an average lead content usually under 10 per cent and sometimes as low as 7 per cent. The bullion produced would carry from 150 to 300 oz. silver per ton. The slag made approximated 30 per cent SiO2, 42 per cent FeO, 21 per cent CaO, and perhaps 3 per cent Zn. The ores varied from hard, coarse material which was passed through a crusher, to a considerable quantity of fines which had to be smelted as it came, as crushing the coarse was the only preparation for smelting.

Jan 1, 1933

By Edmund C. Pechin

I REGRET that I am unable to present this subject in definite form and detail. All I shall attempt at this meeting is to lay before you some curious facts, the bearings and explanations of which must be reserved for future consideration. I hope before the next meeting to have carried experiments far enough to furnish a more important contribution to the science of iron metallurgy. The Wickersham process consists in the introduction into the molten metal, as it runs from the furnace, of air from the hot blast. Mr. Samuel Wickersham is the originator of the plan, as applied in practice, although Mr. Martien had the idea a long time ago, and, I believe, .went to England about it. But at that time Mr. Bessemer was coming before the public with his invention, which engrossed the attention of iron-masters, and Mr. Martien accomplished nothing. The principal difficulty in our experiments at Dunbar was to get a practicable runner or trough, through which the molten metal should pass, and in which it should be exposed to the action of the blast. The runner we used was ten feet long, and perforated on the sides to permit the entrance of the air-currents. When we used a cast-iron and fire-clay runner, the heat was so great that before we were more than half done with a run, the lower part of the runner was melted, and we had a magnificent Fourth of July display of fireworks until the blast was shut off. We had to abandon fire clay. The runner with which we have had the best success ,is made of wrought-iron tubes, 2 1/2 inches in diameter, attached to a wrought-iron frame, and lined with a mixture of crushed conglomerate (quartz) and a little fire clay to give it cohesion. The wrought-iron shell curves inward over the upper edges, so as to catch and throw back into the current the flying sparks and particles of metal thrown out by ebullition. With this we have been able to run 12 to 14 tons at a heat with great ease. Mr. Wickersham has since prepared this material (pounded quartz) into a shaped brick or tile, with the necessary perforations for the passage of the air, which promises to answer every requirement for steady working. As regards the improvement in the quality of the iron, there seems to be no question. A large number of practical tests were made in

Jan 1, 1873

By A. R. Kinkel

THE Shasta copper-zinc district of northern California lies in the foothills of the Klamath Mountains at the northern end of the Sacramento Valley. It contains two main areas of base-metal ore deposits, the East Shasta and West Shasta districts shown in Fig. 1. The East Shasta includes the area from the Afterthought mine, near the settlement of Ingot on U. S. highway 299 East, to the Bully Hill mine, on the north side of the Pit River, 9 miles to the northwest. The West Shasta, a well-defined northeast-trending district about 8 miles long and 2 miles wide, west of the Sacramento River, Fig. 2, is the western part of the ore-bearing area formerly known as the Shasta copper belt. Referred to in the older writings as a copper arc, this belt was thought to form a crescent extending entirely around the head of the Sacramento Valley, the convex side to the north. Recent studies by the U. S. Geological Survey in cooperation with the California State Division of Mines show that there are two districts, one at each end of the so-called copper arc, which are distinct in geologic structure and ore occurrences, and that there is only sporadic and unconnected copper mineralization between them. Ore deposits of the two districts are similar in mineralogy, that is, they are largely massive pyritic ores containing copper and zinc with minor amounts of gold and silver, but the structure and structural control of ore deposition are different. The ores of the East Shasta district are replacements of steeply dipping shear zones in Triassic rhyolite and shale, whereas those of the West Shasta district are replacements of gently dipping rhyolite of Middle Devonian age and are essentially flat-lying. Thus there is marked lateral control of orebodies by shear zones in the East Shasta district and equally marked vertical control of orebodies by the stratigraphy in the West Shasta district. Geologic Setting The Paleozoic rocks of the West Shasta district range in age from Middle Devonian (?) to Missis-sippian. The oldest formation exposed is the Copley greenstone, probably Middle Devonian. It is composed of volcanic flows, volcanic breccias, and tuffs, all of mafic composition, but contains minor amounts of shale and rhyolitic tuff. Largely submarine in origin, it rests upon a base of older marine sediments, as shown diagrammatically in Fig. 3. The lower part of the formation is made up principally of flows, many of which are ellipsoidal, and the upper part contains most of the pyroclastic material. The formation is at least 3700 ft thick. The Balaklala rhyolite overlying the Copley greenstone is made up of many rhyolitic flows and beds

Jan 1, 1956

By Dennis Peterson

INTRODUCTION The business arena has dramatically changed for most producers and consumers of commodities. International debt, currency shortages, political upheavals, etc., require corporations today to be sophisticated and flexible enough to change their purchasing and sales techniques in order to maximize returns. Many external factors, such as interest rates, trading partners, currency changes, and government edicts, can have an adverse effect on a company's bottom line. Totally out of a company's ability to control or predict, these. factors force the commodities based corporation to constantly re-evaluate its operating scope and domain. The principle of back-yard only operations and the laissez-faire with blinders style of management is no longer a viable way to run a business. The industrial world has been operating for the past 10 to 15 years as though there were no commodity nor raw material crisis. For developed countries the primary products sector has become marginal, whereas it was central in the first half of the century. A radical change in the method of doing business is necessary to offset a depression in the industrial economy. The risk of collapse may be heightened by a banking crisis caused by massive defaults on the part of commodity producing debtors, whether in the third world or in our own farm producing sector. The raw materials economy has become divergent with the industrial economy. This is a major change in the world economy with tremendous implications in both developed and developing countries for economic and social policies and economic theories. Basic competition issues, such as low labor costs, are likely to become less of an advantage in international trade. In developed countries these costs are going to account for a smaller portion of total costs. The total costs of automated processes are lower than those of traditional plants with low labor costs. Automation in the commodities sector eliminates the hidden but high cost of not processing at capacity created by poor quality, rejects and maintenance for product change-overs. The cost of capital will become increasingly important in international competition. Over the last ten years the U.S. has become the highest cost country in this area. Reversing the U.S. policy of high interest rates and costly equity capital should be a priority for management decision makers. In the rapid industrialization of this century, Japan developed by exporting raw materials, (principally, silk and tea), at steadily increasing prices. Germany developed by leap frogging into the high-tech industries, mainly in electricity, chemicals and optics. The United States did both. Both avenues are blocked for today's rapidly industrializing countries because (a) the deterioration of the terms of trade for primary products, and (b) it requires an infrastructure of knowledge and education far beyond the scope of a poor country. Many explanations exist for the explosion of international money flows. The shift from fixed to floating exchange rates in 1971 may have given initial impetus by inviting currency speculation. The surge in liquid funds flowing to petroleum producers after the oil shocks of 1973 and 1979 was definitely a major cause. There can be little doubt that the U.S. government deficit also played a big role. The American budget deficit has become a massive void, sucking in liquid funds from all over the world and making the U.S. the world's major debtor country. In reality, a trade and payments deficit is actually a loan from the seller of goods and services to the buyer, that is, to the U.S. From now on, the global ramifications of business will have to be treated in economic theory and business policy alike. Economic theory teaches that the comparative advantage factors of a real economy determines operative and financial policy. These comparisons -- labor costs, productivity, raw materials cost, energy costs,

Jan 1, 1990

By Prince Gelasio Caetani

PRESIDENT DWIGHT'S invitation to be a guest of the American Institute of Mining and Metal-lurgical Engineers was the first of the subsequently very numerous invitations to dinner I have received from my American friends. When I received his telegram I had not yet been even formally appointed Ambassador. I cannot tell you how deeply I appreciated it. It was a hearty welcome in returning to your country which has been for me a second home and it came from the American mining brotherhood which has been my second family.There are two distinct periods of learning in life. The first one are the years spent in school where we learn many things we after-wards forget; the second one are the years of prac-tical apprenticeship which engrave indelible signs in a man's character and shape his life. These latter years I spent in the United States and they have influenced the whole course of my life. I owe very much to my American friends who trained me. The earliest was Prof. Robert Peele, of Columbia University. At the Daly West mine, in Park City, Utah, he curbed my futuristic English spell-ing and had a hard time at it. Prof. James F. Kemp taught me that geology is a guess work just as unre-liable as the prediction of international events; he taught me also that a frank, honest and loyal character will lead a man equally straight through a mining report and through public life.

Jan 3, 1923

By A. A. Steel

DUring the summer of 1905 I was employed by the U. S. Geological Survey to investigate the geology, mining, and preparation of barite in most of the fields of the United States. The Eastern districts have been more or less completely described; the Virginia field in detail by Thomas L. Watson, in his paper, Geology of the Virginia Barite-Deposits,' and other fields in abstract, including statistics of production and references to current literature, by various authors.2 There have also been published a few details of the occurrence of barite in the lead-mines of Washington county, Mo.³ The other accounts of this district are erroneous and meager, and since this field is the most important one in the United States at the present time, a detailed description of the local geology seems doubly desirable. Barite-deposits are scattered over nearly the whole of Washington and adjoining counties, but the product is all mined from the areas indicated upon the sketch-map, Fig. 1, and is shipped from the stations of the St. Louis, Iron Mountain & Southern railway, between Blackwell and Potosi, from 45 to 60 miles SW. of St. Louis. The topography is for the most part gently rolling, with slightly graded streams, usually less than 200 ft. below the higher hill-tops. Along Mineral fork and Indian creek are some steep bluffs and cliffs, affording good exposures of the

Jan 1, 1910