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By D. V. BURR

THE ORIGINAL HUDSON RIVER TUNNEL. NOT quite forty years ago a man of uncommon character entered New York. He had several hundred thousand dollars earned by railroad building in the Nest. He was not an engineer, but he had ideas of engineering work which he was destined to prove correct.. He introduced new ways of tunneling, but his plans had only one distinguishing feature-they were simply interesting as showing how such work could be done; they added nothing to the science, have never been used since his clay, and never will be used again. Engineers of repute ridiculed his proposition ; he was an Ishmael in the profession. But if engineers looked askance at him, he certainly returned their contempt in the heartiest fashion, and had no hesitancy about expressing his views of them individually and collectively. This worked to. his disadvantage when he afterward tried to raise the means to go on with the work. He found that the opinion of engineers was respected by financiers, and that money would not flow contrary to their advice. While his conception of large constructions was distinguishingly original, much more marked was his method of demonstrating the feasibility of, his schemes. In the present clays of great undertakings it is the custom to make the other man pay for the experiments. But the man from the West had other notions of how the thing ought to be done. Having wonderful confidence in his own ability and in his perception of the task before him, he used up all his own money before seeking outside assistance. By building several hundred,, feet of tunnel he proved the correctness of his theory, and the tunnel then dug forms a part of the present tube. The result-he failed to finish the tunnel. He was blind in

Mar 1, 1908

By LESTER H. WOOLSEY

IT IS doubtful whether anything new can be said upon this subject and, therefore, it is with considerable hesitation that l prepare this paper. On account of my recent connection with the Department of State as its law- officer, perhaps I will be pardoned if I discuss this subject briefly from the point of view of that branch of the Government. , I cannot, of course, speak for that department, since I have-no connection with it at-present, but it may be helpful if I set down certain* of the factors which in my opinion and from my experience have a bearing on this international problem. With oil-burning ships, motor vessels, motor vehicles, airplanes-all consuming, astonishing quantities of petroleum or petroleum products; with the United States having within its borders only 12 per cent. of the petroleum resources of the world, and consuming about 70 per cent. of the world's output; with the more enterprising nations wide awake to the necessity ; of obtaining and preserving as large a share as possible of the oil resources extant ; the 'problem is peculiarly and in a, very practical sense an international one.

Jan 1, 1921

By Harry L. Brown, Philip E. Armstrong

Young's modulus doto ore presented for W, Mo. Ta. V, Cr. Ni, Ti, and Zr as a function of temperature up to about 0.7 of the melting points. A plot of reduced temperature us reduced modulus produces a general correlation except for titanium and zirconium. Young's modudlus data for some representatiue commercial graphites are given up to 2400°C. All results were obtained from longitudinal resonance-frequency measzrrements of 4-in. long samples, corrected for simultaneously measured thermal expansion. Comparison of poly crystalline and single-crystal tungsten behavior indicates that all the observed modulus values are frequencv -dependent at the higher temperatures. STATIC measurements of elastic properties of materials at elevated temperatures are extremely difficult to make since the elastic behavior is obscured by relatively large first-stage creep effects. Dynamic methods which avoid this difficulty by utilizing the measurement of the resonance frequency of a simple vibrational mode have been described in the 1iterature.l-3 The authors have extended the operating temperature range of this type of measurement to above 2000°C and have described the equipment elsewhere.~ The Young's modulus data presented here were obtained with this equipment, using samples about 4 in. long and 1/4 in. diam, supported horizontally at the center and excited to the fundamental longitudinal resonance frequency. Young's modulus was calculated by the formula: E = 4f2f2p where E = Young's modulus, / = frequency, 1 = length, and p = density. Dilatometric data were obtained simultaneously by optical measurements of the change of length of the sample. For the metals tested, an attempt was made to obtain modulus values that would be representative of the pure, strain-free, randomly oriented material. All of the graphites studied exhibited a high degree of elastic anisotropy, while the method assumes an isotropic homogeneous material. However , when the values for Young's modulus obtained for AUC graphite were compared with those taken from static measurements at room temperature they were found to be only about 4 pet higher. This is excellent agreement considering the low precision of modulus calculations from stress-strain curves. The difficulty in using data of apparent Young's modulus for anisotropic materials arises when the attempt is made to use these data and shear-modulus data to obtain Poisson's ratio. The results are usually meaningless and sometimes absurd.' RESULTS Table I lists the sources, impurity content, thermal history, and dilatometric constants of the metal samples that were investigated. All the metal samples were tested under a vacuum of 1 to 5 x 10-5 Torr. Where our dilatometric data agreed with previously published data, the table lists the previous values and the literature reference. Where no reference is given, the constants were determined from our dilatometric data. Table II presents the modulus data in units of millions of psi as a function of temperature in degrees centigrade. The numbers were obtained from curves fitted to the experimental data. For some types of calculations, such as those attempting to correlate creep data, the slope of the modulus curve is of interest, and this information also is reported in Table 11. It is always tempting to try to fit physical-property data into some general pattern and then use this pattern to predict the behavior of other similar materials. The general pattern for an elastic modulus of a metal seems to be a linear deoro- with increasing temperature Over the range between 0.1 and 0.4 of the melting temperature, then a progressive1y decreasing value up to the melting point. Metals appear to retain finite moduli

Jan 1, 1964

By Thomas L. Kesler

Present Raw Materials The lithium industry has had exceptional growth since publication of the last edition of this volume, and the present scale of mining and consumption of raw materials is a great many times that of 1949. The materials of present economic importance consist of four pegmatite minerals and lithium-bearing brine. Spodumene, a lithium pyroxene, occurs in greatest abundance, and is the chief source. It has the formula LiAlSi2O6 and theoretically may contain 8.03 pct Li2O, but in the more important deposits the content is 6.5 to 7.5 pct. The hardness is 6.5, the specific gravity 3.1 to 3.2, and the color mostly pale green to white although deep green, lilac, and yellow varieties exist. The crystals are prisms with strongly developed longitudinal cleavages, and crushing characteristically produces lath-shaped particles. Giant crystals up to 47 ft long are known, but in most occurrences the predominant size range is 0.5 to 12 in. long and 0.1 to 2 in. wide. Hypogene* alteration has formed lithia-bearing sericite and coarser muscovite and rarely eucryptite, while supergene* alteration yields kaolinite and hydrous mica. Lepidolite, of second importance, is a mica of varying composition approximating K2Li3-A14Si7O21(OH,F)3. It has lamellate cleavage, book structure, and a specific gravity of 2.8 to 3. The books range in size from microscopic to a diameter of several inches. The color is mostly violet, but other colors include pink, gray, yellow, and white. Most commercial lepidolite contains 3 to 4 pct Li20 and chemically is in the higher grade range of a series of lithium micas that includes polylithionite, zinnwaldite, and protolithionite. In this series, the content of Li2O is exceptionally as high as 7 pct. Petalite and amblygonite are also of economic importance, but are used in smaller amounts. Petalite has the formula LiA1Si4O10 and is white, gray, or pink. The hardness is 6, the specific gravity 2.4, the cleavage in two planes 114° apart, and the Li2O content commonly 3 to 4.7 pct with a maximum of 4.88. Amblygonite has the formula LiA1FPO4 in which OH may substitute for F to form montebrasite. It is white and has polysynthetic twinning in two directions at 90°. Amblygonite superficially resembles potash feldspar, but has a bluish or grayish tint unlike the cream or salmon tint of the feldspar.[t] The hardness is 6 and the specific gravity 3 to 3.1, and the content of Li2O is the highest among lithium minerals that occur in significant quantity, ranging mostly from 7.5 to 9 pct with a maximum of 10.2. The brine of Searles Lake in California30 has been a commercial source of lithium since 1938. See Chap. 7, p. 108. The "lake" is a saline evaporite deposit, and the exposed part has an area of 12 sq mi. To an average depth of 71 ft, this part of the deposit consists of crystalline salts with 50 pct interstitial voids. The voids are filled with brine that contains mainly sodium and potassium compounds, but the brine also contains 0.015 pct Li2O, which is recovered as dilithium sodium phosphate containing 21 pct Li20. This deposit overlies a

Jan 1, 1960

By R. D. Mollison, C. F. Fogarty

Sulfur is widely distributed in nature. It is present in the earth's crust, the ocean, the meteorites that come to us from cosmic space and in practically all animal and plant life. According to Clarke,9 the earth's crust contains 0.06 pct sulfur. Large quantities of free or combined sulfur are found in coal, natural gas and petroleum. Mineral waters contain sulfates and hydrogen sulfide. Sulfur is rather plentiful in the crust of the earth; however, only under special circumstances can it be produced profitably. Sulfur is one of the cheapest raw materials used by industry; and, therefore, the economic feasibility of a given deposit is strongly dictated by the law of supply and demand on local as well as world-wide levels. The forms which are commercially important are elemental sulfur or brimstone, and the sulfides such as pyrite (FeS2), pyrrhotite (FenSn+1), chalcocite (Cu2S), sphalerite (ZnS), and galena (PbS); the sulfates such as gypsum (CaSO4,2H2O), anhydrite (CaSO4), and kieserite (MgSO4,H2O). Elemental Sulfur Elemental sulfur is found in many localities, generally in solfataras and gypsum type deposits. The solfatara deposits are found commonly in the neighborhood of active or extinct volcanoes as in Italy, Japan and Chile, or fumaroles associated with mineral springs such as the Mammoth Hot Springs in Yellowstone Park. Here the sulfur is deposited in tufas or other porous host rocks. This type of sulfur deposit probably results from the oxidation of hydrogen sulfide or the reaction of hydrogen sulfide with sulfur dioxide. Most of the world's supply of elemental sulfur comes from the gypsum-type deposits. Here the mineral occurs as either crystalline or amorphous sulfur in sedimentary rocks in close association with gypsum and limestone. This association is characteristic and occurs in almost all the great gypsum beds of the world, although sulfur is not always present in quantities of economic importance. Various theories have been advanced to account for this association. Bischof5 suggested that the sulfur came from hydrogen sulfide which resulted from the reduction of calcium sulfate by carbon or methane in accordance with the following reactions: CaSO4 + 2C= CaS + 2CO2 CaS + C02+ H2O = CaCO3 + H2S CaSO4 + CH4= CaS + C02+ 2H20 2H2S + 02= 2H20 + 2S All of the sulfur-bearing domes on the Gulf Coast have calcium sulfate in great quantity in the cap. They all show the presence of hydrocarbons. The oxygen for the final reaction could have been supplied by circulating ground waters. The principal objection to this theory is that temperatures of 700° to 1000°C are needed to reduce the sulfate to sulfide with carbon compounds. The geologic evidence is that the temperature of the sulfur-bearing domes of Texas did not exceed 100°C. Proponents of the theory say that geologic time or a catalyst replaced temperature. According to another theory the sulfur in the salt domes is the result of bacterial action. Sulfate reducing bacteria have been detected in sulfur cores and in the formation water issuing from salt domes. It has, therefore, been suggested that these bacteria converted the sulfate to sulfide which subsequently was converted to elemental sulfur.

Jan 1, 1960

By R. G. Charles, E. A. Gulbransen, S. Barnartt

KINETICS of the reaction of zirconium with pure oxygen at elevated temperatures have been studied by several workers for periods of time up to 6 hr.1-1 In two cases,3-4 . the experimental values of oxygen uptake, w, as a function of time, t, were best fitted to the parabolic rate law w2 = kPt + constant. In others,3,4 the cubic rate law w3 = kot + constant, showed better agreement. The most recent data of Gulbransen and Andrew4 indicate that the choice between the parabolic and cubic laws for empirical representation of the data will often be arbitrary. This is particularly true if the first few minutes of the reaction with a clean zirconium surface is attributed to a different oxidation mechanism, for deviations from either rate law were found primarily during the initial period. Thus, the kinetics of this reaction have been too uncertain to permit safe extrapolation to oxidation periods of practical interest (many hundreds of hours). The data to be described are of interest, for they indicate that the cubic rate law applies over long oxidation times. The reaction of zirconium with oxygen at 1 atm pressure was followed at 350" and 450°C for 500 and 200 hr, respectively. Abraded test specimens of pure zirconium sheet' 3.0 X 2.0 X 0.012 cm in size were oxidized by the procedure previously described,3 which included periodic cooling to room temperature for weighing. The surfaces were polished to a 4/0 finish using polishing paper wet with kerosene, then wiped with petroleum ether and washed in redistilled acetone. Fig. 1 shows plots of log ? vs log t. Each curve represents the average of duplicate measurements, and deviations from the average were generally less than 3 pet. The cubic rate law (slope = 1/3) is closely followed. The rate constants, 5.2, x 10 -6 and 2.4, X 10- (mg cm-2)3 per hr at 350" and 450 oC, respectively, are plotted as log k, vs 1/T in Fig. 2, together with cubic constants calculated from the data of Gulbransen and Andrew4 for abraded specimens from the same lot of zirconium. Their data refer to runs of 6-hr duration at a pressure of 0.1 atm 0 and under conditions of uninterrupted heating. In spite of these differences, the latter data yield a straight line which appears to apply equally well to the new extended time data. The energy of activation for the oxidation process, calculated from the slope of this line, i.s 38 keal per mole. This may be compared with the value of 47 keal per mole found by Belle and Mallett3 at higher temperatures. It may be concluded tentatively that extrapolation of short-term oxidation data for zirconium to obtain the long-term behavior is best done through the cubic equation ?3 = kpt + constant. References ' E. A. Gulbransen and K. F. Andrew: AIME Trans., 1949, vol. 185, p. A.515; JouRNal OF Metals, August 1949. 'D.p. Cubicciotti Journal Amer Chemical August1949.Soc., 1950, Vol. 72, P. 3 V. Belle and M. W. Mallett: Joulnal Electro chemical Soc., 1954, ' E. A. Gulbransen 339.and K. F. Andrew: Oxidation of Zirconium Between 400" Gulbransenand 800'C.and AIME Trarzs.. 1957, vol. 209, p. 394; JOUR-Nal of Metals, April 1957. IS Barnartt, B G. Charles, and E. A. Gulbransen: Oxidation of 50 weight pet uranium-zirconium alloy, Journul Electrochemical SOC., 1957, vol. 104, p. 218.

Jan 1, 1959

By A. D. Schwope, L. R. Jackson, A. M. Hall

In the course of an extensive investigation of the comparative properties of several types of copper, data were obtained on the cold working and subsequent recovery and recrystallization of the copper. In this paper, relations between the degree of cold work and the course of re-crystallization are developed. In particular, it is shown that the course of recrystallization over long periods of time and at low temperatures can be predicted with reasonable accuracy from short-time high-temperature recrystallization data. Materials Used in The Investigation Three types of copper were used in this investigation; these were tough pitch, OFHC, and OFHC copper with 15 oz per ton of silver added identified herein as Lots C, D, and F, respectively. The material was supplied by the American Metal Co. Ltd., and processed by the Rome Cable Co. The analyses of the three types of copper are given in Table I. Originally, it started as wire bars 4 X 4 X 54 in. These bars were heated to 871° C in air and hot rolled to % in. rod. This rod was cold drawn to 0.204 in. rod (70 pct reduction) in three passes and annealed at 427°C for 4 hr. A portion of the 3/8 in. rod was saved for more detailed cold-drawing experiments. Starting with the annealed 0.204 in. rod, hard-drawn wires were produced by cold drawing to 0.081 in. wire in 7 passes (84.4 pct reduction in area). Half-hard wires were made by cold drawing the 0.204 in. rod to 0.102 in. wire, (75 pet reduction) in 6 passes and annealing at 427'C for 4 hr. This annealed wire was then drawn to 0.081 in. wire, (37.1 pet reduction) in 2 passes. Square rod was made by hot rolling wire bars to Re in. rod in 8 passes. This rod was then cold drawn to 0.445 in.-diam rod and annealed for 346 hr at 538°C. It was then cold drawn to 0.325 in. rod and again annealed at 538°Cf or 3 1/2 hr Hard square rods were then made by cold rolling this material to 0.257 X 0.257 in. rod, a reduction in area of 20.5 pct. Half-hard square rods were made by cold rolling to 0.268 x 0.268 in. square, annealing for 3 1/4 hr at 538°C and cold rolling to 0.257 x 0.257 in., a reduction of 8.5 pct. Soft wire or rod was made from all types of copper by annealing the hard-drawn material at 343°C for 3 hr in steam. The grain size of the annealed 0.081 in. wire varied slightly among the three lots: from o.o15+.oz5 mm in the silver-bearing OFHC to 0.035-0.045 mm in the OFHC copper. The annealed 0.257 in. wires were more uniform in grain size, averaging about 0.035-0.045 mm. Representative structures are shown in Fig I. Effect of Cold Drawing and Tensile Strain on Strength of Copper Conventional tensile tests were performed on the three types of copper in the various degrees of hardness described above. Results of these tests are tabulated in Table 2. The results in Table 2 are 6

Jan 1, 1949

By R. W. Olson, A. L. Benham

Viscous fingering was studied as it occurred in an open Hele-Shaw model (1 ft x 4 ft x 1/16 in.); it was also studied in the same model packed with 80-mesh glass beads during miscible displacements under unfavorable viscosity ratio conditions. It was determined that the lengths of 20 elements of the front were distributed normally around the average position of the combined elements under all conditions. Represented by the normal distribution, the length of the viscous fingers grew linearly with the distance traveled from the point of finger formation, increased with displacement velocity, and increased with increasing mobility ratio. Results obtained during the first few inches of displacement were of little or no use in predicting finger growth and/or finger length throughout the 4-ft model since the point of finger initiation cannot be predicted and would often occur several inches from the point of injection with either positive or apparent negative coordinates. The fingering occurring during a miscible slug displacement was much greater than would be predicted based upon the actual mobility ratios between in-place fluid and slug and between slug and following fluid, using the results described above for miscible displacement in the absence of a slug. Many of the experiments in the packed model showed that the rate of growth of the viscous fingers was diminishing toward the end of the displacement in the 4-ft long model, indicating that microscopic mixing, such as diffusion or dispersion, was decreasing the viscous fingering effect. INTRODUCTION Viscous fingering is a manifestation of a finger-shaped interface between displaced and displacing fluids occurring during typical miscible displacement projects for oil recovery. Its cause may be traced to the instability of a viscous fluid being displaced by a more mobile fluid. Viscous fingering takes on important significance in the miscible slug process 1.2 where it may be a dominant factor in determining minimum slug size. Experimental1-3 and theoretical4-7 studies of viscous fingering have been made by other investi- gators. However, an exhaustive study of the variables affecting viscous fingering had not been made. The present study was undertaken in an effort to determine the effects of some of the more obvious variables—such as mobility ratio, displacement velocity, distance displaced, and packing—upon viscous finger length and growth in a small laboratory model. It does not necessarily follow that conclusions reached by studying the results of this model study may be applied to the field. Future studies would have to evaluate the effect of model size on extension of these results. EQUIPMENT AND EXPERIMENTAL PROCEDURES A flow diagram for the equipment used in this study is shown in Fig. 1. Basically, it consisted of (1) a constant-rate pump for the injection of displacing fluid into (2) a model made up of two flat transparent plates spaced a small distance apart and (3) provisions for the production of fluid into a calibrated graduate. The displacing fluid contained a dye which allowed visual observation of finger spacing and length. The pump performed at rates from 2.5 cc/hr to 480 cc/hr, while pumping a light mineral oil into a bladder in a closed glass container holding the displacing fluid. The model was made up of two plates of 1-in. Plexiglass with dimensions 1-ft wide by 4-ft long. These were spaced 1/16 in. apart so that the internal model dimensions were 1-ft wide x 4-ft long x 1/16

By W. E. Wrather

CURTAILMENT of production was a matter of far more serious concern to the oil industry through 1933 than the search for new supplies of oil. The huge reserves of crude, built up during past years, instead of inspiring a feeling of security, were viewed apprehensively. The status of past laws and court decisions seemed to guarantee to operators the right to produce oil at will, and this entrenched privilege was so widely adhered to that the market was-in a constant state of chaos. The more modern idea of the ownership of oil in place and correlative rights gained headway slowly, since usually there were enough belligerent producers, staunch believers in the old established order, to defeat the efforts of the majority who sought to' introduce order and restraint. State regulatory commissions were unable to cope, with the rebellion among producers with the result that those who abided by proration rulings were penalized, while those who flouted the rulings and produced unrestrainedly were able to make profits on large volumes of flush oil even at low prices. This situation, known in the vernacular as the "hot 'oil" problem, became so acute that the industry was threatened with ruin. The low price for 36c A.P.I. in the Mid-Continent came in April. at 25c per barrel 'but gradually moved upward to the long-hoped for price of $1.00 per barrel in October, after the Federal Government had taken a hand in the matter and effectively allocated production among the oil producing states and materially curbed the "hot oil" runs.

Jan 1, 1934

By PAUL AUDIBERT

THE downward trend of metal prices seems to act something like a reagent that precipitates selfishness in most business men's hearts; in the same way the upward trend precipitates altruism. Operators do not say: "I continue working my mine without curtailment because I can afford the present prices while my neighbor cannot and thus will give me way." They say: "I continue working my mine because 1 consider it a service for consumers. They will get better prices on a free market. Any curtail¬ment would be an attempt to raise prices artificially, that is to say, bad economics." Copper producers have learned how fallacious is such an opinion. It perhaps was not fallacious in olden times when all mines were worked on a small scale even if operating on a big deposit. At that time the supply and demand law played fair. When prices were too low and profits were vanishing for many mines, they would. shut at once, then little by little the metal scarcity would induce prices to climb up again; finally these prices would reach the point when it became profitable to again work the closed mines. Re-opening and shutting down mines was then a normal custom. Workers and operators weakly deplored this unstability, but there was nothing effective they could, do about it.

Jan 1, 1931

By James T. Kemp

AN historical society of particular interest to mining engineers all over the world was born in Cornwall in 1935. A hundred-year-old winding engine then finished its long labors at the Levant mine on the cliffs near Lands End, England. The engine was to be dismantled and scrapped. A few men living near-by, appreciating that this event was one of the final acts in closing a long century of extraordinary mining and engineering evolution. armed a committee to prevent the destruction of the old mine hoist and succeeded in purchasing the engine. They restored the engine house and in time arranged with the Manor of Trewellard, owners of the land, for a 99-year ground lease on a peppercorn rental.

Jan 1, 1947

By Robert Pack

INTRODUCTION SOONER or later in the development of any natural resource it becomes highly desirable to know the quantity of this resource in the country as a whole, as well as of the part that is being developed, for the general course and. conduct of the development work must be governed to some extent by the total supply available. An accurate estimate of the quantity of any natural resource is difficult to make; yet if one is diligent enough one can obtain a pretty accurate idea of the quantity of marketable timber, the acreage of tillable land, or the horsepower that may be developed from the streams, for these are things that may be measured. But any attempt to estimate the quantity of some mineral in the ground appears to enter the realm of imagination and it seems that the estimate can be nothing more than a blind guess. It may appear to be especially futile to attempt to determine the quantity of oil and gas that is available in the ground, for these minerals are so vagrant that even if the quantity now available should be known quite exactly, the quantity that will eventually be obtained may be much less, for certain losses in the extraction of both oil and gas are unavoidable, and just what these losses will be cannot be predicted. Though necessarily inaccurate, estimates of such mineral reserves are, however, of distinct value, for they summarize the existing knowledge of the deposits of the mineral and thus enable those who are interested in some industry that depends in one way or another on this mineral to formulate a rational commercial policy. Some time ago, when the price of gasoline suddenly rose in a rather spectacular manner, the writer was one of the U. S. Geological Survey geologists called upon to help to estimate the quantity of oil that could be obtained in the United States, for the fear had become widespread that perhaps the rate of increase in the price of gasoline was a measure of the rate of depletion of the supply of petroleum. It thus became his

Jan 8, 1917

By M. R. J. Wyllie, Michael A. Torcaso

With the continued deep drilling of today, increasing numbers of high pressure and high temperature gas-condensate reservoirs are being discovered. Correspondingly, the ranges of properties of gas-condensate reservoir fluids are also being increased. The literature1*'." contains several excellent reviews of the property ranges in presently known condensate reservoirs. When one examines these property ranges, it becomes apparent that the need for reliable data is great if the engineer is to evaluate properly or appraise a gas-condensate reservoir. It is the purpose of this paper to present phase-behavior data that will point out some of the important variables that influence recovery from gas-condensate reservoirs produced by pressure depletion. All these variables may be resolved into two major categories: the hydroc:arbon composition of the reservoir fluid and the physical properties of the reservoir. But the variables which we will consider are those which are usually determined from well tests shortly after discovery and are, consequently, readily available to the engineer. They are as follows: (1) the producing separator gas-stock-tank liquid ratio, (2) stock-tank liquid gravity, and (3) reservoir temperature. Laboratory depletion studies have been performed on several reservoir fluids to illustrate the effect of changes in the cronsidered variables upon ultimate recoveries. The deviation factors, Z, of a series of reservoir fluids were determined experimentally to illustrate their order of magnitude and their effect upon the calculation of in-place reserves existing at high pressurcs and temperatures. The procedures followed in conjunction with the performance of these studies and their associated calculations are illustrated in Fig. 1. For the purpose of this paper, the depletion recoveries are expressed only in terms of pcr cent of initial stock-tank liquid, with the abandonment pressure assumed to be 500 psig. VARIATION OF RECOVERY WITH INITIAL PRODUCING SEPARATOR GAS-STOCK-TANK LIQUID RATIO The producing separator gas-stock-tank liquid ratio has long been one of the principal criteria in assumptions and generalized correlations' used for the estimation of ultimate recovery from gas-condensate reservoirs. Fig. 2 presents a plot of the cumulative recovery of stock-tank liquid at abandonment as a function of the initial producing separator gas-stock-tank liquid ratio. The graphical illustration represents the results of 44 laboratory depletion studies performed on actual gas-condensate fluids. These data are presented not only to illustrate the general trend of ultimate recovery increase with initial producing ratio increase but to emphasize the considerable variation in possible recovery at any given producing ratio. Table 1 presents the properties of two actual reservoir fluids chosen to illustrate the approximate extremities of producing ratios for gas-condensate systems. The fluids designated as A and B exhibited initial producing ratios of 3,400 and 114,000 scf/bbl, respectively. Fig. 3 presents a graphical comparison of the cumulative stock-tank liquid recoveries, calculated from the well-stream compositions and produced volumes for each fluid during depletion. It is to be noted that Fluid A exhibited a recovery of only 16.5 per cent when produced to an assumed abandonment pressure of 500 psig while the corresponding recovery for Fluid B was calculated to be 62.2 per cent. This difference in recovery, which exemplifies the general trend of recovery increase with initial producing ratio increase, is readily explained by consid-

Andrew Carnegie, America's best-known ironmaster and philanthropist, died at his home at Lenox, Mass., Monday, Aug. 11, after a three days' illness. A pioneer in the steel industry, he introduced into this .country the Bessemer process And formed the plans that have resulted in this country's supremacy in the steel markets of the world. Known throughout the world for his, gifts, he is also known to engineers as the donor of the home of their National Societies and as the founder of the Carnegie Institute of Technology, of Pittsburgh. For many years, also, he was an honorary member of the American Institute of Mining and Metallurgical Engineers, the American Society of Mechanical Engineers, and of the Engineers Club of New York. What he considered the secret, of his success is shown by the epitaph he wrote for himself, "Here lies a man who knew how to enlist in his service better men than himself." He was buried Thursday, Aug. 14, in Sleepy Hollow Cemetery, Tarry-town, N. Y., the funeral services being private, in accordance with his wish.

Jan 9, 1919

By Christopher W. Schram, Allan B. Tanner, Frank E. Senftle, George R. Boynton, Philip W. Philbin

A borehole sonde using a 252Cf neutron source and a Ge(Li) gamma-ray detector was field tested in a coal bed in Belmont County, Ohio, to ascertain whether such a device could be useful as a coal-exploration tool. As the sonde was lowered into the borehole, successive spectra were accumulated over short time intervals. The intensities of the capture gamma rays from hydrogen and of decay gamma rays from aluminum were determined simultaneously in each spectrum. A log of the intensities versus depth shows the depth and thickness of the coal bed. With the sonde stationary at points above, in, and below the coal bed, capture gamma rays were measured to show the variation in concentration of certain elements. From the spectrum recorded in the bed, a complete ultimate analysis, the percent ash content, and the heat content were determined without recourse to an external standard. Delayed gamma-ray analyses of the core were also made on the surface in the vicinity of the borehole in a fixed-geometry irradiation facility wing the detector in the borehole sonde. The concentrations of 10 elements were determined by this method on a coal split from the drill core. These experiments show that it is feasible to use a 252Cf- Ge(Li) borehole sonde as an aid in coal exploration.

Jan 1, 1979

By E. J. Krokroskia

Fletcher Mill is located in the southern part of the New Lead Belt in Southeastern Missouri, in the northwestern part of Reynolds County. Shaft sinking began in July, 1964. The mill went on stream in February, 1967, and reached the designed rate of 5,000 tons per day in July, 1968. The ore occurs approximately 1,000 feet below the surface as disseminated deposits of galena, sphalerite and chalcopyrite. There is no oxidation within the ore body and dissemination is not fine enough to present liberation problems with a normal grind. Mining is by the room and pillar method with rubber-tired diesel- propelled drilling and loading equipment. The ore is dumped through a 27-inch square grizzly into a 5,000-ton pocket. The underground primary crusher is automatically fed by a vibrating feeder and discharges directly into skip measuring bins. Hoisting is automatic, in balance, with 8. 5-ton skips dumping into a 1,000-ton mill bin. MILL The concentrator is a 5, 000 tons-per-day single section plant equipped to produce lead, zinc and copper concentrates. Contained under 35, 347 square feet of roof, without fine ore storage or remote crushing, and with sufficient automation to be operated by one man, the plant is compact, unique, and efficient in operation. The design

Jan 1, 1970

By C. A. Stetefeldt

In a former paper (Runs., xxi., 286) I described the plant of the Marsac Refinery, and the manipulations of the process, but cou1d not, at the time, give reliable statistical results. To supply the latter is the object of the present paper. I shall give actual facts as correctly as possible, without any bias one way or the other. For all statistics I am indebted to Mr. W. G. Lamb, who has charge of the Marsac lixiviation-plant and refinery; to Mr. A. Luebeck, assayer at the Ontario mill; and to the Daly Office, Salt Lake City.* Before starting on the work of the year 1892, a most careful clean-up was made, and any remnants were charged to the refinery. During 1892 the Marsac lixiviation-works produced 48.8 tons of so-called "regular" sulphides, which contained, on an average, 11,449 ounces of silver per ton; 11.77 ounces of gold per ton; and 569.8 pounds of copper per ton. To this must be added, 266 pounds of sulphides and by-products left over from the product of 1891, which contained 1380 ounces of silver, 1.41 ounces of gold, and 63 pounds of copper. Before giving the results of the clean-up, a general discussion of the items of expense, methods of assaying, etc., is desirable.

Jan 1, 1895

By E. A. Anderson

IN another paper1 the writer has shown that the low permissible maximum fiber stress in a loaded zinc sheet demands a much closer support spacing than is used for steel. The limiting fiber stress in 13-gage (0.032 in.) sheets having a 1-in. depth of corrugation was found to be about 5000 lb. per sq. in. on a 37-in. span under a load of 40 lb. per sq. ft. Corrugated steel sheets are commonly laid with spans varying from 48 to 60 in. In order to increase the span in 13-gage zinc to 54 in. (a common spacing) the metal must be capable of withstanding, under long-continued loading, a maximum fiber stress of about 10,000 lb. per sq. in. This is known to be impossible with unalloyed zinc. In this paper the writer describes a series of experiments leading up to the development of an alloy capable of safely sustaining this fiber stress. The effect of alloying on the slow creep of zinc was studied by means of static tensile tests, accurate determinations of apparent elastic limits and finally by means of loading tests on full-size roof sections. Two industrial buildings roofed with alloyed zinc sheets on spans involving fiber stresses in excess of 10,000 lb. per sq. in. have been under observation for over two years without signs of sagging.

Jan 1, 1929

Discussion of the paper of James R. Finlay, presented at the New York meeting, February, 1912, and printed in Bulletin No. 75, March, 1913, pp. 487 to .503. CHAIRMAN JOHN BIRKINBINE :-Having been invited to preside at this session, the Chairman feels that the part he takes in discussions should be limited, although the subject presented is one of much interest to him and there are diverse viewpoints concerning methods of valuing expectancies from what may be considered " ore in sight," a term itself subject to various definitions. Estimates of quantities upon which valuations are made may differ without subjecting the estimators to criticism of unfairness if made by a prospective purchaser or by a seller, or if they are used as the basis for taxation. The hopes of the seller may influence a liberal allowance for estimated reserves, while the expectancies of a willing purchaser are less optimistic, and the tax assessor is expected to limit his consideration to the producing capacity of a mine, with possibly modest allowance for reserves. The knowledge that a property contains or yields mineral or the expectancy that it may be a producer of value adds to the estimate placed upon it by any of the above classes, and a just determination of this value is often a complex problem.

Jan 5, 1913

By C. F. Nagel

THIS paper is written primarily for those who are familiar with the processes mentioned but who desire a further insight into some of the fundamental principles. It does not give a complete description of the various practices employed in the working of aluminum and its alloys, but presents a few illustrations of the essential respects in which aluminum differs from other common metals, and emphasizes the controlling factors of the processes under consideration. HEAT TREATING Certain aluminum alloys are capable of having their mechanical properties greatly altered by a heat-treatment process. The degree of this improvement may be illustrated by some typical properties of duralumin (Table 1). It is essential that the material be in the wrought condition in order to obtain maximum heat-treatment effects. [ ] In the case of duralumin, the process consists of heating the metal to a prescribed temperature and then quenching it. Immediately after quenching, the material is relatively soft though not as soft as in the annealed state. If allowed to stand at room temperature, the material changes, increasing in hardness and strength without loss of elongation, but at the expense of the plasticity. This action is very rapid at first, gradually diminishing in intensity and to all practical purposes being completed in about four days. This process of hardening is termed

Jan 1, 1928