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By Philip B. Bucky

[ ] FOREWORD THIS symposium brings together points of view, experiences and ideas on rock bursts from a goodly portion of the globe. Some conceptions, particularly those regarding the necessity of depth, have been fairly well shattered, as we find that they are present in the water tunnels of New York, on the surface at marble quarries in Vermont, and in the coal mines of the United States, as well as in the deep mines of the South African and Kolar gold fields, and in the nickel, copper and gold mines of Canada. Their occurrence under such a variety of conditions is, therefore, a challenge,

Jan 1, 1942

By Joseph Richards

PLATING iron with copper has received great attention from practical sand scientific men, but, aside from the deposit secured by immersion of iron in copper salts, by electro-plating, or by welding together thin sheets of iron and copper, these efforts have met with no success. Failure of these efforts, in the production of copper plating, has been due to the fact that the conditions normally and necessarily present in the plating operation are antagonistic to the production of copper-plated iron. In most, if not quite all of them, a bath of molten copper has been used. The-temperature of a molten copper bath is so high that the iron becomes oxidized before it can be immersed in the molten copper, and unless protective flux for the molten copper is used, the surface of the copper will become oxidized, and, in any event, the plated iron will oxidize immediately on its being withdrawn from the molten bath. I recently had the pleasure of visiting the works of The Metals Plating Co. at Elizabeth, N. J., where I witnessed the plating of iron sheets with copper by a new process.1 The plating metal is applied to the sheet in the form of a liquid mixture by means of rolls, such as inking rolls. The sheet, after being coated with the mixture, is automatically carried forward and deposited on a link-belt conveyor, which carries it through a furnace maintained at a. temperature well above that of molten copper. The basic principle involved in this method lies in the application of the plating metal to the sheet while the sheet is cold and then melting the metal in place on the sheet under conditions which are favorable to the formation of the plating.

Jan 1, 1919

By William P. Blake

The literature of the occurrence of quicksilver-ore in the United States does not contain, so far as the writer is aware, any mention of the locality herein described. In the preliminary report * upon the resources of the transPecos region of Texas, von Streerwitz gives a long list of minerals observed as occurring there, but cinnabar is not mentioned. In the second report upon the same region † mention is made of the reported existence of cinnabarite in one of the mountain ranges north of the Sierra Carrizo and the Bofecillos, but the author adds: " In spite of my careful examination of the float, I have not yet found any traces of this metal (quicksilver) up to the present time." Prof. Dumble, also, in * Geol. Surv. of Texas, E. T. Dumble, 1889, p. 225 (first report). † Geol. Surv. of Texas, E. T. Dumble, 1890, p. 713 (second report)

Jan 1, 1896

By Ian J. Smalley

"Quickclay is an extreme case, it is by far the most mobile of all the common solid materials on the earth's surface. It has both a high water content and a mineral texture that allows it to flow with the utmost ease. A mass of quickclay that has lain undisturbed for thousands of years can be jarred into motion by any sudden shock." The quotation is from the paper by Kerr called, "Quickclay," which was published in Scientific American in 1963. This was probably the most widely read paper on quickclay ever published. It was reprinted by Fred Betz in his Benchmark collection on Environmental Geology (BM 25), A quickclay is an extremely sensitive soil. The sensitivity parameter is produced by dividing the undisturbed shear strength by the remoulded shear strength. If a value greater than 50 is obtained, then the soil can be classified as a quickclay. True quickclays are characterized by a very low remoulded strength of the order of 0.5 kPa. The classic quickclays are found in Scandinavia and Eastern Canada, but the 1964 Alaska earthquake revealed a considerable quick¬clay deposit underlying the town of Anchorage. This was discussed in a classic paper by Kerr and Drew in Engineering Geology in 1967. The Kerr views on quickclays were perhaps most clearly expressed in the paper with Liebling in Geol. Soc. Amer. Bull. in 1965. They suggested that the major critical conditions which contribute to quickclay movement are: substantial quantities of layer lattice silicates of colloidal size (about 40% or more by dry weight), sub¬stantial pore water (44%), a reduction in electrolyte concentration below 5 g/l of salt, and addition of a dispersant. There is still discussion and disagreement about the nature of quickclays and the mechanisms of quickclay slides; the "clay mineral"-based views favored by Kerr still find support, although an alternative "primary mineral" view suggests that it is the finely ground primary minerals

Jan 1, 1985

By J. H. Allport, C. Garnsey

During the latter part of 1916 and the early months of 1917, due to war activities, there was a threatened shortage of coal which resulted in panic among consumers and a rush to obtain coal at once at any price. As a result of this insistent demand for immediate delivery, prices were bid up by the consumers to unprecedented heights; spot coal which had previously been selling at from $1.50 to $2 per ton was bid up to $5, $6, and, in exceptional cases, as high as $7.50 or more per ton. Then when the April, 1917, contract period arrived, contracts could be made only at prices ranging from $3 up to $5 and $6 per ton for the year's delivery. This condition caused such a demoralization of the business, and SO much complaint, that some action to regulate prices was considered essential by the National Administration. Lane-Peabody Agreement In May, 1917, a committee under the chairmanship of F. S. Peabody, of Chicago, was appointed by the Council of National Defense, through Mr. Lane, to consider the whole question of bituminous coal. This committee, with the Secretary of the Interior, Mr. Lane, after numerous meetings and long negotiations with the operators throughout the country, announced on June 29 an agreement between the Committee and the producers, fixing a tentative maximum price for bituminous coal throughout the country at $3 per net ton f.o.b. mines, to which was added 25 c. for selling commission to wholesalers. This plan was based on the idea of fixing a maximum price, high enough to greatly stimulate production, with the expectation that the laws of supply and demand would, with ample production, operate to maintain fair and just prices for coal throughout the country.

Jan 1, 1920

By Ralph J. Schilthis

Several investigators1-8 have reported evidence of the existence of native or connate water in oil-and-gas-bearing strata. Both water and salt have been detected in cores of oil sands that yielded oil and gas exclusively when produced. Electrical logs often reveal unexpectedly low resistivity through oil and gas sands, indicating the presence of some material that is a considerably better conductor of current than oil and gas. Furthermore, calculationsg of the oil and gas content of reservoirs based upon production and reservoir-pressure decline data indicate appreciably lower values than are arrived at under the assumption that the pore space is occupied completely by oil and gas. Origin and Occurrence of Connate Water in Oil-and-gas-bearing Formations The view has been expressed, 10-15 and is generally agreed upon, that the expulsion of oil and gas material from source beds and the subsequent migration and accumulation occurred in the presence of salt water. As the strata that usually form reservoirs for oil and gas were laid down by, or in the presence of, ancient seas, the pore space within the strata must have been saturated with salt water before the entrance of the oil and/or gas. Thus, the accumulation of oil and/or gas in the upper regions of structures suitable for reservoirs must have required displacement of the connate water therefrom. In the absence of any forces other than gravitational, it would be expected that the displacement of the connate water out of the zones finally occupied by gas and oil would be complete, and that the vertical distribution of gas, oil, and water in a reservoir would be strictly in the order of their densities. Apparently, however, surface and interfacial forces that will not permit complete segregation of the fluids are active within the capillary spaces comprising a reservoir. The effects of these forces on both accumulation and production of oil and gas have been the subject of study by a number of investigators.16-37 In general, the view is held that the character of most materials that make up the reservoir rock leads to preferential wetting of the rock by

Jan 1, 1938

By Fred A. Hale

Owing to the large area included in the Yellow Pine mining district, and the varied nature of its mineral deposits, a detailed geological description of the district could be covered only in an extensive monograph. This paper is intended as a description of the most prominent geologic features only with special reference to those of economic importance. The first mention of the district was in 1903 by J. E. Spurr, who briefly describes the structural geology of the Spring Mountain range. In 1906, H. F. Bain2 briefly described the Potosi mine. James J. Hillla of the United States Geological Survey, visited the district for a brief period in 1912, the result of which is an excellent reconnaissance report, covering the district in some detail but necessarily with brevity. Since that time, articles covering special features of the district have appeared in the technical press, including some by the writer, and a notable description of the Boss mine, by Adolph Knopf,4 appeared in 1915. Development of the district during the past few years has progressed so rapidly and with so many notable discoveries, particularly with reference to the rare metals, that a further description at this time may prove of interest. The writer's acquaintance with the district is based on 7 years' continuous residence in the vicinity, beginning with the spring of 1910. A. Location and Topography The Yellow Pine mining district is situated in the southwestern portion of Clark County, Nevada, about 300 miles northeast of Los Angeles, along the line of the Los Angeles & Salt Lake Railroad. The district extends from Mt. Olcott on the north to the California line on the south,

Jan 1, 1918

By J. A. B. Forster

The operations of the Electrolytic Zinc Co. of Australasia Ltd. involve the preliminary roasting of zinc concentrate from Broken Hill, New South wales, at a number of acid-making centers on the Australian mainland. The partially roasted material is shipped to the Tasmanian plant where it was formerly re-roasted prior to leaching,' but this practice was gradually abandoned in favor of the flotation of leach residue for the recovery of a concentrate containing about 22 pct sulphide sulphur and known as secontlary or Risdon concentrate.2 This change, together with increased zinc production, called for new furnaces at Risdon for the roasting of 10-50 tonst of secondary concentrcite and 90 tons of new concentrate per day. The war situation made it imperative that construction be commenced without delay and to save time it was decided to base the design on that of Skinner type furnaces which had been built in South Australia twenty years earlier. This involved some sacrifice of desirable features but did not prevent the incorporation of provisions which had enabled small Herreshoff type furnaces to roast secondary concentrate autogenously. The roasting rate in existing furnaces was 10-12 Ib sulphide sulphur per sq ft of hearth area per day, and eleven hearths, 20 ft in diam, were provided in the two new furnaces in anticipation that they would prove capable of the autogenous roasting of 130-140 tons of concentrate per day from 28-29 pct sulphur down to 4.5-5 pct, with an oxidation rate of 11-11.5 lh S/S per sq ft of hearth area per day. It was soon realized, when the first of the furnaces went into operation, that a much better performance than this might be given, and the purpose of this paper is to show how a treatment rate of 100 tons per furnace day, and oxidation rates approaching 15 lb S/S per sq ft per day have been reached. Furnace Design General specifications for the design were based on the results of experience with several other types of furnace and on the special operating conditions

Jan 1, 1950

By Robert M. Dreyer

Population growth in industrialized economies constitutes an automatic stimulus for expansion of the construction and chemical processing industries, which are a big market for industrial minerals. Of the total value of mineral production in the United States, excluding fuels, about 70 % results from the production of industrial minerals. The value of industrial mineral production rose more than 10 % between 1961 and 1962. A similar growth has occurred during 1963. During the decade 1952-1962, the production of industrial minerals increased in value by 98%, in contrast to an increase of 60% in the value of the gross national product. The accompanying table shows the percentage change in the production of various industrial minerals from 1952-1962, as well as from 1961-1962.

Jan 2, 1964

By William E. Ford, Edward Salisbury Dana

262. Parallel Grouping. - Connected with the subject of twin crystals is that of the parallel position of associated crystals of the same species, or of different species. Crystals of the same species occurring together are very commonly in parallel position. In this way large crystals, as of calcite, quartz, fluorite, are sometimes built up of smaller individuals grouped together with corresponding faces parallel. This parallel grouping is often seen in crystals as they lie on the supporting rock. On glancing the eye over a surface covered with crystals a reflection from one face will often be accompanied by reflections from the corresponding face in each of the other crystals, showing that the crystals are throughout similar in their positions.

Jan 1, 1922

By R. L. Wiegel

Consideration has been given to the merging of a size reduction model and a mineral liberation model to permit prediction of mineral composition as a function of size. The results of this integration of size reduction and mineral liberation models are discussed from both theoretical and practical viewpoints using batch grinding data for a magnetic iron formation sample as a demonstration vehicle.

Jan 1, 1977

Discussion WEDNESDAY AFTERNOON, FEBRUARY 21, 1951 Ralph E. Grim presiding R. E. GRIM, CHAIRMAN-Has anyone a particularly fruitful point to make or question to ask on any of the papers that have been presented at the two sessions held on Monday and one held this morning? GENESIS OF ENDELLITE T. S. LOVERING-I think we are all a little bit embarrassed when we are asked if we have any particularly fruitful point for discussion; I just have a point. I believe that yesterday Bates said that he had found endellite in only hydrothermally altered rocks-he did not find it in sedimentary rocks-but this morning I heard Victor Allen say something about it as the normal product of weathering, and I am confused. My question concerns the genesis of endellite. I want to know whether endellite is found as a normal product of weathering. I understood from the paper by Bates that it was not a product of weathering and in the paper by Victor Allen* endellite was said to be a product of normal weathering. Did I misinterpret these two papers? T. F. BATES-I did not intend to state or imply that endellite is formed only under hydrothermal conditions. We have been studying the North Carolina deposits extensively and I feel that they illustrate very well the result of normal weathering processes acting on pegmatitic material. The resulting clay seems to be largely endellite or halloysite, almost to the exclusion of kaolinite. I may have misled you in the statement I made toward the end of my talk, to the effect that of all the kaolinic clays we have investigated with the electron microscope, we have not yet found halloysite or endellite in samples from clay deposits that are definitely sedimentary in origin. R. E. GRIM, CHAIRMAN-Professor Allen, have you anything to say on the matter of bauxite?

Jan 1, 1952

By A. H. Larson, T. P. McNulty

RECENTLY, an investigation of the absorption of sulfur dioxide gas in molten binary copper alloys was conducted. A Sieverts-type apparatus, consisting of a mercury-filled gas dispensing buret and a mercury manometer, was used initially for determining the volume of gas absorbed as a function of pressure. The equilibration behavior of the alloys studied indicated that the mercury in the gas measuring system was absorbing sulfur dioxide. Owing to the widespread use of mercury as a displacement medium in absorption studies, an investigation was made to determine the nature and magnitude of the mercury - sulfur dioxide absorption effect. The gas measuring system was modified by substituting a Worden Quartz Products Type PDHV fused-quartz-spiral pressure gage for the mercury-filled dispenser and manometer. The dispensed gas volume at known temperature and atmospheric pressure was measured by evacuating a Pyrex vessel of known volume and by admitting sulfur dioxide into the vessel until the attached quartz pressure gage registered atmospheric pressure. Atmospheric pressure was measured concurrently with a separate mercury barometer. The volume of the empty sample chamber and its attendant apparatus was determined by measuring the equilibrium pressure accompanying the addition of a measured volume of sulfur dioxide into the initially evacuated system. The volume of the mercury sample was calculated from the density of mercury at the temperature of the study (25°C). Measured volumes of sulfur dioxide were then dispensed into the system and the equilibrium pressure accompanying each gas addition was determined. From the difference between the system volume and the mercury volume, the number of moles of gaseous sulfur dioxide remaining in the system at each pressure was calculated. The difference between the number of moles of gas dispensed into the system, denoted Enso2: and the number of moles of gas remaining in the system after absorption equilibrium had been attained, denoted nso2(g), was equal to the number of moles of absorbed gas, denoted nSO2. The number of moles of absorbed gas was then converted to absorbed volume, denoted VSo2, in cu cm at stp conditions of (PC and 760 mm Hg. Table I contains calculated values of Snso2, nSo2(g), and VSo2 for different sulfur dioxide pressures. In the original system, denoted Run I, volume limitations of the gas dispensing system prevented absorption studies at equilibrium pressures near atmospheric pressure, so a different gas dispensing system, denoted Run 11, was used for determining the last pressure reading in Table I. The data in Table I are expressed in terms of the absorption of sulfur dioxide in 49.68 cu cm of mercury. In Fig. 1, these data are expressed in terms of the absorption of sulfur dioxide in 100 cu cm of mercury. Since the absorption data plotted in Fig. 1 show a linear relationship, the volume of sulfur dioxide absorbed in mercury is a function of the first power of pressure. The absorption reaction is So2(gas) = SO2 (in Hg) The first-power pressure dependence, coupled with the fact that the sulfur dioxide could be removed from the mercury by applying vacuum, indicated reversible

Jan 1, 1967

By Hertha Freche

THE diffusion of magnesium and silicon from the core into the high-purity coating of Alclad sheet is important commercially, and led to the use of a duplex product for the study of diffusion by means of spectro-graphic analysis of successive layers. It has been found that in the duplex materials the diffusion of magne-sium from an undersaturated aluminum-magnesium alloy into its high-purity aluminum coating is approximately of the same order of magnitude as the diffusion of silicon from a saturated aluminum-silicon alloy into its high-purity aluminum coating. However, if magnesium and silicon are both present in the alloy in the ratio of Mg2Si they appear to diffuse in the approximate ratio of this compound. Finally, if the alloy contains silicon in excess of the amount required by magnesium silicide, the amount of diffused silicon in the high-purity aluminum coating will also be in excess. The interdiffusion of metals in the solid state is of both scientific and technical interest, because it is helpful in the study of the alloy structure and in the solution of problems pertaining to the strength and surface condition of the fabricated product. W. C. Roberts-Austen1 carried out the first quantitative determination of the coefficient of diffusion of gold into lead. This classical experiment was followed by a series of investigations on the diffusion of metals and nonmetals in iron and steel and in nonferrous metals and alloys. Recently the diffusion of copper in coated strong aluminum alloys was investigated by A. Burkhardt2. This appeared to be the first published investigation on the diffusion of metals into aluminum.

Jan 1, 1936

By M. C. Leverett, M. E. True, W. B. Lewis

This paper states the theory underlying the design of two kinds of dimensionally scaled models of parts of idealized oil fields. One of these simulates an oil well and its surrounding sand for a distance of 16 ft. radially from the well. The other model simulates linear flow through layered sands. Construction and operation of the models are described and typical data are given. The unique features in the design of the models are: (I) the treatment of the permeability-viscosity quotient as a single variable and (2) the use of previously reported experimentally developed relations between relative permeability and saturation and capillary pressure, saturation, porosity, permeability and interfacial tension. The models at present simulate flow of oil and water only, through unconsolidated sands. They are superior to unscaled models, which may give rise to erroneous conclusions. The models are designed to study the desirability of various methods of well completion and the effects of various factors on recovery of oil from layered sands. Introduction Recent work on the fundamental behavior of flowing mixtures of fluids in sands has resulted in the development of some new theory in this field, much of which has been presented in previous papers.l-4 However, the application of this theory to the behavior of oil wells or oil fields has proved too complicated for ordinary mathematical techniques, except in very highly simplified cases. A practical solution to this problem appears therefore, to lie in the use of dimensionally scaled models of elements of oil fields. The object of this paper is, first, to present the theoretical and experimental basis of the design of such models, and, second, to describe their construction and operation. Experiments now under way on the models already built will yield material for other reports, which will be devoted to interpretation of the results in terms of oil-field behavior. So far, simple dimensional models of two kinds have been built and are being operated. These models represent different parts of an idealized oil field but obey the same underlying theory. The only fluids represented are oil and water, since certain questionable approximations are necessary for gas-liquid systems. General Theory Dimensional models have been used in other fields for a long time, and their theory is adequately given in the literature. 5 Here, it suffices to state that each physical element entering into a dynamic relation may be given a definite description in terms of three fundamental, but arbitrarily chosen, dimensions. These usually are mass, length, and time, symbolized here by the small letters m, I, and t. Two systems are said to be dimensionally similar or dimensionally scaled if for each element in one system there is a corresponding element in the second system and the ratios of the numerical magnitudes of corresponding elements are constant for all elements of the same dimensional type.

Jan 1, 1942

By W. B. Lewis, M. E. True, M. C. Leverett

This paper states the theory underlying the design of two kinds of dimensionally scaled models of parts of idealized oil fields. One of these simulates an oil well and its surrounding sand for a distance of 16 ft. radially from the well. The other model simulates linear flow through layered sands. Construction and operation of the models are described and typical data are given. The unique features in the design of the models are: (I) the treatment of the permeability-viscosity quotient as a single variable and (2) the use of previously reported experimentally developed relations between relative permeability and saturation and capillary pressure, saturation, porosity, permeability and interfacial tension. The models at present simulate flow of oil and water only, through unconsolidated sands. They are superior to unscaled models, which may give rise to erroneous conclusions. The models are designed to study the desirability of various methods of well completion and the effects of various factors on recovery of oil from layered sands. Introduction Recent work on the fundamental behavior of flowing mixtures of fluids in sands has resulted in the development of some new theory in this field, much of which has been presented in previous papers.l-4 However, the application of this theory to the behavior of oil wells or oil fields has proved too complicated for ordinary mathematical techniques, except in very highly simplified cases. A practical solution to this problem appears therefore, to lie in the use of dimensionally scaled models of elements of oil fields. The object of this paper is, first, to present the theoretical and experimental basis of the design of such models, and, second, to describe their construction and operation. Experiments now under way on the models already built will yield material for other reports, which will be devoted to interpretation of the results in terms of oil-field behavior. So far, simple dimensional models of two kinds have been built and are being operated. These models represent different parts of an idealized oil field but obey the same underlying theory. The only fluids represented are oil and water, since certain questionable approximations are necessary for gas-liquid systems. General Theory Dimensional models have been used in other fields for a long time, and their theory is adequately given in the literature. 5 Here, it suffices to state that each physical element entering into a dynamic relation may be given a definite description in terms of three fundamental, but arbitrarily chosen, dimensions. These usually are mass, length, and time, symbolized here by the small letters m, I, and t. Two systems are said to be dimensionally similar or dimensionally scaled if for each element in one system there is a corresponding element in the second system and the ratios of the numerical magnitudes of corresponding elements are constant for all elements of the same dimensional type.

Jan 1, 1942

By AIME AIME

WHEN a local man has attained high position in business and civic affairs at home, his fellow citizens feel elated if his attainments are given recognition in the form of election to office in an organization of national scope. Eugene Ainsworth White, a new Director of the Institute, is one of the must prominent citizens of Tacoma, where for the past thirteen years he has managed the Tacoma Smelter of the American Smelting and Refining Co. A list of the civic duties he has carried with distinction would be a long one; for recent years it would show that he has been chairman of the Community Chest, vice-president of the Chamber of Commerce. and a member of the Pierce County Taxation Bureau.

Jan 1, 1945

By G. L. F. Powell

Bulk samples of silver have beat undercooled lo a large degree in contact with crystalline siliceous and ceramic oxide materials, indicating lhat stable oxides and oxide compounds are not the heterogeneous nucleants which normally catalyze cryslallization within a feu degrees of the equilibrium freezing point. Since 400-g samples were undercooled 250°C in contact with cristobalite, it is concluded that the undercooling required for homogeneous nucleation of sil11er is greater than 250°C. Undercooling was Jacilitated by precleaning the crucibles with a high-fires -sure blast of gas. IN numerous experiments on the undercooling of metal melts it has been assumed that a solid glassy surface, being non crystal line, will have no effect in catalyzing crystal nucleation from the melt. Conversely, it is usually accepted that any crystalline surface, in contact with a metal melt, will catalyze nucleation of metal crystals from the melt at degrees of undercooling less than that at which homogeneous nucleation will occur. Both these assumptions were implicit in the claim that homogeneous nucleation was observed in experiments1'2 on the undercooling of small metal droplets (10 to 100 mp diam). The droplets were thought to be freed of suspended crystalline particles which would otherwise catalyze heterogeneous nucleation. They were supported on flakes of silica glass which were assumed to be amorphous, and therefore incapable of acting as substrates for heterogeneous nucleation. In later experiments, large samples of molten metal were undercooled to temperatures similar to those achieved by the droplet technique by melting in a fused-silica crucible3 or a boro-silicate glass slag.4 Since these samples were usually fully enclosed in glass at the moment of freezing, it seemed possible that nucleation was homogeneous when maximum degrees of undercooling were achieved, despite the large size of the samples (up to 500 g). In experiments on the undercooling of silver5 the metal was contained in vitreous silica crucibles, the

Jan 1, 1968

By Raymond D. Sloan

During 1944, substantial gains were recorded in practically every phase of the petroleum industry in Oklahoma. With the spotlight of activity focused on other states during the more recent years, the production momentum that was achieved in Oklahoma through the discovery and development of such outstanding pools as Oklahoma City, Fitts. and major pools in the Seminole area during the late 1920's and early 1930's was practically spent by the end of 1943. However, with much of the industry's exploratory efforts greatly reduced in Illinois, Indiana and Kentucky, the strong demand for Mid-Continent crude and the optimism created by some discoveries in the state toward the end of 1943, Oklahoma has again become the recipient of much activity and interest, with its 1944 drilling activity, production and refinery runs to stills registering substantial gains over the preceding year. Development and Exploration Since the discovery of the West Edmond pool in April of 1943, with the substquent drilling and development boom, the scene of exploratory activity has shifted from the central. south and east portions of the state to the general trend of the . Granite Ridge, where leasillg and wild-catting were greatly activated within a wide radius of this high subsurface feature. Leasing activity, however, jumped the confines of the Granite Ridge trend and extended into all of the northwestern counties in the state. Seismograph activity at once began following and keeping pace with this shift in the leasing and exploration locale, by the concentration of a large number of seismograph crews in the area. At one time during the year,35 crews were concentrated in Oklahoma, the majority being west of the Granite Ridge and extending into the northwestern counties. To illustrate the increase in geophysical work done in the state during the year, records indicate that 377 crew months were worked in 1944, which is a 21 per cent increase over the 311.5 crew months activated in 1943. With the discovery in 1943 of several encouraging prospects and the finding of West Edmond as an incentive, drilling operations increased some 54.3 per cent, for a total of 1986 completions during the year. This is compared with a figure of 1287 for wells drilled in 1943, an increase of 699 wells. The industry, with a total of 1064 oil producers, enjoyed a success percentage of 53.6 per cent. Gas wells completed were 223, while 699 dry holes were drilled. In 1943, completions included 587 oil wells, 127 gas wells, and 573 dry holes. The number of oil producers completed during the Year was almost double the numher of wells in 1943. Of the total drilling wells completed in the state, 350, or 17.6 per cent, were wildcat operations—an increase of 5.1 per cent over the 194.3 total of 333. The wildcat success percentage was 13.4 per cent, 47 successful wells being completed for an average initial potential of 160 bbl. In the state, 23 gas wells were completed with an average initial production of

Jan 1, 1945

E. A. Peretti (University of Notre Dame, Notre Dame, Ind.)—Mr. Deitz and Professor Halpern are to be congratulated on a fine piece of work which adds to our knowledge of precious metal—cyanide-solution reactions. I should like to offer the following comments: The authors state, "the rate plots were always linear, indicating a zero order reaction rate." This appears to conflict with the data of Fig. 6 which clearly show the rate to vary with the NaCN concentration. It seems to me that the rate curves are linear because of the experimental setup. The volume of solution is so large that over a three-hour period the change in NaCN concentration is very small. A rough calculation for the experiments of Table I where the initial NaCN strength was 0.0096 mol per liter show a change of NaCN concentration of about 0.0009 mol per liter at the end of three hours. In short, over the period of time that the experiment was in progress, the NaCN strength was practically constant; hence the rate of dissolution remained practically constant. Eq. 10, as written, specifies that 1 mol of H202 and 2 mol of hydroxyl ion are formed when 2 mol of silver react. Is this true? The effect of H,O2 on the rate was made in solutions having an oxygen pressure of 4.8 atm. Were any tests made in solutions containing hydrogen peroxide, but no oxygen? G. M. Willis (University of Melbourne, Melbourne, Australia)—The authors have shown that, under their experimental conditions of high O2 concentrations, the rate of solution of silver in aqueous cyanide solutions is controlled by diffusion of O2 or CN- to the metal surface. With diffusion control, it is generally not possible to obtain further information about the mechanism of a process.

Jan 1, 1955