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By H. J. Snyder

Both the room-temperature and 600°F (315°C) primary solid-solution phase boundaries for the silver comer of the Ag-Cd-In temary system have been determined using X-ray diffraction and metallo-graphic techniques. Solid solubility of indium in silver at room temperature and 600°F (315°C) is shown to be between 20.3 and 21.7 wt pct, and corrects the previously extrapolated value of 18 wt pct appearing in the literature. The solid solubility of cadmium in silver at room temperature, not previously established, is shown to be between 34.9 and 41.3 wt pct. The solid solubility of cadmium in silver at 600°F (315°C) is confirmed as 43.2 wt pct. The shape of the primary phase boundary line for the subject temary system appears straight at room temperature and curves con-vexly towards the solvent (silver) comer at 600°F (315°C). THIS investigation was undertaken to initiate development of the Ag-Cd-In ternary diagram by establishing the primary solid-solution phase boundary in the silver corner of the diagram. At the present time, a diagram for this ternary system is not available, while this system appears to offer potential for a variety of uses. One alloy in the system has already proven to be useful as a control rod material in nuclear reactors.1"3 To encourage additional exploration of the potential of the system an understanding of its ternary diagram would be beneficial. It is towards this end that the present study is directed. LITERATURE SURVEY In undertaking this study, a comprehensive literature survey was first conducted to find information that would be useful for guidance. Useful knowledge did result from investigating the respective solubilities of indium and cadmium in silver as indicated in the binary constitutional diagrams of the systems Ag-In and Ag-Cd and also reviewing possible shapes of ternary primary phase boundaries. Weibke and Eggers~ used metallographic techniques to establish the system In-Ag as illustrated in Fig. Is This diagram shows that silver in the solid state is capable of dissolving approximately 18 wt pct In. This solid solubility of indium in silver holds true from room temperature up to 1276°F (691°C), then decreases continuously up to 1'761°F (960.5"C), the melting point of the silver. The solid-solubility limit of indium in silver established by Weibke and Eggers has been confirmed by Hume-Rothery and Reyno1ds. G Durrant' used a method which consisted of microscopic examination of quenched specimens to establish the Cd-Ag system as displayed in Fig. 2.' The primary phase boundary of Fig. 2 proved to be in good agreement (ie., within 1 wt pct) with other studies*'1' of the Ag-Cd system made using X-rays and metallog-

Jan 1, 1968

By K. A. Natarajan, I. Iwasaki

Platinum electrodes are not inert as often thought to be. The reactivity of platinum electrodes can explain their erratic behavior in many electrochemical measurements of metallurgical interest, e.g, in flotation systems, streaming potential measurements, contact-angle measurements, and in leaching systems. The anomalous behavior of platinum electrodes in redox potential measurements in aqueous systems was studied through Eh and pH measure ments in water-oxygen, iron-water-oxygen, and manganese-water-oxygen systems. Stability relations between Fe++ and Fe (OH), and between Fe (OH), and Fe (OH), were studied to judge the correspondence between experimental and theoretical equilibrium lines. The practicality of redox potential measurements in estimating ferric-ferrous ratios in aqueous systems was investigated along with their suitability as indicators in leaching operations, e.g., the removal of iron by aeration from manganese leach solutions. Platinum electrodes have often been used in the measurement of dissolved oxygen concentrations and of redox potentials (Eh) in a variety of fields, e.g., analytical chemistry,' corrosion," geology and mineralogy,,'' biology,"' sewage treatment,' * hydrometallurgy,"I" and flotation."la The effectiveness of Eh-pH diagrams, first reported by Pourbaix' in 1949, has contributed much towards the theoretical understanding of numerous problems encountered in the metallurgical industry. Not many references are available in the literature, however, wherein attempts have been made to confirm Eh-pH diagrams from experimental measurements. One reason might be that, in spite of the apparent simplicity of the electrochemical technique, the direct measurement of Eh involves complex practical problems.' Factors such as the purity of the solution, the type of electrodes used, the history of the indicator electrode, and the type of atmosphere (namely, oxidizing, reducing, or inert) do have effects on the measured Eh values. The influence of mixed potentials cannot be underestimated. The poisoning of platinum electrodes by organic and inorganic impurities present in the solution may lead to erratic results. Platinum, commonly thought to be an inert electrode material, is not really so, as attested by a number of previous investigators who advised caution concerning the anomalous behavior of platinum electrodes in various electrochemical measurements.'" In the present article, a few pertinent experiments related to Eh-pH measurements in systems of interest in the metallurgical and water pollution fields are described in an attempt to correlate such information with what is already known, especially in the electrochemical literature. Iron-water and manganese-water systems were selected with a view of studying the correspondence between experimentally observed and theoretically established equilibrium lines. The work included an investigation of the behavior of platinum electrodes with respect to pretreatment and adsorption characteristics, the measurement of dissolved oxygen concentrations and their relation to Eh, the determination of the electrode potential of the ferric-ferrous couple at different pH, and the measurement of oxidation potentials in iron-manganese leaching systems. Experimental Procedure A rotating platinum electrode was used in many of the measurements to study the effect of rotation on measured Eh values. The electrode made by the Pine Instrument Co. consisted of a stainless steel rod with a platinum disk soldered to the end. It was covered with a Teflon insulation along the sides, so that only the circular tip of the electrode was exposed to the solution. Prior to its use, the platinum surface was brightened on a metallurgical polishing wheel with alumina as an abrasive, unless specified otherwise. The electrode was rotated with a Sargent cone-drive motor at 350 rpm. The contact of the electrode with the external circuit was made by filling a notch at the top of the stainless steel shaft with mercury and by dipping a copper wire into the mercury pool. The performance of the rotating platinum electrode was compared with the performances of a Beckman platinum button electrode and a platinum wire electrode. All the potentials were measured with respect to a saturated calomel electrode. A saturated KC1-agar bridge was used to minimize the liquid junction potential. A Beckman Zeromatic pH meter together with a Beck-man electrode switch was used to measure both the Eh and pH. A double-walled, all-Pyrex jar with a capacity of about 1 liter and themostated by circulating water of constant temperature was used for a reaction cell. Four equally spaced ports in the cover provided access for a glass electrode, a salt bridge connecting the saturated calomel electrode, a dispersion tube for bubbling gases into the cell solution, inlet and outlet tubes for passing the desired gases over the solution, and a graduated burette for introducing reagents from outside. The rotating platinum electrode was inserted through an opening in the top-center of the cover, and a positive gas pressure was maintained inside the cell to prevent air from entering into the cell compartment. A magnetic stirrer was used to mix the solution inside. For the determination of dissolved oxygen in the test solutions, the polarographic techniquex was used.

Jan 1, 1971

By Clemens Catesby Jones

The substance of this paper, now amended and altered in form for its present use, was the basis of a private report prepared under professional engagement.* A private report is necessarily objective, and deprived of the scope and technicality of a scieintific treatise—which accounts for the prevalence of drawings and succinct mathematical statements rather than full descriptive details in a paper reproduced from data, of which all the original working-notes have been destroyed. In a practical sense the Hudson river valley clay-deposits owe their present existence to the protection afforded by the rock-formations on which they are supported, and, instead of being uniform in depth or continuity, are subject to the irregularities of the rugged masses which preceded and are now concealed by them. The only available information concerning these deposits contained in previous public reports or maps furnished at best a mere photograph of the surface, and as now apparent this was misleading or unreliable. It was the object of this investigation to determine in a practical manner the location, form and extent of all the clay-deposits at present existing in the lower Hudson river valley, and to ascertain with a

Jan 1, 1900

The Institute conducts jointly with the American Society of Civil Engineers, American Society of Mechanical Engineers and American Institute of Electrical Engineers, certain activities as listed below, and is joint owner with them of certain properties. United Engineering Trustees, Inc.* When Mr. Carnegie made his gift which made possible a home for the engineering societies, a separate corporation was organized to act as a holding company and to manage the common property. This was long known as the United Engineering Society but the name has now been changed to one which more nearly reflects the real function of the corporation. It holds title to the Engineering societies Building and to various funds placed in its charge and is managed by a Board of Trustees of which three are chosen by each of the four societies, American Institute of Mining and Metallurgical Engineers, American Society of Mechanical Engineers, American Institute of Electrical Engineers and American Society of Civil Engineers, which own equal and undivided interests in the property. The land and building cost two million dollars. The interest of each of the Founders societies, aside from especial trust funds, is now valued at $493,352. The A. I. M. E. trustees are Arthur S. Dwight, J. V. N. Dorr and H. A. Guess. George D. Barron will succeed Mr. Guess as trustee at the end of this year. The President of the Board is Francis Lee Stuart and the Secretary, Alfred D. Flinn. The Engineering Foundation The Engnieering Foundation was established in 1814 as a result of a gift of $200,000 made by Ambrose Swasey. It is intended not only "for the Furtherance of research" along broad lines but also "for the advancement of" a wide variety of other activities of benefit to engineering as need arises. The endowment fund, which now amounts to $630,000, is administered by the United Engineering Trustees, Inc. Through The Engineering Foundation board, on which the Institute is now represented by J. V. N. Dorr, John M. Callow and Galen H. Clevenger, the income of the endowment, approximately $28,000 a year, and funds contributed for special projects are appropriated for the purposes intended. H. C. Bellinger will succeed Mr. Callow on the board at the end of this year. Alfred D. Flinn is Secretary- and Director. Researches of wide interest in many lines have been aided by Engineering Foundation. . A grant from it to the Mining Methods Committee assisted in the preparation of Volume 72 of the Transactions. For several years the Foundation has aided in support of the study of Blast-furnacc Slags by R. 8. McCaffery at the University of Wisconsin, sponsored by the Institute. The Foundation has raised over $230,000 to support the Alloys of Iron Research endorsed by the Institute and George B. Water-house is serving as Chairman and Director of the Iron Alloys Committee which has been brought together to direct this work. The Foundation has also on recommendation of the Institute made a grant in aid of the studies of Mining and Strata being conducted at Columbia University by P. B. Bucky, which promise information of great usefulness relative to mine subsidence and support of ground. John Fritz Medal Board of Award The medal was established in 1902 and lias since, been awarded not oftener than annually by a hoard of sixteen members, four representatives each from the American Societies of Civil, Mining and Metallurgical, Mechanical, and Electrical Engineers.

Jan 1, 1930

By T. B. Counselman

AFTER several years study, the Universal Atlas Cement Co. decided to rebuild its plant at Leeds, Alabama. The entire old plant, which was to operate during the new construction, was then to be scrapped with the exception of two kilns. The quarry was to be mechanized, new and larger kilns installed, with the most modern type of equipment all through the plant. Raw grinding operations at all of the Universal Atlas plants were dry. However, the dust hazard of this operation and the growing emphasis on occupational diseases made wet grinding attractive. Coal at Leeds is cheap, so that a slightly higher coal practice was unimportant. Power was cheap, so that waste-heat boilers were not desirable. Since new kilns were to be installed, these could be made long enough to make filters unnecessary. Wet raw grinding could be either the old practice of open-circuit compartment mills or closed-circuit grinding in accordance with metal-lurgical practice. The latter saved power and steel wear and saved initial investment. This had been demonstrated in cement plants. Also, the elimination of tramp oversize was a most important advantage. Ease of chemical control was another factor. Blending in the thickener, with elimination of slurry mixers had been found practicable. Therefore, if wet raw grinding were used at all, the advantages were clearly in favor of closed-circuit grinding. Detailed layouts of the most modern possible closed-circuit dry-grinding plant and of a closed-circuit wet-grinding plant were prepared, and careful estimates were made of initial invest-ment and operating costs. Full consideration of all the factors involved resulted in a decision to install wet closed-circuit grinding.

Jan 1, 1939

By W. S. Morris

THE East Texas oil field is the largest in the United States and perhaps the largest 'in the world ; likewise, it is one of the most interesting. The East Texas oil field is a water-drive field. Small amounts of salt water were produced from wells on the western side of the field from the bt-ginning of the development. By the end of 1933 (the field having been discovered in September 1930) water production had reached 9000 barrels per day. By the end of 1936, approximately 2000 wells were producing about 45,000 barrels of water per day, and the problem of salt water disposal attracted the serious attention of the operators. Salt water production in the field has steadily increased and today approximately 450,000 barrels of water per day is produced while the oil production averages about 375,000 barrels. The disposal of this salt water has therefore become one of the major operating problems. Various methods of salt water disposal have been tried in the East Texas field. Evaporation in open pits proved

Jan 1, 1944

By John L. Lamont, Walter Crafts

STUDIES of the effect of composition of steel on hardenability by Grossmann,1 and as-quenched hardness by Field2 and by the authors,3 have made it possible to predict the results of quenching when the composition and cooling rate are known. In order to extend the application of the hardenability calculation to the quenched and tempered condition in which steel is finally used, a survey has been made of the hardness changes caused by tempering. From this study a method has been developed for the prediction of hardness and tensile strength of steel in the tempered condition. The method of calculation was developed from Rockwell C hardness tests on quenched and tempered Jominy specimens and is expressed in Rockwell C hardness units. It is of an additive type in which the degree of softening from as-quenched hardness is estimated. Tempered properties may be calculated within about plus or minus 5 Rockwell C hardness or plus or minus 15,000 lb. per sq. in. tensile strength. This degree of accuracy is less than that necessary for the control of heat-treatment, but is adequate for the comparative evaluation and selection of alloy steels. The formula indicates that tempered hardness is primarily dependent on as- quenched hardness and, as in the hardening reaction, the progress of tempering is controlled mainly by the carbon content- Alloys tend to retard softening by a secondary hardening mechanism in which the alloy appears to migrate from ferrite to the carbide phase. The factors for the effects of alloys in tempering vary so much from the effects of alloys in hardening that different steels of equivalent hardenability may, after lie heat-treatment, differ considerably in tensile strength. PROCEDURE In developing the method for calculating tempered Rockwell C hardness, simple and complex steels were tested over a range from 0.08-to 0.65 per cent carbon and up to 2.68 per cent manganese, 2.18 silicon, 3.50 chromium, 4.94 nickel, and 1.06 molybdenum. The steels were made as small induction-furnace heats at the Union Carbide and Carbon Research Laboratories, Inc. The accuracy of the method was finally checked on a variety of carbon, low-alloy and high- alloy types of heat-treating steels produced under commercial conditions. The method was based on a study of tempered Jominy bars, and its validity was tested by correlation with the center hardness and tensile strength of oil-quenched and tempered bars from ¼ to 4 in. in diameter. The method of calculation was derived from the differences in Rockwell C hardness between as-quenched and quenched and tempered Jominy specimens. Prenormalized Jominy hardenability specimens quenched from a normal temperature for austenitization were used to obtain a range of as-quenched Rockwell C

Jan 1, 1946

By Hsun Hu

Three single crystal strips of a 3 pct Si-Fe alloy with approximately (110) [001], (210) [001], and (100) [001] orientations were rolled at room temperature to 30, 50, and 70 pct reductions in thickness. Their deformation and annealing textures were studied. In most cases, the change in texture upon recrystallization and subsequent growth can be described as rotations around the <I10 > axes. A < WO > rotational relationship was also observed. The temperature dependence of recrystallization textures was discussed. WhILE considerable data have been published on the rolling and annealing textures in silicon-iron crystals, very little study has been made on the texture formation at various stages of rolling deformation, and during the process of recrystallization. Dunn&apos; in some of his early works had studied the orientation of recrystallized grains in crystals cut out from lightly rolled (10 to 20 pct reduction) large grained sheets. He found that in most cases a third-order twin relationship exists between the crystal and the recrystallized grains. This orientation relationship actually corresponds to rotations around the <110> axes. The more recent studies of Dunn &apos; and of Dunn and Koh &apos;5 on the rolling and annealing textures in various silicon-iron crystals were concerned mostly with a cold-rolling reduction of 70 pct and annealing at 980OC for recrystallization. Reductions of similar magnitude were also employed by Walter and Hibbard in rolling columnar crystal aggregates of a silicon-iron ingot. A systematic study of the effect of rolling reduction on the deforma- tion and annealing textures is still lacking. Regarding the effect of annealing temperature on the texture formation, Dunn3 has observed a change in therecrys-tallization texture by annealing a 70 pct rolled (1 10) [001] crystal first at a low temperature then atahigh temperature. But the details of texture formation during the annealing treatments were not thoroughly investigated. The present investigation was undertaken to study the texture developments at various stages of rolling deformation and of the recrystallization process, so that a better understanding on the texture formation in silicon-iron crystals may be obtained. EXPERIMENTAL PROCEDURE The three single crystals used in the present investigation were selected from the group of single crystal strips previously prepared7 from a high grade commercial Si-Fe alloy with 3 pct Si. The thickness of these single crystal strips was 0.040 in. The orientations of the three crystals as determined by the X-ray back-reflection Laue technique are shown in Table I. Each of the three crystals was rolled at room temperature along the strip direction to 30, 50, and 70

Jan 1, 1962

By Alex Hay

THE Sydney coal field, the largest and most valuable in Nova Scotia, is situated on the northeastern coast of the Island of Cape Breton, extending from Mira Bay on the south to Cape Dauphin on the north, a distance of 30 miles, and has a general dip northeast under the sea. (Fig. 1.) The field embraces the mining villages of Morien, Birchgrove and Reserve and the towns of Dominion, Glace Bay, Waterford and Sydney Mines. The city of Sydney is situated about midway between the northern and southern extremities of the field and on the western fringe of the productive coal measures. Sydney harbor crosses the coal field, cutting off direct rail connection between Sydney Mines and the greater part of the field to the southeast. (Fig. 2.) The coal measures are exposed in the cliffs on the coast line, which rise to an average height of 30 ft., and are almost continuous throughout the length of the field. The portion of the coal field under land forms a small segment of a circle, the greatest distance from the coast landwards is 9 miles, and it occupies an area of 200 sq. miles. The greatest distance developed seawards from the shore by mining operations is 2 ¼ miles. The strata maintain a regularity of dip at this distance, proving a submarine area of about 70 sq. miles. How much further the coal field extends seawards is unknown, but the indications are that it extends far beyond the present economical working limit and in all probability there is a vast submarine coal field. The productive coal measures are of Carboniferous age, these being underlaid by beds of sandstone, locally classed as millstone grit, which define the southern limit of the field,, while a spur of syenitic hills cuts off the coal-bearing strata on the north. Two main anticlinal folds having a general course easterly divide the field into three basins named from north to south: Sydney Mines-Lingan, Glace Bay and Morien.

Jan 1, 1929

By S. S. Solomons, V. H. Tillmann, L. Smaniotto

INTRODUCTION The Zinc Corporation, Limited and New Broken Hill Consolidated Limited (ZC/NBHC) mines are situated at Broken Hill, New South Wales, Australia (refer Fig. 1). Both companies are wholly owned subsidiaries of Australian Mining and Smelting Limited (AM&S). Annual production from both mines is 2.3 million tonnes of lead, silver and zinc ore mined by a variety of underground methods. From 1911 to 1968, conventional overhand cut and fill stoping (both open and square set timber) was used almost exclusively, though some trials with shrinkage and sublevel stoping were undertaken. The trial stopes used short holes in conparison with today&apos;s sublevel open stopes. Mechanised cut and fill methods with regular rockbolt support were introduced in the early 1960&apos;s and undercut and fill stoping replaced square set timber stoping for pillar extraction in the late 1960&apos;s. Since 1968, increasing emphasis has been placed on longhole open stoping (LHOS) although some areas of the orebodies are comrnrnitted to the abovemehtioned methods since existing stope development makes it impracticable to change. In 1979, approximately half the total production was mined by LHDS and it is expected that the LHOS proportion will increase in the future. A vertical crater retreat method of longhole mining has also been successfully introduced to replace the undercut and fill stoping of some pillars and it is expected that this stoping method will be used in some future primary ore extraction. This paper reviews the progress of LHOS technology at ZC/NBHC with emphasis on the stope planning and design process and the importance of rock mechanics applications. The objective has been to maximise the primary extraction of the orebody giving due consideration to stability and safety. This has led to the design of a novel sloped wall longhole stoping method which should eliminate the formation of pillars by mining the orebody in a "continuous" manner incorporating a sloped sand interface between the blocks of ore being mined and the previously mined sandfilled stope. The expected results include the complete extract of the orebody without the formation of pillars and with minimal dilution of ore with sandfill. The evolution of the method can be best illustrated by following the mining progress of the relatively new Southern &apos;B1 Lode orebody at the NBHC mine. GEOLOGY Southern &apos;8&apos; Lode is the southern extension of the &apos;Bt Lode orebody, which is currently being mined further to the north in ZC/NBHC (refer Fig. 2). The ore block being developed and stoped extends for a vertical height of 90 metres from No. 17 level down to approximately ten metres above No. 19 level. The ore minerals are sphalerite and galena with the zinc:lead ratio averaging approximately 3:l with a minor amount of silver associated with the galena. There is a sharp contact between the ore and the country rock on the footwall and keel, while the hanging wall gradates into medium and low grade material. The gangue is primarily quartz together with garnet, biotite, feldspar, gahnite, sericite and minor apatite. In various horizons within the orebody, grey feldspar, quartz and garnet pegmatites occur as stratiform layers. The ore and country rock are competent with some inconpetent boundaries.

Jan 1, 1981

By H. J. Maguire

(Presented by invitation at a meeting of the Spokane Local Section, Feb. 17, 1912.) THOSE familiar with mill-practice understand the work required of an average bucket-elevator, but I wish to call special attention to the wear on the buckets. I have been studying in what manner the life and service of the bucket might be improved, and I feel that an adjustable lip, attachable to each bucket without the aid of rivets, will be of material advantage. For illustration, consider the feed-elevator of a typical mill in the Cur d&apos;Alène district. The ore is carried by water in a launder from the feed-rolls and dumped in the "boot" of the elevator, directly in front of the ascending bucket. Middlings from the return-rolls are similarly handled. Under this condition the bucket not only carries the ore, but also picks it up, and this latter requirement determines the life and service of the bucket. It might be said that it would be better practice to convey the feed to the elevator and dump it directly into the bucket, but at one mill at which this plan was tried the results were disappointing and the rubber belt was badly worn. The wear of the bucket is confined to the lip and the corners which have to pick up the material. When the lip on a corner of a 7- by 12-in. malleable cast-iron bucket is worn down about 3 in., the bucket is of no further value as a carrier and has to be replaced. The worn bucket, containing about three¬quarters by weight of the metal of the original bucket, has a scrap value of about 10 per cent. of that of a new bucket. To the cost of the bucket, however, should be added the time-cost of replacing the old bucket by a new one. This time-cost is considerable when the loss per hour, to cease operating the mill, is about $200. It is out of the question to put lips on a bucket unless the latter was originally fitted with this device. For if it is attempted to fit lips upon buckets not originally provided with

Sep 1, 1912

By Michel T. Halbouty

South Texas, one of the world&apos;s important oil and gas-producing areas, continued to hold interest during 1939 as another scries of new fields and new producing levels was developed within its boundaries at a fairly continuous rate throughout the year. There were 1801 wells drilled in this area in 1939, compared to 1678 in 1938; of these, 1515 were drilled in established fields, or as extensions to proven areas (semi-wildcat), and 286 were drilled as rank wildcats, in search of new production. Among these rank wildcats, 22 produced oil, 7 produced distillate and gas and 257 were abandoned as dry holes (see Table 5). Of the 1515 field and cxtension wells, 1213 produced oil, or distillate and gas, 50 produced only gas and 252 were dry; 38 found new productive sand levels in proven ficlds. Jim Wells County led this district in discoveries, having had 9 new fields arid 9 new productive sands found within its border during 1939. Most activc of the 1939 discoveries were Reynold?; and Ben Bolt fields in Jim Wells County and Minnie Bock field in Nueccs County; among producing fields the most activc were: East White Point and Aransas Pass (McCampbell). Production from South Texas in 1939 totaled 55,105,506 bbl. against a total of 56,152,122 bbl. produced in 1938. South Texas should continue its present rate of developrnent and exploration and this should result in the discovery of many fields in its numerous oil-bearing zones, and should also lead to more knowledge of the possibilities of its deeper horizons, such as the Mt. Selman and Wilcox formations; with the latter holding particular interest at the present time. Tide Water Associated Oil Company&apos;s A. M. Bruni No. I, Cole-Bruni field, Webb County, the deepest well drilled along the Mirando trend, was carried to 8959 ft., where it started to blow out from a Wilcox sand topped at 8954 ft., making gas, distillate and mud under heavy pressure. After the well was killed, drill stem beeame stuck and was cemented in place in order to test a Queen City (Mt. Selman) sand logged from 5620 to 5675 ft. This and other shows found in other wells along this trend, but out of this district, have served to increase the importance of this but little explored Sparta-Wilcox trend of South Texas during the year, and more activity along it is to be expected in the near future.

Jan 1, 1940

By Michel T. Halbouty

South Texas, one of the world&apos;s important oil and gas-producing areas, continued to hold interest during 1939 as another scries of new fields and new producing levels was developed within its boundaries at a fairly continuous rate throughout the year. There were 1801 wells drilled in this area in 1939, compared to 1678 in 1938; of these, 1515 were drilled in established fields, or as extensions to proven areas (semi-wildcat), and 286 were drilled as rank wildcats, in search of new production. Among these rank wildcats, 22 produced oil, 7 produced distillate and gas and 257 were abandoned as dry holes (see Table 5). Of the 1515 field and cxtension wells, 1213 produced oil, or distillate and gas, 50 produced only gas and 252 were dry; 38 found new productive sand levels in proven ficlds. Jim Wells County led this district in discoveries, having had 9 new fields arid 9 new productive sands found within its border during 1939. Most activc of the 1939 discoveries were Reynold?; and Ben Bolt fields in Jim Wells County and Minnie Bock field in Nueccs County; among producing fields the most activc were: East White Point and Aransas Pass (McCampbell). Production from South Texas in 1939 totaled 55,105,506 bbl. against a total of 56,152,122 bbl. produced in 1938. South Texas should continue its present rate of developrnent and exploration and this should result in the discovery of many fields in its numerous oil-bearing zones, and should also lead to more knowledge of the possibilities of its deeper horizons, such as the Mt. Selman and Wilcox formations; with the latter holding particular interest at the present time. Tide Water Associated Oil Company&apos;s A. M. Bruni No. I, Cole-Bruni field, Webb County, the deepest well drilled along the Mirando trend, was carried to 8959 ft., where it started to blow out from a Wilcox sand topped at 8954 ft., making gas, distillate and mud under heavy pressure. After the well was killed, drill stem beeame stuck and was cemented in place in order to test a Queen City (Mt. Selman) sand logged from 5620 to 5675 ft. This and other shows found in other wells along this trend, but out of this district, have served to increase the importance of this but little explored Sparta-Wilcox trend of South Texas during the year, and more activity along it is to be expected in the near future.

Jan 1, 1940

By Henry Fay

THE erosion of guns is a complex problem which can be solved only by a detailed study of all the factors involved. In the present paper it is proposed to submit the results of observations and experiments which have extended over several years. Certain facts have been established and preliminary reports have been published.&apos; Conclusions have been reached since then which, it is believed, are worth presenting for the purpose of promoting discussion, and with the hope that ultimately the whole truth will be known. The particular phase of the problem which will be presented here is the hardening of the inner surface of the gun tube. It has been known for a long time that after firing a large caliber gun for some time, the surface of the metal becomes hard and brittle, cracks, and wears away.2 The character of this phenomenon may be learned by an examination of some results which are typical, obtained from a detailed study of a 12-in. gun. The gun was trepanned and rings representing various sections of the gun were cut out for examination. The first ring represented the metal at the muzzle end, and the other rings were removed at approximately 120, 240, 325 and 337 in., respectively, toward the breech end. The appearance of the surface of the metal in the different sections is shown in Fig. 1. The greatest amount of wear and maximum amount of hard surface layer was found in section marked E, which is nearest the powder chamber and at the beginning of the rifling; the maximum amount of cracking in D; the maximum amount of copper deposition in C. Section B showed heat cracks on both lands and grooves, and section A showed heat cracks on the driving edge of the lands only. There was much flow of metal in both sections E and D, and there was progressively less effect noticeable toward the muzzle end. The polished cross-section of these same pieces is shown in Fig. 2. The

Jan 12, 1916

By T. L. McCall

The late Walter Herd1 in 1929 gave a full description of past and present conditions in No. 2 mine, Springhill, Nova Scotia, developed theories regarding the cause of these bumps and made certain suggestions regarding possible methods of future development. Recapitulating briefly from Mr. Herd&apos;s paper, the seam is bituminous coal, averages 9 ft. in thickness and has a well defined parting containing fusain about 14 in. from the roof. This roof coal is somewhat stronger than the rest of the seam and has a tendency to cling to the roof. The pitch of the seam where it is now being worked is about 20". The first manifestations of bumps began when the room and pillar workings had reached a depth of cover of 1900 ft. and under continuously increasing depth of cover these bumps increased to such an extent, both in number and severity, that in the year 1924 it became apparent that some change in the system of extraction was necessary. After closely studying all the factors involved and benefiting largely by valuable outside advice obtained by the Provincial Department of Mines of Nova Scotia,2 the system of working was changed from room and pillar to longwall retreating. Mr. Herd&apos;s paper described in detail three remarkable bumps in the year 1928 in April, July and October that affected the 5700-ft. and 5900-ft. East levels, the last bump being so severe both in intensity and in extent of damage done that this district was abandoned. The longwall workings to the west of the slope had been stopped in the year 1926 owing to an inbreak of water, coming from the flooded waste of No. 3 seam lying some 400 ft. vertically overhead. This inflow was not excessive, but a large quantity of water being impounded in the old workings it was considered advisable to take the prudent course and not incur the risk of possibly increasing the flow by further working. This district has remained idle ever since.

Jan 1, 1934

By Charles Camsell

MORE than one-third of all Canada is embraced in the federal domain known as the Northwest Territories. Its most northern point, Cape Columbia, on Ellesmere Island, is only 500 mi. from the Pole. It includes parts of the main physiographic divisions of the North American continent. In the West there is a strip of 30.000 sq. mi. lying in the Cordilleran region, where peaks in the Mackenzie Mountains rise as high as 8500 ft. East of this strip and extending roughly to a line through Great Bear and Great Slave lakes to the Arctic coast is a section of the interior plains. This section, known as the Mackenzie Lowlands, contains the great artery, the most striking feature of the Northwest Territories-the Mackenzie and Slave river waterway impressive in its width, almost two miles in places, and in it&apos;s navigability for 1357 miles without obstruction to the sea. Adjoining the Mackenzie Lowlands on the East is the greater portion of the mainland of the Territories, which, as well as a large share of the island area, is in the Canadian Shield.

Jan 1, 1937

By T. L. McCall

THE late Walter Herd1 in 1929 gave a full description of past and present conditions in No. 2 mine, Springhill, Nova Scotia, developed theories regarding the cause of these bumps and made certain suggestions regarding possible methods of future development. Recapitulating briefly from Mr. Herd&apos;s paper, the seam is bituminous coal, averages 9 ft. in thickness and has a well defined parting containing fusain about 14 in. from the roof. This roof coal is somewhat stronger than the rest of the seam and has a tendency to cling to the roof. The pitch of the seam where it is now being worked is about 20°. The first manifestations of bumps began when the room and pillar workings had reached a depth of cover of 1900 ft. and under continuously increasing depth of cover these bumps increased to such an extent, both in number and severity, that in the year 1924 it became apparent that some change in the system of extraction was necessary. After closely studying all the factors involved and benefiting largely by valuable out-side advice obtained by the Provincial Department of Mines of Nova Scotia,2 the system of working was changed from room and pillar to longwall retreating. Mr. Herd&apos;s paper described in detail three remarkable bumps in the year 1928 in April, July and October that affected the 5700-ft. and 5900-ft. East levels, the last bump being so severe both in intensity and in extent of damage done that this district was abandoned. The longwall workings to the west of the slope had been stopped in the year 1926 owing to an inbreak of water, coming from the flooded waste of No. 3 seam lying some 400 ft. vertically overhead. This inflow was not excessive, but a large quantity of water being impounded in the old workings it was considered advisable to take the prudent course and not incur the risk of possibly increasing the flow by further working. This district has remained idle ever since.

Jan 1, 1934

By H. H. Stoek

Mine models have three distinct uses: 1. As exhibits in expositions and museums. 2. As exhibits in law suits. 3. As illustrations in teaching mining engineering. All three uses are in a sense educational. The third, or distinctively teaching function, has not been extensively developed in America as it has been abroad, chiefly because of the cost of the models and the scarcity of model makers. In connection with expositions, such as the Columbian, the Louisiana Purchase, and the Panama-Pacific, a number of very good mine and metallurgical models were prepared with funds furnished by State commissions, by mining organizations or mining companies. At the close of these expositions, some of these models have been deposited in National or State museums or in educational institutions, but too many of them haw been lost, or have been stored away in some mining company&apos;s office or in the basement of some State building, where they have been lost sight of and have gradually fallen to pieces. A visitor to a German mining school is impressed by two facts: 1. The mining laboratories are in general inferior to those in America. 2. The mining museums are infinitely superior to ours, particularly in models exhibited. One may reply to this comparison by saying that a museum is necessarily a work of time. From the historical standpoint this is, of course, true, but it is not necessarily true in connection with a working museum intended to illustrate current practice. For instance, the oldest mining school in Germany, that at Freiberg, has much excellent historical material, but very little on modern practice, while Berlin, one of the youngest German mining schools, has a most extensive and valuable collection of modern appliances and models. This is true in spite of the fact that one of the best-known model shops is at Freiberg, from which many of the models to be seen in America have come. Because many of the models in American mining schools have come from

Jan 1, 1918

By P. A. Vukmanic, M. Gensamer

Only recently has it been realized that preferred orientations are common in hot-rolled steels. In a recent paper, N. P. Gossl stated that hot-rolled mild steel exhibits a texture different from that characteristic of cold-rolled steel. No complete study of these hot-rolling textures has been reported using the pole-figure method of Wever. The material used in the work reported in this paper was the same material used by Gensamer and Mehl2 in a recent study of preferred orientations in cold-rolled steel, to which reference may be made for the composition and thermal history of the steel. Automobile-body sheet bar 1/4 in. thick was hot-rolled at two temperatures, 780&apos; and 910&apos; C. (1436&apos; and 1669&apos; F.). These temperatures refer to the temperature of the furnace in which the steel was heated; after each pass the steel was returned to the furnace and held there long enough to return to temperature. Although no accurate method was used to measure the temperature after each pass, it was estimated by color that only a slight drop in temperature occurred. In order to determine the effect of any preferred orientation that might have persisted through the normalizing treatment, one specimen at each temperature was rolled in the same direction as the original working direction and the other at right angles to it. The total reduction in each case was 85 per cent, the specimens having been reduced from 0.250 to 0.0375 in. in five passes. Final cooling was in air. Pinhole reflection photograms were taken of all four specimens, with the rolling direction vertical and the X-ray beam at an angle of 7&apos; with the transverse direction (the transverse direction is defined as that direction in the rolling plane perpendicular to the rolling direction). These photograms, taken with a Mo target at 35 kv., are reproduced in Figs. 1, 2, 3 and 4. They show that a more pronounced texture was developed by the low-temperature rolling (780&apos; C.), and that of the two

Jan 1, 1937

By R. M. Brick

The etched mierostructures of cold-worked alpha brasses, after reductions in excess of about 20 per cent, exhibit dark lines or markings, which have been termed "deformation bands," "etch bands," and "strain markings." The terms will be used synonymously in this report. The markings are similar in their general appearance to etch figures found in cold-worked iron, aluminum and other cubic metals but in certain respects may differ noticeably. At reductions of from about 20 to 50 per cent in brass, they appear as straight dark lines of irregular spacing and at random directions in different grains, but apparently intimately associated with definite crystallographic planes, usually {ill), in each crystal. At higher reductions, the markings on the rolling plane tend to appear in a direction transverse to the rolling direction in all crystals but may bend away at considerable angles, particularly near grain boundaries. Samans,1 on the basis of X-ray and micrographic studies of two single crystals of brass, rolled to a 50 per cent reduction, showed that the lines of deformation were the edges of thin mechanical twins parallel to octahedral planes. Barrett and Levenson2-4 have made comprehensive studies of the deformation of iron and of aluminum. They show that in these two metals the deformation markings originate by division of the original homogeneous crystal into banded areas differing in orientation by an amount that increases with the degree of deformation. The markings thus cannot be twin bands, and Barrett, in a review of this subject,2 attributed Samans&apos; results on brass to an accidental choice of deformation that left the bands in approximately a twinned relationship. On the other hand, Mathewson6 has suggested that in some cases mechanical twinning offers a better rationalization of the coverage of some (111) pole figures of worked brass than the assumption of band rotation into symmetry positions. Considering next a deformed and annealed alpha brass, the most striking aspect of its microstructure is the multiplicity of twin bands.

Jan 1, 1940