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By Nelson Taylor

WITH the extensive deposits of potash minerals which have been dis-covered in the southwestern states, and their rapid development, a permanent. American supply of potassium compounds is now assured. The 325-year history of the potash industry in this country has been told by H. I. Smith1, of the U.S. Geological Survey, and the more recent activities of the Survey and of American potash companies were described last year by the same author2. In fact, it may be stated that so great is the productive capacity that two mines in New Mexico and one in California are able to supply more than half a million tons of crude and refined salts over and above that produced for agricultural purposes. The era of scarcity has given way to an era of superabundance. This situation makes it desirable for the potash producer to look for other applications for his product, and it is with this in mind that the writer presents some information pertaining to present and possible future uses for potassium compounds in the ceramic industry.

Jan 1, 1936

By Georges Ranque

THIS paper by. Georges Ranque is an attempt to reason out the conditions of formation and stability of inclusions and to establish an operative process capable of eliminating or minimizing them. The paper consists of two parts; one in which the author considers the laws of physical chemistry and physics that apply to liquid slag-metal systems and one in which he describes a practice based on the theoretical considerations. Such a paper is bound to contain controversial points and it is therefore your speaker's intention to present Mr. Ranque's side of the picture to the best of his ability without regard for any thoughts or criticisms of his own. RISING VELOCITIES OF INCLUSIONS Most nonmetallic inclusions have densities ranging from about 1.7 to s, while liquid steel has a density of about 7. Under these conditions, ferrostatic pressure should cause the inclusions, being lighter, to rise from the bath and be eliminated. This rising tendency is expressed by Stokes' law, from which may be calculated the rising velocity of a spherical particle in a liquid medium whose density and viscosity are known.

Jan 1, 1947

ANYONE who wishes to make the patterns for statues in order to cast them later in bronze, even though he himself is the artificer who made them, must take many things into consideration: first, whether they are large or small, and whether they are wholly round or only in part; then of what material they are made, for the way that can be followed if they are of wax cannot be used if they are of clay, wood, marble, or even of plaster; likewise he must consider whether or not it has irons inside to support it. There is also a great difference in facility if the support is placed more in. one way than in another. Great consideration should be given to whether it is to be made hollow or solid. If you have not been the workman yourself, you must at least have been an active helper in this and in every other part in order to be able to observe everything without a fault. For if they are large it is necessary to make their moulds in pieces, with marks and measurements so that you can replace them-at will exactly in the same order and in the same places after they have been taken out. But if you are the artificer [as well as sculptor] the process is made easier. Taking the ordinary way and, over an iron, make out of well beaten moulding clay, compounded with cloth clippings a core exactly as the statue is to be or however large you wish the hollow to be. Dry and bake it. On top of this work the wax, thickening it all over as much as you wish the bronze to be and finish it completely, remembering to arrange that the base may come out solid with bronze so as to support the whole work. Then take some rods of hammered bronze one dito thick and one palmo long. Pass these throughs the thickness of the wax and fasten them in several places in the core of clay that you made. [81] Do it so that they, project out of the wax a good three or four dita. These are, put in so that when the wax is removed the core is held in the middle of the mould that forms the outer part, and this outer part is held by the inner part, namely the core, so that the mould may not move in any part from its place even when it is handled. This done, take some of that clay made with well-prepared cloth clippings as I taught you, and mix with it if you wish some wash ashes or

Jan 1, 1942

By Bruce H. Gardner, Stephen A. Miller, Shosei Serata

The Bryan Mound salt dome in Freeport, Texas, has some of the largest and oldest solution caverns in the U.S. There are a total of five caverns of varying shapes and sizes randomly distributed throughout the salt dome. When the caverns were converted from a brine production to an oil storage operation, the effects on long-term stability of the caverns and inter-cavern behavior were analyzed to evaluate the future safety of the storage operation. The analysis was based on a worst-possible-case scenario, including accidental wellhead pressure loss. The impact of this pressure loss upon the thinnest partition between the two closest caverns was analyzed, using a case example of storing lightest weight LPG, thereby creating maximum differential pressures between these two caverns. The finite element method with the REM computer code was utilized for this analysis. Results of the analysis illustrate the basic mechanisms of the long-term behavior of the multiple caverns in the LPG storage operation.

Jan 1, 1985

By F. J. Smit

The Tintic Division of Kennecott Copper Corporation operates the Burgin Mine in the East Tintic District near Eureka, Utah, approximately 75 miles south of Salt Lake City. The Division was organized in 1963 to develop concealed replacement orebodies in the area located by Bear Creek Mining Company, Kennecott's domestic exploration subsidiary. Several accounts of the discovery of these orebodies and the general geology of the area have been given (1, 2). The ore is very complex and of varying degrees of oxidation and alteration. The principal metal values are lead, zinc, silver, and cadmium. The Burgin No. 2 shaft was sunk in 1963 to provide access for mining the orebodies. Much of the ore mined after this shaft was sunk was high grade and shipped directly to smelters, but concurrently it was recognized that concentration would be required to upgrade the lower grade ore in the deposits. Accordingly, in January 1967, authorization was received to construct a 500 tpd concentrator. From the beginning it was expected that the characteristics of the mill feed would vary widely and unpredictably as mining progressed. This paper summarizes the characteristics of the ore, the test work upon which the plant design was based, the engineering and construction, and the present operation of the facility eighteen months after startup. ORE CHARACTERISTICS The Burgin ore is a complex assemblage of minerals from replacement of limestone. The replacement and alteration occurred in at

Jan 1, 1970

By C. Wachmann

The theory presented ill this paper makes possible examination of the phenomenological aspect of secondary oil recovery by alcohol flooding. Limitutions of the theory are contingent on three primary assumptions: (1) chemical equilibrium, (2) no fingering, and (5) no dispersion. The second assumption implies one-dimensional flow. In a geometric sense the theory extends the Buckley-Leverett construction to systems of two slightly miscible fluids and to systems of three components. This is made possible by considering single-phase fluids to be made up two phases, namely of an excess of one phase and a negative amount of the other phase. The procedure is discussed in the paper. The theory also permits direct determination of the relationship between the aqueous phase saturation and the concentration of water in the aqueous phase in a zone of variable composition. The velocity of planes of constant water concentration and of constant saturation can be computted likewise and the existence of saturation discontinuities inferred. Consequently the behavior of such a Zone, which may exist at some time between a displaced and a displacing fluid, May be determined. mathematical details are given in Appendices. Problems of experimental verification are pointed out on the basis of a supporting experiment. Implications of the theory and effects of violations of primary assumptions are discussed briefly. The major conclusion is that, if the primary assumptions are met, with pure alcohol and alcohol-rich .slugs piston-like displacement of oil and water is possible. INTRODUCTION The recovery of oil from porous media by alcohol displacement has been studied for several years. Extensive experimental investigations into alcohol flooding have been carried out in the laboratory although little has been done in the field. A large amount of practical information is available, the extent being indicated by the first three papers cited 1-3 and their respecrive bibliographies. This has permitted the Formulation of inferential theories. A more analytical approach in which theories are developed primarily by reasoning from known physical principles and relationships has, however, lagged behind. In fact, an analytically derived theory of alcohol displacement has not been available. The theory presented in this paper on oil and water displacement by alcohol from a porous medium is a result of the analytical approach. The theory is idealized, as certain assumptions had to be made to make the mathematics tractable and reduce complexity of argument. In particular, major assuptions concerning conditions of equilibrium, interfacial stability, longitudinal mixing, etc., led to the exclusion of fingering, for example, from all considerations. In many laboratory experiments reported in the literature fingering could not be avoided. There is, therefore, disagreement between theories based on experimental evidence available and the analytically derived theory presented here. This theory presented is based on known physical data and makes use of the Buckley-Leverett construction and its suggested extension. The mathematical derivation of the theory is given in Appendices. Three examples relevant to alcohol displacement are discussed to explain the use of this theory: (1) system of two immiscible fluids (the Buckley-Leverett case); (2) system of two slightly miscible fluids involving an extension of the Buckley-Leverett construction; and (3) system of three components, including injection of pure alcohol or alcohol-rich fluid as a special case, which involves a more general extension of the Buckley-Leverett construction. In these discussions strict assumptions were made to impose equilibrium conditions and exclude mixing and fingering. Effects of relaxing these assumptions and consequent extensions of the theory are indicated. The complexity of the alcohol displacement process makes experimental verification of the theory essential. Some relevant evidence is offered in this paper.

Jan 1, 1965

KARL A. PAULY,* Schenectady, N. Y.-We are deeply indebted to Mr. Hobart for a record of the actual experience of the Lehigh Coal and Navigation Co. with electrification. One of the essential features of this test is that it was made under actual operating conditions. In one of the western mining districts I was once discussing the electrification of a large hoist with a mining operator, who told me that they had made a very thorough test and that the results were such as to indicate that electrification was not warranted. When questioned regarding the test, he said that they had called on the mining college in the Territory for assistance, and one of the instructors and a group of students had made the test. They first cleaned the boilers and then operated them at a' continuous load, using the maker's guaranteed steam consumption per indicated horsepower as a guide in estimating the steam consumption under actual hoisting conditions. Such a test is absolutely valueless. The efficiency of the boilers 'is affected by the intermittent demands on the steam. The standby losses, as indicated by Mr. Hobart's paper, are quite equal to the actual fuel consumption required to do the work; very frequently, also, the cost of repairs is either omitted or underestimated. One noticeable feature of Mr. Hobart's tabulation is that there is no mention of steam consumption. Intentionally or otherwise, the steam-hoist builders have befogged the question by making a great point of the steam consumption of hoists. The operator is not at all concerned in steam consumption; it is the actual cost of operation that he is interested in, and it is a comparison between the cost of operation of the two systems, all factors being considered, that should determine the choice. The steam consumption, or its determination by test, is only one step in the problem of estimating the fuel consumption, which, in an actual installation, can be directly measured much more accurately, as was done by Mr. Hobart.

Jan 4, 1918

By F. W. Jessen, John C. Miller

In many areas where carbonate rocks form important parts of the stratigraphic sequence, stratigraphers have experienced varying degrees of difficulty in differentiating and correlating limestone and dolomite units in both surface and subsurface work. With early Paleozoic rocks of the Mid-Continent, insoluble residues yield a remarkable amount of strati-graphic data and relatively good correlations may be carried over broad distances.' Unfortunately, neither such information nor electric logs and radioactive logs have been particularly helpful in interpreting the limestone sections of the Permian Basin of West Texas. This is because: (1) the variations in the sections may be very slight; (2) no completely satisfactory method of interpretation has been developed; and (3) the measurements themselves are not sensitive enough for small variations. Also, such logs are influenced by the fluid content. Paleontology and micro-paleontology remain the ultimate arbiters. As a routine tool, however, paleontol-ogical examination is slow and tedious. Chemical analysis may be used, but this, too, is extremely slow. Although rocks are not classified according to chemical composition, there is considerable variation with rock types. Correlation by chemical composition has two advantages, first, the characteristics determined are subject to minimum human error and interpretation, and secondly, the lithologic changes are not masked by fluid content as in the case of electric and radioactive logs. Some fossils concentrate certain elements which tentatively might be used to date rock units.' Rapid chemical analysis by spec-trographic means could be used as an adjunct to other means employed in correlation work, or might, in itself, present a suitable method. PURPOSE OF THIS INVESTIGATION Sloss and Cooke' have published data concerning spectrographic analysis of limestone rocks specifically for purposes of direct correlation of a single formation. These authors found satisfactory evidence that differences in percentage of four elements (Mg, Fe, Al, and Sr) in the Mississippian limestones of northern Montana were useful in carrying out correlation of this formation over a distance of approximately 50 miles. It was concluded from the preliminary work that the spectrochemical method offered possibilities of solution of some problems of correlation heretofore not possible. Since the work of Sloss and Cooke' was confined to one particular limestone zone, extension of the use of the method to examine two or more geologic formations would aid materially in the over-all problem of correlation of such rocks. Equipment is now available commercially with which very rapid spectrographic analyses may be made, and hence the problem was to determine whether the variations existing in the minor constituents of limestones were sufficient for use in possible correlation. Qualitative and semi-quantitative investigations were made to determine whether significant changes in the chemical condition occurred. It was a further purpose to investigate the geologic time-boundaries to see whether significant chemical variation could be found corresponding to the paleontological breaks. It was desirable to attempt correlation of a thick section of limestone or dolomite rock and to have as much information as possible on the section. Furthermore, it was felt that examination of formations more difficult to correlate by other means would enhance the value of the method should definite points of correlation be found. Samples were chosen from the Chapman-McFarlin Cogdell No. 25 well in the Cogdell field, Kent County, Tex., and from the General Crude Oil Co., Coleman No. 193-2 well in the Salt Creek field, Kent County, Tex. These fields belong to the famous series of "Canyon" reef fields of West Texas. Cores from the above wells were available from the United States Geological Survey, Austin, Tex. THE SPECTROGRAPHIC METHOD The choice of procedure to be followed in this investigation was based on the anticipated requirements peculiar to the problem. Since the problem was primarily to investigate the possibilities of applying the spec-trograph to problems of correlation in thick carbonate sections, a precise quantitative analysis did not appear necessary. A qualitative analysis to show the possible absence of presence of any element, or a semi-quantitative analysis of the elements present to show the relative changes in magnitude of selected elements was required. Both types of analysis were employed. The two most widely applied methods of semi-quantitative estimates are those of Harvey and of Slavin4,5 though various other procedures have been described.6 while the Harvey method has been modified by Addink,7 this refinement did not seem necessary to the present problem. Essentially, the procedure employed is a variation of the total energy method of Slavin with two exceptions: (1) stressing matrix effect, and (2) using densitometer measurements. As measured by a densito-

Jan 1, 1956

By A. L. Barnes, A. M. Rowe

A heat transfer study was made of hot gas injection into oil shale through wells interconnected by vertical fractures. This analysis involved the simultaneous numerical solution of a nonlinear, second-order partial differential equation that describes two-dimensional conduction heat transfer in oil shale and a nonlinear first-order partial differential equation that describes convection heat transfer in the fractures. Three nonlinear, temperature-dependent coefficients were used in this work; they are thermal conductivity, thermal capacity and retorting endothermic heat losses of oil shale. Vertical fractures were considered to be of finite height. Although vertical conduction heat transfer was not considered, an estimate of the error resulting from this limitation was made. The effects of injected gas temperature, injection rate, system geometry, cyclic injection and time upon retorting efficiency were investigated. Results from this study show that the rate of retorting oil shale is a direct function of both injection temperature and rate, and the theoretical producing air-oil ratio:(AOR) is an inverse function of temperature. Retorting rates are constant until "breakthrough" of the 700 F isotherm at the producing well, assuming constant injection parameters. Retorting rates for bounded systems are higher than the analogous unbounded systems and likewise AOR's are less. The use of an alternating injection-soak routine with high injection rates is less efficient than continuous injection at lower rates. These results indicate that injection temperatures on the order of 2000F or greater may give theoretical AOR's in the economic range. INTRODUCTION Over half of the known oil shale reserves are located in the U.S., and most of them lie in the Piceance Creek basin of Western Colorado. The Colorado oil shale outcrops on the edges of the Piceance Creek Basin. At the outcrops the shale beds are relatively thin, from 25 to 50 ft thick. In the center of the basin the oil shale is as great as 2,000 ft thick and is covered with 1,000 ft of overburden. It has been estimated that there are over 1,000 billion bbl of oil in shales having an oil content over 15 gal/ton in this basin. Oil shale does not contain free oil but an organic matter called kerogen. Kerogen yields petroleum hydrocarbons by destructive distillation. It must be heated to approximately 700F, at which temperature it decomposes into shale oil, gases and coke. The U.S. Bureau of Mines and, more recently, oil companies have conducted considerable research on surface retorting methods to economically recover oil from this shale. Another approach to exploit the oil shale deposits, in particular that portion having 1,000 ft of overburden, is to retort the oil shale in place and produce the liquid and gaseous hydrocarbons through wells drilled into the shale. Some research has been done on this approach.l,2 There are several variations to the in situ retorting approach. These variations fall into one of two groups, depending upon the geometry of the system: (1) retorting in a highly fractured or broken up matrix; (2) retorting from single fractures between production and injection wells. The latter is the group studied. Several investigators,3-6 using various assumptions, have studied flow of heat through horizontal systems. The objective of this work was to make a heat transfer study of in situ retorting oil shale by hot gas injection through wells interconnected by single vertical fractures of finite height. The oil shale thermal conductivity, thermal capacity and retorting endothermic heat losses were considered to be functions of temperature. A knowledge of the

Jan 1, 1969

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 James A. Barr

The writer's first experience with flotation was during World War I, in the bene-ficiation of Alabama graphite schist ores. One plant used a cone with a peripheral overflow; dried ore was distributed by a rotating disk onto the surface of the water. No reagents were added' The flake-graphite film floated along with some fine silica. Dewatering screens separated the flake. Naturally unit capacities were low but results were satisfactory. Minerals separation mechanical flotation machines were used in another graphite mill. pine oil was added directly to the head cells, with very good results. All the graphite concentrates from both types of flotation were carefully refined after drying by passing through burr mills, followed by very close sizing on sifters. In March 1927, the writer ran a very successful flotation test on minus 28-mesh, deslimed, Tennessee brown phosphate "sand,"† using a mechanical laboratory machine built in the shops of the Anaconda Copper Mining Co., through the courtesy of Ernest Klepetko. The machine was soon converted to a subaeration type, with improved results. This phosphate research program was greatly enlarged and led to the formation of the phosphate Recovery corporation. The development of nonmetallic flotation followed rapidly. The first flotation machine for bene- ficiation of phosphate was installed in January 1928, in a pilot mill, by International Minerals and Chemical Corporation, at Mulberry, Florida. These machines were Minerals Separation, 24-in., sub-,,,tion types, with weir control of pulp between cells. The sand bleeders were very small—about 1¼-in. diameter. As the feed flake. Is to 25 per cent plus 28-mesh material, the cells choked up frequently. This was corrected by cutting a 2 by 6-in. bleeder opening above the impellers, at grid level, which short-circuited the coarse fractions directly into the feed of the next cell. The matter of size classification and grinding was a considerable problem, which does not come within the scope of this article. Because of the troubles noted above, cascade-type roughers were installed in the second flotation plant, built about 1930. Experimental cells had been tried in 1928. General plant layout is shown in Fig. 1 and details of the cascade construction in Fig. 2. The cascade installation in plant NO. 2 gave good results and eliminated troubles due to choke-ups and coarse feed. The capacities and metallurgical results equaled those of the modified 24-in. Minerals Separation flotation machines in plant No. I The objections to the cascade installation are the floor space and mill height required. In 1939 an improved Minerals Separation machine was tested in parallel with the cascades. Extensive tests indicated

Jan 1, 1947

By James A. Barr

The writer's first experience with flotation was during World War I, in the bene-ficiation of Alabama graphite schist ores. One plant used a cone with a peripheral overflow; dried ore was distributed by a rotating disk onto the surface of the water. No reagents were added' The flake-graphite film floated along with some fine silica. Dewatering screens separated the flake. Naturally unit capacities were low but results were satisfactory. Minerals separation mechanical flotation machines were used in another graphite mill. pine oil was added directly to the head cells, with very good results. All the graphite concentrates from both types of flotation were carefully refined after drying by passing through burr mills, followed by very close sizing on sifters. In March 1927, the writer ran a very successful flotation test on minus 28-mesh, deslimed, Tennessee brown phosphate "sand,"† using a mechanical laboratory machine built in the shops of the Anaconda Copper Mining Co., through the courtesy of Ernest Klepetko. The machine was soon converted to a subaeration type, with improved results. This phosphate research program was greatly enlarged and led to the formation of the phosphate Recovery corporation. The development of nonmetallic flotation followed rapidly. The first flotation machine for bene- ficiation of phosphate was installed in January 1928, in a pilot mill, by International Minerals and Chemical Corporation, at Mulberry, Florida. These machines were Minerals Separation, 24-in., sub-,,,tion types, with weir control of pulp between cells. The sand bleeders were very small—about 1¼-in. diameter. As the feed flake. Is to 25 per cent plus 28-mesh material, the cells choked up frequently. This was corrected by cutting a 2 by 6-in. bleeder opening above the impellers, at grid level, which short-circuited the coarse fractions directly into the feed of the next cell. The matter of size classification and grinding was a considerable problem, which does not come within the scope of this article. Because of the troubles noted above, cascade-type roughers were installed in the second flotation plant, built about 1930. Experimental cells had been tried in 1928. General plant layout is shown in Fig. 1 and details of the cascade construction in Fig. 2. The cascade installation in plant NO. 2 gave good results and eliminated troubles due to choke-ups and coarse feed. The capacities and metallurgical results equaled those of the modified 24-in. Minerals Separation flotation machines in plant No. I The objections to the cascade installation are the floor space and mill height required. In 1939 an improved Minerals Separation machine was tested in parallel with the cascades. Extensive tests indicated

Jan 1, 1947

By Raymond Mancha

The purpose of an accurate underground pressure survey is to obtain a pressure gradient along the circuit or circuits under investigation. The pressure gradient shows the rate of pressure drop between various observation points along a circuit. This determines excessive resistance regions and the economic feasibility of correcting such conditions by cleaning airways, driving additional airways, or modifying existing airways. A pressure gradient is useful for predicting the effect on other parts of the circuit when adjusting the air regulation on any one split or when planning a field airshaft or slope or a new drift to the outcrop. A single-compartment airshaft often produces disappointing results because it relievcs only a part of the circuit instead of the over-all mine pressure. It is valuable to know how the circuit pressure drop is distributed. The underground pressure survey is used also to determine the friction coefficient for various types of airway. High precision work is required to establish these vital data for predicting the characteristics of mine pressure volume when projecting new mine developments. Methods Regardless of the type of instrument used to conduct a circuit pressure survey, the work should preferably be performed at a time when the mine is idle, in order to avoid air-flow disturbances from moving trips and cages or from the opening or closing of trap doors. Preferably the survey should be made when the barometer is comparatively steady, to restrict variation in the air specific weight at observation stations while the circuit is traversed. The two most commonly used instruments for underground pressure surveys are: (I) the altimeter; (2) the inclined manometer with hose extensions. The altimeter is sufficiently accurate for determining the underground pressure gradient and is preferable to the nianometer for such work because of greater flexibility and shorter time required for the traverse. With the altimeter it is possible to select more widely separated observation stations than is practical with the manometer, with its restricted hose extension lengths. The altimeter also permits easier travel along haulage roads between airway observation stations, avoiding badly obstructed airways. The inclined manometer is more reliable than the altimeter for establishing friction coefficients in mine airways. Manometer readings are unaffected by differences in elevations between stations, which require corrections to altimeter data. The manometer provides direct reading without temperature correction, which may or may not be true with the altimeter, depending upon the make of instrument used. The elimination of correction factors combined with the instantaneous, simultaneous and

Jan 1, 1947

By Raymond Mancha

The purpose of an accurate underground pressure survey is to obtain a pressure gradient along the circuit or circuits under investigation. The pressure gradient shows the rate of pressure drop between various observation points along a circuit. This determines excessive resistance regions and the economic feasibility of correcting such conditions by cleaning airways, driving additional airways, or modifying existing airways. A pressure gradient is useful for predicting the effect on other parts of the circuit when adjusting the air regulation on any one split or when planning a field airshaft or slope or a new drift to the outcrop. A single-compartment airshaft often produces disappointing results because it relievcs only a part of the circuit instead of the over-all mine pressure. It is valuable to know how the circuit pressure drop is distributed. The underground pressure survey is used also to determine the friction coefficient for various types of airway. High precision work is required to establish these vital data for predicting the characteristics of mine pressure volume when projecting new mine developments. Methods Regardless of the type of instrument used to conduct a circuit pressure survey, the work should preferably be performed at a time when the mine is idle, in order to avoid air-flow disturbances from moving trips and cages or from the opening or closing of trap doors. Preferably the survey should be made when the barometer is comparatively steady, to restrict variation in the air specific weight at observation stations while the circuit is traversed. The two most commonly used instruments for underground pressure surveys are: (I) the altimeter; (2) the inclined manometer with hose extensions. The altimeter is sufficiently accurate for determining the underground pressure gradient and is preferable to the nianometer for such work because of greater flexibility and shorter time required for the traverse. With the altimeter it is possible to select more widely separated observation stations than is practical with the manometer, with its restricted hose extension lengths. The altimeter also permits easier travel along haulage roads between airway observation stations, avoiding badly obstructed airways. The inclined manometer is more reliable than the altimeter for establishing friction coefficients in mine airways. Manometer readings are unaffected by differences in elevations between stations, which require corrections to altimeter data. The manometer provides direct reading without temperature correction, which may or may not be true with the altimeter, depending upon the make of instrument used. The elimination of correction factors combined with the instantaneous, simultaneous and

Jan 1, 1947

NEW MEMBERS The following list comprises the names of those persons who became members during the period Dec. 10, 1916 to Dec. 31, 1916. BOWMAN, Joseph V., Chem., Andes Copper Mining Co., Chanaral, Chile, South America. CALDER, NORMAN L., Min. Geol., Cia. Minera y de Fomento, Watkins, Fomento Prov. de Santa Clara., Cuba. CONRADS, RALPH A., Met. Engr., Magna Plant, Utah Copper Co., Garfield, Utah. FARR, T. H. POWERS, JR. Asst. Assayer, Argonaut Mining Coy Jackson, Cal HAURY, PETER S., Min. Engr ...Alta Loma, Cal. HOULE, ARTHUR, Supt., Shattuck-Arizona Copper Co., Box 2009, Bisbee, Ariz. LEIB, VICTOR E?, Min. Engr 4204 Ave. D, Austin, Tex. LINDSLEY, THAYER, Min. Engr 82 Beaver St.,. New York, N. Y. POTTER, OCHA Supt., Superior Copper Co., Houghton, Mich. ROCCA, BERNARD T.; Engr., Bluebell Mine, Cons. Arizona Smelting Co., Mayer, Ariz. SAFFOLD, RAY P P.'0. Box 436, Douglas, Ariz. THOMS, JAMES EZRA, Asst. Chief, Milling, -Roasting, Acid Depts., Mineral Point Zinc. Co., Depue, Ill. TOMITA, HARUYOSHI, Met. Engr., Mitsubishi Co., Osaruzawa Mine, Akita-ken, Japan.

Jan 2, 1917

NEW MEMBERS The following list comprises the names of those persons who became members during the period Nov. 9, 1918, to Dec. 10, 1918. ALBERT, EDWARD J 235 E. Upsal St., Philadelphia, Pa. BARRY, D. A Supt. of. Mines, The Big Five Min. Co., Idaho Springs, Colo. BATON, GEORGE S., Cons. Min. Engr., Baton & Elliott, 2412 First National Bank Bldg., Pittsburgh, Pa. BAXTER, HAROLD ALEXANDER, Met. Engr. & Operation Supt., Tacony Ordnance Corpn., Philadelphia, Pa. BENNETT, JOHN S., Chem. and Min. Engr Copiap6, Chile, South America. BOWDEN, MALCOLM, Min. Engr.; Efficiency Engr., Elm Orlu Min. Co., Butte, Mont. BROWN, HAROLD C 2d Lieut., A. S. A. P. BROWN, THOMAS ALBERT, Min. and Met. Engr.; Supt., The Royal Tiger Mines Co., Breckenridge, Summit Co., Colo. BROWN, WALTER S., Investigator, New Jersey Zinc Co. (of Pa.), Palmerton, Pa. BURDETTE, R.. S Capt., Ord. Dept., U. S. A. CALLANDER, IRA C., Asst. Supt., Gauley Mountain Coal Co., Jodie P. 0., Fayette Co., W. Va. COLLINS, J. W., Foundryman, The Aluminum Casting's Co., "L" Plant, Cleveland, Ohio,

Jan 1, 1919

By John D. Wiebmer

There are those in the Colstrip, Mont., area who can still remember the opening of the Rosebud mine in 1923. For 35 years it was a steady employer of 80 or 90 residents who produced coal for the railroad. In 1958, though, mining ceased as diesel locomotives supplanted steam engines. The mine was purchased in 1959 by Montana Power, the parent of Western Energy Co., and production resumed in 1968. Long Construction Co. was chosen as operator of the mine equipment. At that time, reserves appeared virtually unlimited. The thick Rosebud seam coursed through alternate sections of railroad holdings and federal land-then came the federal moratorium on coal leasing in 1971. About the time Western Energy completed the special leasing procedure to extend reserves from an existing mine, a new federal monkey wrench was thrown into the works with passage of the Surface Mining Control and Reclamation Act of 1977.

Jan 12, 1979

NEW MEMBERS The following list comprises the names of those persons who became members during the period of Aug. 10, 1917, to Sept. 10, 1917. ADKERSON, J. CARSON, Mgr., Stockwood Realty Corporation, Inc. Woodstock, Va. ARAKAWA, EIJI, Min. & Met. Engr., Min & Met. Dept., Imperial Univ., Kyoto, Japan. BAINS, THOMAS MELLOR, JR Major, Officers' Reserve Corps, Presidio, Cal. BARTON, Louis ARTHUR.. , . Vice-Pres., Adbar Development Co., Dewed, Minn. BLACKSTONE, ALEXANDER J....Asst. Engr., Honiestake Min. Co., Lead, SO: Dak. BOGARDUS, CHARLES EUGENE, Assayer & Chem., Bogardus Testing Laboratories 90 Columbia St., Seattle; Wash. BOISE, DAVID WELLS Chief Clerk, Chino Copper CO., Burley, New Mex. BREEDING, FRANK OWEN Assayer, Eden Min. CO., Bluefields, Nicaragua. BRUYERE, ALAN, Petroleum Geol., Producers' Oil CO., Box 96, Shreveport, La. BUTTS, ALLISON, Asst. Editor, The Mineral Industry, Lehigh Univ., So. Bethlehem, Pa. CALVERT, CLARENCE E Safety Engr., Anaconda Copper Min. CO., Butte, Mont. CHARLTON, HARRY.... Min. Engr, Commonwealth Edison CO., Taylorville, 111. CLAGUE, HERBERT NADEN, Surveyor.. Duncan, V. l., British Columbia, Canada. CLOSE, FREDERIC BAGLEY The Rampart, Los Angeles, Cal. COLLIER, DAVID HENDERSON, Mine Supt., Thumb, Butte Mines Co., Kingman, Ariz.

Jan 10, 1917

By Charles Sanford, William B. Schmidt, Eugene Moroni, John Murphy, Richard Bullock

An industry/government team sponsored by the Dept. of the Interior completed a study tour of the underground coal mining industries in Great Britain and Germany to review new and emerging coal mining technology. The group found that differences in tradition, mining conditions, and industry capabilities have led to different approaches in technological developments, many of which have the potential for application in U. S. mining. Both countries are working to improve materials and procedures for roadside pack wall. The British are developing a pump-packing system in which bentonite, water, stone, and a special cement are pipelined to the pack area to form a low strength compressible pack wall. The German industry is using anhydrite or blotzdammer to form a high strength pack wall. Both countries are using full-face tunnel-boring machines. The German industry has had considerable success with shield-type longwall supports.

Jan 1, 1977

NEW MEMBERS The following list comprises the names of those persons who became members during the period Jan. 10, 1919, to Feb. 10, 1919. ADAMS, FRANCIS SPEARMAN, Supt., Power Dept., Anaconda Copper Min. Co.; Anaconda Mont. ALDERSON, G. E., Min. & Met. Engr 1317 Sloane Ave., Lakewood, Ohio. BENJOVSKY, T. D., Min. Engr., Cons. & Constr 2045 Vine St., Denver, Colo. BROPHY, OSCAR, Met 1523 S. Broad St., Philadelphia, Pa. BUTTRAM, FRANK, Chief Geol., Fortuna Oil Co., 424 Liberty National Bank Bldg., Oklahoma City, Okla. COCHRAN, R. B., Mine Supt., The Teziutlan Copper Co., Aire Libre Puebla., Mexico. CONNAR, T. C., Civ. & Min. Engr. & Geol.; Chief Engr., Zanesville Coal Co., Zanesville, Ohio. DAVE, E. O Capt., Co. A, 212th Engineers, Camp Devens, Mass. FOLEY, CHARLES B., Electro-Met., Martin Rockwell Corpn., 347 Madison Ave., New York,. N. Y. HOSFORD, WILLIAM F., Asst. Tech. Supt., Western Electric Co., Inc., Hawthorne Station, Chicago, Ill. HOSTER, M. T., Supt., French Creek Mines, E. & G. Brooke Iron Co., St. Peters, Pa. KAWASAKI, SHIGETARO, Chief Geol., Geological Survey of Chosen, Government General of Chosen, Keijo. Korea.

Jan 3, 1919