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By Francis A. Pocock

The writer is continually asked, if this electricity:is all you claim for it, why do not the mines put it in and use it? The best answer was given by Mr. John Fox Tallis, in his paper read before the South Wales Institute of Engineers in 1888, namely, that the reasons are similar to those which have prevented the more general employment of other systems of haulage. Managers, as a rule, are " not experienced mechanical engineers; neither are they all versed in electrical engineering." It may be said that there are a number of " able and practical electrical engineers who could do the work; but those electrical engineers are not conversant with the practical routine of colliery work and are, therefore, placed at a disadvantage by not knowing the actual requirements of mining engineers, and the many little difficulties to be met and contended with in underground workings; and, until mining engineers have acquired the necessary knowledge and a confidence in electricity, it is only natural that they will continue to follow the beaten path." In the above remarks, Mr. Tallis has hit the nail on the head. In the face of the partial failure, financially, of the haulage-plant which the Union Electric Company of Philadelphia had set to work at Lykens Valley, Pa., an electric haulage-plant was installed near Scranton, Pa. The question was not whether electricity could do the work, but whether any electrical company knew enough about the practical difficulties to attack and overcome them. That point being settled, the remainder was easy. The contract for the Erie Colliery haulage-plant was signed in January, 1889. This colliery is owned by the Hillside Coal and Iron Company, Mr. Samuel Hines, President, and Captain W. A. May, Superintendent. The company has been using arc-lamps in its breakers for three years. It is the only company in the Lackawanna Valley which has had enterprise enough to do so. Consequently, it was acquainted

Jan 1, 1890

By Joseph E. Pogue

Proration in the petroleum industry has come to mean a method for curtailing the production of crude petroleum by artificial effort, and it is in this sense that the term is employed throughout this paper. Although a contrived curb on supply has been invoked at various times in the past in particular fields and to meet specific situations, it is not until the past few years that this procedure has become general and assumed a dominant role in the oil business. In the sense that we now understand it, proration had its inception in the Seminole area of Oklahoma in 1927, from which time and place the practice spread to include practically all the flush oil fields of the country, especially those of California, Kansas, Oklahoma and Texas. At present there is perhaps no phase of the oil business that commands more attention than proration, nor one that engages more time and effort on the part of executives in the business. The practice of proration, indeed, has not only become an integral part of the policy of most companies and operators, but it has also taken on the aspects of a "movement" involving two schools of thought with considerable feeling, and at times some bitterness, on both sides. In this atmosphere it is difficult to find calm, dispassionate consideration of proration, for most discussions are either vigorous exhortations by its proponents, or else sharp condemnations by its opponents; although it appears that the majority of the industry is clearly "in favor of" proration. It is hoped that this analysis will be taken as an attempt to appraise the movement as an economic force, without bias and without regard to the incidence of the conclusions upon any preconceptions that the industry may entertain. Evolution of Proration To appreciate the causes that brought proration into being, it is necessary to view briefly the development of the petroleum industry over the past twenty years, approximately the span of the gasoline era., For the first ten years of the period, the industry was seeking capital

Jan 1, 1932

By F. Cadena

Hiwassee Darn, now under construction by the Tennessee Valley Authority on the Hiwassee River, a tributary of the Tennessee River, will require aggregate for approximately 800,000 cu. yd. of concrete. Near the damsite deposits of natural sand or gravel are not available and graywacke, a rock that is found in abundance, suggested itself as a likely source of manufactured aggregate. Graywacke is a metamorphosed sandstone composed principally of a mixture of quartz (65 per cent), mica (25 per cent), and feldspar (10 per cent). Other minerals are present in negligible amounts. The rock varies in different parts of the quarry from very fine to a coarse grain containing particles of about ¼ in. maximum size, although the bulk of the deposit is medium grain. Extensive tests showed that graywacke would be suitable as a source of both coarse and fine aggregates. The aggregate plant available for use at Hiwassee Dam consisted of the coarse-aggregate and sand plant used on the Norris project. The coarse-aggregate plant had also been used at Chickamauga Dam. Although most of this plant equipment is now in use at Hiwassee, the present flowsheet is not only different from that at Norris and Chickamauga but is also unique as compared to the flowsheet of the average crushed-stone aggregate plant. It is hoped that this paper will show the importance of proper arrangement of equipment if the optimum in flexibility and capacity is to be attained. Flowsheet Rock is ioaded by 3-yd. electric shovels into 12-yd. dump trucks, which carry the rock to the primary crusher, a 42-in. Superior McCully gyratory unit set at 4¾ in. (Fig. 1). The primary crusher discharges directly onto a 42-in. inclined belt conveyor, which carries the product to a surge storage pile with a maximum live storage capacity of approximately 3000 tons. A concrete tunnel under this storage pile houses the feed end of a 36-in. belt conveyor (conveyor B) fed by a 36 by 66-in.

Jan 1, 1942

By Günter Petzow, Siegfried Steeb

DURING an investigation of the U-Co-A1, U-Ir-A1, and U-Ni-A1 ternary systems, three previously unknown phases have been identified which correspond to the phases UCoA1, UIrA1, and UNiA1, and which be- long to the C22 (Fe2P) type (P 6 2m). In the following the structure determination of the new ternary phases is reported. The alloys have been prepared in an arc furnace under purified argon from 99.97 wt pct U, 99.83 wt pct Co, 99.99 wt pct Al, 99.95 wt pct Ni, and 99.97 wt pct Ir. The pellets obtained were bright and brittle; chemical analyses agreed with the nominal compositions. To obtain equilibrium, the samples were annealed in evacuated quartz capsules at 950°C for 30 hr and then quenched in water. Guinier photographs were processed and evaluated according to a method already described previously.1,2 The hkl's, measured and calculated sin2 6 values, and in the case of UCoAl only calculated and estimated intensities, are given in Tables I to 111. Lattice parameters refined according to the least-squares method and the respective mean-square variations are presented in Table IV. Lattice parameters, especially the c/a ratio, lead to the assumption that the three phases are crystallizing in the C22-type structure. For the calculation of the intensities given in Table I, the atomic positions recently reported by wyckoff3 have been accepted for the C22 (Fe2P) type. The uranium atoms were assumed to be in phosphorus sites; furthermore the scattering amplitudes of the boron atoms have been averaged in the stoichiometric formula UB2 according to atomic percentages; i.e., for these atoms a statistical distribution on the iron sites was assumed. The two smallest distances between a uranium and

Jan 1, 1967

By E. L. Bruce

GOLD occurs ill many mineral deposits in the rocks of the Canadian Shield. It is present in the ores of many base metals and a considerable quantity is recovered as a by-product from the production of copper at Noranda, of nickel and copper at Sudbury and of copper and zinc at Flinflon. But the greater part of the gold production of Canada is from deposits in which gold is the only metal of value. No gold is obtained from placer deposits within the borders of the Canadian Shield. A brief review of the geological relations of some of the gold deposits of the Canadian Shield will be presented in an attempt to explain certain associations. Only those which are being worked for their gold content will be considered and descriptions will be confined to representative types of deposits, chiefly those of major importance; a few others, differing in certain features from those of the older and larger mines, will be included in order to illustrate the general conditions in which gold occurs in these ancient rocks. Brief summaries will be given of the geological relations of the Beattie and Siscoe mines of northern Quebec, of the mines of the Porcupine and Kirkland Lake areas of northeastern Ontario and of the Howey, Central Patricia and Little Long Lac mines of northwestern Ontario. Genetic relations to igneous rocks of granitic composition, outcropping in the vicinity, have been assumed for many of these deposits. Undoubtedly the ore minerals have been derived from igneous sources and, for some occurrences, there is evidence suggestive of genetic relationship between the ore bodies and neighbouring intrusive rocks. During the past few years, however, many investigators have expressed doubt of the genetic relationship of certain ore bodies to igneous masses near which they occur. As will be seen from references in the following descriptions the importance of the structural conditions in localizing deposition has been realized. This is pointed out for Canadian pre-Cambrian gold deposits by E. T. Dougherty, who also refers to the

Jan 1, 1937

By Karl Sundberg

INTERESTING results were recently obtained in geophysical prospecting at the Questa mine of the Molybdenum Corpn. of America in New Mexico. This paper describes that survey, which was carried out during October and November, 1927, by the Swedish American Prospecting Corpn. It is hoped that the paper will make it possible for the mining man to form an opinion of the applicability of geophysical prospecting under difficult conditions, showing, as it does, the results when prospecting for small small orebodies with comparatively poor conductivity, in a region of rough topography. Some principles underlying electromagnetic prospecting not known to be published previously will also be given in an elementary way, with special attention to the general structure of the electromagnetic field. GEOLOGICAL CONDITIONS AT QUESTA The property is situated in the Taos range of the Rocky Mountains in northern New Mexico. About this region, L. C. Graton says:1 The main range is made up of pre-Cambrian granites, gneisses and schists but in the vicinity of Red River igneous rocks of later age are present almost to the exclusion of the older series. These younger rocks are divisible into two groups. The older of the two, probably pre-Tertiary age, is represented by large intrusive masses of monzonite porphyry, usually containing considerable quartz. The more recent group comprises intrusive' and probably effusive dark-colored andesites and coarse andesitic breccias, some of which contain fragments of the monzonite; there are also flows of rhyolite and beds of rhyolite breccia. The evidence regarding the relative age of the andesite and the rhyolite is not wholly satisfactory, but there is little doubt that the andesite is the older. The ore deposits, although occurring more commonly in the monzonite porphyry than in the rhyolite, nevertheless are believed to be genetically related to the rhyolite. They certainly cut the rhyolite or andesite in places, and hence fall in the late Tertiary.

Jan 1, 1928

By Sir Robert A. Hadfield

The Hadfield method of producing sound steel ingots has been the subject of a paper read before the Iron and Steel Institute, so that it will be unnecessary to describe it fully here. The object of the method is to make poseible the production of steel ingots in which the pipe is almost entirely obliterated, and it is applicable particularly to the production of sound ingots, from which good rails could be rolled. The method in brief consists in casting the ingots on cars, usually with the small end down. Each ingot mold is provided with a sand top, rammed up in the well-known manner. After the mold is filled to the desired height with steel, a layer of slag about 0.5 in. thick is placed upon it and the balance of the mold is then filled with charcoal. Then, through suitable piping, an air blast is directed in numerous jets upon the charcoal, which is burned thereby, the combustion supplying addi, tional heat to the top of the ingot, which helps to keep the top fluid and to retard its solidification, while the lower parts are rapidly losing heat by its transfer to the mold. By one plan the ingots are cast in molds placed upon bogies, movable trucks, or platforms, in the position A, Fig. 1. The ingots are cast vertically on bogies, say four or more ingots on each bogie, as may be found most convenient, and the upper surface of the steel is maintained in a molten condition during the transit of the ingots from the casting pit to the stripper. This is effected by a series of air pipes, for example, three in number, with jets or holes on the under surface of such pipes, placed preferably horizontally, arranged in such a manner as to cause jets of air to impinge on the upper surface of the ingots. These holes or jets are made throughout the entire length of the overhead pipes, the length of such pipes being

Jan 1, 1914

By B. Woyski

Many writers, in discussing defects caused by oxidation and gassing of bronzes and red brasses advocate substantially the same cure for both. But from its nature, oxidation cannot take place if there is an excess of fuel in the furnace, while the gases absorbed by some alloys are products of incomplete combustion of the fuel. Hence the metal can be either oxidized or gassed, but it is doubtful whether these actions can take place simultaneously. Oxidation can be easily overcome by the use of deosidizers or it may be avoided by protecting the molten metal with suitable fluxes. Absorption of gascs is more difficult to overcome: the regulation of the air and fuel, so as to produce complete combustion, and the protection of the bath by mineral fluxes arc the most important factors. Gas expulsion, resulting in gas holes, porosity, unsoundness, and swollen or cauliflower-headed risers, is said to have several causes. One writer1 lists the most common causes in the order of their importance, as follows: Superheated metal, dirty or slaggy furnace conditions, using metals low in quality or those previously subjected to bad melting practice, poor grade of fuel, use of newly lined or damp ladles, indiscriminate mixing of scrap or illogical combinations of metal. Superheating the metal usually occurs when the heat is ready to be poured but for some reason must be held in the furnace. In this case, a careful furnace tender tries to avoid overheating the metal by keeping a mild fire; that is, a reducing fire which, unfortunately, results in gassing the metal. A dirty, slaggy furnace may result in gassing the metal by retarding the heating and prolonging the time necessary to bring the metal to the proper temperature, thereby increasing the chances of gassing in uncertain furnace atmosphere. It is doubtful whether rnetals of low quality have anything to do with gassing molten metal, except, possibly in the case of metals containing

Jan 1, 1923

By Leo P. Tarasov

Magnetic torque studies of ferromagnetic single crystals have been carried out in a number of laboratories during the last decade&apos;s2 and some work has been reported on polycrystalline material showing preferred orientation. Goss3 used the method extensively in developing electrical sheet with desirable magnetic properties, but he used it as a control rather than as a means of studying the texture. Bozorth4 made a quantitative correlation of a torque curve he obtained from some cold-rolled iron with the texture as determined from X-rays, but did not extend his studies beyond the one specimen. Other studies, which have been reported from time to time2,5 have also been incomplete in the sense that no effort was made to study a whole series of samples, differing only in degree of cold reduction or in the annealing temperature, in order to ascertain the effect of such treatments on the texture as revealed by torque measurements. It is the purpose of this investigation to make such a study, mainly in order to see how useful the method can be made when used under favorable circumstances and to find what kind of a correlation can be expected between magnetic and X-ray studies of texture. Before proceeding further, it is desirable to say a little about single crystals, so as to make clear the concepts involved in magnetic torque measurements. Magnetic Torque Method It is fairly well known nowadays that single crystals of ferromagnetic substances have directions of easy magnetization and of hard magnetization. In Fig. 1 are reproduced typical magnetization curves for a single crystal of iron, which show that in a < 100 > direction saturation occurs at low fields compared to those required to saturate the same crystal in a <110> or a <111> direction. (The magnetization intensity I is defined by the equation B = H + 4pI.) At fields high enough to

Jan 1, 1939

By R. L. Templin

In treating a cast metal by any working process such as rolling, drawing or forging, variations in the conditions present in the remelting, casting, chilling and preheating of the initial ingot will certainly have some effect on the physical properties of the final product. In considering the effects of cold working on the physical properties of metals, however, it will be assumed that these factors, being controlled according to best practice, will remain constant and therefore may be neglected. Starting with such a uniform metal ingot, the next operation in the production of wrought metal involves hot working by rolling, forging or extrusion so as to produce a slab, billet or bloom. This working must be sufficient to produce substantial grain refinement and minimize any defects occurring in the initial ingot. Even such a hot-worked product is not suitable as a starting material for determining the effects of cold working because it contains internal strains analogous to those resulting from cold working. It is necessary, therefore, to supplement the hot working with a considerable amount of cold working, followed by a proper annealing in order to obtain a material suitable for use in defining the effects of cold working on the physical properties of a metal. That is, if the effects of cold working are to be evaluated accurately it is necessary to have other effects at least constant if not absent. Such material, unfortunately, cannot always be obtained in commercial practice but the requirements just indicated certainly represent the desired goal; this goal has been attained in the treatment of some metals, one being aluminum. Factors That Must Be Considered Simultaneously with Cold Working So many other factors affect the physical properties of a metal that it is necessary to consider these factors simultaneously with cold working; their effects vary in magnitude with the amount of cold work present. The most important of these factors are: (I) chemical composition, (2) structure, (3) temperature of working, (4) character of working, (5) rate of working, and (6) methods used for measuring results. For

Jan 1, 1930

By B. D. Thomas

GRAVITY concentration is a general term designating processes for separating and sorting granular material by means of forces that depend on the density, size and shape of the particles. When these forces are applied to the particles the latter are caused to move, those of a given density along one path and those of a different density along another, until ultimately they are sufficiently separated to be removed from the operation of the process. The forces producing this separation are in general complex and, unfortunately, no completely rigorous analysis of them has as yet been devised. The science of the hydrodynamics of viscous fluids deals with the little that is known about the problem. Every observer of nature is familiar with the fact that an object moving in a fluid encounters a force of resistance. We have only to walk against a brisk wind or stir a cup of coffee, or observe the slow fall of a grain of sand in water, to experience directly the fact that such forces exist. The exchange of force between an object and a fluid in which it is moving operates on the fluid as well as on the object. Thus a sailboat may be set in motion by the force exerted by the wind on the sail; but the sail also deflects the wind-furthermore, the water in which the boat floats is set in motion by the force exerted by the boat as it cleaves through the water. The wind is thus enabled to do work on the water through the intermediary of the boat. In general, an object moving through a fluid encounters a force that opposes the motion and also acts to change the motion of the fluid. In gravity concentration we are dealing with this force of resistance acting on the granular particles that are to be separated. Furthermore, the motion induced in the fluid by a particle will in turn affect the motion

Jan 1, 1943

By C. D. Young

IN an effort to employ cast steel of a stronger structure than that found in the annealed steel castings, the possibilities of heat treatment which will increase the strength without materially decreasing the ductility may be resorted to. The following abstracted report (which is a brief outline of what has already been clone by the Pennsylvania Railroad Co. at its shops and Test Laboratories at Altoona, Pa.) is of material interest, as it indicates what may be done with steel castings when properly treated, thereby permitting in railway service greater strength of cast steel parts without any increase in weight or space. The question of the heat treatment of alloy steel castings is not taken up in this paper. The obscurity formerly surrounding the heat treatment of steel has been for the most part removed by the development of our knowledge of the critical points of steel, pyrometers, furnace construction, and the testing of the finished product. The operations of the heat treatment proper will be taken up under the heads of (1) heating for quenching; (2) quenching; (3) drawing. (1) Heating for Quenching.-Heating for quenching is best conducted slowly, especially in the case of castings of variable thickness. Cracks may occur either in heating or in cooling, clue to different temperatures at different points of the casting. The castings should be thoroughly soaked at the maximum temperature (generally 1,500° to 1,600° F.), 1 hr. being sufficient for sections 1 ft. in thickness. The minimum temperature which will produce the desired hardening effect will, in all cases, be found to be the most satisfactory, as the grain coarsens when the critical range is exceeded to too great an extent. All temperatures should be governed by a checked pyrometer with the hot junction to the heated object, and with several couples in a large furnace to insure a uniform temperature.

Jan 2, 1914

By John C. Branner

Within a couple of years I have received many inquiries in regard to the manganese-mines of Brazil. These inquiries were doubtless directed to mc because I had lived and traveled in Brazil for more than eight years, and was therefore supposed to be pretty well acquainted with its geology and mineral resources. Somewhat to my chagrin, I not only knew nothing of manganese-mines in that country, but I had never before heard of the mineral having been found here in quantity, and I did not even know in what State the mines were located. The present summer found me in Brazil again, trying to finish up some of my early geological investigations along the northeast coast, and I have used the occasion to find out something about the manganese-deposits. Very little is known of these mines, even in Brazil. While at Pernambuco I was told that they were in the distant interior of the State of Bahia. In August I reached Bahia, and there I found out, concerning the mines and their geology, enough to be worth telling for the benefit of those interested in the mining or using of this mineral. Thus far, all the manganese-ore shipped from this State has come from two mines, the principal one of which is known as the Pedras Pretas mine. This was the first mine opened, is the best developed, and was the original discovery; the second one is on an adjoining tract, and the general geology and natural conditions are about the same in both. The Pedras Pretas mine is on the Nazareth-Amargosa railway, twenty-six kilometers west of the town of Nazareth, which is on tide-water, at the head of navigation, and is reached from the city of Bahia by a small side-wheel steamer that runs across the bay of Bahia and up the Rio Jaguaripe

Jan 1, 1900

By Leo P. Tarasov

Magnetic torque studies of ferromagnetic single crystals have been carried out in a number of laboratories during the last decade&apos;s2 and some work has been reported on polycrystalline material showing preferred orientation. Goss3 used the method extensively in developing electrical sheet with desirable magnetic properties, but he used it as a control rather than as a means of studying the texture. Bozorth4 made a quantitative correlation of a torque curve he obtained from some cold-rolled iron with the texture as determined from X-rays, but did not extend his studies beyond the one specimen. Other studies, which have been reported from time to time2,5 have also been incomplete in the sense that no effort was made to study a whole series of samples, differing only in degree of cold reduction or in the annealing temperature, in order to ascertain the effect of such treatments on the texture as revealed by torque measurements. It is the purpose of this investigation to make such a study, mainly in order to see how useful the method can be made when used under favorable circumstances and to find what kind of a correlation can be expected between magnetic and X-ray studies of texture. Before proceeding further, it is desirable to say a little about single crystals, so as to make clear the concepts involved in magnetic torque measurements. Magnetic Torque Method It is fairly well known nowadays that single crystals of ferromagnetic substances have directions of easy magnetization and of hard magnetization. In Fig. 1 are reproduced typical magnetization curves for a single crystal of iron, which show that in a < 100 > direction saturation occurs at low fields compared to those required to saturate the same crystal in a <110> or a <111> direction. (The magnetization intensity I is defined by the equation B = H + 4pI.) At fields high enough to

Jan 1, 1939

By F. Cadena

HIWASSEE Dam, now under construction by the Tennessee Valley Authority on the Hiwassee River, a tributary of the Tennessee River, will require aggregate for approximately 800,000 cu. yd. of concrete. Near the damsite deposits of natural sand or gravel are not available and graywacke, a rock that is found in abundance, suggested itself as a likely source of manufactured aggregate. Graywacke is a metamorphosed sandstone composed principally of a mixture of quartz (65 per cent), mica (25 per cent), and feldspar (10 per cent). Other minerals are present in negligible amounts. The rock varies in different parts of the quarry from very fine to a coarse grain containing particles of about 1/4 in. maximum size, although the bulk of the deposit is medium grain. Extensive tests showed that graywacke would be suitable as a source of both coarse and fine aggregates. The aggregate plant available for use at Hiwassee Dam consisted of the coarse-aggregate and sand plant used on the Norris project. The coarse-aggregate plant had also been used at Chickamauga Dam. Although most of this plant equipment is now in use at Hiwassee, the present flowsheet is not only different from that at Norris and Chickamauga but is also unique as compared to the flowsheet of the average crushed-stone aggregate plant. It is hoped that this paper will show the importance of proper arrangement of equipment if the optimum in flexibility and capacity is to be attained. FLOWSHEET Rock is loaded by 3-yd. electric shovels into 12-yd. dump trucks, which carry the rock to the primary crusher, a 42-in. Superior McCully gyratory unit set at 4 ¾ in. (Fig. 1). The primary crusher discharges directly onto a 42-in. inclined belt conveyor, which carries the product to a surge storage pile with a maximum live storage capacity of approximately 3000 tons. A concrete tunnel under this storage pile houses the feed end of a 36-in. belt conveyor (conveyor B) fed by a 36 by 66-in.

Jan 1, 1939

By B. Woyski

Many writers, in discussing defects caused by oxidation and gassing of bronzes and red brasses advocate substantially the same cure for both. But from its nature, oxidation cannot take place if there is an excess of fuel in the furnace, while the gases absorbed by some alloys are products of incomplete combustion of the fuel. Hence the metal can be either oxidized or gassed, but it is doubtful whether these actions can take place simultaneously. Oxidation can be easily overcome by the use of deosidizers or it may be avoided by protecting the molten metal with suitable fluxes. Absorption of gascs is more difficult to overcome: the regulation of the air and fuel, so as to produce complete combustion, and the protection of the bath by mineral fluxes arc the most important factors. Gas expulsion, resulting in gas holes, porosity, unsoundness, and swollen or cauliflower-headed risers, is said to have several causes. One writer1 lists the most common causes in the order of their importance, as follows: Superheated metal, dirty or slaggy furnace conditions, using metals low in quality or those previously subjected to bad melting practice, poor grade of fuel, use of newly lined or damp ladles, indiscriminate mixing of scrap or illogical combinations of metal. Superheating the metal usually occurs when the heat is ready to be poured but for some reason must be held in the furnace. In this case, a careful furnace tender tries to avoid overheating the metal by keeping a mild fire; that is, a reducing fire which, unfortunately, results in gassing the metal. A dirty, slaggy furnace may result in gassing the metal by retarding the heating and prolonging the time necessary to bring the metal to the proper temperature, thereby increasing the chances of gassing in uncertain furnace atmosphere. It is doubtful whether rnetals of low quality have anything to do with gassing molten metal, except, possibly in the case of metals containing

Jan 1, 1923

By P. Nicholls

THOUGH the burning of fuels extends far back into antiquity, and though fuel beds are the most common and widely distributed example of chemical actions and engineering practice, there has been little attempt to group fuel beds by types or to define the principles associated with them. This paper does not profess to cover completely the subject of fuel beds. It suggests some of the over-all principles of the two more com-mon types. No new investigational data are included, but the deduc-tions are largely based on a recent publication of the U.S. Bureau of Mines1. DEFINITION OF TYPES There are three primary types of fuel beds: (1) Underfeed, in which the fuel and the air move in the same direction; (2) overfeed, in which the fuel and the air move in opposite directions; (3) crossfeed, in .which the fuel and the air move at right angles to each other. The principle that fixes the type is the relation between directions of the flow of fuel and of air. Fig. 1 shows the three types diagrammatically. All other types are compounded of these three in a simple or more or less complex manner. It does not follow that these three type designations are limited to the methods used in representing them in Fig. 1; they may be turned in any direction, and as long as the relative directions of the fuel and air are the same the type is not changed. For example, A as shown resembles a pot-type stoker, but the air and fuel can move downward as in the so-called smokeless heating boiler furnace. Also, C can be placed hori-zontal, as in chain-grate stokers. For this reason, the terms used to designate the three types are not all that could be desired; more logical ones could be coined, but those used probably are satisfactory until the discussion of fuel-bed types becomes more common.

Jan 1, 1935

By Frederic H. Lahee

The purpose of this paper is to demonstrate the similarity of the oil-producing structures in the Mexial fault zone, and to show how the apparently very irregular well logs in these fields may be use? for the practical interpretation of subsurface conditions. The Mexia oil field, in Limestone County, Tex. (Fig. 1) is closely associated with a fault that trends about 30" east of north and has a displacement of between 200 and 400 ft., with downthrow on the west. Minor slips accompany this major fault, some being roughly parallel to the main break while others are transverse to it. These faults belong to the so-called Mexia fault zone, a belt of fracturing that has been traced in its characteristic features southward to near Kosse, 15 miles south of Groesbeck, in southern Limestone County, and northward at least as far as the Trinity River at the eastern border of Navarro County, and possibly as far north as Hunt and Hopkins counties.2 The Balcones fauil zone, from 30 to 40 miles west of the Mexia fault zone, differs from the latter in that its principal displacement is a downthrow on the east. In this respect, it is exactly the opposite of the Mexia displacement. Between these two zones of major faulting lies a great down-dropped block, or graben, which is broken by numerous minor faults. Oil Fields Associated with Mexia Fault Zone When speaking of oil fields associated with the Mexia fault zone, we refer only to those now producing from the Woodbine sand. In this category belong the Mexia, Currie, Old Richland or Seay-Cranfill, Powell, and New Richland fields, named in the order of their discovery (see Fig. 1). Subsequent development may prove that the gas found in the Boyd Oil Co.&apos;s Connor well, north of Kerens, is coming from another pool in the same fault zone.

Jan 1, 1925

By Oliver C. Ralston

THE two chemical compounds, natural sodium carbonate and sodium sulphate, in their anhydrous condition are dealt in as "soda ash and "salt cake”-names from an earlier day that are not as precise as the present accepted terminology. Once a large part of the sodium carbonate recovered was in the ash of seaweed, so it was logically called soda ash, and the corresponding potassium carbonate, once mainly recovered from wood ashes, was called potash. The term "salt cake" was applied to the sodium sulphate resulting from interaction of sodium chloride with sulphuric acid or sodium bisulphate, to form hydrogen chloride gas and an anhydrous cake of sodium sulphate. It was called "salt cake" and also "glassmaker&apos;s salt cake" because much of it was used in the production of glass. The two salts occur in nature in a variety of forms, but whereas an- hydrous sodium sulphate (thenardite) is fairly common, the anhydrous normal sodium carbonate, Na2CO3, is almost never found in nature. The monohydrate (thermonatrite), Na2CO3.2H2O, is seen occasionally, but it is never a major constituent in natural "soda" deposits. The high solubility of normal sodium carbonate is one reason for this. While both compounds occur widely in brines, the solid salts found in nature are usually trona (Na2CO3.NaHC03.2H2O) and thenardite (Na2SO4). The natural brines containing workable quantities of the two sodium salts are largely found in the arid and semiarid portions of the western United States and other countries. The classical discussion of the resources of these brines are those of Clarke,5 Chatard.4 Packard,19 Gale,11 and Wells.28 From North Dakota to California and from Arizona to the Canadian provinces of Alberta and Manitoba, saline lakes, dried-up lakes, playas, and similar land-locked depressions contain accumulations of saline matter. Sodium chloride is the predominant salt but some of the lakes contain predominantly either sodium carbonate or sodium sulphate. Often sodium carbonate

Jan 1, 1949

THE story of Miami really is two stories. First, that of an excellent Porphyry Copper mine, ably managed as a business enterprise, and always among the leaders in technical progress. Concentrating its first ore in 1911, it had by 1925 paid dividends totaling $30,000,000 or $40 per share on stock that had cost the public $5 per share in March, 1908. The ore, containing 2.5 per cent copper at the start, had become progressively leaner but the recovery had tended to improve. Production costs had gone up during the World War and the early post-war period; and had come down again. In all these respects it had followed the norm. If the mine had been abandoned as exhausted and the company had been liquidated late in 1925 (a program that had been given earnest consideration in 1924), Miami would have gone down into history a first-rate mining venture; as an active and progressive participant in the great Porphyry achievement. But Miami was not liquidated in 1925; instead it started to write the record of its second and really amazing story. Near the old mine was a large body of low-grade ore containing, in place, less than 20 lb. of copper to the ton, and without, incident- ally, any considerable sweetening of gold and silver. Any method of underground mining that was cheap enough would certainly entail some dilution, so that ore as sent to the concentrator necessarily would average much less than 20 lb. As a matter of record, the average for 1929 was 16.6 lb., from which 11.726 lb. was recovered as concentrate. As already said, the exhaustion of the older orebody during 1925 was foreseen; but in 1924 the decision was reached to enlarge the concentrator and develop a new mine. An expenditure of $2,500,000 was entailed in this program. By October, 1925, the

Jan 1, 1933