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By Benjamin N. Webber

THE peninsula of Nicoya contains virtually all of the known manganese deposits of Costa Rica. These are south and west of the Tempisque River, which flows across the peninsula near its juncture with the mainland. This peninsula forms the westernmost part of the province of Guana¬caste, which is the northern of the two Pacific Coast provinces of Costa Rica. The larger villages are connected by ox-cart roads and trails. The area may be covered on horseback without difficulty except during the rainy season, when rivers are in flood and difficult to ford. This is particularly true of the Rio Seco-Guayjiniquil area, where there are no inhabitants and few open trails through the tropical jungle. Santa Cruz and Sardinal are served by the Taca Airlines, two planes a week from San Jose and Puntarenas. The port of Puntarenas has excellent loading facilities but none are available nearer the manganese districts; there ore must be lightered to vessels standing offshore. PHYSIOGRAPHY In Costa Rica there are three physiographic divisions: (I) the central plateau (Mesa Central), a somewhat dissected lava platform upon which are superimposed volcanic peaks, some of which are still active; (2) the Atlantic lowlands and (3) the Pacific lowlands. The peninsula of Nicoya and the larger part of the province of Guanacaste lie within the Pacific low lands. The term "lowland" indicates relation to the central plateau, as the peninsula of Nicoya is largely mountainous. The mountains of Nicoya form the southern extremity of a range of low hills, which are almost continuous along the Costa Rican coast to the Nicaraguan border. The coast line shows evidence of subsidence. The Gulf of Nicoya obviously is the drowned valley of the Tempisque River. The west coast of Nicoya shows many rocks, shoals, bays, inlets and small islands as evidence of a sea encroachment. The altitude of the manganese deposits ranges from 0 to 800 ft. Topography is of the mature type of wide valleys and low ,hills, often with abrupt slopes. The climate is tropical and humid; rainfall of 125 in. falls largely between Sept. I and Jan. I. Vegetation often is very dense, the Rio Seco-Guayjiniquil area being truly tropical jungle, containing many hardwoods. HISTORY AND PRODUCTION The production of manganese ore in Costa Rica apparently dates from the first World War. It reached a peak of about 10,000 tons in the year 1919, then declined rapidly. Evidence of this period of prospecting has rotted away or been swallowed by the jungle. The war now in progress apparently revived the interest in Costa Rican manganese and has encouraged further prospecting. Deposits long known have been redenounced and trails have been cut through the jungle to them. Many new deposits have been discovered in the last

Jan 1, 1942

By Wayne E. Glenn, R. W. French, Lincoln F. Elkins

The Lance Creek Sundance reservoir provides a case history of ro years performance of a reservoir in which unit operation has permitted effective utilization of gravity drainage augmented by primary pressure control with injection of gas into top structural wells. Detailed performance of the reservoir is presented by means of maps of Well status, reservoir pressure, individual well recovery, etc., and by pool-performance charts. Analysis of reservoir performance indicates only minor water encroachment, so that gravity, injected gas, and expansion of gas are the main oil-expulsive agents. A simplified theory of regional drainage of oil from upstructure location to downstructure location due to gravity is presented and checked by means of comparison of "reservoir" permeability and "well" permeability from the pool performance. Good order of magnitude agreement was obtained. Individual well performance and overall reservoir performance indicate possibility that maintenance of pressure makes ineffective those parts of the reservoir in which permeability is too low to permit effective drainage of oil by action of gravity. Oil from these parts can be recovered only when pressure is reduced locally by selective withdrawal or when overall reservoir pressure is finally reduced.

Jan 1, 1949

By Wilson D. Michell

The Magma copper vein trends east-west, dips 70" south, and cuts through a 6000-ft thickness of limestones, quartzites,. shale, diabase, and schist. The vein is itself a fault with a horizontal offset of 500 ft on the formation contacts in the two walls. There are two principal faults of large displacement and numerous smaller steep and flat faults that complicate the prediction of ore occurrence. A study of the geology, its systematic recording to facitliate ready reference, and graphic methods of interpretation of mineralization have aided the exploration, development, 2nd mining of the ore. In making predictions of the distribution of mineable ore bodies and their shape in critical areas, studies are made of "mineralization contours" and "mineralization trends," which are developed on a longitudinal section of the vein from variations in the concentration of the combined base metal content as shown by assays of available openings in the mine. Introduction This paper describes an example of geological work applied directly to mining and exploration problems in a deep vein deposit, and it is presented as being of interest especially to those engaged in working more or less similar veins. In 1944 to 1945 the writer spent a year as assistant to J. K. Gustafson in a thorough geological examination of the Magma mine. Much of the writer's subsequent independent work described in the present paper had its inception in ideas originated by Gustafson during that examination. Objectives of Geological Work at Magma Mine The objectives of geological work at Magma, as at operating vein mines of a similar nature, can be summarized as follows: 1. Direct assistance to the mining department by means of predictions as to the size, shape, grade, and location of ore bodies; by solution of fault problems and irregularities in the veins; by prepara-?ion of detailed ore-reserve estimates in specific areas; by keeping a complete record of the geology and assay results in the mine; and by guiding development work. In short, geology can aid in the realization of the prime purpose of the mining department, which is that of producing the greatest amount of ore in the most economical and expeditious manner possible. 2. Guidance for exploration, especially diamond drilling, in undeveloped areas of the mine. 3. Contributions to the understanding of the general geology of the deposit and its regional setting, including ore genesis, structure, and mineral relationships. Magma Ore Deposit The east-west trending Magma vein, dipping about 70" south, cuts through a 6000-ft thickness of concordant limestones, quartzites, shale, diabase, and schist, named in descending order. These

Jan 1, 1949

By A. R. Kaufman, P. Gordon, C. H. Schramm

AS a part of the general program on alloys of uranium carried out at the Massachusetts Institute of Technology under contract W-7405-eng-175 for the Manhattan Project during the recent war, it was considered desirable to investigate the boundary binary phase diagrams of the ternary alloy system uranium-tungsten-tantalum. Previous work on these alloys was practically nonexistent. A brief statement to the effect that tantalum and tungsten form a continuous series of solid solutions was found in a general paper on tantalum by W. V. Bolton1 but no information was available on the uranium-tungsten and uranium-tantalum systems. The research to be described in this paper has served to delineate the main features of the uranium-tungsten, uranium-tantalum phase diagrams and to check Bolton's work on the tungsten-tantalum diagram. Experimental Details Metals: The tungsten and tantalum used for preparing the alloys were 99.96 and 99.65 pct pure, respectively. The chief impurities in the metals were about 0.02 pct molybdenum in the tungsten, and 0.2 pct columbium, 0.05 pct tungsten, 0.02 pct barium and 0.01 pct silicon in the tantalum. The uranium used was 99.9 pct pure, with the main contaminants being iron and carbon. (An appreciable amount of magnesium was present in the uranium as received, but this distilled off during melting and so is not reported as an impurity.) The composition of specimens indicated in the subsequent figures and tables of this paper are the results of chemical analyses on the cast alloys except for the tantalum-tungsten alloys. For the latter, chemical analysis was not very reliable as a result of the difficulty of separating tungsten and tantalum chemically. Consequently, the nominal

Jan 1, 1951

By F. F. Aplan

The past year has been another year of vigorous fundamental research in mineral processing as evidenced by the active publication of results, particularly in Germany, Japan, United Kingdom, United States and USSR. It was also noteworthy for several significant meetings and conferences. The Basic Science sessions at the AIME Annual Meeting continued to attract an increasing audience and the sessions were especially notable for the active discussion of papers. The third Engineering Foundation Conference on Particulate Matter Systems,1 chaired by F. F. Aplan, was held in Milwaukee in August and attracted over 100 experts from five continents. Sessions at this week-long conference covered comminution, particle characterization, separation of fine particles, fluid-solid separations as applied to pollution control, flotation kinetics, particle-particle interactions and particle agglomeration. This popular conference will be continued under John Karpinski of Bethlehem Steel Corp. as 1968 chairman.

Jan 2, 1968

By S. M. Parmley

Experience has shown that there are some factors connected with the drying of fine washed coal that are not present in drying of slack coal as normally practiced at cement kilns or pulverized coal plants. It is the purpose of this paper to show some of these variations as they have been encountered under actual operation. The Champion No. 1 cleaning plant of the Pittsburgh Coal Co. uses the wet system of cleaning coal. The plant is equipped to produce commercial sizes or mixtures, the primary sizes being plus 6 in. and 4 by 6 in., which are hand-picked. Minus 4-in. sizes are all cleaned by the wet process. To produce a commercial product as free of moisture as possible, the washed coal is first passed over sizing and dewatering screens, then each size except the — ?-in. coal is conveyed to loading booms by slow-moving draining conveyors. As the +?-in. sizes are not heat-dried, no data will be given, as it is the purpose of this paper to describe the heat drying of — ?-in. coal as practiced at the Champion No. 1 plant of the Pittsburgh Coal Company. To fully appreciate the conditions, it must be remembered that the — ?-in. product is now shipped at a lower moisture content than when received from the mine. The incoming coal in the — ?-in. size will average 5 per cent. moisture and the shipped product 3 per cent. moisture. This is a case where a wet process gives a reduction of both ash and moisture in the fine sizes. The shipped product, therefore, is more uniform in all characteristics, and uniformity of product is the most important single factor in coal preparation. The 0 by ?-in. coal is first dewatered on slow-moving continuous bucket dewatering elevators, running at the rate of 40 ft. per minute, with 48-in. perforated buckets with ¼ by 1½-in. slots, spaced ? by 2?-in. centers staggered. The moisture in the coal discharged from the elevators runs 20 to 28 per cent., depending on the fineness of the product. The discharge from the dewatering elevator is further drained on a drag-type conveyor equipped with ½-mm. wedge wire screen. The conveyor discharges coal with an 18 to 25 per cent. moisture to three centrifugal dryers of the Carpenter type. The Carpenter dryers

Jan 1, 1931

NORTH AMERICA Number Members Alaska 43 Canada 340 Mexico 205 Newfoundland 4 United States Alabama 39 Arizona 120 Arkansas 11 California 699 Colorado 168 Connecticut 89 Delaware 18 District of Columbia 140 Florida 20 Georgia 6 Idaho 78 Illinois 214 Indiana 77 Iowa 12 Kansas 24 Kentucky 33

Jan 1, 1936

By A. L. Holley

The general usage of engineers, manufacturers, and merchants, is gradually, bat surely, fixing the answer to this question. In every country rails, boiler-plates, and machinery bars, whether hard or soft, are almost universally called steel, when they are made from cast ingots. Other names for the softer steels, such as " homogeneous metal,'' "Bessemer iron," " Martin iron," and the like, have failed to obtain general recognition. The meaning of the term steel, before it was enlarged to cover newly developing varieties, has been traced, by a recent writer, down through Percy, Shakspeare, and the Bible, in a most interesting manner, from an archœological point of view. Undoubtedly, it did characterize hardness arid other qualities imparted by carbon. It is within the memory of most of us, that all steels were tool steels, and that the soft, structural varieties were introduced—varieties which harden but little, which bend cold, and which, in many physical properties, are akin rather to wrought-iron than to tool-steel. But, since both the hard and the soft steels are made by the same processes, and have their great, distinguishing structural feature in common, viz., homogeneity resulting from fluidity, it has come to pass, despite every other proposed nomenclature, that all the compounds of iron which have been cast in malleable masses, are called steel, the term wrought-iron being still confined to malleable iron made from pasty masses, and hence laminated in structure. No inconvenience has been found, so far, in distinguishing between the more or less carburized products, in general, by the terms " highsteel," "low-steel," "tool-steel," etc., and, in particular, by prefixing the percentage of carbon and other ingredients, to the terra steel. Steels which contain distinguishing ingredients other than carbon, are called "chrome-steel," "titanium-steel," and the like, just as variously compounded bronzes are called " phosphor bronze," " aluminium bronze," etc. Thus the combination of several words or symbols, and figures, may completely disclose the characters of the metal, in terms that are subject to no misunderstanding. But inasmuch as several high metallurgical authorities and clever writers have of late proposed to disturb this natural and somewhat settled nomenclature, it seems important to consider the claims of the various classifications. I shall attempt, in this paper, to show

By W. R. Opie, O. W. Mole

By confining the electrolytic reduction of TiCl4 to the interior of a porous basket-cathode the electrolyte between the anode and the cathode can be kept free of reduced chlorides of titanium eliminating undesirable reactions of reduced titanium chlorides with brickwork or oxygen in the cell atmosphere. Semiwalls are not needed. Operating conditions are given and discussed. Titanium yields based on TiCl4 introduced are 93 pct. Cell voltage and amperage characteristics are adaptable to multiple cathode-series cell urmngements. EXPERIMENTS conducted in the National Lead Co., Titanium Division, Research Laboratories showed that titanium metal could be deposited in an electrolytic cell in which titanium tetrachloride was introduced through a tubular cathode.' The reduced chlorides as formed were confined to the vicinity of the cathode. They were reduced to form a cocoon-shaped growth of sponge titanium metal at the end of the cathodic tube below the surface of a sodium chloride-strontium chloride electrolyte. No diaphragm was needed.' Although high-purity, coarse crystalline metal was produced in the cocoon growth, the yields of metal removed from the cell, based on the amount of titanium introduced as TiCl4, were usually only 40 to 60 pct. The growth of the cocoon deposits was away from the cathodic tube for introduction of TiC14 toward the anode following the flu lines. The reduced chlorides of titanium diffused through the deposit and were reduced to titanium electrolytically within the deposit or on the outer surfaces. Deposition within the pores of the cocoon was detrimental to further deposition because it plugged the passages used by the reduced chlorides to diffuse away from the point of titanium introduction. As plugging due to deposition in the pores proceeded, the reduced chlorides in the center of the cocoon would force their way out by forming a channel and would escape from the vicinity of the cathode without being reduced to metal. Some work had been done previously1, 2 which indicated that if the end of the cathodic tube for introducing TiC14 was surrounded by a screen connected to the tube so that it too was cathodic, growth could be made to occur within the screen. Direction of growth was observed to be from the screen toward the point of TiCl4 introduction. Through a series of design modifications a cathode evolved which consisted of an introduction tube surrounded by a perforated metal basket as shown in Fig. 1. Modifications of this design are described in Refs. 3, 4, and 5. This basic cathode designa" was incorporated in electrolytic cells containing graphite anodes and constructed of high-silica brick refractory for containing the electrolyte (see Fig. 2). The inner crucible was surrounded by insulating brick and the entire unit contained in a welded steel shell. Suitable cooling chambers with inert gas atmospheres were devised so that the cathode could be removed from the cell without exposing the deposit to air while hot. Various alkali and alkaline earth chlorides were used as electrolytes.

Jan 1, 1961

By Paul Tyler

THE ferroalloying elements are connecting links between the steel industry and the nonferrous metal industries. Although ferroalloys are distinctly nonferrous themselves, they serve the steel industry either in the manufacturing process or in modifying the product-in some cases so that it may compete in the markets with nonferrous metals. Of the 92 elements generally accepted by chemists as constituting the primary building blocks of matter, all but the very rarest have been investigated with a view to employing them in steel manufacture. The surprising thing is that so few have been found commercially acceptable. Despite the relatively small number of elements involved, the employ-ment of alloys in steelmaking is one of the most complicated and probably one of the least well understood of modern industrial enterprises. A great deal has been written regarding the action of individual elements and a profuse and somewhat acrimonious literature covers pretty much the whole field of ferroalloy ore supplies. In the middle ground between the miner and the steelmaker developments are less carefully watched by most observers, and except for an occasional description of the technique of some conversion process or the tariff hearings in Congress, very little is said about them. The purpose of the present paper is to describe in relatively nontechnical terms this highly complex industry and to study its relations to our national progress.

Jan 1, 1933

By Portland P. Fox, Berlin C. Moneymaker

THE development, within recent years, of core drills capable of drilling holes up to 72 in., or even more, in diameter, has made possible an entirely new and valuable method of geologic exploration. Although little used until recently as an exploratory tool except in the United States, by the Tennessee Valley Authority and the Corps of Engineers of the U. S. Army, for the exploration of damsites, the large-diameter core drill may be used to good advantage in other types of geologic exploration. Its principal utility is that of supplementing, rather than replacing, other means of exploration. Although core is frequently recovered intact, the greatest advantage of large-diameter drilling is that the holes produced are large enough to be entered by the geologist and engineer, and thus afford an excellent means of examining undisturbed rock. The walls of the holes are smoothly cut, and in some rocks nearly or quite polished, so that the most minute details of structure and stratigraphy are clearly disclosed. Such features as faults, joints, bedding planes, weathered "seams," and beds or layers of soft materials, which are not always amenable to disclosure by cores recovered from small-diameter holes, are conspicuously displayed in the walls of large holes. Frequent reference to the drilling of large-diameter holes is made in engineering literature, but comparatively little emphasis has been placed on their value in geologic investigation. It is, therefore, intended that the present paper acquaint the geologist, as well as the engineer, with the large-diameter core drill and the technique involved in its use, and also with its advantages, disadvantages and limitations as an implement of geologic exploration. THE EQUIPMENT The equipment generally employed in the drilling of large-diameter holes consists of a trunnion-type drill head mounted on a sliding base, which allows it to slide clear of the hole and thus permit the introduction

Jan 1, 1938

By Ernest Lilley

THE tin deposits of Cornwall appear to have been worked for at least 3000 years. Prior to the sixteenth century, the tin came exclusively from alluvial deposits. At that time, shallow pits or mines were started in the hill sections. Mining of copper seems to have begun at the same time, but does not appear to have been especially important until about 1700. From that time until the close of the nineteenth century, copper was of major importance. Lead, and to a lesser extent, other metals, such as antimony, iron and manganese, were produced in commercial quantities during the same period. With the opening of the eighteenth century carne increasing difficulties with water because of the increasing depth of the mines. Among the efforts made to overcome this difficulty was the construction of the "Great County Adit," begun in 1748, taking 20 years to complete, and with its branches having a length of 20 miles. Adits proved capable of handling-only a few of the water problems, and led to rapid adoption of the steam pumping engine in the latter part of the eighteenth century and the early part of the nineteenth. It was in this period that the Cornish pumping engine, still considered by Cornishmen to be the most satis-factory unit for handling large quantities of water, carne into existence. The development of a means of controlling the water made possible the opening up of a number of rich deposits where profitable work-ing was further assisted by numerous improvements in mining and milling machinery. During the middle of the past century, Cornwall, with an average yearly production of 10,000 tons of tin metal and an even slightly larger tonnage of copper, enjoyed a period of unprecedented prosperity. How-ever, the relatively high prices of both copper and tin served not only to encourage prospecting (and much speculation) in Cornwall, but also in other countries. The rapid development of copper mines in the United States, together with sudden impoverishment of the lodes with increasing depth in the greatest of the Cornish copper mines, brought the copper boom to an abrupt end, the production of copper at the close of the cen-tury being negligible in importance and being secured in large measure

Jan 1, 1932

By R. A. Matuszak

This paper discusses the major portion of the hoist (drag or crowd) system and it shows how static control accomplishes its major aims. In 1959, the first truly static control for Ward-Leonard equipped electric excavators was designed, developed and placed in service. The control system, originally intended only as a more modern electronic type of alternate to the proven rotating amplifier control system has since proven to be much more. When they conceived the original system, the designers had much more in mind than simply replacing the rotating amplifier with one that had no moving parts. The long range plan, which started with the initial system consisting of an SCR (silicon controlled rectifier) preamplifier and magnetic amplifier power amplifier, called for eventually, a control system low in cost and maintenance, relatively simple in design and extremely reliable. The plan also included the elimination of as many of the shortcomings of the rotating system as possible. No small accomplishment, when it is considered that the rotating control system had been, with only minor modifications, the standard of the industry for 20 years. The final step in the original design plan called for the eventual development of an amplifier that could be used as one of the basic building blocks of the future. DEVELOPMENT RESULTS Since the successful unveiling of the first static control system, continuous development has resulted in a slow, but sure progression along the path described by the original plan. The first version of the new control corrected one of the shortcomings of the rotating system by removing the necessity of operator anticipation. This was accomplished by making the system faster in response so that the operator noticed virtually no delay between his movement of the master controller and that of the machine. Thus, after the operator became familiar with the operating characteristics of the machine, he was able to become more relaxed while digging. The natural result of this accomplishment was higher production. All of the subsequent versions of this new control were even faster than the initial design. Although it was not distinguishable by the operator, the further increase in response resulted in large gains in the limiting of transient torque peaks applied to the machine while digging. Also, a more effective control of the torque and power peaks was obtained when plugging the motion being controlled to a stop. (Plugging is the use of the Ward-Leonard ability to regenerate power and absorb energy from the load to

Jan 1, 1964

By Henry A. Ley

Kansas ranked fourth on the list of oil-producing states during the year 1930. Progressive statistics show that total production for the year will approximate 42,729,085 bbl. When final figures are compiled for Kansas the production may exceed this estimate, and thereby threaten the all-time record of 43,253,470 bbl. in 1918. Throughout the year the cumulative volume of potential drilled-up production has been increased by new discoveries and by extensions to proven areas in the territory west of the Nemaha (granite ridge) Range. Scattered drilling and leasing operations of a constructive nature occurred, but completions declined to the lowest levels in more than 11 years. Average initial production of current completions climbed to a new all-time high of 512 bbl. to the well. Proration measures were applied to the flush pools. The resulting shut-in potential production, as of December 15, is estimated at 110,000 bbl. This estimate is a wild guess. If all wells of the state were permitted to flow wide open for a period of six months production would not exceed 150,000 bbl. a day. The outstanding development of the year was an intensive drilling campaign in southwestern Kansas, which contributed at least 1,000,000 acres of contiguous natural-gas lands to the natural-gas resources of the United States. Production and Development Prospecting for oil in Kansas began shortly after the initial prospecting at Titusville. Operations and interest in the potentialities became active about 1870. This development was restricted to the shallow districts of northeastern Kansas. By 1895 operations had extended southward to the Oklahoma state line and sufficient prospecting had taken place to prove the potentialities of the state. Active prospecting was extended westward by the discovery of oil on the Nemaha Range in Butler County about 1916. The discovery of oil in Russell County added an extensive borderland province in 1923. The important discoveries of oil in Sedgwick County revived interests and operations throughout this territory in 1928. The development of widespread natural-gas lands in extreme southwestern Kansas during 1930 carried active exploration to the western boundary of the state.

Jan 1, 1931

By George W. Maynard

In the death of Sir William Siemens, the Institute loses its most distinguished honorary member, one who, without exaggeration, may be ranked among the greatest Men of the century. In justification of this claim, I quote in part the words of two other men eminent in the walks of science. Professor Huxley, addressing the Royal Society, spoke of Siemens as "a marked example of vast energy, large scientific acquirements, and intellectual power of a high order," and as one " who had no superior in fertility and ingenuity of invention, while hardly any living man so thoroughly combined an extensive knowledge of scientific principles with the power of applying then] in a commercially successful manner. The value of his numerous inventions must be measured, not merely by the extent to which they have increased the wealth and convenience of mankind, but by the favorable reaction on the progress of pure science which they, like all such inventions, have exerted, and will continually exert." Dr. Wedding, in his address before the Verein zur Befarderung des Gewerbefleisses in Preussm, speaks of Siemens as being "so fortunate as to combine German erudition with British activity in such a manner that both nations, Gertnan as well as English, were equally proud of him; and, now that his rich life is ended, regret is expressed on both shores of the North Sea, first by the Germans that his entire life had not been spent in Germany, and his powers dedicated to Germany, and by the English that he was not born a Briton." Germany may well be proud of being the birth-place, not only of such a man, but of such a family; for where in history shall we find in a single family such a wide range of knowledge so successfully applied to the arts? The least distinguished name in the following list has added to the world's knowledge enough to satisfy the desire for fame of any ordinary man. This constellation is made up of:

Jan 1, 1884

By W. C. Lacy

THE Cuajone porphyry copper deposit is the northernmost of a group of three deposits in southern Peru controlled by the Southern Peru Copper Corp.-Toquepala, Quelleveco, and Cuajone— all within a 20-mile belt. Although small pockets of high-grade copper oxide ores were worked in the Cuajone area in the 19th century, it was not until 1939 that its potentialities as a disseminated deposit were recognized by 0. C. Schmedeman. An exploratory drilling pro- gram was begun in December 1942 and continued until early 1945. The program was revived in November 1952 and completed early in 1954. Early exploration was by diamond drilling. Later exploration was predominantly churn drilling, with diamond drilling used only for wildcat holes. Along this northwest-trending belt of deposits. which follows the western slopes of the Andean Range, quartz-monzonite has invaded earlier dio-rite intrusives and a series of warped and tilted Cretaceous volcanic flows. Little faulting of consequence has been recognized within the mineralized areas. Sulfide minerals were introduced into all these diverse rocks, and mineralization was followed by erosion, oxidation, and enrichment. In Late Tertiary and/or Quaternary time the entire

Jan 1, 1959

By H. A. Wheeler

History ILLINOIS has so recently attained the third place in the oil production of the United States that few realize its great importance, or are aware of its highly profitable character. Since 1907 Illinois has furnished about 15 per cent. of the United States output and about 10 per cent. of the world's production. The value of the output in 1913 is estimated at $30,000,000, of which about $20,000,000 is profit. The present prosperity dates from 1905, but efforts have been made since 1865 to develop production and geologists have been very sanguine as to its future for over 25 years. Had the oil operators been as confident as the geologists, the field would have been opened at least 30 years earlier. For the rich Eastern Illinois oil field is located along the La Salle anticline, that was mapped 46 years ago by Professor Worthen in the

Jan 5, 1914

By C. A. Heiland

The Eötvös torsion balance permits the measurement of certain second derivatives of the gravity-potential, which are known as the gradients of gravity and the curvature values for an equipotential plane of gravity. These quantities are influenced on level ground by the configuration of the masses underneath. Hence, the torsion balance has gained great importance for the location of geological structures and thus indirectly for the discovery of oil and other mineral deposits. If the ground is not level, however, the measurements become more difficult, because the superficial mass-irregularities also produce more or less considerable disturbances. It is necessary, therefore, to determine the shape of the surrounding topography by leveling as well as by consulting topographic maps and to compute its influence upon the torsion balance. The correction thus determined is called, in general, the topographic correction; it is composed of two constituents, the terrain correction and the cartographic correction. The terrain correction would be that part of the topographic correction as derived from the direct leveling of the area surrounding the station, whereas the data for the computation of the cartographic correction are obtained from a topographic map, usually beginning with a radius of LOO meters, as under most circumstances it is difficult to level along a arger concentric circle about the station. Principle of Topographic Correction The principle of all topographic corrections is to assume a homogene-ous compositon of the masses around the station in regard to specific gravity as well as a mathematical shape of the topography. The results become the more accurate the closer this mathematical shape is to the actual configuration of the terrain, but naturally the amount of necessary computation also increases. If a standard correction with fixed dis-ances is adopted, the middle error of this method will, therefore, increase as the irregularity of the terrain. Hence, the application of the torsion balance in mountainous areas may be successful only if the disturbances due to heavy masses underneath the surface are so large as to exceed onsiderably the increased middle error due to rugged topography, or,

Jan 1, 1929

By Eugene McAuliffe

TWO years ago the American Institute of Mining and Metallurgical Engineers made a memorable contribution toward a better understanding of the problems that have for many years confronted the coal industry. Specific suggestions toward betterment were then advanced, certain of which were taken up, amplified and endorsed by men who were conscien-tiously interested in the work of lifting this great industry out of the morass it has lain in for years. Two certain suggestions then made-provision for seasonal variations in railroad freight rates that would tend to encourage the purchase and movement of coal during the low summer production period, and provi-sion for the collection by the United States Government of all the facts surrounding the industry-were intro-duced in the form of legislation in the United States Senate by a member of that body, a man whose personal character, antecedents and business training put him above and beyond all suspicion of demagoguery; however, as the result of the insistent, vindictive opposition of the industry itself, these two bills, con-structive in their nature, were buried under an ava-lanche of misrepresentation. Today, with all mines that employ union labor at a stand still, the work of stabilizing the industry is yet before us. As aptly stated by Herbert Hoover, in March, 1920, when he was president of the Institute; An engineering organization is particularly the body to under-take this work. It is an economic problem, an engineering pro-blem within the ken of our experience; it is a problem that requires not only constructive thought but quantitative thought and wise social thought. The engineers of the United States occupy a position midway between capital and labor. They enter upon problems of this kind without prejudice either way, and they have that faculty of mind for quantitative thought, as distinguished from qualitative thought, that takes such problems as this out of the region of politics into the region of matter-of-fact solution.

Jan 5, 1922

By Albert Mendelsohn, Charles F. Jackson

The system of stoping described in this paper was first introduced at the Champion mine of the Copper Range Co., Painesdale, Mich., in 1929, and since that time has been developed to a high state of efficiency. The method was devised to overcome some of the objections to the system of horizontal cut-and-fill stoping formerly employed at this mine and has done so successfully. The objections to the old system became more pronounced as the depth of mining operations increased and a change became a matter of necessity. While the combination of conditions encountered at the Champion mine is rather unusual, it is believed that the sublevel system developed there could be employed advantageously at other mines, though certain modifications might be necessary. This paper describes the method and the results obtained through its use, and suggests modifications for making it applicable under quite different conditions from those at the Champion mine. Champion Lode The lode being mined at the Champion mine is the heavily brecciated top of what is known in the district as the Baltic lava flow. The brecciated portion of the lode varies from 6 to 50 ft. in width. Under this breccia is the thinner, tighter, amygdular portion of the lode; under the amygdular portion is the trap footwall. Native copper is found deposited in the rock fragments of the breccia, in the cementing material of the breccia, in the amygdules and in the trappy rock under the amygdular part of the lode. In some places masses of copper many tons in weight extend far into the footwall of the lode. The Baltic lode on Champion property is 8000 ft. long, very straight along the strike, and dips uniformly 70' to the west for 3000 ft. in depth, at which point the dip begins to flatten slightly. The width of the copper-bearing portion of the lode varies from 10 ft. to as much as 80 ft. in a few places; the average width now mined is 17 ft. The lode rock is hard—the standard one-man drilling machines used in the mine drill from 10 to 14 in. per minute when mass copper is not

Jan 1, 1932