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By C. David Mann

Metal prices continued to improve in 1964, resulting in the opening of new mines and re- activation of old ones. Larger and deeper shafts are being bored. At the AEC's Nevada Test Site, a 72-in. diam shaft is being bored to 3200 ft. In New Mexico a 1650-ft shaft was bored with a 48-in. bit, then reamed to 124 in. to 935 ft, and 102 in. to 1650 ft. Deviation was only 26 in. In California a shaft sinking machine has been developed which combines drilling and mucking equipment into one mobile, integral unit.

Jan 2, 1965

By C. Zener

HE present paper has its origin in an attempt A by the author, extending over the last several years, to understand the influence of the magnetic properties of the constituent atoms upon the various properties of metals and alloys. During this study the author has been impressed by the important role which magnetism plays in the many facets of metallurgy. In writing this paper he has attempted to convey to his colleagues some concept as to the role magnetism will play in the future development of metallurgy. In some of the subjects herein discussed, such as the influence of magnetism upon phase boundaries and upon mechanical properties, only general thermodynamical properties associated with ferromagnetism are introduced. For these subjects, it is not anticipated that any serious differences of opinion will be encountered. A discussion of the other subjects requires the adoption of a quite specific model of the magnetic structure of the metal. This model is discussed under "Magnetic Shells and Their Interactions." The simple model adopted in this paper has been criticized' as being mathematically inconsistent. This criticism has been ably silenced by Dr. W. J. Carr' of this laboratory. The simple model adopted in this paper has been criticized as being inconsistent with observations on magnetic structure using neutron diffraction. This apparent discrepancy has been resolved by Bader3 who has shown that the finite velocity of neutrons prevents neutron beams from detecting the anti-ferromagnetic structure of the type predicted by the simple model adopted in this paper. Magnetic Shells and Their Interactions An electronic shell of an atom is specified by two symbols.' The first symbol is a number and denotes the total quantum number of the shell. The second symbol is a letter and denotes the orbital angular momentum of each electron within the shell. The letters s, p, d, f are used to denote an orbital angular momentum of 0, 1, 2, 3, respectively, in units of h/2a, where h is Planck's constant. As we pass from scandium to nickel in the first transition period, we eraduallv fill the 3d shell. This shell is responsible for ferromagnetism and hence may be called the magnetic shell. The component of the orbital angular momentum along some specified direction must be an integral multiple of h/2~. Thus, for a d electron this component can have any one of the values —2, —1, 0, 1, 2 times h/2a. In addition to its orbital angular momentum, each electron has an intrinsic angular momentum, hereafter called spin, due to a rotation about its own axis. This spin can have either of two components + Yz (h/2a) or — Yz (h/2~) along the specified direction. A fundamental principle of atomic structure, known as Pauli's exclusion principle, is that no two electrons in a given shell may have identical components of orbital angular momentum simultaneous with identical components of spin. The 3d shell thus may have at most ten electrons. Since an intrinsic angular momentum of a charged particle is necessarily associated with a magnetic moment, the spin of an electron may be thought of as referring to either this angular momentum or to the associated magnetic moment. The electron configuration of the ground state of the isolated atoms in the first transition row is reproduced in Table I. The superscript represents the number of electrons in each shell. For the purpose of this paper, the most important principle of atomic structure relates to the manner in which electrons are added to a shell as the atomic number is increased. This principle, commonly known as the principle of highest multiplicity or more simply as Hund's rule, states that within a given shell the maximum number of electrons have spins pointing in the same direction as is consistent with Pauli's exclusion principle. An application of this principle to the d shell is illustrated in Fig. 1, where the spin structure is given for shells containing from 1 to 10 electrons. The physical basis of Hund's rule is the exchange energy discussed first by Heisenberg in 1928. This is a coupling between electrons with parallel spins (spins pointing in the same direction), the coupling

Jan 1, 1956

By J. J. Stokes

Literature on the electrolysis of aluminum from cryolite melts and on the structure of these melts is surveyed critically. Data on density, freezing point, and other properties are reviewed. Theories of the electrolysis are examined in the light of these data. Two theories are presented which account equally well for the observations. ALTHOUGH the production of aluminum is a large-scale industrial process, consuming approximately 3 pet of all of the electric current generated in this country, the mechanism of the Hall Process remains a 70-year-old mystery. It is a remarkable fact that the aluminum industry, which was established largely through research and owes much of its growth to research, still employs as its basic process the one developed by Charles Martin Hall while he was still a young man working in a woodshed. There are, of course, modifications in detail and a tremendous expansion of the size of the units used, but basically the process employs carbon anodes and a carbon-lined iron vessel as a cathode for the electrolysis of alumina dissolved in molten salt. Of the almost infinite variety of salts available, the relatively minor Greenland mineral, cryolite, 3NaF.A1F3, is still the only one which gives good performance in the electrolysis. In the early days, the process was thought of as a simple one. The dissolved alumina dissociated and, during the electrolysis, the aluminum was carried to the cathode where it was discharged and collected in a pool of metal. The oxygen was carried to the carbon anode where it reacted to form primarily carbon dioxide together with some carbon monoxide. About the only virtue that can be claimed for this hypothesis is that of simplicity. The actual mechanisms must be tremendously more complex. This paper is devoted to a rather narrow part of the whole subject, namely, what ions are present in the bath, and by what mechanism the current is carried. The complexity of the literature on this system is demonstrated in Table I, which shows the ions postulated as being present during the process. This system is not easy to investigate. Cryolite melts at about 1000°C, so that all the investigations are at relatively high temperatures. Molten cryolite fumes in air, particularly if excess aluminum fluoride is present. The cryolite changes composition on heating at 1000°C, principally by reaction with moisture in the air, but apparently also by reaction with oxygen. Cryolite reacts with most of the customary materials of construction, and those that are not attacked by cryolite seem inevitably to react with molten aluminum. Graphite is the only common material that is inert to the electrolytic bath. Pure cryolite can be held in platinum. There is hope that some of the newer refractories will stand up in bath, and their development for this purpose would be a major advance in the field. The techniques to be discussed, then, are not the most advanced ones. Rather, they are examples of old standardized methods applied under difficult conditions. The principal methods that shed real light on the mechanism are density, electrical conductivity, freezing-point lowering, transport number, viscosity measurements, and reactivity of bath with carbon dioxide. The first measurement to be discussed is density. This procedure is relatively straightforward. A hollow platinum bob is suspended by fine platinum wire from an analytical balance into the melt being investigated. Density1-4 of the system sodium fluoride-aluminum fluoride is shown in Fig. 1. There is a maximum in the density near the cryolite composition, but actually the maximum is on the NaF-rich side of cryolite, close to the composition NaF - Na3AlF8. Density measurements are also useful in giving a clue to the nature of cryolite-alumina melts.1, 4 On the first addition of alumina, density decreases, Fig. 2, although the density of alumina, either solid or liquid, is higher than that of cryolite. These density results indicate that the systems are not simple. A great deal of effort has been spent in measuring the electrical conductivity of molten cryolite and of cryolite with various additives. Conductivity measurements are quite easy for fused salts that can be measured in a dip cell, but no successful dip cell has been made available yet for cryolite. Recourse is had

Jan 1, 1959

By ROBERT H. BOOTH

THE happy intra-plant relationships of the Bridgeport Brass Co. are largely attributable to the interest of the management in this important business factor. In furtherance of this development Carl F. Dietz, President of the Company and a member of the Institute, has contributed the novel plan for the objective presentation of business economics, described herein. All of the officers of the corporation are active in its management and they together with many other workers filling both executive and subordinate positions have a substantial financial interest in the enterprise. The viewpoint of this organization is fairly reflected by the following quotation from Roosevelt's "The Foes of Our Own Household."

Jan 1, 1924

By Oscar A. Glaeser

MINE VENTILATION is an important factor in mine maintenance as well as having direct bearing on labor efficiency. Effective ventilation systems are costly, especially those for the deeper mines, but with intelligent direction the worth of a system is usually greater than its cost. In most mines using mechanical ventilation, and practically all deep mines, it has been found beneficial to equipment, timber, and the ground, to run the fan or fans continuously even though production has been curtailed or entirely suspended. Therefore, economies in ventilation may be overlooked when general cost reductions are necessary. The operating costs of a well-designed ventilation system should be capable of reduction during periods of curtailed or suspended operations. A mine that is ventilated by splits, or that can be sectionized, can reduce its fan-power costs considerably, and provisional divisions can sometimes be made in other mines, in which the air is ordinarily coursed through all the workings, without harmful effects.

Jan 1, 1932

By CHARLES M. A. STINE

IN fighting a war the all-absorbing intent is to win. There is little time to analyze the rush of events or to appraise their consequences beyond the war's end. The united objective is, rightly, success for our arms. Yet under the pressures of a great war there may be compressed scientific, economic and social developments that might have taken many decades to achieve under less urgent conditions. Their effects on our lives and all civilization may be more wide-reaching and lasting than any military conquest. They constitute one of the must imperative incentives to victory. No American, least of all any scientist worthy the name, conceivably could endorse war as a justifiable means to progress. The destruction of life and property wrought by the present war far exceeds the havocs of a century's earthquakes. Most of mankind is burning itself on an altar of paganism. Nonetheless, one fact is inescapable Despite the recurrent malady of war history's overall course is forward. Mankind has the habit of rising phoenix-like from its own ashes to attain greater heights. Progress is immortal.

Jan 1, 1942

By George J. Young

(San Francisco meeting, October, 1911.) THE nature of slimes handled in the treatment of gold- and silver-ores has been discussed in technical literature to a considerable extent. The subject of slime-filtration from the practical worker's stand-point has also received much comment, and scattered through the literature of the subject are descriptions of many slime-filtration installations. Articles of this nature serve a valuable purpose and assist materially in the design of new and the improvement of old plants. The subject of the physics of slime-filtration has been touched upon to only a slight extent. The underlying principles are worthy of more intensive study and experimentation than they have received, and the main purpose of this paper is to present the results of such study and experimental work as will serve to make clear in part at least many of the principles which control the filtration of slime. Nature of Slime. Much has bean written concerning an accurate definition of the term ? slime," but no comprehensive definition seems to be generally accepted. The reason for this is clear. A slime consists of at least three different substances, each, when separated, possessing distinctly different physical and to a certain extent chemical properties. These substances are extremely fine sand, a colloidal material which may be and generally is in a coagulated condition, and a colloidal material which is in a non-coagulated condition. Suspending a slime in a relatively large volume of water by shaking and allowing sedimentation to take place, results in the fine sand settling out with comparative rapidity, followed by the coagulated material, which settles much more slowly and finally a certain portion remains

Nov 1, 1911

By E. J. Lintner

CLAY mining in the 'United States is by no means a small industry for approximately ten million tons of shale and clay are recovered yearly. The bulk of this tonnage enters into the manufacture of paving, building and refractory brick, draintile, pots, sewer pipe, stoneware, and wall and floor tile. This group of manufactures is commonly known as the heavy clay products industry. The winning of the raw materials for this industry constitutes merely a step in the manufacturing process because the manufacturer usually owns and operates his own source of supply. The mining of kaolin and the whiteware and chinaware claps, however, is usually a separate industry.

Jan 1, 1936

By Lyon F. Terry

ACCEPTED current practice for A the valuation of mineral property is based upon Hoskold's theory and valuation tables first published in 1877, and popularized by Herbert Hoover's "Principles of Mining" issued in 1909. In more recent years the procedure has been developed further in the course of the extensive valuation work required for Federal taxation purposes. The 1-aluation of oil and gas properties and of mines is based upon the same principle-the estimation of the present worth of future net revenues. However, in valuing oil and gas properties the method used for discounting future revenues differs somewhat from that adopted for mines, owing principally to the nature of the re- source. production from oil and gas properties usually declines from year to year, whereas coal and ore de- posits are adapted to a more uniform rate of output.

Jan 1, 1940

By D. H. Gray, G. Bergamini, I. Fatt

A method developed by soil scientists for measuring permeability anisotropy of soils has been adapted for use in studies of sandstone permeability aniso-tmpy. Studies on Berea and Bandera sandstone show that permeability of these materials decreases upon application of simulated overburden pressure. Permeability reduction of Berea and Grubb sandstone cores subjected to simulated overburden pressure is shown to be a function of the ratio of radial to axial stress. INTRODUCTION The effects of mechanical stress on reservoir rock parameters are now generally accepted as being important in reservoir engineering calculations. In several oil fields the unique behavior of the reservoir has been attributed to the influence of overburden pressure or internal fluid pressure on rock permeability or fluid content. l Although the gross effects of overburden pressure on permeability, porosity, waterflood efficiency, electrical resistance and sonic velocity have now been established,3-9 there are some very interesting, and perhaps important, details of rock behavior under stress that have not heretofore been studied. In this paper we will show that permeability anistropy of several sandstones is a function of overburden pressure. We will also show that permeability reduction of cylindrical samples of two sandstones, when subjected to mechanical stress, is a function of the ratio of radial to axial stress. Most studies of overburden pressure effects made in the past have attempted to duplicate reservoir conditions by applying hydrostatic external pressure on all surfaces of the sample. Assuming perfect elasticity, that is, no viscoelastic flow during geological time, reservoir rock in situ cannot be under hydrostatic stress as is apparent from the value of 0.25 for Poisson's ratio for most rock. In the absence of tectonic forces the horizontal stress component If there are directional permeability effects, as has been reported from field and laboratory studies, l0,11 then one would expect hydrostatic stress as used in the laboratory to give a different permeability reduction from that occurring under reservoir stress conditions. The influence of stress on directional permeability was measured by a modification of the method first described by Maasland and Kirkham for use on soil samples.12 Their method permits calculation of the permeabilities along each of the three mutually perpendicular axes of a cubic sample. The modification reported in this paper extends the method to observing these permeabilities when the sample is under hydrostatic stress. The Hassler sleeve type of core holder is satisfactory for studying overburden pressure effects on permeability if a known force is applied to the end plugs. Wyble6 used a sleeve core holder but did not load the end plugs. In this paper we combine sleeve pressure and axial force to give permeability changes which we believe are close to those occurring in reservoirs when reservoir pressure changes. The combination of sleeve pressure and axial force assumes, however, that the sleeve pressure simulates both vertical stress and horizontal stress in one direction. METHOD PERMEABILITY ANISOTROPY The Maasland and Kirkhaml2 method of measuring permeability anisotropy uses a cube of porous material which is Open On three faces and has discs with a Center hole for an air inlet cemented to the other three mutually perpendicular faces (Fig. 1). The rate at which air pressure falls in a bottle of known volume, and pressure slightly above atmospheric, when the bottle discharges through each disc, is

Jan 1, 1883

By JOHN R. SUMAN

IT SEEMS particularly appropriate that the Institute's Regional Meeting should be held in Minnesota this year. Whether we like it or not, we cannot help looking at things now in the light of the World War and the all-out effort we, as a nation, are making to defend our resources, our institutions, and our way of life. The ability to do this lies in large measure in the ability to forge weapons of defense-the machines of war. The basic ingredients of any defense system, or war machine, are the raw materials of industry-iron ore, providing steel for guns, shells, tanks, and warships; coal for stoking the nation's furnaces; oil to furnish power for war planes, ships, trucks, and mechanized weapons; and all the other materials that play a vital role in the operation of modern armies and navies. The tremendous requirements of full-scale defense programs are indicated by the large number of commodities that are now under priorities because the supply is not sufficient to meet both defense needs and all normal civilian consumption. But out of all these items two are of paramount importance-steel and petroleum. In this age no nation can hope to main¬tain a position as a first-class power in the world without a highly developed industry, particularly the heavy industries based on steel, and without access to the necessary resources for those industries. In 1918, 70 per cent of the iron and steel production of the United States was required for defense purposes. In 1940, 15 per cent of our iron and steel production was consumed for defense purposes, and with the acceleration of the defense program, it appears that the proportion of steel output required for defense purposes will reach 40

Jan 1, 1941

By H. S. McQueen

The insoluble-residue method for the examination and correlation of limestones and dolomites, or other sedimentary rocks containing calcium and magnesium carbonates, originated and was developed in the laboratory of the Missouri Geological Survey. The numerous and ever-increasing problems in the field of applied geology, and the need for a tool or aid in the solution of them, led to experimental work with samples collected from deep wells, in the early part of 1924. The success attained, almost at the outset, with this method was so great that the method has now been developed from the state of the experimental to the realm of large-scale, every-day routine. In a previous paper the writer1 described the procedure in detail and the characteristics of the residues obtained from certain Paleozoic formations in Missouri. The purpose of the present paper is to discuss the economic application of the insoluble-residue method. Developmental History Within the Ozark region of southern Missouri the geologic column consists of Lower Ordovician (Canadian of Ulrich) and Upper Cambrian formations, which are composed mainly of dolomite with subordinate amounts of sandstone, shale and limestone. Chert is found to some extent in all except one of the dolomite formations. The stratigraphy of the region is complex because the dolomites have lithologic similarities, fossils are few and often poorly preserved, and identifiable horizons within the comparatively thick formations are not common. Although considerable stratigraphic work of an areal nature had been done for a period of many years by the Missouri Geological Survey, the detailed geologic succession had not, until a few years ago, been systematically worked out. The problems of subsurface stratigraphy were even more complex. This region constitutes the main ground-water province of the State of Missouri and within it wells of varying depths are drilled in order to obtain supplies of ground water. In the work of the State Geological Survey in connection with the drilling of water wells for public supplies * Published with the permission of the Director, Missouri Geological Survey and Water Resources. Manuscript received at the office of the Institute Feb. 20, 1936. Assistant State Geologist of Missouri; Missouri Geological Survey, Rolla, Mo. References are at the end of the paper.

Jan 1, 1937

HUDSON MAXIM, Brooklyn, N. Y.-Immediately after the creation of the Naval Consulting Board, Admiral Strauss, Chief of the Bureau of Ordnance of the Navy, told members of the Board that the most important problem for the scientists to solve was erosion in large guns. The Navy, for years, had been working on the problem with marked suceess, but there was much yet remaining to be accomplished. As Chairman of the Committee on Ordnance and Explosives of the Naval Consulting Board, I communicated with several experts in the manufacture of steel, principal among whom was Prof. Howe. He generously agreed to help in every way possible, and the work that he has done and the time that he has spent upon it can he appreciated only by reading his paper. Prof. Howe asked for some rings. from a, certain 14-in. gun which Admiral Strauss had mentioned in particular, and in which, he had informed us, at each shot the bore of the gun, was enlarged about 0.001 in.,' and that after a relatively small number of rounds it was considerably eroded. It has puzzled scientists for a long time to account for the peculiar erosive effect produced by the powder gases in a gun, arid: what Prof. Howe has done in his paper is worthy of Sherlock Holmes. He is a veritable Sherlock Holmes of science.

Jan 4, 1918

By L. H. Robinson

Triaxial compression tests on Indiana limestone indicate that chemical additives in the pore fluids can increase or decrease the strength in plastic failure but not in brittle failure. Tests using a series of the sodium salts of dicarboxylic acids show that odd-number carbon-atom chains decrease the yield strength as much as 3.0 x 10 3 psi, and even-number carbon-atom chains increase the yield strength as much as 9.0 x 102 psi. ,The most effective chemical (sodium citrate) decreased the yield strength of Indiana limestone from 16.0 x 103 to 12.0 x 103 psi. The chemical additives investigated have no influence on microbit drilling rate when drilling with zero differential pressure. However, when drilling at a 2.0 x 103-psi pressure differeniial and using an odd-number carbon chain compound as the circulating fluid, the roller bit drilling rates were slower than with water whereas the drag bit drilling rates were faster. One even-number carbon chain compound added to the circulating fluid produces the opposite effect: the roller bit drilling rate is slightly faster than with water and the drag bit slower than with water. INTRODUCTION A Russian book by Rehbinderl published in 1944 generated much interest in the possibility of aiding and accelerating the destruction of solids by the action of a liquid in which the solids are deformed. This book describes a process in which microcracks are generated during elastic deformation. To describe this process, the rock is divided into three zones: (1) the zone in which the destruction takes place, (2) the predestruc-tion zone (an affected area immediately below the destroyed zone) and (3) the undisturbed specimen. Consider a load applied normally to a surface of an infinite slab of rock. Immediately below the point of application of the load, the rock is destroyed by compression or shear forces. Below this area of destruction, because of a great number of discontinuities ranging from defects to weak points in crystals of discontinuities in crystal latices, very small cracks are created in or between the crystals (often referred to as microcracks). Upon removing the load, the broken rock in the destroyed zone could be removed. In the lower predestruction zone, however, the microcracks in and between the crystals could disappear by the process of rehealing, i.e., the molecular attraction from one side of the crack to the other side being sufficient to completely eliminate the crack. Thus, a large number of these microcracks possibly exist only for a relatively short period of time. The concept of small cracks being generated within the crystals of a rock is not unreasonable. If the rock matrix is deformed below the yield point, some of the defects present within the crystalline structure could start small cracks through the interior of the grains. Upon removal of the load, these microcracks reheal (or the newly generated surfaces come back together) so that all evidence of cracks completely disappears. Under various types of loading, and in various types of fluids, the rehealing of these cracks would be time dependent. If a liquid adhered to the surface of a rock, it could penetrate into the microcracks and thus delay or prevent the rehealing process. This suggests that the prevention of healing of the microcracks may be dependent upon the wetting characteristics of the solid. Thus, rocks which are water-wet should be more easily destroyed in water than in nonpolar hydrocarbon liquid. Adsorption of a liquid could also reduce the free surface energy which could explain the decrease in strengths of materials under nonrepetitive-type loading. Rehbinder's work prompted Boozer, Hiller and Serdengecti 2 to examine the effects of pore fluids on the deformation of rocks subjected to triaxial compression over a range of confining pressures, temperatures and strain rates. Fluids which strongly adsorbed on the rock grain surfaces decreased the strength of sandstone and limestone, which deformed plastically. For certain strain

By Hjalmer Sjögren

AMONG the feldspar-rocks there are certain types which occur constantly in different areas-viz., the aruphibolitic plagioclase- rocks and the granulitic rocks Composed of quartz and alkaline feldspars. Among the latter soda: granulites as well as potash are met with; also the corresponding gneisses occur. GROUP I.-THE ORES OF THE ARCHEAN CRYSTALLINE SCHISTS. The Rocks. The ore-bearing rocks of the ore-province of central Sweden are chemically and petrographically unlike the more monotonous gneiss- and granite-areas which surround them. On the whole, they constitute a quartz-feldspar formation in which purer quartzitic rocks, limestones, " skarn " rocks, and ore-bodies are very subordinate members. (Skarn is the Swedish name for rocks of varying composition, mostly consisting of lime, magnesia, iron, and alumina, silicates of the pyroxene, amphibole, and garnet groups; as secondary minerals, epidote, chlorite, biotite, and talc occur. The skarn is scarcely an independent rock but is connected with the ore-deposits. It is formed through an interchange between the silica of the quartz-feldspar rocks and the basic constituents of the ore-formation.) [A BRIDGED SUMMARY.-The amphibolites must be considered as stretched and dynamo-metamorphosed dioritic rocks. The granulites are divided into two groups, one showing predominant plagioclase, the other equal or predominant orthoclase. Evidently, the iron-ore deposits are connected in some way with the

Jan 1, 1913

By O. E. Kiessling

A GROWING uneasiness in the oil fields indicates that doubts are arising as to the efficiency of the present technical, economic and legal arrangements affecting production. Recent documents of the federal government, debates in state legislatures, editorials in the daily press and statements of oil company executives re-echo the notion that the present methods of producing oil satisfy neither the business man nor the public. Such intimations are of utmost importance, since oil is a vital clement in modern industry and dependence upon it increases as new uses develop. SECTION I-PRESENT SCHEME OF COMPETITIVE EXPLOITATION IS WASTEFUL The oil industry has convinced itself, for very good reasons, that the present scheme of competitive exploitation results in losses, both in terms of quantities of oil and in terms of profits. The story of these losses is familiar enough, and it is necessary only to distinguish and summarize briefly certain factors that are of importance to the following argument. Oil pools are exploited under a competitive economic system based on private ownership and contract; the hope of profits attracts capital and enterprise, and competition is supposed to serve as a regulative factor. Whether such a scheme of industrial organization works is partially dependent on the ability of the producer to withhold or produce is commodity as he sees fit, in accordance with the dictates of market demand.

Jan 1, 1927

By G. H. Cutter

SAFETY in mining depends on wire rope to as great, if not greater, extent than in any other industry. Sudden failure of a shaft-hoist rope might easily result in death or serious injury to the operators and workmen, extensive damage to expensive equipment, and a loss in production while repairs are being made. A wire rope is only as good as its component parts. It must be made from wire properly drawn and treated. It must be fabricated on machines large enough and capable of imparting the necessary qualities to meet the stringent service conditions. However, unless the fundamental requirement of good ropemaking is recognized, all other operations, no matter how carefully performed, will not impart reliability and quality to the product. This fundamental requirement is steel that is homogeneous, of high resistance to fatigue, and of a type suitable for rope wire. Most wire-rope manufacturers agree that rope wire should be made from acid-open-hearth steel. It is comparatively easy to meet the same physical properties with basic steel, but such properties are only part of the requirements for good wire. It is absolutely necessary, particularly for rope service such as mining, where reliability is essential, that the wire be uniform throughout its entire length. Most manufacturers feel that this highly important requirement is better met by acid-open-hearth steel.

Jan 1, 1936

By Allen F. Agnew

Geologic studies for the Federal and State governments in the Wisconsin-Illinois-Iowa zinc-lead district were begun in 1835, and subse¬quent surveys were made in the three states at in¬tervals until 1916, see Table I. The current study of the district, Fig. 1, by the U. S. Geological Survey was begun in 1942 in the hope that a systematic investigation would help in¬crease production of zinc and lead, then in ex¬tremely short supply. Major emphasis of the USGS program was on detailed mapping of the geologic structure and ore deposits. Preliminary maps and reports covering localities of intensive mining ac¬tivity have been published during the course of this study, Fig. 2. By 1950 the objectives of the study by the USGS were revised; 7Y2-min quadrangles of relatively unprospected localities as well as inten¬sively mined localities are now being mapped in Wisconsin. Since 1945 the investigation in Wiscon¬sin has been made in cooperation with the Wiscon¬sin Geological and Natural History Survey, and since 1951 the geologic mapping of areas of particu¬lar interest in Iowa has been performed in coopera¬tion with the Iowa Geological Survey. At intervals since 1943 the Illinois State Geological Survey has mapped the geologic structure and ore deposits of localities in the Illinois part of the mining district, see Fig. 2.

Aug 1, 1955

By F. Peter

I. GENERAL INTRODUCTION. TECHNICAL progress takes place in two directions: the improvement of methods, affecting the quality of the product; and increase in the economy of operations, affecting its cost. In the iron-industry, practice is pretty well settled, and. revolutionary changes of method are, for the present, not to be expected. Hence, in this industry, the principal endeavor is to reduce costs by the use of labor-saving inventions, such as the machines brought into use during the last decade. But it is not alone necessary to reduce the labor-cost; complete economy requires also a saving in raw material. Under this head we may rank the coal employed as metallurgical fuel; and it follows that progress includes the economic use of fuel, so managed as not to injure quality of product. In the present paper it will be shown how, by suitable utilization of the heat from the furnace, a large portion of it may be made available for other purposes. Such utilization of waste-gases is important in all industries which employ furnaces (especially heating- and smelting-furnaces); and in the first rank of these stand the iron-, glass-, and porcelain-manufactures. The following pages are devoted chiefly to the waste-gases of smelting-works, and especially to those reverberatory-furnace gases which are not combustible.'

Jan 12, 1913