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By ARTHUR THACHER

PRIMITIVE man supplied his wants as they arose; as he became more civilized he anticipated them by producing more regularly and storing the products for future use. This tended to cheapen' production and prevent ' violent fluctuations and therefore tended to increase consumption. In order to anticipate our wants, we must know what these wants will be, and this can be .determined only by statistics. 'While we have made great progress in gathering statistics, they are still far from what they should be; especially metal statistics. We determine fairly, well the amount produced, but this does not answer all inquiries because of the erratic conditions of mining, it is necessary to carry larger stocks of metals than of most other articles; moreover, as metals are more or less durable, it is difficult to determine the actual consumption. We often count under consumption what is being produced and sold, while the actual consumption is what is being worn out.

Jan 1, 1921

By Richard J. Gowen

THE FUTURE The environment in which we live appears to change so slowly that most of us are unaware that any change has occurred at all. As the years pass, we notice increasing smog in our cities, new variations in weather, the shifting landscape with changing populations, and subtle but ever present alterations in the quality of life. In considering the future of our environment, we find we must grapple with questions concerning the very future of life as we know it today. Questions of resources, technology, society, governance, and purpose. Let us focus on the future of our environment and, in particular, raise the question of who is responsible for the environment. We know that action, or lack of action, will clearly influence our future environment. It is fashionable to catalog the many short-sightedness of our forefathers in developing the technologies which support the style of living to which we have become accustomed. However, I shall struggle to resist the temptation to list the well known ills of our present environment. Rather, let us concentrate on the future in our consideration of the priority of the multitude of options proposed to relieve our current energy crisis. We have recently witnessed the dramatic effects of air pollution produced by Mount St. Helen's eruptions. In the state of South Dakota, we watched our blue skies turn hazy and felt our eyes sting with the presence of volcanic ash. We were appalled at the dramatic effects on the landscape, crops, transportation, and all aspects of life in communities immediately downwind of the volcanic eruption. But in a few weeks, life had returned to near normal on the earth's surface leaving the volcanic ash in the atmosphere to ultimately

Jan 1, 1983

By Albert Sauveur

THE senior author of this paper has expressed the belief that when gamma iron transforms into alpha iron on reaching the A3 point, each gamma grain does not change bodily into one or more alpha grains but that the alpha phase forms first at the boundaries and along the crystallographic planes of the austenite grains.1 To quote: On cooling through the point A, at about 900° C., iron passes from the gamma condition to a. new allotropic form generally designated as alpha. This transforma¬tion, however, is not instantaneous. There are good reasons for believing that it begins at the grain boundaries and along the octahedral planes of the crystals and that it progresses until each grain of gamma iron is changed into a grain of alpha iron, the resulting structure being similar to that of gamma iron. Were it possible to retain at room temperature pure iron but partially transformed, it seems probable that a Widmanstättian structure, or rather, as later explained, a martensitic structure would be observed (Fig. 1), consisting of alpha iron at the boundaries and at the octahedral planes, and of a groundmass of gamma iron. In order to confirm, if possible, the accuracy of that view, a number of experiments were conducted. Polished samples of electrolytic iron were heated in a vacuum, maintained in the gamma range for several hours and quenched in different media. It was hoped by such means to produce and retain on the polished surfaces a pattern which would reveal the mechanism of the allotropic transformation. The samples were placed in evacuated quartz tubes, heated to 1000° C. and held 2 hr. at that temperature. The tubes were then immersed in the quenching bath. Iced brine and liquid air were used first. The polyhedral austenitic structure existing at the time of immersion was very clearly revealed (Fig. 2). This is generally ascribed to iron volatilizing at the grain boundaries.

Jan 1, 1929

By R. H. Lee

WITHOUT doubt, one of the most frequent and serious annoyances connected with the practical running of a blast-furnace, especially in single-furnace plants, is caused by low steam, in spite of the fact that all boilers at blast-furnaces have grates for burning coal, and that coal is more or less continuously burned upon them, from three to a dozen men being pretty constantly engaged around the boilers as firemen or coal- and ash-handlers. At times, when the furnace is ? tight," all available men are put on to assist the regular firemen; yet sufficient steam cannot be got to keep the engines up to their regular number of revolutions, while the stoves, deprived of the gas which has been sent to the boilers, run cold, so that, when the furnace loosens-up and resumes the regular rate of driving, the blast is very considerably below normal temperature, and a.' cold," or at best a " high-sulphur," east is the result. Again, it often happens that a furnace, running at its best, becomes temporarily a little too hot; the pressure rises; the amount of gas made' is diminished; the steam soon commences to go down; and a small scaffold is likely to form before the furnace has been brought back to the proper rate of driving, and thus enabled to take its regular amount of blast. The usual remedy is either to "jerk" the furnace by a sudden, brief intermission in blowing, or to cool the furnace by lowering the heat of the blast; but if the lower blast-temperature be maintained too long, the hearth and descending stock may be cooled below the " critical temperature " mentioned by Mr. .Johnson, and the furnace may go to the other extreme, and become cold. This is especially the case when coal or coke, high in sulphur, is used:

Jul 1, 1906

By Frederic Dewey

(New York Meeting, February, 1913) This old and well-known method of determining, silver is, in bullion work, so far superior to the furnace-assay that it is looked upon with reverential awe by many, if not by most, users, and its-ease of execution, with proper equipment, commends it highly where much commercial bullion work on silver is required. The method is so thoroughly well known that a, description of it here may seem to be unnecessary, but many thousands of determinations are annually made by it in the U. S. Mint Service and its practice is there reduced to an art. This is necessary both for the sake of economy of time, acid because high-grade work with it requires constant practice. It is useless for a person who uses it only occasionally to expect to attain high accuracy with it, without spending more time upon a determination than is warranted in a busy commercial laboratory. It is always employed in the Mint service whenever possible, but its chief field is in the determination of silver in standard silver (ingots and coin), which is 900 fine in silver and 100 fine in copper, and I shall first briefly outline its use on this metal and then take up various points in detail, especially as related to the accuracy of the results obtained.

Jan 4, 1913

By W. C. Knopf, G. Samsel

For several years International Minerals & Chemical Corp. has used a radiation method to assay potassium content of products from potash and feldspar beneficiation. The procedure is rapid, accurate, and inexpensive and is easily handled, if necessary, by nontechnical personnel. Data are presented to show the accuracies that may be expected if the technique is used for control of pilot plants or large- scale plants. Natural potassium is composed of three isotopes -K39, K40 and K41. Five other isotopes, artificially produced, have been detected. In natural potassium only the K40 isotope, with a half life of 1.4 x 109 years, is radioactive. Its modes of decay are beta and gamma rays, positrons, and x-rays. Only the more abundant beta rays, however, are important in radiation measurements using geiger tubes.

Jan 10, 1958

By Garth M. Crosby

Seven mines with important production records in the Coeur d'Alene lie adjacent to the Gem stocks -the Frisco (Gem), Hercules, Interstate, Rex (Sixteen to One), Success (Granite), Sunset, and Tamarack. Old records are incomplete, but avail- able data given in Table I show these mines have produced 10,550,721 tons of ore containing more than 50 million oz of silver, more than 1.5 billion lb of lead, and about 1 billion lb of zinc (approximately 1.25 million tons of lead and zinc combined). Average ore grade is 4.8 oz of silver per ton, 7.2 pct Pb, and 4.6 pct Zn. This impressive production represents about 12 pct of the District's yield. At present metal prices, with modern beneficiation, the gross value would be more than $400 million.

Jan 7, 1959

NOW continuing with the preparation of the moulds I say that it is necessary to give the greatest attention to the differences of the clays as well as to the differences of those things that you wish to mould; and to know that every concavity in the mould produces a convexity and every convexity a hollow following the shape of the original pattern that you have. The pattern should be a body of a harder mated than the thing [78] you wish to mould with and of a substance that is not swollen or disintegrated by moisture. Its archetype may be of marble, bronze, lead, or any other metal, or also of wood, wax, tallow, gypsum, sulphur, or other plaster compositions-in short, of whatever you may have or whatever succeeds best for you, depending on whether the works are large or small and easy or &cult to mould. If you wish to cast them in bronze, you must mould them with loam, covering them with it and then drying it. There are some things in which it is enough to form only one part, such as half- or bas-reliefs. These are easy if they have no undercuts. Some other patterns that are easily handled are formed in two halves, or in three or four pieces, if they are of a hard material. There are also moulds for large statues, which, if one desires to make them of bronze, are first made of wax according to the ordinary procedure. I have in mind to describe every one of these processes in their own place. There are like- wise some moulds that are difficult to make, like scenes on a plane to which figures in full relief are attached, or twisted ornaments or other detached things that cannot be withdrawn from the mould without break-

Jan 1, 1942

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

By G. Donald Sherman

THE intense chemical weathering of geological materials in the tropical regions has produced soils that are very rich in their content of iron and aluminum oxides. These soils are commonly referred to as laterites. There is considerable confusion as to the definition of a laterite, since there are workers who consider it to be entirely a ferruginous horizon and others who insist that laterite must have a high content of free aluminum oxide. How¬ever, in general the former is the accepted definition. The indurated ferruginous clay was given the name "laterite" by Buchanan,' not because of its bricklike appearance but rather because bricks were cut from it and used as a building material. Many of the temples of India and Siam are built of this material. This term has come to mean to the geologist a material that includes hard masses of concretionary, cellular, pisolitic ironstones. The soil scientists have deviated from the original meaning of the word and their writings show very little respect for Buchanan's definition or an understanding of the ma¬terial described by him. Pendleton," a life-long student of tropical soils, has insisted that the term laterite be restricted to Buchanan's definition; namely, an alluvial horizon, largely of iron oxides, with a slaglike, cellular or pisolitic structure, and of such a degree of hardness that it may be quarried out and used for building construction. More recently DuPreez2 and Sherman" have eliminated from Buchanan's definition the requirement of a hardness for building construction purposes. In doing this they eliminate the lithological implications in favor of a description of a product, soil, which originates and is developed by pedogenic processes. The confusion of the definition of a laterite is made greater by workers who insist that it must contain bauxite of different degrees of purity. Many of the tropical soils are rich in aluminum oxides. It is natural for the workers who have studied these tropical soils to emphasize the importance of the hydrated aluminum oxides. Hollands reported that the alumina in a laterite existed as bauxite. Fermor3 insisted that a laterite must have a high content of aluminum oxide hydrate, and Fox,4 in 1923, made the suggestion that if a laterite contained enough hydrated aluminum oxide to be used as an aluminum

Jan 1, 1952

By Michael E. Zellars

The environment for deposition of marine phosphorite is controlled by the relationship of prevailing climatic, oceanographic, structural, and sedimentary conditions. The set, or sets, of conditions that has evoked the accumulation of economic concentrations of phosphorite has been the subject of a number of previous works. Phosphorite presently considered ore is generally in excess of 10% P205 with an extractable phosphate product in excess of 30% P2O5. The concentration of the product in the ore, its amenability to state-of-the-art extraction, and thickness of the overburden are major controlling factors in determining its mineability. A recent survey of phosphorite deposits in the south-eastern United States included a review of the depositional and structural setting for the major areas of occurrence. The application of previous work regarding phosphorogenesis has led to the establishment of a general depositional model for most mid-Miocene primary phosphorites, and, is also possibly applicable to the Bone Valley (Pliocene-Miocene) district of central Florida.

Jan 12, 1978

By Joseph Singewald

I. THE GENESIS OF THE DEPOSITS THE ore deposits at Firmeza have been worked continuously since 1884; those at Daiquiri since 1895. It is surprising, therefore, that they have not been the object of careful geologic study until quite recently. It is true that considerable attention was paid to these deposits by A. C. Spencer, in 1901, in the report on the geology of Cuba, by Hayes, Vaughan, and Spencer,1 but this was only incidental to a hasty general reconnaissance of the Island. As far as the Daiquiri deposits are concerned, this gap has been filled by the appearance of the two papers by Prof. James F. Kemp2 and by Prof. Waldemar Lindgren and Clyde P. Ross respectively.3 Max Roesler, first holder of the Emmons fellowship, made a detailed study of the Firmeza deposits during the past summer, so that soon we can expect a full description of them. Consequently, there is no. demand at the present time for a description of the deposits from other sources, rind that is not the purpose of this paper. The papers on Daiquiri, however, leave unsolved problems in regard to the age of the rocks of the district and certain phases of the genesis of the deposits, and it is with the. hope of aiding in the solution of some of these problems that this contribution is offered. Kemp, and Lindgren and Ross agree in assigning these deposits to the type of contact metamorphic deposits. They disagree in part on the question of their localization. The deposits occur in an extensive area of diorite which includes numerous blocks of limestone, and some-

Jan 3, 1916

By Stephen Taber

INTRODUCTION THE term asbestos, as commonly used, includes half a dozen minerals all having a well-developed fibrous structure, but differing in chemical composition and in some of their physical, properties. In its strict application the name is limited to the fibrous varieties of the monoclinic amphiboles. Commercially, however, the most important of the asbestiform minerals is chrysotile, a fibrous variety of serpentine. About 95 per cent. of the asbestos used in manufacturing is chrysotile, and it commands a much higher price than any of the other fibrous minerals now on the market. Although the production of asbestos has increased rapidly in recent years, comparatively little has been published concerning its origin. The present paper is preliminary in its nature, and therefore does not pretend to exhaust the subject. The ideas herein developed are the result of field investigation, laboratory experiments in the growth of fibrous

Jan 10, 1916

By Stephen Taber

JOHN C. BRANNER, Stanford University, Cal. (communication to the Secretary *).-Wideawake teachers of geology are constantly on the lookout for good illustrations of veins, especially where the processes of formation are either clearly shown or suggested. And I long ago found out that one who would learn nature's laws must despise nothing. It thus happened that in 1910, Dr. George J. Peirce of the depart-ment of botany at Stanford University called to my attention a cracked and broken yellow earthenware dish, 8 ½ in. across the top and 2 ½ in. deep, that, to the ordinary observer, seemed to be of no further use, and quite ready for the waste can. The striking thing about this dish was that the thin glaze over much of the outside surface and over the upper margin of the inside surface had been lifted in small scales, varying in. diameter from ½ cm. to 1 cm., and thrust outward and held there by some sort of white fibrous mineral. The process looked very much like one we are familiar with in the Southern States where. we often see in the winter pebbles and soil thrust out from a clay bank or lifted from a clay soil and held there supported by what is popularly known as needle-ice. Upon inquiry I learned the following facts in regard to the history of this particular dish: In the summer of 1910, it had been partly filled with a concentrated salt solution taken from one of the salterns of the Stauffer Chemical Co. at Redwood City, Cal. A qualitative analysis of the original brine showed: Present: iron, magnesium, sodium, potassium, chlorides, sulphates, nitrates (trace), bromides, carbonates, borates (trace), and considerable amounts of organic matter. Absent: calcium, lithium and iodides.

Jan 3, 1917

STEPHEN TABER, Columbia, S. C. (communication to the Secretary?). -The fibrous salt crystals described by Dr. Branner are interesting, and I am glad that he has put this additional evidence on record. It confirms the results that I obtained in growing fibrous crystals in the laboratory. Much similar evidence of value to science in interpreting the laws of nature has doubtless been lost through failure to appreciate little things. Mr. Dresser points out that the boundary between chrysotile veins and massive serpentine is finely irregular 'when examined under the microscope. This fact I have observed in studying chrysotile veins and also, mode recently, in studying veins of fibrous calcite and fibrous gypsum. For the latter veins the statement holds true when the walls are of shale as well as when they are of the same material as the veins, but in no instance have I observed any evidence of replacement. The description of the vein walls given in my paper (pp. 1984 to 1985) was megascopic, not microscopic. The fact that chrysotile veins have sharply defined boundaries and are easily separated from the wall rock is evidenced by the small amount of waste adhering to the "crude asbestos" which has been shipped in such large quantities from some of the Canadian mines. Mr. Dresser has good ground for his statement that there seems to be no obvious reason why the term "mass fiber" should be restricted to anthophyllite. I have never examined the serpentine at the East Broughton mines; but in studying other serpentines under the microscope I have noted that much of the so-called "massive serpentine" is really finely fibrous (see pp. 1974 to 1975). The texture of such rock is, however, altogether different from that of mass-fiber anthophyllite, and I believe that the fibers have developed in a different way (see pp. 1981 and .1998). Mr. Graham raises certain objections on the ground that the laboratory production of fibrous crystals was limited to substances which go into solution with decrease in volume. Since my paper was written, however, I have succeeded in obtaining fibrous crystals of ammonium nitrate, a salt that dissolves with expansion in volume.

Jan 5, 1917

By John R. Don

In the South Island of New Zealand an unusually favorable opportunity is offered for the analysis of the older crystalline rocks, underlying the sedimentary rocks which form the "country" of the gold-deposits. The Manipori formation of this island, comprising the greater part of the mountainous district west of lakes Manipori and Te Anau, in Otago, consists of an enormous thickness (estimated by Professor Hutton1 at 160,000 ft.) of crystalline schists, gneiss, syenite, and syenitic gneiss, with associated masses of granite; the whole forming the most picturesque fart of New Zealand. The famous West Coast sounds occur in this formation. No paying auriferous lodes have been discovered in it; and for this reason an examination of the rocks is specially interesting here. Stelzner, Posepny, and others, who have criticised the conclusions of Sandberger, have laid great stress on the fact that all the silicates analyzed by him were taken from the vicinity of orebodies containing those heavy metals which he notes as occurring in the silicates of the country-rock; their contention being that these metals, supposed to occur as silicates in gneiss and other crystalline rocks, were really contained as sulphides, and were therefore impregnations from the neighboring orebodies. The same objection, whatever be its weight, might be urged with equal justice against Mr. Becker's derivation of the mercury and gold of the lodes of the Pacific Coast from' the granite underlying their country-rock. In the case of the

Jan 1, 1913

By S. F. Emmons

IN a report upon the geology of Leadville and vicinity, which is still in the hands of the Public Printer, I have given, at some length, my conclusions as to the genesis of the remarkable silver-lead deposits of that region, and the data, gathered during a long and careful consideration, upon which my views were founded. In the brief abstract of this report, published in 1881, the bare conclusions are given, with but few of the facts upon which they were founded. Since that time, these conclusions have been variously criticised, and it has even been assumed that the views I expressed with regard to these deposits were intended as a theory of ore-deposits in general. Had my final report been printed, no such misconception could have occurred; for, in that I explicitly disclaim any intention of general application of the theories there presented. Even in the abstract I am unable to find any statements which would. justify such a conclusion. Since my Leadville work, however, I have had further opportunities of examining ore-deposits, and have given the general subject much thought and study, and, as a result, I have made in my own mind certain generalizations, which, I am conscious, need the test of a far greater number of practical applications than I have yet been able to make, but which, I think, it may be well to present to the members of the Institute as suggestive, that their own observations may further prove or disprove them. I shall use my Leadville observations and the criticisms which have been made upon them as a sort of text for my remarks. The salient facts, which I thought to have determined with regard to the Leadville deposits, which, as is well known, are silver-lead deposits in a dolomitic limestone, overlain and in

Jan 1, 1913

By Franz Posepny

CONTENTS. Introduction. Part I. General Facts And Theories. [ ]

Jan 1, 1902

By Waldemar Lindgren

CONTENTS. [ ] THE following pages are a resun16 of some of the conclusions reached during a study of the copper-deposits near Clifton The field-work was finished in 1902 and a complete report is now in the press. A preliminary description of the district was published in 1903, in Bulletin U. S. Geological Survey, No. 213. pp. 133-140

Jan 1, 1913

By Max Boehmer

(Pittsburg Meeting, March, 1910.) AFTER 30 years of development and after an output of $350,000,000 in value of gold, silver, lead, zinc, and copper, there has not been published a satisfactory explanation of the origin of the immense deposits of the Leadville district. The original examination find survey of Leadville by members of the U. S. Geological Survey was a most magnificent piece of work, but their attempt to explain the origin of the ores was based upon the then-accepted theory of lateral secretion, originated by Sandberger, which theory was afterwards disproved in many cases by further development in numerous districts. This theory contended that the ore in the veins had been leached by surface-waters from the eruptive rocks in the immediate vicinity, and it had its origin in the fact that the neighboring eruptive rocks all contained, to an appreciable degree, the several metals found in the ore-deposits. But the practical miner, reasoning in a simple manner from the condition of things as he found them underground, soon discovered the fallacy of this proposition. He reasoned that, in the case of the Leadville deposits, this theory could not be true, because, if the ores were leached from the overlying eruptive rocks by surface-waters, they would as a matter of necessity be controlled by the action of gravity, and the main bodies would collect in- natural depressions of the underlying limestone, and at all points where such depressions existed. But this was not in accord with the channels of ore as he found there ; and hence the theory of lateral secretion in this district was never accepted. Another objection to it consisted in the fact that large areas within the ore-bearing district contained no ores whatever, although their formation was the same, and the same limestones were covered by the same thick sheet of

Feb 1, 1910