Search Documents

By Benjamin L. Miller, Charles H. Breerwood

From earliest recorded times, limestone has been employed in the industrial life of peoples of all sections of the world where it exists. It is widely distributed and therefore has been available in almost every country and has been employed for a variety of purposes. Its earliest use was for buildings, since it is more easily quarried and dressed than most other kinds of rocks and so could be utilized by early inhabitants, poorly equipped with tools. The next use was in the manufacture of lime, which was employed by the ancients in mortar. These two uses of limestone are still all important, but they have been overshadowed in scores of regions by literally hundreds of new applications for raw limestone or products made from it. Anyone familiar with modern manufacturing processes can quickly call to mind many industries in which limestones are essential, and new uses are continually coming to notice. Any enumeration would probably be incomplete and soon out of date. Origin of Limestone Disregarding details and unusual types concerning which often there is insufficient evidence and considerable difference of opinion, limestones have been formed by the precipitation of calcium carbonate from solution through the action of organisms, both plants and animals, or in a limited number of instances by chemical reactions without the intervention of living forms. Some of the organisms extracted the calcareous material in order to build up hard structures, either as bony skeletons or as coverings (clams, snails, etc.), whereas others in their life functions emitted substances that resulted in the precipitation of the soluble constituents outside the organisms themselves. In some instances the organisms utilized only calcium carbonate but in some cases other compounds as well were precipitated. Various materials have been found in the hard parts of animals, and for that reason it is almost impossible to find a pure natural limestone; that is, one composed entirely of CaCO3.

Jan 1, 1938

By Charles H. Breerwood, Benjamin L. Miller

From earliest recorded times, limestone has been employed in the industrial life of peoples of all sections of the world where it exists. It is widely distributed and therefore has been available in almost every country and has been employed for a variety of purposes. Its earliest use was for buildings, since it is more easily quarried and dressed than most other kinds of rocks and so could be utilized by early inhabitants, poorly equipped with tools. The next use was in the manufacture of lime, which was employed by the ancients in mortar. These two uses of limestone are still all important, but they have been overshadowed in scores of regions by literally hundreds of new applications for raw limestone or products made from it. Anyone familiar with modern manufacturing processes can quickly call to mind many industries in which limestones are essential, and new uses are continually coming to notice. Any enumeration would probably be incomplete and soon out of date. Origin of Limestone Disregarding details and unusual types concerning which often there is insufficient evidence and considerable difference of opinion, limestones have been formed by the precipitation of calcium carbonate from solution through the action of organisms, both plants and animals, or in a limited number of instances by chemical reactions without the intervention of living forms. Some of the organisms extracted the calcareous material in order to build up hard structures, either as bony skeletons or as coverings (clams, snails, etc.), whereas others in their life functions emitted substances that resulted in the precipitation of the soluble constituents outside the organisms themselves. In some instances the organisms utilized only calcium carbonate but in some cases other compounds as well were precipitated. Various materials have been found in the hard parts of animals, and for that reason it is almost impossible to find a pure natural limestone; that is, one composed entirely of CaCO3.

Jan 1, 1938

By Charles S. Barrett

There is a road into the microscopic realm that has remained untraveled through all these years of intense activity with high-power optical and electron microscopy. The road is worthy of careful scouting by metallurgists and other investigators, for it leads into relatively new country and it makes some areas accessible that heretofore could be reached only by very indirect paths or by the use of imagination. And when the road passes through familiar territory it frequently permits a new view of commonplace things that should prove of value from time to time. An accepted way to interest people in new sights such as this is to present an illustrated travelogue. This I propose to do, using many pictures taken in my recent exploration of this road. In the manner of travelogues, I shall touch briefly upon a large number of different subjects in physical metallurgy and shall attempt to give an exhaustive treatment of none, for the objective is to provide a means for further research, to interest others in it, and to indicate what appears at the moment to be profitable directions for it to take. The method I shall present involves X-rays, but does not make use of the usual accompaniments of X-ray research such as reciprocal lattices, Fourier series, or the stereographic projection. The method is so simple in its fundamentals that it could have been developed 2o years ago, or perhaps even 30 years ago. It is well to have a destination for our travels, so that when we are through we shall have explored some region of importance, despite our preoccupation with the novel means of transportation and our interest in the sights to be seen along the way. So let us name the Cold-worked State as our destination, and make side trips into the territories known as Recovery, Recrystallization, and Precipitation-hardening. A great many investigations have been made of the nature of cold-worked metal, and a great variety of methods used, many of which are indirect, such as X-ray line intensities, X-ray line widths, calori-metric measurements, and magnetic measurements. Since comprehensive reviews of these investigations have been published in recent years, they need not be discussed here. The investigations that were the direct forerunners of the present work should be first mentioned. In 1931 I became interested in the structure of individual spots in X-ray diffraction patterns.l When a crystal is placed in the narrow pencil of X-rays in a Laue camera, the spots recorded on the film are not always uniformly black, but may have an internal structure. The meaning of this may be understood from Fig. I, which represents a narrow beam containing X-rays of many wave lengths (''general radiation") penetrating a crystal in the direction of the arrow and forming a pattern on the vertical film at the right.

Jan 1, 1945

By Zay Jeffries

TUNGSTEN has the highest melting point of all the known metals, namely 3350° C.; it is one of the hardest of the metals; it has the highest equiaxing or recrystallization temperature after strain hardening, of any pure metal known. It is particularly distinguished because, when composed of small equiaxed grains, it is extremely. brittle and fragile at room temperature, and when possessing a fibrous structure it maybe ductile and pliable at room temperature. The common ductile metals act in exactly the opposite manner in this respect. The present paper will include a brief note regarding the manufacture of wrought and. ductile tungsten. The metallography of wrought and ductile tungsten in the various stages of manufacture will be considered more or less in detail. The general relationships between the properties of tungsten and other metals will also be considered. A discussion will be given explaining why fibrous tungsten is ductile at room temperature, even though past experience with other metals would indicate that it should be brittle. Finally, a brief note regarding some new fundamental metallographic propositions relating to all metals will be given.

Jan 6, 1918

The United States has never been a large coal exporting nation, and normally such shipments, aside from those to Canada, have been relatively small. Since the first railroad was built across the Allegheny Mountains, the imports have been quite small also, although fairly large tonnages of Canadian coal have moved into the extreme northeastern and northwestern states at times. In Table 21 are shown all data available about these shipments from 1790 to 1939, inclusive.

Jan 1, 1942

SHELBY M. HARRISON,* New York, N. Y. (written discussion ?).¬Your secretary requested a brief description of the Russell Sage Foundation, in order that members of the Institute, if they should desire to avail themselves of it, would know what type of service is offered to them through our institution. The foundation was established in 1907 by the gift of Mrs. Russell Sage of $10,000,000 as a capital fund, the income of which is to be spent for the improvement of social and living conditions in the United States. One of the lines of activity which the foundation has felt would lead toward this end is the development and promotion of community surveys; and because the scope and methods followed in these surveys are very similar to the scope and method of much of the institution's work in general, an idea of its main activities can perhaps be given best by describing one of our surveys. Incidentally, it may be pointed out that antecedent to the survey stand at least two important facts: first, the recognition. that communities are active, not static forces, that they develop, that changes in. material and human relationships occur continuously, and that with them come new social and civic problems which must, in many cases, be diagnosed and prescribed for anew; and second, the reality of scientific advances along lines which make possible at least some measure of solution of the problems. Evidences of these changes are abundant; many of them are found in the rapid growth of cities in the last few decades. Villages in agricultural districts, places where everybody knew everybody else, where the pulpit had been long the chief or only influence molding public opinion, where the air was unclouded by the smoke from factory stacks, where the water supply was not affected by pollution, where sunlight and building

Jan 5, 1918

A discussion at a joint meeting of the New York Section of the American Electrochemical Society and the American Institute of Mining Engineers, Nov. 20, 1913. Chairman Lawrence Addicks:-Our program this evening represents an attempt to set before you the present situation and outlook in the metallurgy of zinc. It is a time-honored custom to throw bricks at the zinc man. The accusation is that he has borrowed a lime kiln and a gas retort and part of a sulphuric acid plant, hitched them together, and spent the last 50 years in regarding with holy veneration the reactions which take place in that retort. The copper man, who thinks of zinc as something with which copper is adulterated to make brass, and the iron man, who regards it as a sort of paint for corrugated sheets, and the lead man, whose opinion as to zinc is not fit for publication, have long felt that, when two or three of the minor details of their respective metallurgies were put in order, they would take a few clays and fix up zinc on a modern basis. But somehow there still seem to be some unsolved problems at home, and while we are waiting it seems only fair that the case for the defense should be adequately presented. There is probably no man in this country to-clay better able to do this than Mr. George C. Stone, of the New Jersey Zinc Co., on whom I have pleasure in calling to talk to us on "Progress in the Metallurgy of Zinc." George C. Stone:-It is frequently stated that there has been no change in the metallurgy of zinc since the first Belgian furnaces were built in the early part of the last century. It is true there have been no such spectacular and radical changes as were worked in the metallurgy of copper and iron by the introduction of converters; but, in the essentials, I believe the progress in zinc metallurgy has been as great as in that of the other common metals. The main reason that there have not been revolutionary changes is that the chemistry of zinc differs radically from that of the other metals and these differences control the type of apparatus that can be used. The differences are: 1. The temperature at which zinc is reduced by carbon is much above the volatilizing point of the metal and it is therefore always produced as a vapor.

Jan 1, 1914

By R. M. Larsen

The Rocky Mountain region is defined with some variations for different purposes or by different organizations. For oil and gas development, Wyoming, Montana, Colorado, northwestern New Mexico, and Utah are included in the order of their apparent importance. Portions of adjoining states, such as North and South Dakota, Nebraska, Arizona, Nevada, and Idaho, arc attributary to this region, but have little or no oil or gas production. Nebraska and New Mexico are considered separately (see pp. 412 and 415), and most of the discussion in this report will be confined to Colorado, Montana, and Wyoming. Utah has produced about 200,000 bbl. of oil from the San Juan and Virgin fields, which are isolated and shut in at present. The Clay Basin field in northeastern Utah produces natural gas and distillate, and the Farnham field in central Utah produces carbon dioxide gas. Other Utah areas of some interest are listed in Table I. The Cedar Creek (Baker-Glendive) field in southeastern Montana extends into North Dakota, but is listed under Montana. The other states are in the main wildcat areas, and exploration in 1944 was at a minimum. However, geological and geophysical parties are reviewing them for further testing. Oil production in Colorado, Montana and Wyoming was 459,000 bbl. more than in 1943. Increases of 713,000 bbl. in Colarado and 731,000 bbl. in Montana offset a loss of 985,000 bbl. in Wyoming. This was the first decline in Wyoming since 1938. Field production figures and state totals are given in Table I. Total drilling activities in these three states and Utah increased from 687 wells making 1,442,511 ft. of hole in 1943 to 916 wells making 2,245,803 it. in 1944. Wildcat drilling increased from 163 wells making 331,193 ft. of hole in 1943 to 171 wells making 389,144 it. in 1944. These figures include all drilling wells making footage, not starts or completions, and represent an all-time high in drilling. The year 1944 witnessed the greatest concentration of seismograph activity that the region has had. The Rocky Mountain Oil Scouts Association reported that in 1943, the previous peak year, 91 crew months of work were performed; in 1944, the time was 254 crew months. About 67 per cent of the work was in Wyoming, 18 per cent in Montana, and 12 per cent in Colorado. Twenty-three blocks totaling 400,000 acres were reported assembled in Colorado, and 161 blocks totaling 4,000,000 acres in Wyoming. Information about other states was not given. Fourteen unit agreements were approved by the Department of the Interior, as compared with 13 in 1943. The 1944 agreements were all in Wyoming. In five of the unit areas, oil or gas discoveries were made, four were dry, and five were drilling Or pending' Oil companies find it advantageous to unitize blocks containing any proportion of public domain. Units for

Jan 1, 1945

By G. G. Sarkar

SHARPNESS of separation and washing efficiency are often confused. The sharpness index indicates the precision of a washing unit; the washing efficiency takes into account not only the unit's precision but also the washability characteristics of raw coal and the near-gravity materials at the effective density of cut. A sound basis for evaluating the sharpness index is essential in comparing the sharpness of separation attained by different cleaning units. Sharpness Index and Related Criteria: Washing plant sharpness of separation has been well represented by Hancock's efficiency chart and Tromp's curve of migrated materials. Some useful coefficients derived from Tromp's curve—the error area, probable error, and imperfection value—have been widely used to measure sharpness of separation. These are defined in a number of papers presented at the first and second International Coal Preparation Colsference held in Paris (1950) and Essen (1954).1-5 In evaluating the performance of a dense medium separator at four different gravities, Yan-cey and Greer6 bserved that even with similar operating conditions and the same size grading of feed, the imperfection value of a washing plant varies through a greater range than the probable error. The present writer also observed the same type of anomalies in comparing the imperfection values of one plant which were determined under almost identical conditions. He therefore devised a graphical method to evaluate a washing unit's sharpness of separation and define it by a single coefficient, which is substantially independent of coal characteristics under normal operation of the unit. Unlike imperfection value, the new coefficient can be expressed on a percentage basis. Coal preparation engineers generally agree that the amount of misplaced material resulting from any separation in a washing plant is almost directly related to the amount of +0.10 sp gr (near-gravity) materials. In actual practice, however, misplacement is not restricted to the 20.10 sp gr range. It will be evident from a study of Tromp curves that this misplacement often extends over unequal specific gravity ranges on the two sides of the actual density of separation. The same condition exists for near-gravity ash distribution and the resultant misplacement of ash units during any separation. But so far as the same unit is concerned, the total misplacements bear a definite ratio to the amount of near-gravity zone materials that is affected by misplacements. This ratio should be constant not only for various densities of separation but also for different qualities of feed coal treated in the same plant. This ratio, multiplied by 100, directly represents the inefficiency of the plant. When the plant inefficiency value is subtracted from 100, the re- ' sult is designated as sharpness index. Evaluating the Sharpness Index: The method of evaluating the sharpness index is explained here with reference to Fig. 1. Fig. 1 is a reproduction of the familiar diagram used by Cerchar of France to represent the inefficiency of a separation in terms of "triangle of errors," which is a measure of organic loss. It will be observed that the characteristic (yield/fractional ash) curve of the raw coal represented by GHAPR

Jan 1, 1958

By H. C. George

IN 1901, the United States produced 69 million barrels of crude oil, which was 41.4 per cent of the world production. By 1931, these figures were 850 million barrels and 62.1 per cent respectively, showing over this period of thirty years an increase in the world production of 718 per cent. Over this same period, the increase in the demand for technically trained men in the industry was much greater than the increase in crude-oil production. This was because much of the increase in production was secured by the application of geology and physics to the finding of new oil fields and by .the development of engineering methods and equipment incident to drilling and producing from much greater .depths.

Jan 1, 1934

By Frank F. Poland

TEE purpose of this paper-is to describe a new process for the refining of secondary copper-base metals and a specially designed high-temperature electric-resistor furnace used in the process for the distillation of zinc from these metals. The process was used for the conversion of nickel silver to cupronickel and to recover the zinc content in metallic form. It also proved applicable and economical for the treatment of scrap brass for separating and reclaiming the copper and zinc. The relatively large furnace developed for the distillation of zinc is described in detail, for it made economically possible the direct recovery of metallic zinc from scrap brass, which is a new step in the processing of such material. Considerable interest has been shown in the utilization of the distillation furnace for other metallurgical processes, where it is of advantage to operate in a controlled neutral or reducing atmosphere, or to avoid having the processed metal in contact with refractories other than carbon, or to operate at temperatures between 3000 and 4000°F. PURPOSE OF DEVELOPMENT It was recognized early in the war effort that nickel would become a critical metal, therefore all nickel stock and alloys containing relatively high percentages of nickel were frozen immediately. Among these alloys were considerable quantities of various grades of nickel silver, an alloy containing copper, nickel, zinc, and in some grades lead, also minor amounts of iron, manganese and other constituents. At the time there was no existing plant or process to eliminate the zinc, lead, and minor constituents so as to convert this metal to cupronickel, one of the important alloys needed by the U. S. Navy for condenser parts. Therefore the Bureau of Industrial Conservation of the War Production Board requested the executives of the leading nonferrous metal companies to have their metallurgical staffs study the problem of converting this metal to cupronickel conforming to U. S. Navy Specification 44T40. The composition specified therein is as follows: nickel, 29 to 32 per cent; zinc, 1.00; iron, 0.00 to 0.60; lead, 0.05; tin, 1.20; manganese, 0.00 to 1.00; total of other elements (maximum), 0.50; copper, remainder. The problem in converting these alloys to cupronickel was the elimination of zinc, lead, iron, manganese, and other elements without appreciable loss of nickel to slags or other by-products. Revere Copper and Brass Incorporated, through its Research and Development Department, undertook to solve this problem. A Government-owned plant was built at Rome, N. Y., and there the con- version was successfully made.

Jan 1, 1946

By J. D. Prater, H. R. Spedden, E. E. Malouf

With the expansion of copper leaching of the various mine wastes at the Kennecott properties, additional copper recovery facilities have been required. A research and development program has been pursued to determine a suitable economic approach to the processing of the additional leach solutions contemplated. lnvestigations on laboratory and pilot plant scales covered electrowinning, solvent extraction, launder and vat type cells, activated launders, precipitation drums, and precipitation cones. This paper contains information on the development and use of a new precipitation-cone-type copper recovery plant, which provides many advantages over older systems. The application of research findings to the old art of leaching copper from copper-bearing mine waste has resulted in a significant contribution of copper to over-all copper production. For example, at the completion of the current expansion program at the Kennecott properties in the United States, copper produced from waste dump leaching will amount to about 25% of the total production. Formerly only 2% was derived from this source. This planned expansion of copper leaching focused attention on the problem of developing more efficient methods for the recovery of copper from greatly increased volumes of copper-bearing solutions.1 The detailed investigations which have been made in laboratory pilot plant and plant tests for the recovery of copper from copper-bearing solutions have included electrowinning, solvent extraction, ion exchange and cementation with iron in launders, precipitation drums, activated launders, and precipitation cones. The results of these investigations have led to the development of a new precipitation cone-type copper recovery system providing many advantages over older methods. ELECTROWINNING OF COPPER FROM COPPER-BEARING SOLUTIONS The direct electrowinning of copper from relatively dilute solutions of copper-bearing mine water, namely solutions containing 10 to 20 lbs of copper per 1000 gal, has always been an attractive possibility.2,3 By this method, high-purity copper powder can be recovered with a power consumption of 3.5 kwh per Ib of copper. However, once the solution strength de-

Jan 1, 1967

By G. H. Clevenger

Continuing the discussion of the paper of James Johnston, presented at the New York meeting, February, 1914. See Trans., xlviii, 3 to 32 (1914). This paper cannot fail of being of great interest and value to all who are interested in the cyanide process, on account of the important developzn~ents which it records. Mr. Johnston is to be commended for the large amount of detail which he gives, and the company and its management for permitting the publication of data of this character, which while of great value to others could well be considered private property. It might be discussed from a number of standpoints: First, as an example of recent practice in mill and cyanide plant construction; second, the mill practice; third, the cyanide practice; and fourth, the new features in cyanide treatment involved. Perhaps a more vivid way of expressing it would be: First, the equipment or tools with which the various operations are carried on, are they the best and most efficient which could have been selected for their respective uses; and, second, is the best use in every case made of these tools? It may be well inquired is the highest possible recovery of silver made at the lowest cost per ounce recovered? For after all, the making of the greatest ultimate profit is inseparably associated with successful metallurgical practice; there must therefore be at all limes a careful balance maintained between recovery and cost of obtaining it. I wish to call attention in a very general way to the equipment used and to an anticipation of questions which are bound to arise in this connection. However, the bulk of my discussion will be confined to the presentation Of certain additional data, together with a more or less general discussion showing the line of development which leads up to the present practice and the applicability of certain features of it to similar problems elsewhere. There are a number of vital points of broad general interest involved in Nipissing low-grade practice upon which metallurgists will by no means be agreed to which I wish to call particular attention in the hope that it will lead to the presentation by others of data of practice in other districts which will assist in reconciling this divergence of opinion.

Jan 1, 1915

By D. E. Swets, R. C. Frank

It is well known that hydrogen is introduced into iron or steel as a result of many chemical processes (acid pickling, electrolytic cleaning, plating, etc.). One of the reactions that has been of recent interest1 is the reaction between an iron surface and water vapor. It was shown a few years ago2-4 that hydrogen can be introduced into steel at an accelerated rate during abrasion as a result of this reaction. Grun-berg and Scott have also observed that water in mineral oil lubricants increases pitting failure in ball bearings5 and they have suggested that hydrogen from the water is the primary cause of this effect.' In this laboratory, the question was raised as to whether or not hydrogen is also introduced into the metal surface of a bearing as a result of the decomposition of the hydrocarbon lubricant itself, and an experiment was performed to try to find a satisfactory answer. All steel parts contain some residual hydrogen. Therefore, it appeared that the best way to carry out this experiment without the need for highly accurate quantitative analyses was to use deuterium as a tracer. The natural abundance of deuterium in H2 is only 0.015 pct. The tracer was obtained in the form of deuteroparaffin (CD,(CDJ, CD,) and 0.25 g were dissolved in 20 cc of mineral oil to form the lubricant to be used in the tests. The bearings used were New Departure Type QOLOO ball bearings with a ball diam of 0.187 in. Prior to adding the mineral oil-deuteroparaffin lubricant, the bearings were cleaned in warm trichloroethylene to remove the packing grease. After packing with the new deuterated lubricant, the bearings were operated in a bearing fatigue test machine under a radial load of 190 lb and a thrust load of 190 lb at a speed of 3800 rpm. The expected life under these conditions is about 500 hr. Two tests were made; one for a period of 27 hr and the other for a period of 102 hr. The bearings achieved a temperature of 120o F during the tests. When the tests were stopped the balls were mechanically removed from the bearings and were immediately placed in liquid nitrogen to reduce degassing until the analysis for deuterium could be made. Before analyzing, the balls were warmed to room temperature and scrubbed with several degreasing agents to remove all traces of the deuteroparaffin mixture. This cleaning procedure was shown to be satisfactory by running a control test in which one ball bearing was subjected to all parts of the test except running in the fatigue machine. The hydrogen and deuterium were removed from the balls using a hot extraction apparatus attached to a mass spectrometer. Four balls from each bearing were analyzed. Each one was analyzed separately by removing it from a cold storage volume of the hot extraction apparatus and transferring it to the oven tube with a magnet. As the gases were evolved they were analyzed with the mass spectrometer. Since the hydrogen and deuterium pass through steel in the atomic form and since there are many more hydrogen atoms than deuterium atoms in the sample, the probability of forming an HD molecule is greater than forming a D2 molecule. For this reason the evolution of HD and H was followed as each ball was placed in the oven. The results showed that as each ball from the test bearing was dropped into the oven, the mass spectrometer recording of the HD evolution increased by about ten divisions. When balls from the control test bearing were dropped into the oven, the increase was about one division or less. The hydrocarbon background in the mass spectrometer was also monitored to see if hydrocarbons or deuterocarbons were given off when the balls were dropped into the oven, but no change in the hydrocarbon peaks was observed. Since the balls contained a fair amount of residual hydrogen, isotope ratio measurements were made on the gas obtained from each ball. The D/H value found for those balls which had been operated in the fatigue testing machine was consistently about 0.3

Jan 1, 1962

By J. J. Crowe, G. K. Burgess

PAGE, Theories of Allotropy of Iron........... 667 Previous Determinations of A2 and A3 in Iron........ 668 Critical Ranges as Determined by Expansion........ 669 Critical Ranges by Thermoelectric Observations........ Critical Ranges in Terms of Crystalline Structure....... 670 Critical Ranges as Detected by Mechanical Methods...... 670 Critical Ranges as Given by Electrical Resistance....... 670 Critical Ranges as Determined Magnetically........ 671 Critical Ranges as Determined Calorimetrically....... 673 Critical Ranges from Heating and Cooling Curves....... 673 Summary of Previous Determinations of A3 and A2 in Pure Iron.... 675 The Present Investigation............ 678 The Experimental Method........... 678 Arrangement of the Apparatus.......... 679 The Measurements of Temperaturc.......... 679 The Measurement of Time........... 679 The Thermocouples............ 681 Temperature Scale and Calibration of Thermocouples...... 681 Mounting of Thermocouples........... 682 The Differential Measurements.......... 682 The Furnace and Accessories........... 682 The Vacuum Pump............ 683 The Energy Supply............683 The Rheostat.............. 683 The Materials Investigated............ 685 Sources of Iron............. 685 Preparation and Description of Samples......... 685 Chemical Analyses............. 687 The Experimental Data............. 688 The Preliminary Observations.......... 688 The Definite Series............691 Description of the Plotted Curves........... 694 The Effect of Plotting at Different Intervals........ 694 The Curves of the Definite Series.......... 695 . The Curves of the Preliminary Series......... The Existence of Other Critical Ranges......... 696 The Microscopical Examination........... 697 Summary and Conclusions............ 698 Bibliography............... 701 Plates................ 704

Jan 1, 1914

Jan 1, 1953

By Arthur Notman

IN VIEW of the wide publicity given to the charges by the Couzens Committee of the United States Senate of discrimination by the Bureau of Internal Revenue in favor of the copper companies, it becomes a matter of interest to consider the basis for these charges. The point to be determined is whether they rest on a foundation of fact or are purely and simply matters of opinion. The whole question boils down to the purpose of the Tax Law as applied to mines, which is to afford the same protection to them as provided for all other taxpayers, namely: that they were to be allowed to pay back as depletion to their owners the values of their properties as they existed or were estimated to exist on May 1, 1913, free from tax. To determine these valuations it was? necessary to select from a wide range of possibilities a set of values for a number of essential factors.

Jan 1, 1925

By R. G. Bowman

Discussions of processes for the manufacture of white lead generally open with the statement that white lead is the oldest chemical pigment known to man. This fact is of more than historical interest; in the light of the present extensive use of white lead, it indicates that the compound possesses characteristics that make it unique among white pigments, and superior to all in its particular field. A greater variety of processes have been proposed for manufacturing white lend than for any other one chemical compound. Only a few of these processes have come into commercial use, however, and a large part of the present production here and abroad is made by the process used in ancient times. The outstanding disadvantages of the old process are that it is slow and laborious, affords no control of the product, and yields at best an impure material lacking in uniformity. Improved processes, sometimes classed all together as "quick processes," have had as their main object the shortening of the time required. Most of them accomplish this and some have yielded a superior product as well, but only two or three are now in use commercially. For centuries the manufacture and mixing of paints have been treated as an art, and the practice has been much influenced by tradition and precedent. There is a reluctance to abandon old materials for this purpose, and as few new uses for white lead have been developed, the adoption of the quick processes has been slow. The electrolytic production of white lead is not new, a large number of processes and forms of apparatus have been proposed and patented within the past 25 years, all directed toward the production of white lead, wholly or in part, by electrolysis. One or two of these processes were tried commercially but proved unsuccessful. Process The Sperry process, used by the Anaconda Lead Products Co., is the invention of Elmer A. Sperry, and was worked out to a commercial basis at the East Chicago plant. It resembles, in a general way, earlier methods, but embodies the features that make it possible to operate

Jan 1, 1926

By Anthony Lucas

THE discovery of oil in 1901 on the Spindletop dome, Texas, inaugurated a new industry on the Gulf Coast, an industry which has grown with the discovery of successive fields, until today it engages the services of thousands of workers and employs enormous capital. New fields are being discovered from time to time and doubtless some still remain to be found, though of late years discoveries have become more infrequent. Nowadays several hundred dry holes are drilled each year in a fruitless and blind effort to discover new fields, for as yet geologic science has developed no effectual method of locating the coastal oil deposits in advance of drilling. Moreover, despite the occasional discovery of new fields, the total production of the Gulf Coast is today no greater than it was in 1906, for the added production of the new fields has been offset by the rapid decline and more or less complete exhaustion of some of the older ones. Careful geologic work within the fields has in some cases increased the production temporarily, but has developed no really new supplies. The Gulf Coast oil industry seems to have passed its period of greatest expansion and to be declining at a fairly steady rate, and this condition is naturally viewed with alarm by the more farsighted operators. In my opinion, the time has come for the adoption of radical and aggressive methods of prospecting, and a fraction of the money wasted yearly in drilling shallow wells in hopeless locations might well be devoted to this purpose. Many facts lead me to believe that all the salt-dome oil has had a common origin; that it has migrated up from considerable

Jan 7, 1918

By Theron Wasson

Michigan's production of 17,301,000 bbl. in 1945, which is in line with previous years, has been maintained by extensions to old fields like Deep River, Adams, Fork, and others. There were a number of new discoveries but, as in the past, these are not given very much importance because enough drilling has not been done to develop their potentialities; however, judging by the past, some of them will develop enough production so that 1946 -will probably be in line with other years. Activities in Michigan were confined to the Basin area of the lower Peninsula, which has been under development since 1925.

Jan 1, 1946