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By E. S. Leaver

THE presence of soluble base metals in precious-metal ores usually precludes cyanidation as the best method of treatment. The laboratory experiments described in this paper show the possibility of cyanidation of gold-silver ores containing less than 0.5 per cent. of cyanide-soluble copper and the effect of zinc in the cyanide solution. PART 1.-COPPER IN CYANIDATION The proposed process of cyanidation of precious-metal ores containing copper is based on the regeneration of about 80 per cent. of the cyanide used in the dissolution of the copper. The method of regeneration involves a combination of the sulfide and the acid precipitation of the copper and silver. The resultant solution is made alkaline with lime, and the gold is precipitated with zinc dust.

Jan 1, 1929

By Erland Johnson

BRINE was discovered at Avery Island, La., in 1790, but it was not until 1862 that rock salt was found about 13 ft below surface-the first discovery of rock salt on the continent. Maximum elevation of the island is 152 ft and elevation at the shaft 31 ft. The mining level is 530 ft below elevation at the shaft and the shallowest salt about 12 ft below surface. A shaft was sunk in 1869 when the mining operation started. In 1898 the present shaft was sunk, and the mine has been operated by International Salt Co. ever since.

Jan 6, 1957

By B. K. Miller, R. S. Bradley

THE principal producing areas of fire clay in Missouri are: (I) the east central district, which includes Audrain, Callaway, Montgomery, Warren, and Boone Counties [ ] (Fig. I); (2) the St. Louis district, which includes St. Louis and St. Louis County; (3) the north central Ozark district, which includes Franklin, Gasconade, Osage, Maries, Phelps, and Crawford Counties. [ ] Most of the semiplastict fire clay is found in Audrain, Callaway, Montgomery and St. Louis Counties, and in St. Louis. Flint fire clay is found in Callaway, Audrain, and Montgomery Counties and in most of the north central Ozark district. High-alumina [ ] diaspore clay is found only in the north central Ozark district, except a few deposits found in Montgomery County. This paper is concerned with the semiplastic fire clay that occurs in the east central Missouri district near Mexico, Audrain County, Missouri, which is mined by the open-pit method as practiced by the A. P. Green Fire Brick Co. About one-fourth of the semiplastic fire clay in that district is mined in shaft mines, and three-fourths in open pits.

Jan 1, 1941

By L. W. Kemph, K. R. VanHorn

During the recent development of aluminum alloys for free-cutting screw-machine rod, it became desirable to know something of the solubility of lead and bismuth in liquid aluminum and in some aluminum alloys. The literature is not particularly helpful in supplying this information. These portions, therefore, of the constitutional relationships of aluminum-bismuth and aluminum-lead alloys were investigated by thermal analysis and by chemical analysis of samples taken from aluminum-rich melts in equilibrium with precipitated lead or bismuth. The solubility of lead and bismuth in some liquid aluminum-copper alloys was also investigated. Some consideration was also given to the solubility of these elements in solid aluminum. Among the earliest investigators of the aluminum-lead and alunlinum-bismuth systems was Wright,' who reported that melts of aluminum and lead formed two layers indicating limited liquid solubility. Under his conditions, the aluminum-rich layer was reported to contain 1.91 per cent Pb and the lead-rich layer, 0.07 per cent Al. Subsequently, Pecheau2 found that in aluminum-rich alloy melts with more than 10 per cent Pb three layers were distinguishable. He reported that the middle layer contained from 3 to 10 per cent Pb. He also found that the melting point of aluminum appeared to be lowered slightly by the addition of lead. Gwyer3 investigated these alloys and found evidence of a slight lowering of the freezing point of aluminum by the addition of either lead or bismuth. He found no evidence of solid solubility in either case and made no attempt to determine the liquidus curves. Hansen and Blumen-tha14 reported that the addition of lead distinctly lowered the solidification point of aluminum. They also found that bismuth lowered the melting point of aluminum. Guillet5 reported almost complete mutual immiscibility for the aluminum-bismuth alloys in the liquid state. Bohner6 examined the effect of various concentrations of lead and bismuth on the electrical conductivity of aluminum. He found decreases in conductivity on annealing at 500' C. as compared with the conductivity of the same alloys on annealing at 300' C.

Jan 1, 1939

By L. W. Kemph, K. R. VanHorn

During the recent development of aluminum alloys for free-cutting screw-machine rod, it became desirable to know something of the solubility of lead and bismuth in liquid aluminum and in some aluminum alloys. The literature is not particularly helpful in supplying this information. These portions, therefore, of the constitutional relationships of aluminum-bismuth and aluminum-lead alloys were investigated by thermal analysis and by chemical analysis of samples taken from aluminum-rich melts in equilibrium with precipitated lead or bismuth. The solubility of lead and bismuth in some liquid aluminum-copper alloys was also investigated. Some consideration was also given to the solubility of these elements in solid aluminum. Among the earliest investigators of the aluminum-lead and alunlinum-bismuth systems was Wright,' who reported that melts of aluminum and lead formed two layers indicating limited liquid solubility. Under his conditions, the aluminum-rich layer was reported to contain 1.91 per cent Pb and the lead-rich layer, 0.07 per cent Al. Subsequently, Pecheau2 found that in aluminum-rich alloy melts with more than 10 per cent Pb three layers were distinguishable. He reported that the middle layer contained from 3 to 10 per cent Pb. He also found that the melting point of aluminum appeared to be lowered slightly by the addition of lead. Gwyer3 investigated these alloys and found evidence of a slight lowering of the freezing point of aluminum by the addition of either lead or bismuth. He found no evidence of solid solubility in either case and made no attempt to determine the liquidus curves. Hansen and Blumen-tha14 reported that the addition of lead distinctly lowered the solidification point of aluminum. They also found that bismuth lowered the melting point of aluminum. Guillet5 reported almost complete mutual immiscibility for the aluminum-bismuth alloys in the liquid state. Bohner6 examined the effect of various concentrations of lead and bismuth on the electrical conductivity of aluminum. He found decreases in conductivity on annealing at 500' C. as compared with the conductivity of the same alloys on annealing at 300' C.

Jan 1, 1939

By H. LeChatelier, B. Bogitch

Page Introduction........................... 134 Methods of Investigation....................... 135 The Tridymite Network...................... 137 Independent Variables....................... 146 Manufacturing Operations..................... 153 Introduction Silica brick are indispensable in the manufacture of steel because they alone are able to withstand the high temperature of regenerative furnaces. All attempts to replace silica brick by other refractory materials for this purpose have failed, but the reason for this failure has remained obscure; we shall give an explanation later in this paper. Before the war, silica brick employed in France came principally from abroad, for which reason, since the beginning of hostilities, certain French steel works have been seriously handicapped. Our attention was first directed to the question by M. Bied, Engineer of the Teil Works. With him, we began certain investigations, at first using our laboratory and the furnaces of neighboring steel works. The larger part of our experiments, however, have been made in the laboratory of the Faculty of Sciences at the Sorbonne. For the heating of our samples, we are deeply obliged to MM. Charpy, Yeatmann and Guerineau. In undertaking these studies, our first aim has been to render assistance to French industry, by indicating, as precisely as possible, the necessary conditions for the manufacture of high-grade brick; but at the same time me have

Jan 1, 1919

By R. P. Smith

The diffusivity of carbon in iron, cobalt, and alloys of 89.7 and 79.3 wt pct Co has been determined by a decarburization method for the temperature range 850° to 1100°C. The Plots of log D us 1/T for the two Fe-Co alloys are linear through the region of the Curie temperature, showing that, unlike some cases of substitutional diffusion, carbon diffusion in these alloys is not affected by electron spin order. RECENT investigations1-' have shown that for substitutional diffusion in iron the change in diffusivity with temperature does not follow an Arrhenius equation, at temperatures near the Curie temperature. Data on the diffusivity of carbon in a iron5"9 indicate that this anomaly does not exist for interstitial diffusion; however, this has not been definitely established. Since cobalt and Fe-Co alloys, 80 to 100 pct Co, have Curie temperatures in a temperature range convenient for carbon-diffusion measurements they are suitable systems for studying the relation of interstitial diffusion and the Curie temperature. EXPERIMENTAL The carbon diffusivity, D, was determined by a decarburization method. The diffusion cylinders, made from small vacuum melts of electrolytic cobalt and plastiron, were about 0.76 cm diam and 6.3 cm long. A small amount of carbon was added to each melt to keep the oxygen content as low as possible. The cylinders were first treated with a hydrogen-3 pct water vapor mixture at 1100°C to constant weight, then carburized to the desired initial carbon content with a suitable CO-C02 gas mix-

Jan 1, 1964

By K. C. Ten Brink, Allen D. Garrison

A rrevious paper1 reviewed some of the properties of clays and shales and presented some data on the nature of the gelling phenomenon. It included a brief discussion of origin of clays and shales, their composition, structure, retention of water, ionization, base exchange, and the nature of the gelling of water suspensions. Other publications of the Institute2-8 have discussed the properties of clays and their relations to drilling-fluid behavior and control. It is the purpose of this article to present some new data obtained and arranged in a different manner and making possible a better understanding of the chemical reactions involved in the control of drilling-fluid characteristics during the normal drilling operations. Experimental Procedure The difficulties involved in the measurements of the flow characteristics of plastic fluids are too familiar to recite. The possible applications of some of the well-known instruments to this problem have been adequately discussed by Hobson9 and he has given an excellent bibliography. Although there are many viscosimeters of varied design, none of them appear to fulfill the most obvious demands of accuracy in the measurement of clay or shale suspensions. Since the fluid characteristics are dependent on the rate of flow of the fluid, and the viscosity usually falls off very rapidly as the rate is increased, it is clear that the first requirement is that the instrument shall be capable of a wide variety of speeds. The viscosity of the fluid at any fixed and constant rate of flow is also a function of time, so that the second demand is that the instrument shall be capable of a constant and continuous motion for a prolonged period of time.

Jan 1, 1940

By K. C. Ten Brink, Allen D. Garrison

A rrevious paper1 reviewed some of the properties of clays and shales and presented some data on the nature of the gelling phenomenon. It included a brief discussion of origin of clays and shales, their composition, structure, retention of water, ionization, base exchange, and the nature of the gelling of water suspensions. Other publications of the Institute2-8 have discussed the properties of clays and their relations to drilling-fluid behavior and control. It is the purpose of this article to present some new data obtained and arranged in a different manner and making possible a better understanding of the chemical reactions involved in the control of drilling-fluid characteristics during the normal drilling operations. Experimental Procedure The difficulties involved in the measurements of the flow characteristics of plastic fluids are too familiar to recite. The possible applications of some of the well-known instruments to this problem have been adequately discussed by Hobson9 and he has given an excellent bibliography. Although there are many viscosimeters of varied design, none of them appear to fulfill the most obvious demands of accuracy in the measurement of clay or shale suspensions. Since the fluid characteristics are dependent on the rate of flow of the fluid, and the viscosity usually falls off very rapidly as the rate is increased, it is clear that the first requirement is that the instrument shall be capable of a wide variety of speeds. The viscosity of the fluid at any fixed and constant rate of flow is also a function of time, so that the second demand is that the instrument shall be capable of a constant and continuous motion for a prolonged period of time.

Jan 1, 1940

By B. K. Miller, R. S. Bradley

THE principal producing areas of fire clay in Missouri are: (I) the east central district, which includes Audrain, Callaway, Montgomery, Warren, and Boone Counties [ ] (Fig. I); (2) the St. Louis district, which includes St. Louis and St. Louis County; (3) the north central Ozark district, which includes Franklin, Gasconade, Osage, Maries, Phelps, and Crawford Counties. Most of the semiplastic[$] fire clay is found in Audrain, Callaway, Montgomery and St. Louis Counties, and in St. Louis. Flint fire clay is found in Callaway, Audrain, and Montgomery Counties and in most of the north central Ozark district. High-alumina diaspore clay is found only in the north central Ozark district, except a few deposits found in Montgomery County. This paper is concerned with the semiplastic fire clay that occurs in the east central Missouri district near Mexico, Audrain County, Missouri, which is mined by the open-pit method as practiced by the A. P. Green Fire Brick Co. About one-fourth of the semiplastic fire clay in that district is mined in shaft mines, and three-fourths in open pits.

Jan 1, 1941

By Adrien Berton

FOR nearly a century, the Corocoro deposit has been renowned among geologists from the fact that it shares with the Lake Superior deposits of the United States the distinction of being the only important copper districts where native copper is worked commercially. The Corocoro district, named after the city of Corocoro, the capital of the Province of Pacajes (Department of La Paz, Bolivia) is situated towards the western edge of the Bolivian high plateau, at an altitude of a little over 13,000 ft. The most interesting part of the district is that immediately surrounding the city of Corocoro, at a distance, by railway, of 65 miles from La Paz and 210 miles to the Chilean port of Arica on the Pacific Coast. The climate of the region is that of the semi-desert, dry and relatively cold, with big differences of temperature between day and night. The rainy season begins in December and ends in March. The cupriferous lodes of Corocoro have not attracted as much interest as the silver mines of Potosi but they have been known for a long time. In the precolonial period the Indians were using the charquis, or natural native copper sheets, to make small brass objects, and the beautiful pale green brochantite of the outcrops as a source of green pigments. During the colonial period, the oxidized ores of the outcrops were worked for copper, which was used by the mint at Potosi for making currency. The native copper ores were neglected because the Spanish miners were at a loss how to concentrate and smelt them. About 1830, work by rudimentary processes, which were improved little by little, was begun on the native copper ores. The total production of native copper in the following hundred years amounted to 100,000 tons. This native copper, which was remarkably pure, was much appreciated on the European markets before the introduction of electrolytic copper. It was useful for making special ornamental brass or bronze and the granular concentrates of native copper, called barrilla, containing 80 to 85 per cent copper were suitable for making copper sulfate by direct oxidation and subsequent leaching with sulfuric acid.

Jan 1, 1936

By R. S. Bradley, B. K. Miller

The principal producing areas of fire clay in Missouri are: (I) the east central district, which includes Audrain, Callaway, Montgomery, Warren, and Boone Counties (Fig. I); (2) the St. Louis district, which includes St. Louis and St. Louis County; (3) the north central Ozark district, which includes Franklin, Gasconade, Osage, Maries, Phelps, and Crawford Counties. Most of the semiplastic‡ fire clay is found in Audrain, Callaway, Montgomery and St. Louis Counties, and in St. Louis. Flint fire clay is found in Callaway, Audrain, and Montgomery Counties and in most of the north centra! Ozark district. High-alumina diaspore clay is found only in the north central Ozark district, except a few deposits found in Montgomery County. This paper is concerned with the semi-plastic fire clay that occurs in the east central Missouri district near Mexico, Audrain County, Missouri, which is mined by the open-pit method as practiced by the A. P. Green Fire Brick Co. About one-fourth of the semiplastic fire clay in that district is mined in shaft mines, and three-fourths in open pits.

Jan 1, 1942

By B. K. Miller, R. S. Bradley

The principal producing areas of fire clay in Missouri are: (I) the east central district, which includes Audrain, Callaway, Montgomery, Warren, and Boone Counties (Fig. I); (2) the St. Louis district, which includes St. Louis and St. Louis County; (3) the north central Ozark district, which includes Franklin, Gasconade, Osage, Maries, Phelps, and Crawford Counties. Most of the semiplastic‡ fire clay is found in Audrain, Callaway, Montgomery and St. Louis Counties, and in St. Louis. Flint fire clay is found in Callaway, Audrain, and Montgomery Counties and in most of the north centra! Ozark district. High-alumina diaspore clay is found only in the north central Ozark district, except a few deposits found in Montgomery County. This paper is concerned with the semi-plastic fire clay that occurs in the east central Missouri district near Mexico, Audrain County, Missouri, which is mined by the open-pit method as practiced by the A. P. Green Fire Brick Co. About one-fourth of the semiplastic fire clay in that district is mined in shaft mines, and three-fourths in open pits.

Jan 1, 1942

By Robert S. Moehlman

Is recent years, exploration and development by diamond drilling has become a popular attack on the problem of finding new ore shoots and developing extensions of known shoots. Diamond drilling has been used in recent years in extensive sampling of disseminated copper deposits, in preference to churn drilling. At the Harvard gold mine, near Jamestown, California, Philip R. Bradley, Jr., general superintendent, reports that: "The Harvard work was a singular example of the reliance that can be placed on diamond drilling in evaluating an ore body." Drilling at the Harvard mine will be discussed in a subsequent section of the paper. So popular has diamond drilling become, indeed, that many who have had slight experience with drilling are inclined to regard it as a cheap cure-all. This paper proposes to show some of the limitations on the application of drilling and some of the steps that should be followed in drilling programs to obtain reliable results. Cost oF Drilling Drilling has the advantage, over shaft sinking and drifting, of lower cost and greater speed. As compared with churn drilling, the advantage of bringing up a coherent sample instead of fine cuttings for a sample is obvious. Diamond drilling is generally more expensive, however, and more engineering effort is required in combining the average of core and sludge samples. Exploration of drift walls by hammer drills to a depth of less than 30 ft. is generally cheaper than diamond drilling, but beyond this depth the diamond drill is cheaper and more efficient. The principal factor in determining cost of drilling is the character of the ground drilled. Broken ground with many fissures is most expensive to drill. Hard ground is less of a problem with diamond drills than with ordinary machine drills. Hardness or softness affects only the speed of drilling. Caving, easily washed, sandy or clayey ground requires continual cementing and casing, which is the greatest cost problem. Thus, soft, incompetent ground is more costly to drill than hard, massive ground. Cost of drilling per foot in good to fair ground varies from less than $I per foot, achieved in some districts in Ontario, the Mother Lode, and Missouri, to $5 per foot in many western states. In bad drilling ground, costs may range from $5 to $15 or more per foot, thus approaching the cost of drifting. Other factors that increase the cost per foot are: I. Short total length of hole drilled, so that the cost of moving in crews and equipment must be spread over a relatively few feet. 2. Cost of drilling per foot increases with depth beyond about 500 ft.. as more time is consumed in pulling rods' 3. Cost of preparing drilling stations, getting air underground to stations? etc' 4. Inaccessibility and lack of water on the job make for higher costs.

Jan 1, 1946

Report of the Secretary TO THE BOARD OF DIRECTORS AND THE MEMBERS OF THE AMERICAN INSTI¬TUTE OF MINING AND METALLURGICAL ENGINEERS GENTLEMEN As will be shown by the special reports of the Finance, Membership, Library, Papers and Publications, Increase of Membership, and other standing Committees, together with that of the Treasurer, the year 1927 was one in which the Institute made very satisfactory progress in a number of directions. In total numbers the membership is no larger but in revenue from dues there has been a marked increase. This has been due to the promotion to full membership of Junior Associates of earlier years, to the larger proportion that come in originally as members rather than juniors, and to the keener interest in the work of the Institute reflected in prompter payment of dues. The latter is important, since experience shows that of those who fall behind a large number must ultimately be dropped for non-payment. Conditions in the mining in¬dustries have been healthy though not booming. It has been much easier for members to find employment and meet their financial obligations but there has not been that flow of young men into mining, and hence in part into the Institute, that characterized certain earlier years. Rather the tendency toward centralization and larger industrial units has re¬stricted the number, though not the scope, of opportunities for technical men in the mineral industries. The Institute is constantly receiving resignations from members crowded out of mining into other lines of activity. On the other hand, those who remain in mining and metal¬lurgy have a greatly increased necessity for information and contacts with technology. A few years ago many superintendents and most foremen were non-technical men. Today the reverse rule obtains and shift bosses and men who occupy even lower positions in industrial units are called upon to know and to apply such an amount of technical knowl¬edge that graduate engineers are the rule rather than the exception. The curious situation has obtained that with a much smaller enrollment of students in the schools of mining and metallurgy there has been at times an actual shortage of young engineers for beginners' jobs. The young men retort that the conditions of employment and pay offered in mining are not equal to those in other lines and, while it is undoubtedly true that the young engineer beginning in mining is able to start under conditions markedly better as to pay, living, and responsibility than did the men who are now leaders, they are required to know much more and have usually spent more in time and money to qualify for their jobs. The whole matter is one which warrants much more attention than has been given to it. For the Institute it is important since the young men

Jan 1, 1923

By H. Hansen, A. U. Seybolt, P. Yurcisin, B. W. Roberts

The Bi-Mn phase diagram in the region near BiMn was investigated, using principally thermal analysis and changes in magnetization with temperature. Of chief interest are the findings related to the magnetic transformation in Bi-Mn. THE Bi-Mn system is of both theoretical and practical interest because of the occurrence of the compound BiMn which exhibits unusual ferromagnetic properties. Because the Bi-Mn phase diagram reviewed by Hansen' (see Fig. 1) in 1936 is based on work done by BekierY in 1914 and by Siebe" in 1919, which left considerable doubt about the nature of the diagram. it appeared desirable as an aid in understanding the alloying characteristics and magnetic behavior to examine the pertinent regions of the phase diagram. The most interesting reaction is the peritectic at 445°C which forms BiMn by the reaction: Liquid + Mn(sulfield) ? BiMn(sol field) There is also a eutectic at 262° C between pure bismuth and BiMn. Hansen draws in BiMn dotted, since in 1936 evidence for its existence was uncertain. Experimental Materials—Preparation of Alloys Electrolytic manganese of about 99.97 pet purity and bismuth of 99.99 + pet purity were used as starting materials.

Jan 1, 1957

By T. K. Perkins, L. R. Kern

A study of fluid mechanics, rupture of brittle materials and the theory of elastic deformation of rocks shows that, for a given formation, crack width is essentially controlled by fluid pressure drop in the fracture. Operating conditions which cause high pressure drop along the crack (such as high injection rate and viscous fluids) will result in relatively wide cracks. Conversely, operating conditions which cause low pressure drop (low injection rates and thin fluids) will result in relatively narrow cracks. Charts and equations have been derived which permit the estimation of fracture widths for a variety of flow conditions and for both horizontal and vertical fractures. INTRODUCTION There has been considerable speculation concerning the geometry of hydraulically created fractures in the earth's crust. One of the questions of practical importance is the width of fractures under dynamic conditions, i.e., while the fracture is being created and extended. Such width information could be used, for instance, to help estimate the area of a fracture generated under various conditions. Also, there has been a recent trend toward the use of large propping partiles.13, 15 Therefore is is desirable to know what factors can be varied in order to assure entry of the large particles into the fracture. There has been some work on fracture widths reported in the literature. In particular, there have been several Russian publications dealing with this sub-jeCt.1.31,3 These papers have dealt principally with the elastic theory and the application of this theory to hydraulic fractures. These studies have not led to an engineering method for estimating fracture widths under dynamic conditions. A recent paper3 has reviewed and summarized the Russian concepts. An earlier paper- from our laboratories also discussed the application of the elastic theory to hydraulic fractures. This first approach, based largely on photoelastic studies, has proved to be too simplified to accurately describe the fracturing process. However, these early thoughts have served as a guide during the development of more exact concepts. We would like to present in this paper our current concepts regarding fracture widths and some estimates of hydraulic fracture widths for several conditions. We believe that it is now possible to predict with fair accuracy the factors influencing fracture widths. Furthermore, the method of prediction has been reduced to a simple and convenient graphical or numerical calculation. CRACKS IN A BRITTLE, ELASTIC MATERIAL Many investigators2, 4, 30 have shown that competent rocks behave elastically over some range of stresses. Of course, if the tensile stress imposed upon a rock exceeds some limiting value, then the rock will fail in tension. In similar manner, there are some limiting shear stresses that can be imposed upon rocks. Hubbert and Willis11 have discussed the shear conditions which will lead to failure. Under moderate stress conditions (such as those likely to be encountered when hydraulically fracturing) and when stresses are rapidly applied, relatively, most rocks will fail in a brittle manner. Hence, for this discussion of hydraulic fractures in the earth's crust, we assume the rocks behave as brittle, elastic materials. Let us develop the discussion in the following way. (The following thoughts are applicable only to brittle materials.) 1. First we consider a brittle, elastic system. An energy balance will show the minimum pressure necessary to fracture rock, and from this pressure we calculate the minimum crack width resulting from extension of a hydraulic fracture. 2. Then we will show that, under ordinary fracturing conditions, fracture widths are appreciably greater than the minimum widths of extending fractures. In fact, we will find that crack width is controlled by fluid pressure drop in the fracture. 3. We will discuss pressure drops in fractures and resulting crack widths for various operating conditions and both vertical and horizontal fractures. 4. Finally, we will discuss the significance of these concepts, their relationship to fracturing pressures, etc. First, consider minimum fracture extension pressures. We can shed some light on this question by considering the theory proposed by Griffith7, 8 Yo explain the rupture of brittle, elastic materials. Griffith recognized that solid materials exhibit a surface energy8 (similar to surface tension in a liquid). The fundamental concept of the Griffith theory is that, when cracks spread without the application of external work (in the interior of an elastic medium which is stressed

Elected Died 1895 ABBOTT, AI ATTHUR 1908 1882 ABBOTT, ARTHUR V 1906 1905 ABE, MASAYOSHI 1909 1903 ADAMS, CHARLES C. 1905 1906 ADAMS, JOHN C. 1913 1905 ADAMS, WILLAMS 1909 1903 ADAMS, W. EDWARDS 1910 1884 ADDY, MATTHEW 1896 1906 AFFLECK, WILLIAM A. 1911 1889 AKERS, WILLIAMS A. 1906 1905 ALABASTER, RUPPERT C. 1911 1899 ALBERGER, LOUIS R. 1911 1894 ALLEN R B 1896 1905 ALLEN, R. SCOTT 1906 1886 ALLISON, ROBERT 1916 1874 AMIOT, H. 1892 1886 AMSLER, CARL 1894 1898 ANDRSON, JOHN W 1905 1895 ÅNGSTROM, CARL 1901 1887 ARCHBALD, JAMES 1910 1900 ARLETT, GEORGE H 1906 1895 ARMSTRONG, JOHN F 1898 1905 ARNOLDS, LEO F. 1917 1882 ARNOLDS, HUGO 1886 1875 ASHBURNER, CHARLES A 1889 1872 ASIIBURNER, WILLIAM 1887 1883 ATKINS, C M , JR 1885

Jan 1, 1923

By Zay Jeffries

From the title of this chapter the reader could expect an attempt to out- line the anticipated shape of things to come, mineralwise. We have no crystal ball and if we possessed one we could claim no expertness in its use. In the first place no one can tell the future status of man. No one has any way of knowing to what extent peace will prevail, nor to what extent changes may occur in national sovereignties or forms of government or in international relationships. So future man is an uncertainty. Nor can we predict new developments that may result in significant changes in man's status or in the mineral industry or both. If, for example, this chapter had been written in the middle 1930's, nearly everything that has happened since in the fields of atomic energy and space technology would have been missed. Yet what vast changes these I have made in the status of man! Also the changes in the mineral industry have been important. A writer would have been bold indeed had he prophesied that uranium would play such an important role. But we need not confine our foggy vision to these fields. The steep rise in the use of aluminum, titanium, and germanium reflects the unpredictable in what may be thought of as the more normal pursuits. This should not discourage one from using the past and currently observable trends as bases for limited predictions. To do this, however, it is desirable to make certain assumptions about man's status without pretense that these assumptions have a high probability of fulfillment: 1. Only minor changes will occur in the geographical boundaries of the nations of the world. 2. World War III will not take place in the near future. 3. As a consequence of (2), man will not destroy himself by wanton use of atomic weapons. 4. Disarmament will take place, if at all, gradually rather than all at one time. Under the above assumptions the world will enjoy a period of relative peace even though the status may be one of an armed truce. The assump-

Jan 1, 1964

By C. K. Leith, W. J. Mead

One of the most significant developments in the iron industry in recent years has been the discovery and opening of enormous reserves of low-grade ore in eastern and northeastern Cuba. The two principal fields are the Mayari and the Moa, situated on Nipe bag, in the Province of Oriente. A less well-known district of the same type is that of Baracoa, at the east of the island, and another is in Csmaguey Province in central Cuba. In the comprehensive estimates of the iron-ore reserves of the world, published during the summer of 1910 by the International Geological Congress in Sweden,' these Cuban deposits are estimated at about 2,000,000,000 tons. Certain it is that the reserve is a large one. The Spanish-American Iron Co., the Juragua Iron Co. (Bethlehem Steel Co.), the U. S. Steel Corporation, and others have been active in this exploration. The Spanish-American Iron Co. has established a port for the handling of these ores at Felton, has built a railway 16 miles to the ore-fields, and has operied up deposits for steam-shovel mining. Its expenditures have reached an aggregate of about $6,000,000 in preparation for the handling of these ores. Shipment of the ore to Sparrow's Point, Md., has begun and may be expected to rise to a considerable amount in the near future.

Jan 1, 1912