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By John Chipman, A. M. Samarin

It has been long known that the gas evolved during the boil in the open-hearth furnace is mainly carbon monoxide associated with smaller quantities of other gases. A number of attempts have been made to determine the precise effects of carbon and oxygen content of the bath, and of other factors, such as temperature, upon the evolution of carbon monoxide. In his investigation of the carbon-iron oxide product in liquid steel, Hertyl showed that the value of this product at equilibrium could be approximated by plotting the value of the product observed in open-hearth reactions against rate of carbon elimination, and extrapolating to zero rate. The results of this study showed a slight but definite effect of temperature upon the carbon-iron oxide reaction. Experimental studies of the evolution of gases from rimming-steel ingots have not yet attained the degree of precision necessary for an exact understanding of the effects of pouring temperature, carbon content, and iron oxide in the metal upon the composition of these gases. Klinger2 showed that the gas consists mainly of carbon monoxide, and that considerable variation in its composition occurs during the solidification of the ingot. In order that these variations may be understood in their proper relationship to the progress of solidification of the ingot and the segregation that accompanies solidification, it is essential to have a knowledge of the condition of equilibrium in the several chemical reactions by which the gases are being formed. It is also necessary to understand the effects of temperature upon the equilibria, and further, to know the manner in which the temperature of the liquid metal within the ingot changes as the skin of the ingot is being built up. The reactions in which we will be chiefly interested are those involving in the one case the oxides of carbon, and in the other case steam and

Jan 1, 1937

By M. R. Louthan

The susceptibility of titanium to stress orientation of hydride precipitates was investigated. It was determined that, when hydride precipitation occurred in titanium under an applied tensile stress of 30,000 psi, the hydrides precipitated on the titanium habit plane oriented most nearly perpendicular to the stress axis. Stress orientation of the hydride platelets occurred because the precipitation of the lower density hydride phase perpendicular to the stress axis caused expansion of the matrix in a direction that tended to relieve the applied stress. The Ti-H system has received considerable study in recent years, mainly because of concern over the effects of hydrogen on the mechanical properties of titanium. The amount of hydrogen present in commercial titanium is now quite low and should have no appreciable effect on its mechanical properties; however, many titanium applications require ex- posure to hydrogenous atmospheres under conditions in which hydrogen pickup is likely. In such cases continued exposures may cause the hydrogen content to increase to the extent that titanium hydride does precipitate as a second phase. The hydride phase has been shown 1,2 to have an adverse effect on the mechanical properties, particularly the impact properties, causing reductions in strength and ductility. BACKGROUND The behavior of titanium is often quite similar to that of zirconium and zirconium-base alloys, and the technology developed on one metal can often be applied to the other. Marshall and Louthan3,4 have shown that Zircaloy is susceptible to stress orientation* of zirconium hydride platelets, and that the platelet orientation has a pronounced effect on the mechanical properties of Zircaloy. They showed that when zirconium hydride precipitated in Zircaloy under an applied stress the hydride platelets tended to be aligned parallel to a compressive stress and perpendicular to a tensile stress. They also showed

Jan 1, 1963

By Robert Glass Cleland

THE BEGINNING of a large enterprise is often as in- significant as a lump of leaven hidden in a bowl of meal or a handful of mustard seed that the wind blows across a field. In 1950 the company known today as the Phelps Dodge Corporation had nearly thirty-two thousand stockholders, paid salaries and wages of about fifty million dollars to some thirteen thousand persons, produced nearly four hundred and ninety million pounds of copper, and possessed net current assets of approximately one hundred and six million dollars. For the origin of this great business, one must go back approximately a hundred and fifty years to an obscure saddle-making shop in the small town of Hart- ford, Connecticut. Anson Greene Phelps, proprietor of the shop and master saddler in his own right, was born in 1781-the year of the Battle of Yorktown, the surrender of Cornwallis, and the close of the Revolutionary War Anson's forebears had come to America in the great Puritan migration that left fields, shops, pulpits, and hearthstones in the reign of Charles the First to transplant the strong, tough roots of their race, culture, and institutions in the New World.

Jan 1, 1952

By Oswald J. Heinrich

SINCE my communication to the Institute at the Baltimore meeting in 1879,* in which I took the lead in emphasizing the importance of a new method in the manufacture of soda, already practiced to some extent in England and on the Continent of Europe, five years have passed. I.then referred particularly to the advantages offered in the United States for this peculiar method, by the ammonia process, namely: 1. At the present time, at least, we have but one mine in this country where rock-salt is mined, namely, at New Iberia, La. On the other hand, we have many localities where brine of various degrees of strength, up to that of cold saturation, is obtained in large quantities. 2. We have excellent fuel, in close proximity to most of the brinecenters. 3. Our supplies of pyrites, to use in the manufacture of sulphuric acid, for use in the manufacture of soda by the Leblanc process, are mostly too far from the brine-centers to permit competition in that line with the more favorable conditions existing in England. 4. Unlike our foreign rivals, we have no large and costly plants, erected on the Leblanc plan, which must be abandoned and exchanged for new but cheaper plants, before the ammonia-soda process can be adopted. 5. We have a constantly increasing demand for soda, which is almost entirely supplied by importation. If slow progress has been made hitherto in this country in the extension of this manufacture (only one plant at Syracuse, erected . under the Solvay patent, having as yet been placed in operation), I still feel gratified in saying that developments in England, and particularly on the Continent of Europe, give ample proof of the

Jan 1, 1885

By George H. Eldridge

The existence of phosphate of lime within the State of Florida has been known for over a decade; but until the spring of 1887, the extent and value of its deposit.;, possibly with one exception, were unsuspected. In that year Col. T. S. Moorehead, induced by a statement made by Mr. J. F. Le Baron, examined the gravels of the Peace river, recognized the importance of the deposits, acquired such tracts as were regarded as desirable, and established the pebble-phosphate industry, making his first shipment in May, 1888, to the Scott Manufacturing Company, of Atlanta, Ga. The establishment of the pebble-phosphate industry upon Peace river was followed, a year later, by the discovery in Marion county of an entirely different class of phosphate, now commonly known as hard-rock phosphate. This discovery was made early in June, 1889, by Mr. Albertus Voght, in a well which he was sinking upon his place near the site of the present town of Donnellon, about 20 miles southwest of Ocala. To it, more than to any other cause, is due the rapid and remarkable development of the present great industry of the State. It was, however, Mr. John F. Dunn, of Ocala, who turned to advantage the accidental discovery of Mr. Voght. After acquiring a knowledge as to the chemical composition and value of the material, Mr. Dunn and hid associates purchased several thousand acres of land and organized the Dunnellon Phosphate Company for active operations. From Dunnellon as a center, prospecting rapidly extended in all directions, until at the present day important mines have been opened over a well-defined tract more than 200 miles long and about 6 miles wide. This tract lies par-

Jan 1, 1893

By K. A. Johnson, H. F. Yancey

Physical properties have been used for a long time in characterizing different kinds of coal, and such physical properties as friability and slacking have been included along with chemical properties in grouping coals according to the widely used system of classification adopted by the U. S. Geological Survey. Nevertheless, the usefulness of physical properties for classifying the different ranks or kinds of coal has been limited because it has not been possible to express these properties in definite form as numerical values. Because of the present wide interest in the formulation and adoption of a satisfactory system of coal classification, the Northwest Experiment Station of the U. S. Bureau of Mines, in cooperation with the College of Mines of the University of Washington, has recently completed a study of the physical and chemical properties of approximately 100 different coals ranging in rank from lignite to anthracite. Purpose and Scope For this investigation samples were collected in approximately 45 mines and prospects in Washington and 23 mines in other states. The following studies, in addition to proximate and ultimate analyses, were made of the samples: Determination of (1) friability, (2) slacking or weathering characteristics, (3) yield of products by low-temperature carbonization in a laboratory retort, and (4) agglutinating value. Most of the coals examined were subjected to each of the tests enumerated, but with coal of some ranks this was unnecessary in some instances, and in others it was not feasible to do the work involved. A report which includes the analyses of the coals and the details of the methods of examination used in the investigation is being published by the Bureau of Mines.' It is the purpose of the present report to show the results of the friability, slacking, low-temperature and agglu-

Jan 1, 1932

By L. D. Hall, S. J. Rothman

The diffusion of lead and of trace amounts of bismuth in liquid lead have been investigated by the capillary method, using ROD and ROE as tracers. The results are compared with existing theories of diffusion in liquids, the agreement with theory being fair. The heat of activation for self-diffusion in lead is found experimentally to be close to the corresponding activation energy obtained from viscosity data. The pioneer data of Groh and von Hevesi for the self-diffusion of liquid lead, using ThB as a tracer, fit in with the present results. OMPARED with the volume of effort expended on solid state diffusion, there has been little attention paid to diffusion in liquid metals. A review of experimental work in this field, covering most of the studies up to 1951, was given by Jost.' More recent papers include those by Hoffman2 on self-diffusion in mercury, Morgan and Kitchener" and Stark, Shchilishchev, and Kazachkev4 on the diffusion of various elements in liquid iron, and Grace and Derge on the diffusion of bismuth in bismuth-lead alloys. The need for more experimental data to aid in the evaluation of existing theories prompted the

Jan 1, 1957

By A. D. Hodges

The great mining region of Peru is a mountainous belt of country, running nearly the whole length of the republic, and comprising the two grand ranges of the Andes with the elevated table-lands between them. On the east of this belt are the extensive plains and fertile valleys of the Amazon and its tributaries. On the west is a narrow strip of coast 20 to 50 miles wide, for the most part a sandy desert, but producing abundant crops where irrigated ; and here are found petroleum (Department of Piura), salt (at Huacho and elsewhere), nitrate of soda in enormous amounts at the south, silver in a few localities (Province of Tarapaca), copper and other mineral products. The Western Cordillera, running nearly parallel with the shoreline, rises like a wall on the eastern side of the coast-belt, with passes from 15,000 to 18,000 feet high and peaks attaining 18,000 to 20,000 feet. Further east, at a varying distance, is the Eastern Cordillera, composed of broken mountain ranges which, considered as one group, have a general parallelism with the western chain, but individually vary greatly in direction, sometimes running nearly east and west, in places projecting out into the Amazonian lands, or here and there curving around to unite with the western ridge, and with this enclosing immense inter-alpine plains. These general features are indicated in Fig. 1. The surface of these plains is uneven and traversed by lower ranges of hills which surround large lakes, or rolling pampas, or fertile valleys; and through many of these last run rivers of considerable size. The whole country has a high altitude (averaging up to 15,000 or 16,000 feet), and slopes gradually north and east towards the Amazon, into which drain all its waters. Its bounding mountain chains are scored on all sides by narrow, picturesque and pre-

Jan 1, 1888

By Arthur Dwight

ARTHUR SMITH DWIGHT, president of the American Institute of Mining and Metallurgical Engineers, was born in Taunton, Mass., on March 18, 1864. He is descended on both sides from early settlers, one of whom was Richard Warren, of the "Mayflower." His forebears included Col. Benjamin Church, Tim-othy Dwight, and the Rev. Jonathan Edwards, third president of Princeton College. Mr. Dwight was graduated in 1882 from the Poly-technic Institute of Brooklyn, N. Y., and three years later from the Columbia School of Mines, with the degree of Engineer of Mines. In 1914, he received the honorary degree of Master of Science from Columbia. On leaving Columbia in 1885, he went to Pueblo, Col., and for thirteen years was associated with the Colorado Smelting Co. Beginning as assayer he rose to be general superintendent. When he gave up the latter position he became connected with several large companies in the mining and smelting of lead, copper and the precious metals in the Rocky Mountain region. This work occupied him from 1897 to 1906, and six years of that time were spent in Mexico. He was general manager of the Greene Consolidated Copper Company at Cananea, Mexico, in 1906, when trouble first developed against the régime of Diaz. A general uprising was planned to seize the mines, and with money and supplies so obtained, carry the revolt through the interior. Mr. Dwight turned his industrial organiza-tion into a military unit almost over night, stemmed the tide of revolution, and had the situation well in hand before the arrival of troops. In the fall of 1906 he returned to New York and began practice as a consulting mining and metallurgical engineer. He next developed important metallurgical patents for the roasting and agglomeration of fine ores, known as the Dwight and Lloyd sintering process, now extensively used ail over the world.

Jan 3, 1922

By Harrison R. Cooper

Measurement of process material composition with on-line instrumentation has commanded attention of metallurgical plant management as a logical extension of the sampling operation, making possible immediate determination of essential data needed to maintain efficiencies at the highest possible level. The current status of methods employed for online composition analysis of slurries and solid materials is reviewed.

Jan 1, 1984

By A. W. Ruff

In the last ten years large gains have been made in the field of blasting. These gains have been both in the theoretical and in the practical application of explosives. One of the most publicized changes in the practical application of commercial explosives is the now-prevalent use of ammonium nitrate and fuel oil. The new water-compatible mixture of ammonium nitrate and TNT should also have a large field of application. Most of the theoretical gains have been concerned with the actual rock breakage obtained with explosives. In the last ten years, large gains have been made in the field of blasting. These gains have been both in the theoretical and in the practical application of explosives. One of the most publicized changes in the practical application of commercial explosives is the now prevalent use of ammonium nitrate and fuel oil. The new water-compatible mixture of ammonium nitrate and TNT should also have a large field of application. Most of the theoretical gains have been concerned with the actual rock breakage obtained with explosives. EXPANDING-GAS-BUBBLE THEORY There has been an outstanding change in the conception of how an explosive produces rock failure. The early theory which explained rock breakage was correct for some of the first force-producing agents such as quicklime. When a drillhole was filled with quicklime and water added, the material expanded and steam was generated. The expanding material and the steam exerted a slowly increasing pressure on the sides of the drillhole. The force broke the rock by splitting. Because a great quantity of gas was produced by the deflagration of gunpowder, the same process of the gas pressure splitting the rock was assumed to take place. Even after 80 years of use, the rock-breaking action of all high explosives was thought to be caused entirely by the expanding gas bubble which tore and split the rock. Fig. 1 shows a vertical section through an exploding spherical charge of high explosive. It illustrates the early theory which attributed the entire breakage to the expanding gas bubble. The basic idea of this theory is that the breakage started at the explosive charge and progressed toward the free face. REFLECTED-WAVE THEORY me expanding-gas- bubble theory has gradually been replaced by the reflected-wave theory. The reflected-wave theory explains rock failure by explosives in the following manner: The enormously high gas pressure in the drillhole produces fracturing of the rock on the sides of the drillhole. The fracturing around a 1 1/2-in. diam drillhole is usually confined to an area with about a 6-in. diam. In the fractured area, the pressure of the gas is reduced until the force on the walls is no longer capable of fracturing the rock. Although the gas pressure does not continue to fracture the rock, the pressure imposes a high impact stress on the wall rock. In addition, a pressure or seismic pulse is produced in the rock. The pulse is probably entirely a compression pulse when originally produced in the rock. But, with distance, part of the energy of the compression pulse is transformed into a tension pulse which follows the compression pulse. The explosive charges and burdens used in conventional mine blasting are such that the tension pulse of the original wave is probably too small to be considered in a practical evaluation of the theory. The compression pulse is transmitted through the rock with no associated fracturing.

Jan 1, 1961

By C. S. Duncan, S. Scuro, D. R. Muss

Work is vepurted which was aimed at accentuating the pec14liar attributes of the GaAs laser diode, namely its sutzull size and its high efficiency. This has been done by reducing- transport losses in the bulk p and n regions of the diode and combining many of. these diodes into series stacks with common optical cazlities. The result of this effort is a nearly monochromati source at about 8450A With a luminous areu 0.05 by The GaAs laser diode is an attractive pulsed light source in the near ir because of its ability to emit very large pulse powers and its small size. In addition to this, the device is efficient; and the higher the 0.05 cm emitting peak pulse po we rs at greater than 300 LC at repetition rates below 200 pps into a cone about 0.01 steradians when operated at 77°K. The results of nzeasuvetnents of peak optical power and spectra frorr~ these stacks are reported and some conclusions are drawn about the vole the individual diodes play in the stacked operation. peak output power, the more efficient it is. The limit for the amount of power that these diodes can emit is the transient and average dissipation associated with the pumping pulse. This power dissipation arises primarily from transport across the bulk regions of the diode; this fact, along with the relatively low thermal conductivity of the GaAs, led us to the conclusion that higher power

Jan 1, 1968

By Allen L. Hatch

A survey of all phases of the world's lead and zinc production in 1968 from ore through to refined metal was conducted by sending questionnaires to individual companies ad the results of this survey are tabulated at the end of the paper. The paper goes on to review changes in the geographical distribution of the world's lead and zinc mine and metal production and in the trading patterns of raw materials, present and future utilization of metal production capacity, developments in metal smelting and refining processes and the growing importance of marketing, product development and research in the 1950's and 1960's.

Jan 1, 1970

By Mehl, Robert F.

IT has been shown by numerous studies that the orientations of new metal crystals are determined by the orientations of the crystals in the original matrix, whether these new crystals are formed by recrystalliza-tion, by precipitation from solid solutions, or by transitions in the solid state. The orientations of crystals formed by recrystallization of cold-worked worked metals that bear preferred orientations are occasionally simply related to the initial preferred orientation; often, however, the relation-ship is not simple, but complicated and obscure in origin.1 The orientations of crystals formed by precipitation from solid solu-tions have been shown by many studies in this and other countries to be determined by the orientation of the crystals of the solid solution stable at the higher temperatures, though here again complicated cases have been found and no general theory is available .2 Related to this latter class

Jan 1, 1934

To THE BOARD OF DIRECTORS AND THE MEMBERS OF THE AMERICAN INSTITUTE OF MINING AND METALLURGICAL ENGINEERS GENTLEMEN: Herewith are transmitted the joint report of the Treasurer and Finance Committee for 1935 and the reports for the same year of the Chairmen of the following Committees: Admissions, Membership, Papers and Publications, Library, MINING AND METALLURGY, and Rocky Mountain Income. . To these reports you are referred for details of the year's activities. Finances. : Income continues to increase the total for the year 1935, being $141,754 compared with $134,967 in 1934, and $121,689 in 1933, which was the lowest reached during the depression. The principal increases were $2000 in Current Dues; $2400 in Dues from New Members; $2000 for Advertising in the monthly magazine MINING AND METAL¬LURGY; and $1600 in Sales of Authors' Reprints and TRANSACTIONS volumes. Income from Dues in Arrears was $1000 less as a consequence of the fact that arrearages had been largely reduced during 1934, so that there were fewer from which to draw.

Jan 1, 1936

Jan 1, 1907

By L. H. Robinson

Triaxial compression tests have been performed to determine the strength characteristics of limestone, sand-stone and shale rocks subjected to controlled stress conditions. This control tuns exercised by varying the liquid pressures within and around a plastic-encased rock specimen. The pressure in the pores of the rock was varied throughout the range from atmospheric to 15,000 psig; the external pressure was changed over the same range with various positive pressure differences between is and the intertnal pressure. The data show that the rock strength increased and the mode of failure changed as the pressuire. surrounding the rock became greater than the pressure in the pores of the rock. These observations and the resu1ts of microbit drilling experiments indicate that the increased rock strength under pressure may bc an important effect in reducing drilling rare, but that other factors are probably of even greater importance. INTRODUCTION A large part of the research conductcd to reducc thc cost of drilling is directed toward improving present drilling technology and dcveloping new drilling methods. In spite of the fact that drilling is essentiaIly the act of making rocks fail, many details of the mechanism of failure are not known. It seems probable, therefore, that continuing studies of the fundamentals of rock failure can lay a foundation for future improvements in drilling technology. One of the factors which affects rock failure is the stress applied to the rock. This effect has been known for many years.'.'.; As an example, stress studics have been published by engineers' concerned with the strength characteristics of concrete in large dams. More recently, a number of investigators4-12 have explored the effects of stress on the strength of geologic formations and the geologic implications of their findings. During the last few years some research'" on rock strengths has also been conductcd in an attempt to gain additional insight into the factors which affeet rock drillability. In detcrmining the strength characteristics of rocks under different stress conditions, investigators have conventionally used triaxial compression equipment. wherein a jacketed rock cylinder is uniformly loaded from all directions and then compressed longitudinally. The results of this work have demonstrated that the mode of failure (brittle or malleable) is dependent upon the loading pressure, and that the strength of the rock increases as the loading pressure increases. These results clearly manifest that the stress, which is determined by the loading pressure, affects rock strength, and this implies that rocks under stress should be stronger and hence harder to drill. During the drilling of a porous rock the stress conditions are determined not only by the pressure surrounding the portion of the rock undergoing failure (confining pressure) but also by the pressure of the interstitial fluids within the rock (pore pressure). The importancc of both these pressures on the drilling rate of rocks has already been demonstrated by a number of investigators. Murray and Cunningham" found in microbit drilling expcriments that at constant pore pressures the drilling ratc decreased as the hydrostatic pressure surrounding an unjacketed, impermeable rock increased. Later Eckel" found that for jacketed Iimestone specimens the differcnce between hydrostatic (wellbore) pressure and formation (pore) pressure had an important effect on drilling rate. These observations of the effect of pressure on drilling rate emphasize that for drilling studies triaxial compression tests should be conducted under conditions of confining and pore pressure which simulate conditions underground. In the past, triaxial tests have been made under conditions which do not reproduce those underground. In particular, most of the tests on porous materials have keen made at varying confining pressures but with atmospheric pore pressures. In only one group of tests' was any data on the effect of pore pressurc reported, and these few data were on materials not representiltive of those encountered in drilling earth formations. The research described herein was initiated to deter-mine the importance of both internal pore pressure and confining pressure on failure characteristics of limestone. sandstone and shales. Triaxial loading equipment was used to obtain strength data at pressures up to 15,000 psig. An additional objective of this research was to apply these results to drilling rate studies by comparing them with the previously published drilling data of Murray and Cunningham" and of Eckel12. The work reported here is but one step in determining and evaluating the fundamental mechanisms which control drilling rate. Additional research is needed to clarify other aspects of the drilling process. The better

By C. W. Hazelett

This paper is a resume of some of the accomplishments in direct rolling of strip from molten metal, and a description of some experimental developments in recent years. In all the early developmental work, we used a pair of rolls with a bath of metal between them, maintained by flanges or plates at the ends of the rolls. These flanges produced an excess cooling of the metal and built up enormous pressures at this point as the metal went through the bight of the rolls. Many means were tried for compensating for this excess cooling, such as thickening the strip at the edges, heating the end dams directly or by flowing more of the molten metal against them, leaving an open crotch below the end dam and above the bight of the roll, where the excessive pressures built up could be relieved by some of the metal squeezing out at this point, and so forth. All of these helped somewhat to solve the problem, so that very large heats of many metals melting up to 200°F., having commercially uniform gauges, could be rolled up to 24 in. in width. The rolls were made by mounting heavy rings on heavy shafts, and pressures up to 75,000 lb. per inch in width were used. Cooling of the rolls was generally done by spraying water on the outside surface of the rolls that came in contact with the molten metal. Roll life was commercial with brass, barely satisfactory with copper, and totally impractical with steels. The greatest difficulty encountered in all this work was caused by lack of uniformity in the product, owing to a folding action in the mill. Those who are familiar with the operation of a rolling mill know that a bar entering a mill moves at a lower speed than the peripheral speed of the roll. However, the metal solidifying from a bath in a direct rolling mill is cast at exactly the peripheral speed of the roll. This results in irregular folding of the metal, some irregular remelting of the previously solidified sections, and it is difficult, if not impossible, in some cases to exert enough pressure to weld these folded sections sufficiently into a sound product. In addition to this melange of solid, semisolid and liquid metal in the bath, we know that pressure near the freezing point of any alloy in which the constituents have different melting points—and I believe all of them have—causes the lower-melling-point constituent to be squeezed back until it becomes cold enough to solidify and go through the mill. This segregates all alloys, the segregation increasing with the pressures and the freezing ranges of the metals. Add to these problems the excessive roll-maintenance costs with high-melting-point metals and then, the greatest difficulty of all, the vanity of homo sapiens where a matter of possibly large importance is being considered, and the problems seemed almost insuperable. It was long ago obvious to me that something much more than the size of a corporation's money and self-assuradce was necessary if this process was to be made commercial. I should like to show you first the performance of the only mill we ever really designed and built, to see what might be done with a well constructed mill. We accomplished something new in history with this prccess, first, by producing at Scovill Manufacturing Co. coils of brass

Jan 1, 1945

THOSE NOT MARKED ARE MEMBERS; MARKED THUS ?ARE ASSOCIATES. HEAVY-FACED TYPE SIGNIFIES HONORARY MEMBERSHIP JUNIOR MEMBERS ARE MARKED ' . THE FIGURES AT THE END OF THE ADDRESS INDICATE THE YEAR OF ELECTION. AARONS, J. BOYD See Honor Roll. '05 ? AARONSON, ALFRED E Pres., Tuloma Oil Co., Unity Bldg., Tulsa, Okla. '18 ABADIE, EMILE R., Min. En r Box 291, Porterville, Tulare Co., Cal. '76 ABBOTT, CLARENCE E., Gen'l Supt., Iron Mines Div., Tenn. Coal, Iron & R. R. Co., 1405 Minnesota Ave., Bessemer, Ala. '04 ABBOTT, Louis BENJAMIN, Chief Engr., Consolidation Coal Co., Elkhorn Div., Jenkins, Ky. '15 ABBOTT, ROBERT R Met. Engr., Peerless Motor Car Co., Cleveland, Ohio. '12 ABE, ASAKA Fujitagumi Taiwan Office, Taipeh, Formosa, Japan. '14 ABBY, HIROSHI Min. & Met. Engr., Mitsubishi Co., Tokyo, Japan. '17 ||ABOUCHAR, S. S., Cia. de Minerales y Metales, S. A., Minas Viejas, Villaldama, N. L., Mexico. '17 ABRAHAMS, A. I 1391 Madison Ave., New York, N. Y. '14 ?ACKER, E. O'C., Met.,128 East Washington Lane, Germantown, Philadelphia, Pa. '86 ? ACKERMAN, ERNEST R., Pres., Lawrence Portland Cement Co., Plainfield, Union Co., N. J. '15 ACOSTA, J. N., Min. Engr., Cons. Engr Hotel Brewster, San Diego, Cal. '15 ADACHI, JINZOO 11 Shiba Park, Shiba-Ku, Tokyo, Japan. '88 ADAMI, CHARLES J., Min. Engr., Gen'l Supt., St. Joseph and Doe Run Lead Companies, Bonne Terre, Mo. '12 ADAMS, ARTHUR K., Min. Geol., Andes Copper Min. Co., Casilla 230, Antofagasta, Chile. '06

Jan 1, 1923

By Henry S. Washington

During the last twenty years or so the chemical investigation of rocks has made great advances, and it is now generally recognized that a knowledge of the chemical composition is as essential as that of the texture or mineral composition—if not more so—for the proper classification of rocks and study of their origin and relationships. Rock-analyses have vastly increased in number and, what is of greater importance, in quality. New and improved methods permit of greater accuracy than was possible in the early days, and the list of chemical constituents frequently determined has risen from the seven or eight of the greater part of the nineteenth century, to twenty or more. Indeed, rock-analyses with determinations of so many constituents are now commonly made by the chemists of the United States and Australia, while in Germany, Great Britain, France, and Italy the rarer constituents are determined more frequently than formerly. As a consequence of this modern, accurate work, it has been discovered that some elements which were formerly supposed to be rare are of wide-spread occurrence and are often present in considerable amount. The fact is further being developed that the elements tend to show certain relations of occurrence or abundance in connection with each other. This is a fact which is applicable to the rarer elements, and which also finds a broad geological and petrological expression in the recognition of petrographic provinces. We are beginning to obtain some definite, though as yet rudimentary, knowledge of the distribution of the elements among igneous rocks. Some of the results along these lines obtained by study of the vast accumulation of analytical data now available are well known to petrologists, while others do not seem to be so gener-

Jan 1, 1909