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By J. W. Stewart

THE aim of this paper is to point out the various ways in which design is taught in standard four-year mining engineering curricula in American colleges and universities; to discuss the reasons apparently justifying the great diversity of procedure that exists along this line; and to indicate possible solutions to the difficulties now attending the teaching of design. A study was made of typical four-year mining engineering curricula in 15 colleges and universities of the United States (Table I). Great diversity in content of the various design courses, if taught as described, became apparent immediately. It appeared that it might be both interesting and instructive if the cause for this colorful variety could be found. Was the cause local mining conditions, departmental individuality, or actual necessity? Study of the school catalogues revealed that the various design courses could be classified into two fairly distinct types; namely, (I) those dealing with mine equipment or structures, and (2) those dealing with underground layout of mine workings. It seemed reasonable to label the first type of course "mining design" and the second type "mine design." Some such distinction must have been in the minds of mining educators, for we find both names (i.e., mine design and mining design) used to designate the design courses included in the various mining curricula. Unhappily, the name and the apparent content of such courses do not, in all instances, conform to the classification made here, although in most instances such conformation does obtain (Table I). It is possible that in the exceptional case the method of teaching a design course, and consequently the content of it, may have been changed at some time without change in the name of the course. Apparently only 3 of the 15 schools made an effort to cover both types of design in their curricula (Table I). Two other schools did not list or describe any course of study that could with certainty be taken as a design course. Of the remain¬ing to schools, 9 gave a mining-design type of course and one gave a strictly mine-design type. Obviously, the preponderance of design courses afforded are of the mining-design type. Why? To answer this question, it is necessary to make a study of the prerequisites for the two types of design courses taught. In all schools the design courses were taught in the senior year; in eight, design was taught throughout both semesters; in two, it was taught during the first semester only; and in three it was taught during the second semester only. Consequently, excepting the last three cases noted, it is obvious that all prerequisites for a design course should be completed by the end of the junior year. PREREQUISITES What are the probable prerequisites for the different kinds of design courses as they appear to be taught? Let us take first the case of the mine-design type of course, having to do with layout of underground workings. Here it would seem that logical

Jan 1, 1941

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 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 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 R. M. Asimow

The magnetization curves for specimezs containing superparmagnetic particles are considered. It is shown that the curves may differ from a Langezlin function because of particle anisotropy, particle interactions , and the presence of a size distribution of particles. The various causes of particle anisotropy are considered, and magnetization curves for specimens with cubic and uniaxial anisotropy are presented. The magnetization curves depend on the In the particle-size below 100A it is quite difficult to obtain quantitative size and shape information on precipitate particles. All of the available techniques have their limitations; however, quantitative applications of superparmagnetism have not been developed as fully as possible due to a lack of analysis of the complete magnetization curve. With such an analysis it appears possible to obtain from a single magnetization curve of a specimen containing randomly oriented SPM (superparamagnetic) particles a quantitative volume distribution and a description of the particle shape.* sign of the anisotropy energy and in the case of a negative uniaxial anisotropy (prolate spheroids) the resulting curves may differ very considerbly from a Langevin function. A graphical technique is developed whereby it is possible to separate out the effects of the size distribution, the particle interaction, and the particle anisotropy. Thus it is possible to obtain quantitative values for both the particle shape and the size distribution. Langevin function2 I/Is = ctnh(HVIs/k T)-k T/HVIS [ 1 ] where I, is the saturation magnetization, V the particle volume, H the applied field, T the particle temperature, k the Boltzmann constant, and I the magnetization in the direction of the applied field. Such behavior is rarely if ever observed in actual systems. One explanation for this is that the SPM particles do possess a significant anisotropy and thus the magnetic energy associated with the particle depends on the direction of magnetization in a more complicated way than for the isotropic particle of Eq. [I]. In general the magnetic energy E of an isolated SPM particle embedded in a nonmagnetic matrix can be expressed as a sum of several contributions: E = Eh + Ed+Es+Ec [2] where Eh is the external field energy, Ed the energy resulting from the particle demagnetizing factor, E, the magnetostriction energy, and E, the crystalline anisotropy energy. In each term we consider only the part dependent on the orientation of the magnetization vector and the particle axes as the shape of the magnetization curve will be determined by these contributions. Following the same procedure used in deriving the Langevin function,

Jan 1, 1965

By Paul Billingsley

WHEN I was an undergraduate at the Columbia School of Mines, the mining curriculum was subdivided into two major branches's known respectively as the Metallurgical and the Geological Options, which diverged rather widely as the course progressed. When I duly elected the Geological Option, I believed, I am sure, that this divergence would continue throughout the years. The facts have proved otherwise. The mining industry is a closely knit entity in which the search for its raw materials, called mining geology, cannot be separated from the conversion of these raw materials into marketable form, called metallurgy. The mining geologist searches for materials which the metallurgist can utilize, and only such; and whenever an advance in metallurgy opens the gates for new materials, the geologist's problem is correspondingly modified. No better instance of this relationship can be given than that seen in the Salt Lake region in recent years. Our mineral industry here is of long standing. The three principal tributary districts, Bingham, Park City and Tintic, were discovered in the 1860's and have been vigorously and intelligently developed for many decades. Their production has made the Salt Lake valley one of the world's great smelting centers. The maintenance of this industry has for years depended upon the continual development of new orebodies to take the place of those being extracted. Intensive exploration in the old districts has been supplemented by prospecting in outlying districts of lesser prominence. . Many new orebodies have been discovered, such as those of the Daly West, Silver King, and Judge mines in Park City, the Utah Apex in Bingham, and the Sioux, Colorado Chief Consolidated and Tintic Standard in Tintic. New mines in other districts have been discovered also, but without affecting the dominance of the three major districts. In all cases discoveries, to be of value, had to be of ore amenable to treatment in the available metallurgical plants. This meant that, for the most part, zincy ores, both oxide and sulfide, must remain untouched, and also that ores high in iron and ores high in silica had a fictitious value, either high or low, set by the balance of these

Jan 1, 1928

By Paul Billingsley

When I was an undergraduate at the Columbia School of Mines, the mining curriculum was subdivided into two major branches's known respectively as the Metallurgical and the Geological Options, which diverged rather widely as the course progressed. When I duly elected the Geological Option, I believed, I am sure, that this divergence would continue throughout the years. The facts have proved otherwise. The mining industry is a closely knit entity in which the search for its raw matcrials, called mining geology, cannot be separated from the conversion of these raw materials into marketable form, called metallurgy. The mining geologist searches for materials which the metallurgist can utilize, and only such; and whenever an advance in metallurgy opens the gates for new matcrials, the geologist's problem is correspondingly modified. No better instance of this relationship can be given than that seen in the Salt Lake region in recent years. Our mineral industry here is of long standing. The three principal tributary districts, Bingham, Park City and Tintic, were discovered in the 1860's and have been vigorously and intelligently developed for many decades. Their production has made the Salt Lake valley one of the world's great smelting centers. The maintenance of this industry has for years depended upon the continual development of new orebodies to take the place of those being extracted. Intensive exploration in the old districts has been supplemented by prospecting in outlying districts of lesser prominence. Many new orebodies have been discovered, such as those of the Daly West, Silver King, and Judge mines in Park City, the Utah Apex in Bingham, and the Sioux, Colorado Chief Consolidated and Tintic Standard in Tintic. New mines in other districts have been discovered also, but without affecting the dominánce of the three major districts. In all cases discoveries, to be of value, had to be of ore amenable to treatment in the available metallurgical plants. This meant that, for the most part, zincy ores, both oxide and sulfide, must remain untouched, and also that ores high in iron and ores high in silica had a fictitious value, either high or low, set by the balance of these

Jan 1, 1928

By T. Egleston

For several years 1 have been engaged in studying the behavior of iron and steel under varying conditions of tension and compression, as well as of shock and abrasion. Some of these observations have been communicated to the Institute at various times. Within the past year I have been looking at the various observations that I have made as a whole, and have been led to the conclusion that there is a regular law of fatigue and refreshment of metals, and that the change which produces either the fatigue or refreshment, is a. chemical one, which is, however, in almost all cases accompanied by physical and molecular changes at the same time. That metals under conditions that were more or less well understood became worthless, has been known for many years. It has been known to blacksmiths that iron and steel, when improperly treated in their fires, become "burned," as they call it, and could no longer be used, and some of them have had a scrap heap into which such material was thrown. A few of them knew that after a period more or less long the iron or steel recovered some of its original properties and could, with many precautions, again be used, but that these phenomena followed any law has not to my knowledge been announced. My attention was first attracted to the varying conditions under which iron and steel rails break in service. It was not long before I became convinced that there was a general law applicable to all metals which allowed of their being used with safety within certain limits, and caused their rupture when the use extended beyond these limits, and this law I have called the law of fatigue- of metals. When me observe the causes of deterioration in iron and steel rails, we find that they are principally shocks, either slight and frequent, like those produced by the passing of a train over a road-bed in good order, which produces a vibration sensible to the ear laid on the rail, for very long distances, but distinctly audible for only a short one; or from sudden and heavy blows, like the descent of the locomotive and each car successively from a high to a low rail.

Jan 1, 1880

By James Kitson, Abram S. Hewitt

I HAVE now the duty—the very pleasant duty—to perform, of presenting to the Hon. Abram S. Hewitt the Bessemer gold medal for distinguished services to the iron and steel trade. When this matter was brought under consideration in London it was well known that, as Mr. Hewitt would be the first to acknowledge, there is more than one man in America upon whom we would gladly have cm ferred this distinction, and to whom this merit might be justly at tributed ; but Mr. Hewitt has been long known to our distinguished members on the other side of the Atlantic as one of the most active minds in the investigation of new methods of manufacture, and one of the most enterprising metallurgists on this side of the Atlantic. Well, gentlemen, we proposed to Mr. Hewitt that he should receive this gold medal, but I think it is quite right, and is his due, that I should state that he at once declined to receive it; and he declined in a manner which rendered it impossible to any one but very per sistent friends and very obstinate Englishmen to refuse. When we heard that our American friends had conferred once more upon Mr. Hewitt the distinction of President of the American Institute of Mining Engineers, and particularly with reference to our contem plated visit, and when we heard that he had been elected unani mously to that position, we felt that we had received the stamp of approval from this side. Gentlemen, as I said before, Mr. Hewitt has long been known to many of us in England as an advocate of scientific education. A report which he made of the metallurgical products at the Paris Exposition in 1867 was one of the matters which drew very clearly and distinctly the attention of the English iron and steel trade to the necessity of further improvement in our technical education as to iron and steel; and it was one of those beginnings which led ultimately to the foundation of the Iron and Steel Institute. The development of the ideas which 'he there investigated undoubtedly led

Jan 1, 1891

By E. C. Harder

HERBERT K. SCOTT, London, England (communication to the Secretary*).-I am acquainted with the manganese-ore deposits of Russia, India and Brazil, and agree generally with the statements contained in the paper regarding those deposits. The information given by Mr. Harder regarding the Chilean deposits is very welcome. When examining the Caucasian deposits, I endeavored to determine the quantity of ore originally contained in the deposit, and by deduction, the amount remaining for extraction. These calculations were rendered possible by the great extent of the outcrop and the extensive work that had been carried on in the deposit. In making the first estimate, the quantity of manganese ore and associated sterile material in the bed was measured in a large number of

Jan 12, 1916

By James M. Winston

When I began my career (the first assignment was mucking the "drainage" ditch) an experienced miner told me, "Remember son, happiness is a journey, not a destination. . . ." If you missed the 100th Anniversary of AIME in New York this year, you are missing the journey. There are not enough superlatives to describe the event. Especially since New York is "known to have it all." An Indefinable Plus There was a little something different at this meeting. I cannot explain what, but there seemed to be more of everything. There were more wives there this year-what a pleasure to see all the lovely women mingling through the conference- which was reflected through our own attire and mannerisms. In fact, everyone looked so great, we checked to see if it really was a convention of miners. You wives keep coming to all of the events, because so much is added by your presence.

Jan 1, 1971

By R. W. Rausch

BELT-CONVEYOR 'history in this country dates back to the end of the eighteenth century. Up to 1896 they were crude in design and application. The second era, dating from 1896 to about 1920, saw special study given to belt construction and idler design. The latter part of this era saw the beginning of the present-day antifriction idler. The third era followed World War I, when industry began to expand rapidly. Mines and quarries, steel mills, and power-generating plants became larger and greater quantities of ore, stone, and coal were being handled. It became vital that belts handle larger capacities, that they be longer, and that they be dependable for 24 hours per day. In this third era a radical change in belt conveyor design and application occurred. The design has became more scientific. Studies have been made to find out what factors influenced the power required for a belt conveyor and it was found that the sag of the belt between idlers and the flattening of the load between idlers had considerable effect on power requirements. So definite initial tension was put into the belt at the loading end and idler spacing was reduced at the foot end to limit this sag. Belt manufacturers made tougher and stronger belts.

Jan 1, 1947

By Emile Gyss

THE speed of drilling rock has become an impor-tant factor in mining operations, while the place-ment of holes, kind, and quantity of explosive used. are equally important. These are a function of the rock hardness and toughness. Both of these fac-tors must be considered in compiling a table that will enable a mine operator or engineer to estimate drilling speeds in a given rock, knowing its hardness, and from its toughness, the dynamite required. The hardness of a homogeneous rock may be defined as its resistance to a penetrating medium, such as a drill-steel bit, and toughness, its resistance to with-stand rupture by the tearing apart of its minerals or parts of the same mineral. Rock hardness, as it has here been defined, is a function of the hardness of the component grains composing it, as well as grain size, shape, arrangement, and binding minerals. Rock tough-ness depends on substantially the same factors, but is measured by a totally different method. The units in which rock hardness is usually ex-pressed are either relative values or alphabetical desig-nations which carry no definite quantitative meaning. R. M. Raymond has suggested the measurement of com-posite rock hardness, based on mineral hardness as ob-tained by the Moh scale. This is done by multiplying the percentage of each mineral in a rock by the Moh mineral hardness and dividing by 100. These values convey a clearer conception in the minds of men in-terested in rock work -and are the basis of the units used in Tables 1 and 2. The hardness of rocks as it has been variously de-fined may be determined by different methods. The first method is one in which the proportionate average of the hardness of minerals making up a rock is the basis for classification. The other factors of grain size, shape, arrangement, and binding power are not considered.

Jan 6, 1927

By H. R. Collins

The purpose of pulverizing coal before burning it is to make available every heat unit it contains. Machinery has been developed which will pulverize coal in one operation, delivering it to bins in front of the furnaces at an expenditure of about 17 hp.-hr. per ton, in a medium-sized plant. The cost of the operation depends upon the amount of moisture that must be expelled before pulverizing, the cost of labor, and the cost of coal delivered at the plant. At a small plant, requiring a pulverizer with a capacity of only 1/2 ton per hour, the cost per ton pulverized will naturally be greater than at a plant requiring the largest pulverizer, with a capacity of 7 tons per hour. :The first step is to reduce large lumps to a size suitable for drying uniformly, before passing to the pulverizing mills; this is done in rolls, at a single pass. The second step is the elimination of moisture, in order to facilitate pulverizing to great fineness, while also increasing the heating effect and the temperature attainable when the coal is burned. There are other mechanical advantages in the handling of dried coal. Driers are now manufactured which are able to eliminate moisture without distilling any of the volatile combustible matter in the coal; they are fired by hand or with pulverized fuel. The heat first surrounds the shell of the drier, being confined within a chamber where complete combustion takes place; the heated gases are then led through a duct to the discharge end of the drier and enter the inside of the shell at a temperature not exceeding 300" F. This temperature is maintained by the operator and is indicated by a pyrometer. Volatile combustible matter is not likely to be distilled until the temperature rises above 400" F. On discharging from the drier, the coal is usually passed over a magnetic separator in order to prevent pieces of iron from going to the pulverizer. Two types are used: a magnetic pulley which automatically discharges its collection of iron, and a lifting type, from which the iron is removed by hand when convenient. In the operation of pulverizing, the coal should preferably be reduced until 95 per cent. will pass through a 100-mesh and 70 per cent. through a 300-mesh sieve. Such a product is obviously an almost impalpable powder.

Jan 1, 1920

By Clyde E. Williams

IN planning a postwar program for manufactured products, it is essential that the bases for the plans be wisely chosen. First we must make certain assumptions as to the war's ending. Let us assume: (1) complete victory by the United Nations, (2) peace terms that will ensure the direction of the economy of all nations of the world toward peaceful pursuits, and (3) an early ending of the war, that is, before the nations of the world, excluding the enemy, are near the point of physical and spiritual exhaustion. Thus, our manufacturing plants and transportation facilities will still be in good shape. The plants and transportation facilities, as well as the cities of a large part of Europe, however, will be badly crippled. The rich mineral and other raw material resources of the world, little of which was under control. of the Axis powers before the war or will be after the war, will not be used up. Control of these raw materials, or at least an important part of them, will remain in the hands of the strong peaceful nations.

Jan 1, 1943

By Clarence Claghorn

ONE of the simplest and most easily effected steps toward mechanization and concentrated mining in coal mines is the substitution of transport or room conveyors for the customary tracks in rooms, thus bringing the coal to the cars instead of taking the cars to the coal. As this involves little or no change in the established room and pillar layout, it appeals to the conservative operator who is more or less fearful of changes in system involving the element of roof con-trol. An increasing number of these room conveyors would seem to attest the favorable commercial results secured. Rooms are naturally driven as wide as roof conditions permit, providing maximum tonnage from each room cut. If the rooms are more than 12 to 14 ft. in width the room conveyor is usually set along one rib, a porta-ble face conveyor being set along the face itself and within easy shoveling distance of it, so arranged as to discharge to the transport conveyor. As the room ad-vances the latter is lengthened and the face conveyor moved up laterally. The advantages of this layout are, briefly, low lifts, no shoveling, no waiting for cars. It gives easy shovel-ing conditions and continuous production so long as there is loose coal at the face. Several loaders are usually employed at the face and the room is loaded out several times each shift. In fact, where the rooms are fairly wide, by judicious management, cutting and load-ing may go on simultaneously. Under these conditions, naturally, the face conveyor plays an important part as it is the appliance on which the coal is actually loaded. Someone has aptly stated that the loading is a question of "foot pounds," which is an appealing way to put it, for it is the number of pounds to be moved by the number of feet which measures the work to be done. It can easily be seen that the design of the face con-veyor is a matter of importance. It might be an im-perfect target for the shovel or of an awkward shape and height, and so involve extra effort on the part of the loader, tiring him when kept up continuously and at the same time slowing up his shoveling speed.

Jan 12, 1927

By Carl L. Shapiro, Jerome and Strauss

This is a critical examination of the theory that the amount of carbon necessary to form the iron-carbon (carbide) eutectoid is lowered by the addition of any carbide-forming element. Although this theory has been built up over a long period of years, it appears, in the light of recent published investigations upon the ternary constitutional diagrams of iron with carbon and other alloying elements, to be no longer tenable. A survey of these new results, summarized below, shows that (as is known) some metals lower the carbon content of the iron-carbon (carbide) eutectoid, whereas others raise it, but (as not heretofore clearly set forth) some first move the eutectoid in one direction and then, at higher concentrations, shift it in the opposite direction. Moreover, these differences in behavior exist even among the common alloying metals classed as carbide formers. PART I Influence of Body-centered Cubic Elements The effects of the various body-centered cubic metals (chromium, tungsten, molybdenum, vanadium, columbium and tan. talum) are reviewed individually. Iron-carbon-chromium System.—In the monograph on Alloys of Iron and Chromium, Kinzel and Crafts1 concluded that the carbon content of the eutectoid is lowered by increasing the chromium content. The quantitative influence of chromium on the eutectoid point of iron-carbon alloys was shown by Monypenny2 (Fig. I) and no data have been forthcoming to refute his findings. Iron-carbon-tungsten System.—Gregg,3 in the monograph on Alloys of Iron and Tungsten, accepted the data showing that tungsten decreases the amount of carbon required to form the eutectoid. The influence of tungsten on the eutectoid percentage of carbon as determined by Oberhoffer and Daeves4 is shown in Fig. 2; these results have received general approval. , I ron-carbon-molybdenum System.—In the monograph on Alloys of Iron and Molybdenum, Gregg5 reviewed the work of Guillet,6 Swinden,7 and ReedI8 all showing that molybdenum lowered the carbon content of the eutectoid, whereas Takei9 contradicted this conclusion. Svetchnikoff and Alferova,10 a little later, showed that large additions of molybdenum shift the eutectoid to the right. These last-named investigators found that molybdenum, up to 1.2 per cent, shifts the pearlite point and the point of maximum solubility of cementite in the gamma phase only slightly in the direction of lower carbon content; on the other hand, increasing amounts of molyb-S

Jan 1, 1944

By Jerome and Strauss, Carl L. Shapiro

This is a critical examination of the theory that the amount of carbon necessary to form the iron-carbon (carbide) eutectoid is lowered by the addition of any carbide-forming element. Although this theory has been built up over a long period of years, it appears, in the light of recent published investigations upon the ternary constitutional diagrams of iron with carbon and other alloying elements, to be no longer tenable. A survey of these new results, summarized below, shows that (as is known) some metals lower the carbon content of the iron-carbon (carbide) eutectoid, whereas others raise it, but (as not heretofore clearly set forth) some first move the eutectoid in one direction and then, at higher concentrations, shift it in the opposite direction. Moreover, these differences in behavior exist even among the common alloying metals classed as carbide formers. PART I Influence of Body-centered Cubic Elements The effects of the various body-centered cubic metals (chromium, tungsten, molybdenum, vanadium, columbium and tan. talum) are reviewed individually. Iron-carbon-chromium System.—In the monograph on Alloys of Iron and Chromium, Kinzel and Crafts1 concluded that the carbon content of the eutectoid is lowered by increasing the chromium content. The quantitative influence of chromium on the eutectoid point of iron-carbon alloys was shown by Monypenny2 (Fig. I) and no data have been forthcoming to refute his findings. Iron-carbon-tungsten System.—Gregg,3 in the monograph on Alloys of Iron and Tungsten, accepted the data showing that tungsten decreases the amount of carbon required to form the eutectoid. The influence of tungsten on the eutectoid percentage of carbon as determined by Oberhoffer and Daeves4 is shown in Fig. 2; these results have received general approval. , I ron-carbon-molybdenum System.—In the monograph on Alloys of Iron and Molybdenum, Gregg5 reviewed the work of Guillet,6 Swinden,7 and ReedI8 all showing that molybdenum lowered the carbon content of the eutectoid, whereas Takei9 contradicted this conclusion. Svetchnikoff and Alferova,10 a little later, showed that large additions of molybdenum shift the eutectoid to the right. These last-named investigators found that molybdenum, up to 1.2 per cent, shifts the pearlite point and the point of maximum solubility of cementite in the gamma phase only slightly in the direction of lower carbon content; on the other hand, increasing amounts of molyb-S

Jan 1, 1944

By R. W. Raymond

Four portraits have recently been hung in the rooms of the Institute, in recognition of four illustrious men with whom we, as mining engineers and metallurgists, may claim fellowship. Luther. Martin Luther is often spoken of as a miner's son; but it is less generally known that John Luther, his father, was, in a small way, a metallurgist as well as a miner, and that Martin Luther himself, in his youth, worked in a forge or bloomary established by his father at Mansfeld, Saxony. Since this is the only manual occupation on his part of which we have ally record, it is fair to assume that the great scholar and reformer derived from his work in this department the practical familiarity with the conditions of human labor so abundantly evinced in the homely illustrations which accompany even his serious arguments, and in the witty apothegms of his famous " table-talk." At the same time, I must confess that I have not been able to find in any of the works of Luther distinct allusions to mining or metallurgy. Körner. Theodor Körner, a student at the Mining Academy of Freiberg, Saxony, threw himself into the German War of Freedom in the first decade of the 19th Century. He was a poet of no mean rank; and his " Song of the Sword " is one of the great lyrics of literature. This poem was written but a few days before he died in battle. In many respects, Körner may be compared with our American hero Theodore Winthrop, who similarly met a glorious fate, and left behind him prophetic indications of geniue, of which his premature death prevented the complete fulfillment. I am informed by a member of the Institute that Körner's admirable collection of minerals is still preserved at Dresden.

Jan 1, 1909