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DR. PeRsifor Frazer, Philadelphia, Pa. (communication to the Secretary):* Mr. Campbell's very interesting contribution, after complimentary mention, finally decides against the acceptance of the classification proposed by me in a paper bearing the same title and read at the Wilkes-Barre meeting, May, 1877.2 That paper was written primarily for the Second Geological

Jan 1, 1906

By C. R. Hayward, H. O. Hofman

The aim of instruction in a metallurgical laboratory is to make real the principles on which metallurgical processes and operations are based, and to foster the spirit of investigation. The materials with which experiments are carried out are ores, metals, and metallic compounds. The method varies with the end sought. A class may work as a whole, each member contributing his share to the solution of a problem, or the students may carry on investigations independently; the former exemplifies class-research; the latter, individual research. It is with a branch of the former, with special reference to ore-treatment, that the present paper deals. In smelting an ore by a well-established process, the result is shown by analyzing the products to see whether their compositions correspond to those calculated in making up the charge; by taking account of stock to show the distribution of metal in the different products made and the losses from dust and volatilization; by casting a thermal balance to find the distribution and losses of heat; and by making a cost-sheet to ascertain, as far as possible, the necessary outlay of money. In lixiviation and amalgamation, the mode of operating has to be varied to adapt a process to the individual ore. Here a number of tests become necessary. Each will consist of a series of experiments with one variable, in order to find the conditions under which the variable gives the best result; a summary of several tests will give the best method of operating. Working a number of charges with the best method will furnish the data desired for ascertaining the recovery of metal,

Jan 1, 1910

By C. D. Haynes, S. C. Gambrell

The practice of roof bolting in WORLD-WIDE mining activities is very well-known, having been used extensively for over 50 years. The theory of roof bolting, however, is extremely complicated, and only recently have investigators attempted to explain the theory. Various means of stress analysis have been utilized in rock mechanics, most of which reduce rock to an isotropic, homogeneous medium that can be easily analyzed. One of the indirect research methods is the photo-elastic technique, the theory of which is widely known and needs no elaboration. This technique has been used extensively to examine the state of stress around underground openings of various shapes in certain types of strata, and under various loading configurations.'-" In-Situ Mine Roof Trusses The photoelastic technique was employed here to evaluate the state of stress above a mine opening where support is provided by the in-situ mine roof truss. This support configuration, shown in Fig. 1, has gained popularity in recent years, particularly in mines with bad roof conditions." To the authors' knowledge, no scientific determination has been made of the advantages roof trusses may offer over conventional bolting configurations comparable to roof trusses. Ordinary mine roofs usually sag or bulge downward soon after mining. Normally, after some movement the roof begins to stabilize, but the face of this bulging mine rock is usually in tension and will almost always fail unless supported. Because rock fails easily in tension, it is desirable to "preload" the roof, that is, to impress a compressive force on the mine roof to prevent bulging and subsequent tensile failure. Ordinary rock bolting installations, particularly if the bolting is perpendicular to the mine roof plane, do not produce a preloading effect. Although bolting installations squeeze the strata together and produce a beam effect desirable for support, they do not have the advantage of actual uplift. They pull down at the anchorage point with a force equal to the bolt tension which sometimes causes a separation in the plane of the anchorage detrimental to roof strength. In-situ mine roof trusses require the installation of steel tension rods in the roof of the mine much the same as conventional roof bolts, except that the rods are arranged to produce a stress pattern above the upper surface of the opening similar to that of a prestressed beam. The roof rock acts to transmit the compression force. The simplest form of truss consists of two steel rods anchored to the back of holes drilled at an angle of approximately 45 over the mine pillars. These rods are collared near the middle of the room, and the lower ends of the rods are connected by tie rods and turn-buckles. Used in this manner, a small-diameter steel rod can provide essentially the same support as a wide-flange steel beam. By tightening the turnbuckles, an uplift on the roof can be produced. Objective of the Investigation The objective of this investigation was to determine qualitatively the state of stress that exists above a mine roof after the installation of the in-situ mine roof truss vs. that of two angle roof bolts, hereafter referred to as "roof bolts," drilled and placed in the same configuration, that is, 45" above each pillar and connected together in the middle of the room by a bearing member such as a steel beam. Each state of stress was to be identified, insofar as possible, as compression or tension above the mine opening. Model Construction A photoelastic model of a mine opening was coil-structed from -in. thick PLM-4B birefringent plastic and was machined to specification shown in Fig. 2. The dimensions of the opening were chosen to simulate a width-to-depth ratio of 3 to 1. Two % -in. holes were drilled at 45" angles, as shown, to provide for the loading devices. After construction, the model was annealed at 240°F to remove stresses produced during machining.

Jan 1, 1971

By C. W. Vaupell

The Huitzuco mines lie in north central Guerrero, Mexico; production has been about 90,000 flasks of quicksilver since 1873. Near-surface ores fill extinct mud geysers and the deep deposits are chambered veins, stock-works in brecciated blocks, and replacements in limestone. The epigenetic minerals livingstonite, stibnite and sulphur occur in limestone, gypsum and dolomite through a developed vertical range of 260 meters. The deepest workings expose an increased amount of stibnite, which probably indicates that the lower limit of mercury mineralization is being approached. A resurgence of heat and water formed geysers over an extended area after the period of mercury mineralization. Mud geysers, which are situated, in the outcrops, contain the secondary mercury minerals, cinnabar and barccnite in the gravel and mud filling the vents. A 150-ton flotation plant is in operation concentrating stope fills that assay 3.0 kg. of mercury per ton. In one open stope, which is more than one hectare in area and 60 m. high, 150,000 tons are available. Introduction The Huitzuco mercury mines are of interest because of the unusual occurrence of ore in extinct geyser vents and the presence of several rare mercury minerals. Some of the deposits have typical characteristics of the telethermal zone and there is a gradation towards typical epithermal mineralization in depth. Halse,1 Villarel1o,2 Mactear3 and Merri114 have described the geology and the early operations in the district, and Bar-cena5 and Mallet6 have described the rare mercury minerals, livingstonite and barcenite, found at Huitzuco. Location The village of Huitzuco lies in the north central part of the State of (Guerrero, Mexico, 27 km. (16.7 miles) east of Iguala, which is the largest and most important town in the area. Iguala is served by the Mexican National Railways and also by the Mexico City-Acapulco highway. The highway is surfaced from Mexico City to Iguala, a distance of 200 km. (124 miles) by road, and there is a fairly good, level, dirt road from Iguala to Huitzuco. The elevation above sea level is about 1000 m. (3280 ft.). The climate is warm and very dry except during the rainy season, from June to

Jan 1, 1941

By C. W. Vaupell

The Huitzuco mines lie in north central Guerrero, Mexico; production has been about 90,000 flasks of quicksilver since 1873. Near-surface ores fill extinct mud geysers and the deep deposits are chambered veins, stock-works in brecciated blocks, and replacements in limestone. The epigenetic minerals livingstonite, stibnite and sulphur occur in limestone, gypsum and dolomite through a developed vertical range of 260 meters. The deepest workings expose an increased amount of stibnite, which probably indicates that the lower limit of mercury mineralization is being approached. A resurgence of heat and water formed geysers over an extended area after the period of mercury mineralization. Mud geysers, which are situated, in the outcrops, contain the secondary mercury minerals, cinnabar and barccnite in the gravel and mud filling the vents. A 150-ton flotation plant is in operation concentrating stope fills that assay 3.0 kg. of mercury per ton. In one open stope, which is more than one hectare in area and 60 m. high, 150,000 tons are available. Introduction The Huitzuco mercury mines are of interest because of the unusual occurrence of ore in extinct geyser vents and the presence of several rare mercury minerals. Some of the deposits have typical characteristics of the telethermal zone and there is a gradation towards typical epithermal mineralization in depth. Halse,1 Villarel1o,2 Mactear3 and Merri114 have described the geology and the early operations in the district, and Bar-cena5 and Mallet6 have described the rare mercury minerals, livingstonite and barcenite, found at Huitzuco. Location The village of Huitzuco lies in the north central part of the State of (Guerrero, Mexico, 27 km. (16.7 miles) east of Iguala, which is the largest and most important town in the area. Iguala is served by the Mexican National Railways and also by the Mexico City-Acapulco highway. The highway is surfaced from Mexico City to Iguala, a distance of 200 km. (124 miles) by road, and there is a fairly good, level, dirt road from Iguala to Huitzuco. The elevation above sea level is about 1000 m. (3280 ft.). The climate is warm and very dry except during the rainy season, from June to

Jan 1, 1941

By George S. Rice

Instantaneous outbursts of gas in underground workings are similar in effect to great blasts of explosives, but without heat effects. Fortunately they occur only in a few localities in exceptional coal fields of the world and under exceptional geologic conditions. Such violent outbursts should not be compared with the ordinary outflows of gas into coal mines or with explosions of gas and dust. The phenomenon is essentially one of gas held in circumscribed areas under very high pressure and as a mining face or heading approaches such a place and the mining excavation sufficiently weakens the natural surrounding dam or shell, this is burst by the pressure just as by the discharge of a mass of explosives. The outbursts, so far as known to the writer, have been confined to coal beds and have not occurred in other mineral deposits. Hence, as discussed later, he believes that it is the relation of the gases to the coal material that is a factor in conjunction with others in producing conditions which permit the phenomena to occur when mining is done. The gases in most instantaneous outbursts have been hydrocarbon gases but in two coal fields they have been definitely found to be chiefly or wholly carbon dioxide. One of these localities in which CO2 outbursts have been frequent and have caused loss of life is in the southern part of the Gard basin, near Alais, in southern France. In 1919, the writer visited the Fontaine mine in this field the day following the occurrence of an outburst by which two men were smothered by carbon dioxide and fine dust. After 24 hr. the CO2 had not been entirely removed by the ventilating current. Occasional outbursts of CO2 have also occurred in other small basins in France, causing accidents, as in Puy-de-Dome. However, mines in the Gard basin, north of those in which CO2 outbursts have occurred, have experienced hydrocarbon gas outbursts. In the Lower Silesian coal field, Germany, there is a group of mines which have been subject to many instantaneous CO2 outbursts, some causing serious accidents, but the greatest disaster occurred recently

Jan 1, 1931

By D. J. Wynnemer, G. W. Preckshot

Precise electromotive force measurements have been made on the zinc-cadmium system over the temperature range 700° to 900°C. Activity coefficients, partial free energies, enthalpies, and entropies have been determined .for the entire composition range. The integral heat of mixing is positive and compares favorably with calorimetrically determined values. Vapor-liquid equilibrium compositions were determined .for a total pressure of 1 atm and these agree well with previous values determined in other ways. The use of electromotive force measurements to obtain thermodynamic data for liquid metal systems is a simple and well-known method. Several reviews of the various experimental methods and results have been published.2,3,11 However, most of the past work using this technique was carried out at temperatures slightly above the melting point of the alloy system where alloy composition changes due to vapor transport and increased metal solubility in the electrolyte are not important factors. One advantage of extending the electromotive force measurements up to and including the normal boiling point of the alloy is that it is then possible to evaluate the vapor-liquid equilibrium of the alloy at various pressure levels up to 1 atm. A detailed discussion of the thermodynamics of reversible electromotive force cells can be found in most advanced physical chemistry or chemical thermodynamic textbooks. The expression stating the inter-relation of the electromotive force and the thermodynamic functions is the Gibbs-Helmholtz equation.

Jan 1, 1962

By T. T. Field, M. Gell

MUCH has been learned about plastic deformation behavior in crystals through the use of dislocation and slip band etchants. Slip in nickel and nickel-base alloys has previously been revealed by various etching techniques.l-5 The techniques for nickel-base super-alloys4,5 were successful only in the Udimet 700 composition in specific heat-treated conditions. The objective of this work was to develop a more generally applicable slip-band etching procedure. The nominal compositions of the alloys used in this study are listed in Table I. The low carbon Mar-M2OO alloy referred to in the text is the same as listed in Table I with the exception that the carbon content is less than 100 ppm. Mar-M200 and Udimet 700 were solutionized at 2250" and 2150°F, respectively. The aging treatment for both cast alloys was 32 hr at 1600°F and for wrought Udimet 700 was 4 hr at 1975"F, 24 hr at 1550°F, and 16 hr at 1400°F. The new slip-band etching technique consists of a chemical etch followed by a short electropolish, Table 11. Fig. l(a) shows the best result obtained on an internal section of a plastically deformed single crystal of Mar-M2OO when using a conventional slip-band etching procedure which consists of electropolishing followed by etching. Ghostlike traces corresponding to planar slip bands are observed, but the contrast between the bands and the background is weak. Fig. l(b) shows the same field using the new slip-band etching technique. After the etching step of this technique, the same ghostlike traces of Fig. l(a) are observed, but the subsequent electropolishing accentuates the slip bands and the subgrain boundaries while the rest of the matrix is being polished. Longer electropolishing obliterates the slip bands. The new slip-band etching technique makes use of the etchants and electrolytes that are normally used for a given material. Because of this, it should be possible to slip-band etch other nickel-base superal-loys by using existing etchants and electrolytes for a material and following the procedures outlined in the "Comments" section of Table 11. All the illustrative examples given below show internal plastic deformation in single crystals of regular and low carbon Mar-M200 in the solutionized and

Jan 1, 1970

VITRIOL is likewise a mineral substance from whose exhalation, according to the opinion of some, are generated and produced the elemental materials or substances which produce metals, particularly gold. It is not a fumosity from metal nor is it a thing from which metal is extracted in any manner, although it shows in certain ways that it is not entirely without metal since it produces a certain trace of it. It is a thing that has a great resemblance to alum; it has a biting substance, is sharp to the taste and pungent to the tongue, and has an astringent nature. It dissolves in water and every damp place in a short time. They say that the reason for this lies, as with every other mineral, in its poorly joined watery substances. Nor does this mean that it does not contain much earthiness; on the contrary it seems to me that there are in it five. [2.9v] different participating qualities, that is, the property of sulphur, the action of alum, the corrosion of niter or of salt, and from the metals, the properties of copper and of iron. Its ore is mined in the valleys of mountains in wild but not too rugged places. It is more a gray earth or soft dead rock than a hard stone. It always has in it some yellow and green spots or near it is some sulphur mineral, either large or small.. When it is beneath the earth it exhales a sharp and very strong foul odor of scorching similar to that of sulphur. And the waters that rise where it is are all foul, earthy, and thick, some boiling with great fumes and others without great fumes, so that they surely appear to be infernal products in many places where there is a large quantity of it. After you have excavated and sorted well the quantity you wish, the ore must be put in a heap in open airy places before the vitriol can be extracted from this soil or ore, however you wish to call it. And it is left thus exposed to the weathering of the rains, the cold, and the sun for five or six months. It must be turned several times in order to bring to the surface that which was underneath; and always when this is done it is broken small with the eye of a mattock so that it is better heated and baked throughout. When it has been brought to this point it is covered over by a shed built above it or it is carried under a hut that has already been made. Here it is left to stand for another six or eight months before it is worked.

Jan 1, 1942

By Albert R. Ledoux

I AM indebted to The Kaolin Co. of West Cornwall, Conn., and particularly to its engineer, Mr. M. Wanner, for permission to make public, through the Transactions of the American Institute of Mining Engineers, the interesting results of his experiments, having in view the winning of kaolin from deep deposits without shaft-sinking or removing of the overburden. So far as I am aware, nothing like it has been accomplished heretofore, although it reminds one of the methods successfully employed in Louisiana for the winning of sulphur from deep beds by the sinking of pipes one within another, injecting superheated steam under pressure through one pipe, the heat of the steam liquefying the sulphur and the pressure forcing it up through the other pipe to bins at the surface. The kaolin-deposit at Nest Cornwall is an alteration in situ-that is, it is not sedimentary. A series of clay-veins dipping about 500 from the vertical, lie between a foot-wall of limonite and a hanging-wall of gneiss and hornblende schist. The clay-veins alternate with veins or seams of more or less broken quartz, and unaltered feldspar. The deposit, which occurs at a point about 600 ft. above the Housatonic river, was opened five years ago, and about 5,000 tons of a superior grade of washed kaolin has been extracted from open pits and sold. It soon became evident that this node of extracting the product would prove unremunerative, by reason of the dip of the vein and the intercalary strata and lenses of -quartz, and a more satisfactory method of working the deposit was sought. It is well understood, that, in the preparation of all clays for market, especially residuary kaolin, the most important as well as the most difficult step is the washing of the crude product. The difficulties increase with the percentage of foreign matter, especially quartz and mica, contained in the product, hence a sys-

May 1, 1906

By H. C. H. Darley

The principal causes of unstable boreholes* have been known for many years. For example, in a paper published in 1938, Halbouty and Kaldenbachl listed nearly all the classes of troublesome shales that we know today. Much progress has been made since then, but we still have difficulty in identifying the cause of hole problems and consequently in selecting the right technique for combatting them. This subject was discussed at length by Kelly2 in a recent paper and much valuable information was provided. In the Shell Laboratory it was felt that there was a need for a better understanding of the basic mechanisms underlying the various forms of hole instability, and accordingly, a study was undertaken. This entailed reviewing the physics and chemistry of shales, developing tests for characterizing shales, and constructing a model to study borehole stability. Full simulation of underground conditions was not attempted; for example, we used reconstituted shale specimens, and often simple solutions or suspensions rather than practical drilling muds. Such procedures are necessary in order to establish mechanisms, but caution must be exercised in applying the results to the more complex conditions in the field. Part I — Compaction Swelling and Dispersion of Shales Compaction of Sediments Shales are formed by the compaction of sediments. Water is expressed as sediments are buried by subsequent layers, and the degree of compaction is proportional to the depth of burial, provided the water is able to escape easily to permeable formations. The younger sediments, when recovered at the surface, soften and disperse when mixed with water; the older shales have undergone diagenesis (alteration of the clay minerals, secondary cementation, etc.), and remain hard and unaffected by water. In this paper we shall apply the term "shale", as the drilling engineer does, to everything from clays, which are highly reactive to water, to completely lithified materials such as claystones and slates, which are completely inert. However, because these materials behave quite differently when encountered in the drilling well, it is desirable to develop a simple means of characterizing them. The feature that distinguishes the various shales is their dispersibility in water —soft clays disperse readily, harder shales disperse slowly when agitated, the lithified materials will not disperse at all unless milled. In the dispersibility test used in our study, a weighed amount of dry shale particles in the 12-to-100-mesh-size range was placed in a tube filled with distilled water and allowed to soak for 16 hours. The

Jan 1, 1970

By R. I. Jaffee, H. R. Ogden, D. J. Maykuth, W. L. Finlay

Titanium with up to 7.5 pct Al forms single-phase a alloys that are work hardening, not heat treatable, and ductile as welded. The high aluminum Y phase alloys are not usefully ductile, despite their low hardness, but they have excellent oxidation resistance and hot hardness. LITTLE has been published on the effect of aluminum on the mechanical properties of titanium, despite the fact that two of the first four commercial alloys released by titanium alloy producers contained aluminum as an important alloying ingredient. These were both a-ß type alloys, one containing 4 pct A1 and 4 pct Mn and the other containing 3 pct A1 and 5 pct Cr. However, neither of these alloys reflects the true alloying nature of aluminum, since each contains important amounts of the ß-stabilizing addition, manganese or chromium. In a previous publication on the constitution of Ti-A1 alloys,' the authors showed that aluminum had a high solubility in a titanium and was strongly a stabilizing in nature. About 25 wt pct A1 is soluble in a titanium at room temperature. With as little as 5 pct added aluminum, the a transus temperature is increased from 882" to 970°C, and the correspond- ing ß transus to 995°C. The first intermediate phase in the Ti-A1 system is the ordered face-centered tetragonal TiAl phase, which extends from 34 to 46 wt pct Al. The present paper presents hardness data over the entire titanium-rich region of the system, through the TiAl phase, and mechanical property data on the alloy range capable of being fabricated. Methods of Investigation The materials used and general preparation of alloys, as well as experimental techniques used in the investigation of Ti-A1 alloys, have been adequately described.' Briefly, the preparation consisted of arc-melting the desired amount of high purity aluminum (99.99 pct purity) and iodide titanium (maximum hardness 100 Vickers, as deposited) together on a water-cooled copper hearth under a partial pressure of argon. The resulting button ingot was of such form that it could be fabricated without further treatment. All work was done using ingots weighing 10 to 15 g, which were hot-rolled to strip form whenever possible. Tensile samples were 3.25 in. long, 0.5 in. wide, and 0.040 in. thick, with a reduced section 1.25 in. long by 0.250 in. wide. The gage length used was 1 in. Electrical strain gages mounted on the

Jan 1, 1954

By William D. Klopp, Joseph R. Stephens

Chromium alloys were coated with silicon, alumi-nuw, and boron by pack cementation. None of these simple coatings provided adequate nitridation/oxida-tion protection for a Cr -0.17pct Y alloy substrate as shown by a substantial Increase in the ductile -brittle transition temperature after air exposure for 100 hr at 2100°F. Iron-modified silicide coatings afforded good protection, holding the transition temperature of air-exposed specimens to 350° F compared to 200° F for uncoated unexposed specimens and 800°F for un-coated exposed specimens. Additional attractive cant-binations of modi-tying elements included Fe-mo, Fe-Mo-W, Fe-,Mo-W-Ti, and V-Mo-W-Ti. THE desirability of increased operating tempera-tures as a mcans of improving the performance of ad-vanced air breathing engines has resulted in emphasis on the development of materials with high operating temperature capabilities. Chromium, because of its relatively low density (7.19 g per cu cm), high melt-ing point (3410°F), and adequate strength upon alloy-ing, is a candidate material for turbine buckets and stator vanes of advanced air breathing engines. How-even, chromium is not without severe limitations, the major one being susceptibility to nitrogen embrittle-ment upon exposure to air at high temperatures.1,2 For example, a 25-hr air exposure of a Cr-5 pct W* * All compositions in wt pct. alloy at 2100°F produces a 600°F increase in the duc-tile-brittle transition temperature.' Although dilute alloying with such elements as yttrium, lanthanum, arid thorium3,4 or strong nitride formers5 has been shown capable of reducing nitrogen embrittlement, it is apparent that some additional form of surface protection, such as coatings or claddings, will be required for long time service in air breathing engines. Studies of aluiminide6 and silicide7 coatings and of nickel-base claddingsl on chromium alloys to date have suggested that these protection systems are inadequate. Of the aluminidc systems Studied,6 a simple aluminum and an Fe-Al coating on a Cr-5 pct W-0.1 pct Y alloy showed the lowest air exposure weight gains. However, the air exposures raised the ductile-brittle transition temperature of the coated specimens to above 1600°F from an initial level in unexposed specimens of about 500°F. A second in-vestigation for protection of Cr-5 pct W-0.1 pct Y employed gas pressure bonded alloy foils as protective claddings.1 An aluminized Ni-20 pct Cr-20 pct W alloy plus an unalloyed tungsten barrier layer gave the best performance with air exposure lives based on appearance and weight gains of over 600 hr at 2100°F. However, the bend ductile-brittle transition tempera-ture was increased to at least 1000°F after 100 hr at

Jan 1, 1970

DURING September, the Coal Commission pre- pared for issue a series of 18 reports on varied aspects of- the bituminous coal industry; the final report, dated Sept. 22, sums up the facts and offers recommendations addressed to Congress, to the industry, and to the public. The few following paragraphs are selected: Bituminous coal is the real foundation of that great industrial and transportation structure which enables more than a hundred million people to live in America and be so well supplied with things necessary for their health, comfort; and convenience; it also furnishes domestic fuel for two-thirds of the homes of the land. The distribution of the output of the bituminous mines tells the story: 28 per cent. goes to the railroads, 25 per cent. to the boiler houses of factories and mills of all kinds, 15 per cent. to the coke ovens and gas plants, 10 per cent, to the homes, 7 per cent. to steel plants and the same percentage to power plants and street railways, 4 per cent. is exported, 2 per cent is used for power at the coal mines, and the remaining 2 per cent. goes to the seaboard for steamship fuel. Bituminous coal enters into interstate commerce on a scale approached by no other commodity; less than a fourth of the coal mined in the United States fails to enter interstate com-merce. All but one of the 45 coal producing districts in the United States ship coal outside the State in which it is mined. Three hundred miles of cars loaded with coal is the daily output of the bituminous mines of the United States. The public-welfare element in coal is seen in the dependence of public health and safety on an unfailing supply of fuel, in the close connection between the prosperity of most industries and the uninterrupted operation of the coal mines, and in the obvious fact that without coal the great network of railroads which binds together this great country would be idle. The railroads and the public utilities, themselves so clearly obligated to render what-ever public service is demanded of them that the constitutionality of their public regulation is unquestioned, are of all industries most dependent upon coal. Thus, coal makes up over 35 per cent. of the operating cost at the gas plant and over 25 per cent. at the electric power station, and in the operating expenses of. a railroad the cost of coal is the largest single item, next to labor. The practical logic that half a century ago clothed with a public interest the steam locomotive and in later years the electric-power station must recognize a large element of public service in the coal mine that furnishes the necessary energy to both locomotive and power-plant.

Jan 10, 1923

A High-speed Dilatometer and the Transformational Behavior of Six Steels in Cooling. By Arthur L. Christenson, Edward C. Nelson and Clarence E. Jackson. (With discussion).................................606 Dilatometric Studies of the Graphitization of Cast Iron. By N. A. Ziegler. With discussion) 627 An Interferometer Type of Dilatometer and Some Typical Results. By- L. '4. WIlley and W. L. Fink. (With discussion).........................642 The meeting was held in the Pine Room of the Statler Hotel, Cleveland, Ohio, on Tuesday afternoon, October 17, 1944. The chairmen were F. M. Walters, Jr. and Howard Scott. Introduction F. M. Walters, Jr.—The principal advantages of the dilatometric method perhaps are two, as compared with the method of thermal analysis. One is that the dilatometric method can be applied with a large variety of rates of heating and cooling, whereas thermal analysis—that is, the study of the transformational characteristics by means of heat evolution—is limited to the rates of heating and cooling that reveal the evolution of heat. The dilatometer can be used for the study Of reactions at zero rates of heating and cooling; that is, isothermal reactions. As you will hear this afternoon, the rates have been pushed up as far as 500°C. a second. The other advantage is that the dilatometric method shows that a two-phase region is a two-phase region, whereas the thermal analysis merely reveals the temperature at which the rates of heat evolution are greatest.

Jan 1, 1945

The Howe Memorial Lecture, in memory of Henry Marion Howe, Past President of the Institute, was authorized in April, 1923, as an annual address to be delivered by invitation under the auspices of the Institute by an individual of recognized and outstanding attainment in the science and practice of iron and steel metallurgy or metallography, chosen by the Board of Directors upon recommendation of the Iron and Steel Division. The following were the Howe lectures and lecturers for the years indicated 1924 What is Steel? By Albert Sauveur. 1925 Austenite and Austenitic Steels. By John A. Mathews. 1926 Twenty-five Years of Metallography. By William Campbell. 1927 Alloy Steels. By Bradley Stoughton. 1928 Significance of the Simple Steel Analysis. By Harry D. Hibbard. 1929 Studies of Hadfield's Manganese Steel with the High-power Microscope. By John Howe Hall. 1930 The Future of the American Iron and Steel Industry. By Zay Jeffries. 1931 On the Art of Metallography. By Francis F. Lucas.

Jan 1, 1923

By Harold F. Yde

Hydraulic tailing fill in the Butte deep-level mines resulted from studies made in 1958 by The Anaconda Co. Mining Research Department. At the time of the study, dry mine tailing was hauled via rail cars from the Anaconda tailing ponds, 25 miles distant, to the tailing fill plants of the underground mines at the Leonard, Anselmo and Mt. Con mines. Presently, tailing from the Weed concentrator in Butte is delivered to the Kelley shaft via pipeline and stope filling has become automated. Tailing at 30% solids is pumped 8000 ft horizontally and upward from the concentrator to the Kelley fill plant, where it is dewatered and deslimed by three Krebs cyclones. These discharge the material into the cased and grouted mine delivery boreholes at desired densities of up to 70% solids. The vertical boreholes and 4-in. rubber-lined Victaulic pipe carry the material downward to horizontal distribution lines, which in turn tap into the 3-in. stope-filling, unlined Victaulic pipelines.

Jan 1, 1970

THE CHAIRMAN (EDWIN LUDLOW, Lansford; Pa.).-Mr. Wang's paper reminded me that some years ago I was asked if I would not go into the Tien Tsin district and take charge of Americanizing a Chinese mine. They said the trouble was that, while wages were only 9 c. a day, the coke cost $2 a ton delivered to the cars. Reading Mr: Wang's paper would indicate the need of a little Americanization in the Manchurian field. Wages are only 40 c: a day, yet the cost is $3.60 a ton. An efficiency engineer would have an excellent opportunity in that field. T. T. READ, New York, N. Y.-It is always true that low-priced labor is inefficient, wherever we find it; for example, in Japan, where wages are low, but not so low as in Manchuria, working costs are not relatively much lower than ours. Mr. Padshah, describing his experience in India, once told me that, while wages were only about one-fifth as high

Jan 4, 1918

The Howe Memorial Lecture, in memory of Henry Marion Howe, Past President of the Institute, was authorized in April, 1923, as an annual address to be delivered by invitation under the auspices of the Institute by an individual of recognized and out- standing attainment in the science and practice of iron and steel metallurgy or metallography, chosen by the Board of Directors upon recommendation of the Iron and Steel Division. The follow- ing were the Howe lectures and lecturers for the years indicated: 1924 What is Steel? By Albert Sauveur. 1925 Austenite and Austenitic Steels. By John A. Mathems. 1926 Twenty-five Years of Metallography. By William Campbell. 1927 Alloy Steels. By Bradley Stoughton. 1928 Significance of the Simple Steel Analysis. By Henry D. Hibbard. 1929 Studies of Hadfield's Manganese Steel with the High-power Microscopa By John Howe Hall. 1930 The Future of the American Iron and Steel Industry. By Zay Jeffries. 1931 On the Art of Metallography. By Francis F. Lucas.

Jan 1, 1937

NEW YORK LOCAL SECTION Executive Committee Louis D. HUNTOON, Chairman ARTHUR S. DWIGHT, Vice-Chairman THOMAS T. READ, Secretary, Woolworth Bldg., New York, N. Y. E. MALTBY SHIPP, Treasurer GEORGE F. KUNZ W. DE L. BENEDICT Meeting, Jan. 16, .1914 A meeting of the New York Local Section of the American Institute of Mining Engineers was held at the Engineering Societies Building, 29 West 39th Street, New York City, Jan 16 1914 the Chairman, -L. D. Huntoon, presiding. Forty members weld present. In the absence of the Secretary, C. A. Bohn was appointed Secretary pro teen. N. H. Darton, Geologist of the U. S. Geological Survey, delivered an address on. The Occurrence of Gas in Coal, illustrated by lantern slides of charts, curves, and tables showing various features of gas occurrences. J. W. Richards, J. T. Beard, W. L. Saunders, L. D. Huntoon, and Mr. Darton participated in the discussion which followed the address. THOMAS T. READ; Secretary.

Jan 3, 1914