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By W. N. Page

The Red-Ash colliery was the scene, March 6, 1900, of an explosion by which some fifty men were killed or wounded, and much property was injured or destroyed. On March 19th, the earliest date at which entrance was practicable, I examined the mine with the view of determining the extent, cause and point of origin of the explosion, and with the permission of Mr. F. Howald, the manager, and the owners of the property, for whom the examination was made, I present in this paper some results of that examination, comprising the essential portions of my report to them. Location and Plan of the Mine. The Red-Ash colliery, situated on the south side of New river, next below the Rush Run mine, with which the underground workings are connected, is a drift-mine, the entrance to which is on a slope, about 500 ft. above the river. (Fig. 1 is a plan of the workings, in which the points where human bodies were found are designated by numbers.)

Jan 1, 1901

By W. M. Courtis

In compliance with the suggestion in Mr. Emmons's paper on the Genesis of Certain Ore-Deposits (Trans. xv., 125), that facts should be accumulated for study and future compilation, I wish to put on record, before the data are lost, a section of the Animikie series of rocks and the vein-phenomena exposed by the explorations at the Duncan mine, Port Arthur, Thunder Bay, Lake Superior. This may serve as a supplement to my paper on this district (Trans. v., 473). I trust this information will not be without interest at. the present time. The recent discoveries of very rich silver-ores at Rabbit and Silver Mountains, on the same belt, have brought the district once more before the public; and a study of the facts here set forth may assist some fellow-engineer in the determination of the value of property offered for sale in this neighborhood. The vein at the Duncan mine was tested to a depth of over eight hundred feet by shaft and drifts, and to nearly a thousand feet with

Jan 1, 1887

By T. C. Rao

Oil agglomeration experiments were carried out on coal fines to study the effect of process variables such as pulp density, bridging oil dosage and intensity of agitation on (i) size distribution and (ii) yield of agglomerated product. It has been observed that the growth of agglomerates follows a self-preserving behaviour and using this, a characteristic curve has been derived. This curve has been found to be independent of the process variables. It has also been noted that the growth of agglomerates follows second order kinetics. In an attempt to model the process for predicting the size distribution and yield of agglomerates at different levels of the variables, the cumulative 50 percent of the agglomerates passing size (d50) has been correlated with the variables (i) through the kinetic equation and (ii) directly. These equations, coupled with the characteristic curve can predict the size distribution of the agglomerates at any levels of the variables tested. The yield of agglomerates has been found to follow a definite relationship with d50.

Jan 1, 1984

By Sir John Cadman

IN THE changed circumstances which now confront the world, an international open-door policy is the only way to keep pace with the world's demand for oil. You may rest assured that as far as the British Empire is concerned, American capital for the develop-ment of oil resources is welcome, and little obstruction will be found in the way to permit the use of foreign capital in the group of countries which constitute the British Empire. In the war days we worked in close cooperation and harmony, but in disbandment of the Petroleum War Service Committee, when the war ended, I feel that it left its task unfinished. In the wake of war there appeared a ghost of war-time conditions in the form of belief that Great Britain was straining to corner the petroleum resources of the world. I am certain that if the war-service committee had continued its work in the period of reconstruction the real story would be known and this sinister ghost would have long since vanished before the truth.

Jan 2, 1922

By Forbes K. Wilson

"For his vision, determination, dedication, and leadership in the conquest of the remote and rugged Ertsberg and the technical and human barriers to its development and for his lecture ..." It is a great honor for me to be included among the Jackling Award recipients, many of whom have been close friends and associates. My subject is the development of the Ertsberg, a copper mine located 4' south of the equator, 70 miles (113 km) from the south coast of Irian Jaya---the easternmost province of the republic of Indonesia at an elevation of 12,000 ft (3658 m) in an area which was inhabited by a few "stone age" people when I first arrived there in 1960. Persistence, tenacity, immagination and innovation were all required to bring the Ertsberg into production. The technical, financial and political problems that have been faced over the past 16 years were unique in many respects. I hope that my paper will give some encouragement and help to future developers of mines in difficult and inhospitable surroundings.

Jan 1, 1978

By S. Frederick Ravitz

IN most applied sciences there are two distinct methods of carrying out research and development work. One of these, the theoretical, attempts to solve problems that may arise and to predict facts of practical importance by the application of the various laws of science, the other, the experimental method, attempts to each the 'same goal by obtaining data and trying out various processes in the laboratory. Since individuals frequently find themselves better adapted for one or the other type of procedure, it is natural that -two groups should 'arise, both working toward the sane objective but with somewhat different points of view, although many in each group are thoroughly competent in both fields. Metallurgy, in particular, offers an excellent opportunity for a comparison of the two methods.

Jan 1, 1935

By G. K. Burgess

J. W. RICHARDS, South Bethlehem, Pa.-I think my affections are still rather with the radiation pyrometer than the optical pyrometer, for practical use, and I wish that Prof. Burgess would use the two together, under the same conditions, using the optical as his standard, if he prefers. Then, assuming the optical emissivity which he feels is correct for the optical pyrometer, he could calculate the thermal emissivity for use with .the radiation pyrometer. If we could thus get reliable values for the thermal emissivity, we could then use the radiation pyrometer, and would avoid the use of the standard lamp, which has to be frequently calibrated for use in the optical pyrometer. It is very advisable to distinguish carefully between the terms optical emissivity and thermal emissivity. There -is considerable confusion caused by the bare statement that molten iron has an emissivity of so much, meaning by that its optical emissivity, for a light wave of a certain length; whereas what we want in the radiation pyrometer is its total ther-

Jan 4, 1917

By Walter Weeks

THE process of cooling air by allowing it to expand and do work in an engine is well known, but the theory of obtaining cold air by free expansion without the aid of an engine operating with cutoff has been little discussed. CASE I If compressed air is allowed to expand to the atmospheric pressure through an orifice in an air line that is supplied by a running compressor, no cooling results except the negligible one due to the Joule-Thompson effect, which will not be considered in this discussion. The effect of moisture will also be neglected.

Jan 1, 1937

By A. Eilers

THE telluride of gold and silver, the " Tellurgold-silver" of Hausmann, and " Petzite" of other mineralogists, has been found in so few localities, that a late discovery of the mineral in a new locality may not be uninteresbing. So far this mineral has been found in Europe only in a few mines in Transylvania, and in Hungary; and in the United States in the Stanislaus Mine, in Calaveras County, California, in the Golden Rule Mine, Tuolumne County, California, and in a mine in Montana, the precise locality of which I have forgot, ten. The new locality referred to is at the Red Cloud Mine, Gold Hill District, Boulder County, Colorado.

By J. Parker

As a practicing mining engineer, I face many rock mechanics' problems daily and would like to mention one or two examples to illustrate the current gap between laboratory investigations and actual field problems. I would like to endorse Dr. Obert's suggestion that more field measurements and observations should be undertaken. There is an ever-increasing body of data beginning with Hast's results in Sweden,l then measurements at Elliot Lake, Canada, and so on, including our own measurements at White Pine, which clearly indicate that the horizontal stresses underground. are often at least as large as the vertical stresses. Visual observation of the deformation of roof and pillars (including failure due to horizontal compres- sion) also demonstrates that the horizontal stresses are often most important: Yet almost every laboratory investigation begins with the assumption that the only stresses acting are vertical. Roof spans in layered formations. for example, are calculated on the assumption that the rock behaves as a gravity loaded beam. This is all too often unrealistic.

Jan 1, 1967

Arthur Jarman, Sydney, New South Wales, Australia (communication to the Secretary*):—All designs for modern metallurgical and chemical laboratories should provide each student's desk with a hood or cupboard for the removal of fumes, but I doubt the advisability of placing air-baths and similar apparatus close to the hot plate. It seems to me that unless the draft be exceptionally strong the fumes from ordinary wet assay work will corrode the iron-work of the fittings, in which case the baths would have to be removed to a general desk in order to lighten the work of the laboratory attendant. Since the laboratory described by Mr. White has been in use for two years, I should like to ask if any inconvenience has resulted from this corrosion. If not, it is certainly an important improvement to have the air-baths and similar apparatus placed on the student's desk. The hoods described by Mr. White are supplied with a good draft by means of a fan, which gives them a great advantage

Jan 1, 1905

By AIME AIME

THE World. Engineering Congress closed as it opened, with a brilliant and dignified ceremony. On Oct. 29, 1929, there were hearty speeches of welcome and of hope for the successful issue of this international gathering; on Nov. 7, the farewells were even more heartfelt expressions, and anticipation gave place to, realization. H. I. H. Prince Yasuhito of Chichibu, who had graciously opened the Congress; was unavoidably absent at the closing ceremony, being on duty with his command at the Army maneuvers, so that the principal speech was made by the President of the Congress, Baron Furuichi. The outstanding statistics of the meetings were: an over-all attendance, delegates and members, of 800 from overseas and 2800 Japanese 83 sectional meetings, all. meetings having practically capacity attendance, this being especially true of Section 11, mining and metal¬lurgy, where standing room only was commonly the rule; and 780 papers were presented, in full or in abstract or by title. H. I. H. Prince Chichibu attended each section on Oct. 31. The large attendance of Japanese students was notable at most sections.

Jan 1, 1929

By AIME AIME

THE annual meeting of the Auxiliary to the A. I. M. E. was marked by the most delightful cordiality and warm spirit of welcome on the part of the members of the New York Section and an equally charming spirit of cooperation and appreciation on the part of the visitors. On Monday Mrs. Ernest H. Wolfes and Mrs. Charles A. Bohn had charge of registration and most efficiently .provided everyone with the necessary tickets and badges. The reception hall and regisfration booth were gay with beautiful flowers that reflected the welcoming spirit one found there. The smooth efficiency with which the whole program ran was due largely to the tireless efforts of Mrs. Donald M. Liddell and Mrs. Louis D. Huntoon, joint chairmen of the Ladies' Committee, and Miss Margaret Callow, chairman of the Junior Committee. After registering, the ladies proceeded to- the fifth floor, where they had luncheon with the members of the A. I. M. E. On that day Mrs. W. H. Bassett and Mrs. Lucius W. Mayer were the hostesses.

Jan 1, 1929

By L. I. Hewes, Joseph W. Roe

A graphic solution of Kutter's formula for the flow of water has been worked out by Dr. L. I. Hewes in connection with his course in Graphic Computations, given in the Sheffield Scientific School, Yale University, which may be of interest to those who deal with canals, flumes and streams. 1.811 0.002811 , 41.66+ -n+-S- I Kutter's formula, V= - n 0 .00281 78- 1+(41.66 + 0.00281)7B781 is probably the most accurate of those proposed determining the flow of water. But it is extremely cumbersome, and if many calculations are to be made their solution becomes drudgery. The purpose of this chart, Fig. 1, is to furnish a rapid solution, sufficiently accurate to be well within the limits of the observed data. The chart consists essentially of three parallel scales, one for the mean velocity, V, one for the hydraulic radius, R, and one for the slope; a diagonal line, not graduated ; and a set of curves for the various values of n, the factor which involves the na-

Jan 1, 1910

James DouGlas, New York, N. Y. (communication to the Secretary*):—In my paper on the Conservation of Natural Resources, I referred to the slow replacement of bee-hive ovens by the by-product ovens as a most notable instance of waste. And I quoted from Mr. Parker's report for 1906 an explanation given by him in accounting for the small production of by-product coke. It was that the market for the by-products of the coke-ovens was so limited that some of the ovens constructed were out of operation. His report on the manufacture of coke in 1908' does not record an improvement, and attributes the strange fact that we alone, of all the industrial peoples, delay the adoption of this cardinal improvement from the continuance of the same almost inexplicable cause. To quote again from his report, he says (p. 241): "The year 1908 was not marked by any notable gain in the construction of byproduct coking plants, though some new work was done. There was a net increase

Jan 1, 1910

By R. G. Carlson, F. E. Westermann

HOT pressing of powder particles has gained importance recently, since it affords a method in which high densities are rapidly attained. In a recent study on hot pressing of alumina powders, Mangsen, Lam-bertson, and Best1 have shown within the limits of their experiment, the validity the rate equation for densification in hot pressing, originally proposed by Murray, Livey, and Williams.2 i.e., where D = fraction of theoretical density, t = time, P = pressure and 77 is the viscosity, all in appropriate units. This equation was derived from earlier work of Shuttleworth and Mackenzie3 which is based on the closing of spherical pores under the action of surface tension. The integrated form of this equation yields a straight-line relation between log (1 - D) and t. Such conditions were found by Felten4 to be true only after extended periods of pressing. In an endeavor to quantitatively evaluate the exactitude of this equation in the initial sintering stage, i.e., prior to sealing of the pores, spherical anti-

Jan 1, 1962

By B. C. Craft

The outstanding event of the year 1932 in this area was the intensive drilling activity in the Zwolle field of Sabine Parish, Louisiana. More new development work was undertaken and completed than during the previous year. This was due in part to the increased price of oil and in a Includes 19 parishes: Beauregard, Bienville, Bossier, Caddo, Caldwell, Catn-houla, Claiborne, Concordia, DeSoto, Grant, Lincoln, Morehouse, Natchitoches, Ouachita, Red River, Richland, Sabine, Union, Webster. B H. K. Shearer: Oil and Gas Development in South Arkansas, North Louisiana and Mississippi in 1931. Trans. A. I. M. E. (1932) 98, 159. a Includes 14 counties: Ashley, Columbia, Dallas, Drew, Hot Springs, Lincoln, LnFayette, Little River, Miller, Ouachita, Pike, Sevier, Scott and Union. * H. K. Shearer: Oil and Gas Development in South Arkansas, North Louisiana and Mississippi in 1931. Trans. A. I. M. E. (1932) 98, 159. part to the fact that production is below local market demands. Exploration during 1932 resulted in the discovery of a new oil field and a new gas

Jan 1, 1933

By J. C. Swartz

Measurements of the effect of precipitation stresses on the solubility of cementite (Fe3C) precipitates in a iron are reported. Solubilities were determined from measurements of the Snoek relaxation due to interstitial carbon after quenching from various equilibrium treatments. Stress-free precipitates were obtained by a spheroidizing treatment of vacuum-melted Fe 0.06 wt pet C. Subsequent equilibration treatments were designed to suppress nucleation of other precipitates. The results for stress-free cementite give a heat of solution of 14.8 i 0.2 keal per mole and an entropy change of 1.1 i 0.2 eu in the temperature range 400" to 715°C. Comparison with previous data indicates that the heat of solution increases about 6 keal per mole as temperature increases from 700" to 1000°C. Data on self-stressed cementite in quench-aged specimens of Fe 0.013 wt pet C indicate 1) an apparent heat of solution of 12.1 i 0.4 keal per mole in the range 280" to 690°C, 2) a strain energy of- 1.1 keal per mole Fe3C accompanying precipitation at 280°C, and 3') a gradual decrease in the strain energy of precipitation with increasing equilibration temperature. In com-parison with 2 and 3 the strain energy calculated for an isotropic model is 1.7 keal per mole Fe3C. The lower values obtained from the experiment indicated substantial stress velaxation by dislocation motion. WHEN a supersaturated solution of carbon in a iron is aged at temperatures in the range 200o to 700oC, the carbon clusters by interstitial diffusion and forms cementite (Fe3C) precipitate particles. Unstressed cementite has a volume per iron atom 9 pet higher than that of a iron;' hence, cementite precipitate particles are usually under pressure from the iron matrix. The pressure would tend to increase the solubility of cementite in iron.' This report describes anelastic measurements of the solubilities of self-stressed and stress-free cementite in a iron. Previous determinations of the cementite solubility are summarized in Table I. The method of cementite formation for each reference was studied to ascertain the state of stress of the cementite. The results judged to be for stress-free and stressed cementite are distinguished in the table. In the next section an estimate of the stress effect is obtained which is clearly too small to account for the large difference between the previous results in parts A and B of the table. THEORETICAL Let AGO be the standard free-energy change of the reaction Fe3C (eem.) = 3Fe (a) + C (in a) [1] in the absence of stresses. Since cementite precipitates appear to be rather pure10 and the carbon is so dilute in the iron,8 the cementite and iron of Eq. [ I] for the stress-free case have essentially unit activities and the activity of carbon equals its atom fraction xoC Then the stress-free equilibrium is expressed by RT In XoC = -?GO 121 To first approximation the change in the chemical potential of carbon due to the precipitation stresses equals the elastic strain energy W accompanying precipitation of a mole of cementite.2 Hence, in the presence of the precipitation stresses the equilibrium is described by RT In x sq = -?G° + W [3] where xsC is the mole fraction of dissolved carbon in the stressed case. An approximate value of W can be obtained from analysis of the inclusion problem in elasticity theory. The inclusion is a small portion of the matrix phase which has suffered a transformation while still imbedded in the matrix. In the absence of the constraint of the matrix the transformation would be equivalent to a uniform dilational strain eT. Both the matrix (a) phase and inclusion (0) phase are assumed to be homogeneous, isotropic materials. When the a and 0 phases have the same elastic moduli, which is approximately true for iron and cementite,11 the total strain energy per mole ß is12 2µVß(eT)2(3 +4 µx)-I [4]

Jan 1, 1968

By P. K. Lucke

One of the interesting features connected with the great continental uplift, which formed the table land of Mexico, is the great depth to which oxidation and secondary enrichment of orebodies occurred. This table land lies at altitudes ranging from 4000 to 7000 ft. (1219 to 2133 m.) above sea level. Several cases could be cited of oxidized zones in copper and lead mines which reached depths of upward of 1500 ft. (457 m.) below the surface, and it is universally admitted that the oxidized zone in a mine is limited by the permanent water level. Mexico, however, like many other countries in which deserts occur, is visited at rare intervals by tremendous floods, which sometimes cause variable water levels over long periods. The following cases bear out the idea, and lead to interesting conclusions of commercial value. My paper demonstrates that carbonates of ores may occur below water level and sulfides above, and I will endeavor to explain the causes of the phenomena in certain specific instances. Case I.—Fig. 1 in this case shows that sulfides of lead remained

Jan 1, 1920

By J. O. Brittain, N. R. Adsit

It has been suggested that grain boundary motion during creep is a two-stage process, i.e., sliding followed by migration. Wienbergl found alternate sliding and migration of aluminum tricrystals tested in shear. He concluded that curves of grain boundary sliding (G. B. S.) vs time were not reproducible from specimen to specimen. Couling and Roberts,' who worked on polycrystalline magnesium, found that sliding and migration were interdependent. They were able to correlate the amount of sliding with the number of sliding-migration cycles, i.e., the amount of migration observed metallographically. Rhines, Bond, and Kissel found that the curves of grain boundary sliding vs time were spasmodic but they did not find any migration of the boundary. Some recent creep tests on bicrystals of high-purity zinc (99.99 pct) help to elucidate the role of grain boundary migration in the G. B. S. process. The experimental technique and apparatus are described elsewhere. The tests were conducted in vacuum or a protective atmosphere of argon. All specimens were stressed in simple shear along

Jan 1, 1961