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By D. J. Carney, J. Chipman, N. J. Grant

G. A. Moore—The tin-fusion method has been a very favorable possibility for many years. The authors apparently have settled the question that delayed the method for a long time by showing that no hydrogen is absorbed in the tin. This, of course, is very important. I want to make a few remarks concerning the absolute accuracy of analysis, which must be the final basis for deciding among the various methods. From the figures in the paper, there seems to be some remaining slight discrepancy on the actual amount of hydrogen present in various samples which may be presumed essentially identical. (This is of the order of the precision of individual analyses but appears in averaged results.) From the analyst's viewpoint, the tally of hydrogen content can be regarded as occurring in three portions. First is a large portion which comes off easily and automatically during sample storage and later on heating in the apparatus. This is fairly easily analyzed. Second is an item which may be either positive or negative in the tally sheet. In warm or hot evolution, this is a portion which, in practice, can never be re-

Jan 1, 1951

By W. Rostoker

PART of a program of research on the Ti-A1 system1 involved a study of the lattice parameters of the titanium-rich a solid solution, which has a hexagonal close-packed structure. For this work, a 14 cm Debye-Scherrer powder camera and filtered CuK, radiation was used. For each pattern, the parameters were calculated by a least squares solution of the five strongest high angle lines. This provides an accuracy of i0.005A or better. The results are shown graphically in Fig. 1. It will be seen that an unusual change of slope occurs in the curve for the C parameter at high aluminum contents. Such anomalous changes in slope have been recorded by RaynorV or several magnesium-rich solid solutions. The effects were interpreted in terms of a special contribution to the lattice distortion due to factors of electronic origin predicted by Jones." Jones' theory, in substance, suggested that an unusually large expansion of the lattice would begin when the electron per atom concentration in the alloy was increased to a value at which an overlap just began from one Brillouin zone to another. Con-

Jan 1, 1953

By F. Lynwood Garrison

As the specific gravity of low-carbon steel seems to be attracting considerable attention as a means of détermining the quality and value of the metal, I give here a few of the results of a long series of experiments recently made by me. The object of the experiments not requiring more than approximate correctness in the third place of decimals, the extreme precautions to obtain accuracy which are sometimes used in determining specific gravity were not observed. But each piece of metal was carefully cleaned to remove scale, rust, dirt, etc., thoroughly dried, and then weighed in air, all weighings being carefully repeated. The balance used was one of Troemner's finest, and sensitive to one-tenth of a milligram. Before weighing in distilled water, care was taken to remove, as far as possible, the air enclosed in the pores of the metal. The pieces of metal were suspended by means of fine silk thread, a correction of course being made for the weight of the silk. Care was taken that the water in which they were weighed should he always at the same level, and, as far as possible, at the same temperature.

Jan 1, 1887

During the year 1915 the Committee received 161 manuscripts, which were treated as follows: 3 accepted for. New York Meeting (110th) . 64 accepted for San Francisco Meeting (111th) 49 accepted for New York Meeting (112th) 3 accepted for Arizona Meeting (113th) 29 rejected 4 returned to authors for revision and not yet accepted 9 in committee. 161 Every paper which was presented at the San Francisco Meeting was published in advance in the Bulletin with one exception. The work of the Committee has been systematized and. the Executive Committee of the Committee on Papers and Publications has given prompt attention to all manuscripts, with the result that every paper received by the Committee on Papers and Publications is in the hands of the, printer within 30 days thereafter, unless delays occur owing to questions as to acceptability, in obtaining from the author permission for revision, or other like causes.

Jan 2, 1916

A special committee on the Classification of Surface Mining Methods was appointed by the A.I.M.E. Board of Directors on Nov. 17, 1939. The committee was headed by Gerald Sherman, and the members were Chester A. Fulton, C. F. Jackson, Earl E. Hunner and Arthur Notman. The following form of classification was reported to the Board by the Committee on May 16, 1940, as its unanimous recommendation. SURFACE MINING Dry Mining Bottom Benching Bank Mining < Top Benching Dry Mining Dry Mining Bottom Benching Hydraulic Mining Pit Mining Dredging Dry Mining Top Benching Wet Mining Top Benching River Bed Dredging Subaqueous Mining Lake Bed or Dredging Ocean Bed (Hand Mining Ground Sluicing Hydraulicking Dredging In most cases the terms used in the accompanying outline define themselves. Bank Mining is distinguished from Pit Mining by its situation. In Pit Mining the ore is taken from an operation below the level of the surrounding surface. In the secondary classification, Bottom Benching is an operation in which a bench is attacked from below, but the material mined might be hauled up out of the pit or moved out horizontally or downward.

Jan 1, 1940

A special committee on the Classification of Surface Mining Methods was appointed by the A.I.M.E. Board of Directors on Nov. 17, 1939. The committee was headed by Gerald Sherman, and the members were Chester A. Fulton, C. F. Jackson, Earl E. Hunner and Arthur Notman. The following form of classification was reported to the Board by the Committee on May 16, 1940, as its unanimous recommendation. SURFACE MINING Dry Mining Bottom Benching Bank Mining < Top Benching Dry Mining Dry Mining Bottom Benching Hydraulic Mining Pit Mining Dredging Dry Mining Top Benching Wet Mining Top Benching River Bed Dredging Subaqueous Mining Lake Bed or Dredging Ocean Bed (Hand Mining Ground Sluicing Hydraulicking Dredging In most cases the terms used in the accompanying outline define themselves. Bank Mining is distinguished from Pit Mining by its situation. In Pit Mining the ore is taken from an operation below the level of the surrounding surface. In the secondary classification, Bottom Benching is an operation in which a bench is attacked from below, but the material mined might be hauled up out of the pit or moved out horizontally or downward.

Jan 1, 1940

By R. E. Maringer, A. Schwope

IT has been recognized that oxygen in minute quantities is extremely detrimental to the room-temperature ductility of molybdenum. Early fracto-graphic studies&apos; of the cast metal indicated that oxides are formed preferentially at the grain boundaries. Additional verification of this preferential segregation has been obtained from internal friction studies on poly crystalline molybdenum (average grain diameter varied from 0.039 to 0.065 mm) and from observations of the effect of oxygen on specimens of extremely large grain size. Specimens A, B, and C, of 0.040 in. diameter commercial molybdenum wire (Lot FW 13-40) were heat treated in the vacuum furnace described by Few and Manning according to the specifications given in Table I. Internal friction studies of these specimens were carried out using a low frequency (approximately 1 cycle per second) torsional pendulum completely enclosed in a vacuum tank. As the pressure of oxygen in the heat treating atmosphere changed, the portion of the internal friction vs temperature curves ascribed to grain boundary relaxation changed correspondingly, Fig. 1. The decrease in the damping capacity at high temperatures as the pressure of oxygen in the heat treating atmos-

Jan 1, 1955

The following members were appointed on the Committee Advisory to the U. S. Bureau of Standards: Arthur S. Dwight (Lead). John Fairfield Thompson (Nickel). The reports of the Committee in charge of the Arizona Meeting and the Committee on Transportation to the Arizona Meeting were accepted with the thanks of the Board. The By-Laws of the Nevada Section of the Institute were approved. The subscription price of the Bulletin to non-members of the Institute was increased to $12, per year beginning with January, 1917. This increase does not affect the reduced price of $5 on extra copies of the Bulletin which are sold to members, libraries and sister societies.

Jan 7, 1916

By Edna A. Dancy, Ronald L. Pastorek, Gerhard J. Derge

In an earlier study1 in this laboratory, it was found that there is a minimum in the specific conductance of Ni-S melts in the region of the stoichiometric composition, Ni3S2. This and similar observations on other sulfide1 and telluride2 systems suggest that short-range order exists in the molten phase for several hundred degrees above the melting point, and a qualitative energy-band model has been proposed, with intrinsic semiconduction at the stoichiometric composition and degenerate electron and hole conduction at metal- and tellurium-rich compositions. This suggestion has been substantiated for the telluride systems by Seebeck coefficient measurements which showed a change in sign from negative on the metal-rich side to positive on the tellurium-rich side. In the present investigation, in order to substantiate still further the proposed model, Seebeck coefficient determinations have been extended to the Ni-S system over a composition range in the vicinity of Ni3S2. The experimental method was essentially the same as that used for the telluride systems, with minor modifications on cells for high sulfur melts to permit the use of tungsten wires and W— W-Re th~rmocouples instead of the chrome1 or alumel wires and chromel-alumel thermocouples originally used. Chrome1 and alumel both deteriorate very rapidly in atmospheres containing sulfur. The Ni-S alloys were prepared as described in the conductivity paper. Initially, a portion of the solidified melt was analyzed at the end of a run, but after this was found to be inaccurate because of segregation during cooling, the whole sample was analyzed. The nickel content, only, was determined, the sulfur content being obtained by difference. The results are summarized graphically in Fig. 1, and clearly show a change in the sign of the Seebeck coefficient in the region of the stoichiometric composition. This change of sign near Ni3S2, coupled with the minimum in the conductivity, is suggestive of an intrinsic semiconductor at the stoichiometric composition, with degenerate electron and hole conduction on either side of this composition, in keeping with the proposed model. The negative temperature coefficient of conductivity, normally indicative of metallic conduction, is not inconsistent with this model. In the completely degenerate region it would be expected, while in the vicinity of Ni3S2 the suggestion originally made by Argyriades, Derge, and pound3 for the Fe-S system can probably be applied. They proposed that the forbidden gap between the valence band and the conduction band is small, and that the increase in the number of the conducting species with increase in temperature is not large enough to compensate for the loss of mobility through thermal scattering. The research was sponsored by the Office of Naval Research under Contract NONR-760(22) Project NR 039-081. &apos;E. A. Dancy and G. J. Derge: Trans. Met. Soc. Aime, 1963, vol. 227, pp. 1034-38. &apos;E. A. Dancy: Trans. Vet. soc. AIME. 1964, vol. 233, pp. 270-77. &apos;D. Argyriades, G. Derge, and G. M. Pound: Trans. Met. Soc. . 1959, vol. 215, pp. 909-12.

Jan 1, 1965

As far as rapid determination of oxygen in liquid steel by means of a galvanic cell is concerned, I should like to summarize in a few words the activities of Centre de Recherches Metallurgigues (CRM) in Belgium. This work has been conducted both in a laboratory (Tammann and Induction furnaces) as well as on an industrial scale (converter and ladle). The galvanic cells developed by CRM are of two kinds: one with an air reference and one with a solid reference. As far as galvanic cells with air reference are concerned, we have tested numerous solid electrolytes (zirconia, spinel, and alumina). We finally chose zirconia sheathed with quartz. In order to be in a position to accurately determine the time when thermal equilibrium is reached, it was deemed useful to fit the galvanic cell with a Pt/Pt, Rh thermocouple, so as to follow the temperature variations at the interface of the solid electrolyte, until the temperature becomes equal to that of the bath. In actual fact the solution is highly interesting since it is possible to determine both the oxygen activity and the temperature of the bath with a single cell.

Jan 1, 1972

By James L. Calver

Fuller’s earth is an inexact term applied to certain clays that have a marked ability to adsorb coloring materials from animal, vegetable, and mineral oils. Many clays have this adsorbing power to a slight or very limited degree, and certain other clays, chiefly bentonites, as well as minerals such as bauxite, can be made highly adsorbent by activation with acids or alkalies, but the term fuller&apos;s earth is generally reserved for clays that are naturally highly adsorptive. In most fuller&apos;s earths and practically all activable clays montmorillonite is a dominant mineral. No definite clay mineral or group is implied in the name fuller&apos;s earth, and the distinction between fuller&apos;s earth and other clays that have more or less bleaching power is not sharply drawn. The name as generally used has no genetic or mineralogical significance. The fuller&apos;s earth produced in the Florida-Georgia district contains the clay mineral attapulgite. This mineral name was first used in 1930 by DeLapparent to apply to a hydrous aluminum magnesium silicate found in the fuller&apos;s earth from Attapulgus, Ga., and Quincy, Fla. An essential component of its structure, determined by Bradley in 1940, is that the silica chains of the molecule are arranged similarly to those of the amphibole minerals. The fibrous nature of the lath-like crystals of attapulgite is apparent under magnifications reached by the electron microscope. The ideal formula, [(OH,), (OH), Mg, Si, 0,-4H,O], contains no aluminum, but there is considerable replacement of the magnesium by aluminum. In the classification of clay minerals, attapulgite is associated with sepiolite and polygorskite rather than with mont-morillonite.

Apr 1, 1956

By C. G. Dunn

THE present note, which was given in the form of a Research in Progress item,&apos; traces the origin of secondary recrystallization grains produced on annealing a cold rolled bicrystal specimen. The investigation began with the realization that a recently acquired conception for the origin of secondary grains produced on annealing cold rolled single-crystal specimens might require modifications for the case of polycrystalline materials. The stated conception2,3 begins with several conditions to be met by primary recrystallization: 1—a primary re-crystallization structure to consist of many small primaries and relatively few large primaries (diam- eters two or three times the average); 2—a primary recrystallization texture to consist of one strong preferred orientation or component and one or more weak components; and 3—a primary recrystalliza-tion structure-texture combination with some of the large primaries belonging to the weak components of the texture. When these conditions occur, some of the large primaries from the weak components of the texture

Jan 1, 1955

By Albert Arents

This test is based upon the fact that metallic copper will precipitate gold and silver upoil its surface from acid solutions. Of course, the fact is not new, but its application is probably so. I have used the method with success; it recommends itself by the rapidity and ease with which it may be carried on. An auriferous cyanide solution, if made acid with sulphuric acid and boiled with finely divided, pulverulent, metallic copper, will, within a short time, deposit its gold-content on the copper. Any silver in the solution is also precipitated. If this mixture is now filtered, the filter and contents may at once be subjected to a crucible assay treatment, and its lead buttons cupelled and determined. If, instead of taking cement-copper, or any metallic copperpowder, a solution of bluestone is used after acidification, and a few small pieces of sheet aluminum are added, and the solution boiled until all the copper has come down, the result as to the precipitation of gold and silver is the same. This modification takes more time and attention in boiling. If aluminum has been used, it should go into the crucible with the filter and

Jan 1, 1904

H. 0. Hofman, Boston, Mass. (communication to the Secretary*) :—The experimental demonstration by Professor H. Ries, of the fact that a mixture of clay and finely-ground flux will melt more readily than one in which the flux is less fine and therefore less intimately mixed, is very striking, and will be appreciated especially by those who have to discuss, before classes of students, fusions on a small or a large scale. The statement, that I " rather disputed" the influence of size of flux-particles on the ease with which fire-clay mixtures fused, is an erroneous inference from the paper written by Mr. B. Stoughton and myself in 1898.&apos; We did not undertake to study the influence upon fusibility of the sizes of the particles, either of clay or flux. What we did try to find out was, whether the common practice of finely grinding raw or burnt clay, or a mixture of the two, before testing with Seger cones for resistance to heat and to fluxes, xould give the same results as if the materials were tested just as they were going to be

Jan 1, 1904

By Willard L. Thorp

AFTER the first session which Secretary Marshall had with the Foreign Relations Committee, the members of the press asked what he had said His only comment, in summarizing his two-hour conference was, "The world is in a very critical condition " Undoubtedly he had many different aspects of the world in mind, but I wish to underline today the truth of the statement with reference to the economic field V-E day was 22 months ago, V-J day was 19 months ago The hoped-for world of peace and plenty gives signs of attaining the peace, but the plenty seems tragically remote For great areas in the world, the present level of economic activity is very, very low Men are not working, goods are not being produced, whole areas of activity suffer from economic paralysis We in this country do not fully appreciate the situation because the United States is above prewar levels in economic activity We are the exception The same cannot be said for the world in general There are still large areas where industrial activity is not more than half the prewar level

Jan 1, 1947

The separate outputs of Burma and India in 1937 were 274,664,365 gal. valued at £4,474,147 and 75,657,857 gal. valued at £1,030,591, respectively. The corresponding figures for the year 1938 were 263,823,-265 gal. valued at £3,766,810 and 87,082,371 gal. valued at £1,234,563, respectively, which is a slight increase in total quantities but a fall in value for the combined outputs of Burma and India. The appreciable increase from India in 1938 is due to an increase of over 11 million gallons from Attock and a little from Digboi, while the decrease from Burma is due to a fall of nearly 9 million gallons from Yenangyaung, over 3 million gallons from Yenangyat (and Lanywa) and half a million gallons from Minbu (Table 1). The &apos;amount&apos; of gasoline produced from natural gas during the year 1938 was 10,587,291 gal. in Burma and 496,163 gal. in the Punjab.

Jan 1, 1940

The separate outputs of Burma and India in 1937 were 274,664,365 gal. valued at £4,474,147 and 75,657,857 gal. valued at £1,030,591, respectively. The corresponding figures for the year 1938 were 263,823,-265 gal. valued at £3,766,810 and 87,082,371 gal. valued at £1,234,563, respectively, which is a slight increase in total quantities but a fall in value for the combined outputs of Burma and India. The appreciable increase from India in 1938 is due to an increase of over 11 million gallons from Attock and a little from Digboi, while the decrease from Burma is due to a fall of nearly 9 million gallons from Yenangyaung, over 3 million gallons from Yenangyat (and Lanywa) and half a million gallons from Minbu (Table 1). The &apos;amount&apos; of gasoline produced from natural gas during the year 1938 was 10,587,291 gal. in Burma and 496,163 gal. in the Punjab.

Jan 1, 1940

The 139th meeting* of the American Institute of Mining and Metallurgical Engineers was held at New York, February 17 to 20, 1930, the attendance totaling approximately 1800. The meeting consisted of the annual business session, 34 technical sessions at which were presented 166 papers, two meetings of the Board of Directors, two meetings of Section Delegates, two formal lectures and one special lecture, five group dinners and one group luncheon, luncheon daily for members and guests, fourteen committee meetings and conferences, the President&apos;s reception, the dinner-dance, an informal dance, a smoker, an exhibition of rare minerals and metals, two meetings of the Woman&apos;s Auxiliary and a special program of entertainment for the ladies. The Petroleum Division held seven sessions, including two general sessions featuring, respectively, a symposium on unit operation of oil pools and reports on developments in the petroleum industry during the previous year. The Iron and Steel Division held four sessions, at one of which Dr. Zay Jeffries delivered the Howe Memorial Lecture, the title of which was "The Future of the American Iron and Steel Industry." The Institute of Metals Division held six sessions, including two devoted to a symposium on the Melting and Casting of Metals, and the general session at which Dr. S. L. Hoyt delivered the annual Institute of Metals Lecture. The title of his lecture was "Hard Metal Carbides and Cemented Tungsten Carbide." The Coal and Coal Products Committee devoted one session and the greater part of another to Coal Classification and at a third session organized as the Coal Division of the Institute. The Committees on Mining Methods and Ground Movement and Subsidence each held a session, besides which they met jointly. Sessions were held by other Technical Committees as follows: Nonferrous Metallurgy, 1; Geophysical Prospecting, 2; Nonmetallic Minerals, 2; Milling Methods, 1; Rare Minerals and Metals, 1; Mining Geology, 2; Mine Ventilation, 2; Engineering Education, 1. At the annual business meeting on February 18, the following ticket was elected, and the reports of the President, Treasurer and Secretary were presented: William H. Bassett, President; Scott Turner, Vice-president; Henry Krumb, Vice-president; R. C. Allen, Cadwallader Evans, Jr., John M. Lovejoy, John A. Mathews and Milnor Roberts, Directors. At an executive session of the Directors on Tuesday afternoon, H. A. Guess was elected Vice-president to fill the vacancy created by the

Jan 1, 1930

By M. K. Yen

The distortion of crystal structures referred to as "biege gleitung",1 "local curvature"2-4 and "deformation bands"5,6 is believed to be an unavoidable characteristic of deformed single crystals. The presence of asterism on Laue photograms of Al single crystals either deformed by pure shear7 or extended in a condition relatively free from the grip effect2 indicates strong evidence substantiating this point of view. The type of localized bending described in connection with the bending test of Al single crystals by Yen and Hibbard8 could conceivably exist either microscopically or submicroscopically in all types of deformation. The purpose of this note is to extend this idea to the postulate of a hypothetical "microbending site," as applied to the mechanism of slip in a general sense. The mosiac structure, as postulated by Darwin,9 is that crystals were actually composed of small blocks which have a linear dimension 10—4to 10-6 cm on the edge and deviate from each other by an angle of about one-tenth of a degree. The following discussion is based on the assumption that when slip is propagated from one mosaic block to the adjacent one, bending of the lattice at the region of their boundary is produced in order to maintain the continuity of the gliding process along a certain slip plane. Consider a two-dimensional diagram of two ideal mosiac blocks on the cross-section perpendicular to the slip plane and containing the active direction of slip. When an external force is applied, the localized bending or "microbending site," would be generated at the region as illustrated in Fig 1A at point B. A schematic diagram of a "microbending site," generated at a mosaic boundary, is illustrated in Fig IB. It may be seen that once the curvature of the bending site reaches sufficient magnitude, the interaction force encountered by pairs of atoms symmetrical with respect to the center of the bending is equal but opposite in sign. Consequently, the overall energy required to displace the atoms near the center is approximately zero.10"12 Based upon the finding that the misalignment between two mosaics is 0.1 degree,9 the assumption is made that "microbending sites" may possibly exist in the region where one plane will have one more row of atoms than an adjacent plane. It is probable that the origin of the bending site will be where the distance between two mosaic boundaries is "2d" as shown in Fig 1A at point B, where " d" is the interatomic distance. Thus, the distance between two "microbending sites" is in the range of about 600 interplanar spacings. In the case of aluminum, the spacing between two octahedral planes is about 2.33 A. The distance between two bending sites will be approximately 2.5 X 10"5 cm. It is interesting to note that according to Woods13 these values approach closely the size of the domains of a cold-worked metal whose minimum

Jan 1, 1950

[PRESIDENT GEORGE OTIS SMITH, District 4 WASHINGTON, D. C. PAST PRESIDENTS SAMUEL A. TAYLOR, District 3 PITTSBURGH, PA. E. DEGOLYER, District 0 NEW YORK, N. Y. FIRST VICE-PRESIDENT W. H. BASSETT, District 1 WATERBURY, CONN.]

Jan 1, 1928