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TO THE BOARD OF DIRECTORS AND MEMBERS OF THE AMERICAN INSTITUTE OF MINING AND METALLURGICAL ENGINEERS GENTLEMEN: Submitted herewith are the report of the Treasurer for the year 1939 and reports for the same year of the following standing committees: Admissions, Membership, Papers and Publications, Mining and Metallurgy (Magazine), Library, Speakers for Local Sections and Student Societies, and Student Relations. These reports present additional details. Membership.-For the second year in Succession membership reached a new high level for all time, as indicated in the accompanying tabulation in which "Members" includes all categories except Student Associates. [END 1938 END 1939 NET GAIN Members9, 57 610, 163 587 Student Associates 2,898 3,760 862 12,474 13,923 1,449] Net gain in membership (aside from Student Associates) was 587 compared with 744 in 1938, despite the fact that applications received in 1939 exceeded those received in 1938 (1271 against 1162). The smaller net gain is accounted for in three ways: (1) A greater lag in enrollment of those elected in the last quarter of the year; (2) an increase in the number of applications involving change of status from Junior Member to Member; and (3) an increase of 167 in the loss by death by resignation and by suspension in 1939 as compared with 1938. Experience shows that at the end of a year of less prosperous conditions in the mineral industries, and, therefore, among engineers engaged in these industries, resignations and suspensions are more numerous. Business and industrial indexes all show 1938 to have been somewhat less prosperous than 1937; but the improvement in 1939 should be reflected in the record for 1940.

Jan 1, 1940

By H. P. Greenwald

THE Committee on Rock-Dusting was formed after the fall meeting of the Coal Division in Chicago in 1938. Its primary task was to study the recommended American practice for rock- dusting coal mines to prevent coal-dust explosions as approved by the American Engineering Standards Committee. After approximately two years' work he committee concluded that although certain portions of the recommended practice could well be revised, information needed for a logical revision was not at hand, and it was inadvisable, therefore, to make revisions

Jan 1, 1943

By Dennis Peterson

INTRODUCTION The business arena has dramatically changed for most producers and consumers of commodities. International debt, currency shortages, political upheavals, etc., require corporations today to be sophisticated and flexible enough to change their purchasing and sales techniques in order to maximize returns. Many external factors, such as interest rates, trading partners, currency changes, and government edicts, can have an adverse effect on a company's bottom line. Totally out of a company's ability to control or predict, these. factors force the commodities based corporation to constantly re-evaluate its operating scope and domain. The principle of back-yard only operations and the laissez-faire with blinders style of management is no longer a viable way to run a business. The industrial world has been operating for the past 10 to 15 years as though there were no commodity nor raw material crisis. For developed countries the primary products sector has become marginal, whereas it was central in the first half of the century. A radical change in the method of doing business is necessary to offset a depression in the industrial economy. The risk of collapse may be heightened by a banking crisis caused by massive defaults on the part of commodity producing debtors, whether in the third world or in our own farm producing sector. The raw materials economy has become divergent with the industrial economy. This is a major change in the world economy with tremendous implications in both developed and developing countries for economic and social policies and economic theories. Basic competition issues, such as low labor costs, are likely to become less of an advantage in international trade. In developed countries these costs are going to account for a smaller portion of total costs. The total costs of automated processes are lower than those of traditional plants with low labor costs. Automation in the commodities sector eliminates the hidden but high cost of not processing at capacity created by poor quality, rejects and maintenance for product change-overs. The cost of capital will become increasingly important in international competition. Over the last ten years the U.S. has become the highest cost country in this area. Reversing the U.S. policy of high interest rates and costly equity capital should be a priority for management decision makers. In the rapid industrialization of this century, Japan developed by exporting raw materials, (principally, silk and tea), at steadily increasing prices. Germany developed by leap frogging into the high-tech industries, mainly in electricity, chemicals and optics. The United States did both. Both avenues are blocked for today's rapidly industrializing countries because (a) the deterioration of the terms of trade for primary products, and (b) it requires an infrastructure of knowledge and education far beyond the scope of a poor country. Many explanations exist for the explosion of international money flows. The shift from fixed to floating exchange rates in 1971 may have given initial impetus by inviting currency speculation. The surge in liquid funds flowing to petroleum producers after the oil shocks of 1973 and 1979 was definitely a major cause. There can be little doubt that the U.S. government deficit also played a big role. The American budget deficit has become a massive void, sucking in liquid funds from all over the world and making the U.S. the world's major debtor country. In reality, a trade and payments deficit is actually a loan from the seller of goods and services to the buyer, that is, to the U.S. From now on, the global ramifications of business will have to be treated in economic theory and business policy alike. Economic theory teaches that the comparative advantage factors of a real economy determines operative and financial policy. These comparisons -- labor costs, productivity, raw materials cost, energy costs,

Jan 1, 1990

By W. H. Somerton

The effects of drilling variable on rotary drilling rates and efficiencies have been studied by a series of laboratory drilling tests. TWO-cone 1.25-in. diameter hits were used to drill vertically upwards into rock samples at corltrolled weights and rates of rotation. Shale, sandstone and specially prepared concrete samples were used in this study. Power input to the ririllirig systeln was measured and drilling chips collected for energy — .size reduction studies. Reasouably good correlations between drilling variables and rates of penetrotion were found. Qrrantities that are difficult to evaluate include rock strength parameters and the effects of bit wear. Effects of bit size and geormetry require further investigation. Analysis of the drilling chips confirmed the premise that, for rocks containing two or more mineral constituents of diflerent strengths, a greater amourrt of rock breakage occurs in the weaker constituent. Drilling conditions which required greater amounts of energy produced finer drilling chips. As bit tooth wear progressed, drilling chips became finer. Efficiency of rotary drilling as a rock breakage mechanism was extremely low. Comparison was made with theoretical energy requirements and with energy requirements for size reduction by comminution methods. INTRODUCTION Many technological developments and innovations have made possible the successful drilling of oil wells by the rotary method to depths exceeding 20,000 ft. Bigger, more powerful rigs, better steels, improved bit design and more careful control of the circulating system have all contributed to this success. Despite these advances comparatively little is known regarding the basic mechanism of rock breakage by the rotary drilling process. Future improvements and, in particular, reduction of drilling costs will undoubtedly require a clearer understanding of the variables controlling effectiveness and efficiency of rotary drilling. Rotary drilling is inherently an inefficient means of producing rock breakage. Loss of energy in transmission from the surface to the cutting mechanism may be large, thus limiting the total amount of energy which may be applied to rock breakage. Increased efficiency may be realized by improved energy transmission methods such as the turbodrill. Conversion of transmitted energy to rock breakage by use of rotating cutter teeth is likewise inefficient. Improvement of cutter efficiency has been obtained essentially by empirical means —changes in bit tooth size, shape and spacing, and tooth deletion to give clean bottom-hole patterns. The present work was undertaken to investigate the factors controlling rates of bit penetration under laboratory drilling conditions. Laboratory drilling apparatus is shown in Fig. 1. The effects of rock strength and bit wear on drilling rates were investigated. Drill cuttings were analyzed to determine the character of breakage and to compare this with other methods of producing rock breakage. VARIABLES INVOLVED IN ROTARY DRILLING Some of the variables controlling bit penetration rates can be studied conveniently by dimensional grouping. R/DN f(F/D2S) or

By C. S. Corbett

There is much comment at present in the ranks of the oil industry regarding unit operation of oil fields and the benefit that would accrue if it could be extensively applied. It seems certain that, as an immediate corrective of the present situation, overproduction could be effectively curtailed with all the advantages of proper conservation of petroleum resources and with no important loss to anyone connected with the industry. Unit Operation in Certain Foreign Fields Many an oil operator in America would doubtless like to have exclusive control of one or more oil-bearing structures for development in accordance with the economic position of the industry and especially in accordance with the best production practice known. A few operators now have this privilege, particularly in certain foreign fields, and are following lines of procedure which show that they are aware of the great opportunity that is theirs. We find in an article by Professor Strigeoff,1 and in a paper read by Captain Comins2 before the American Petroleum Institute, the outlines of procedure adopted, respectively, by the Soviet Government for the nationalized Russian oil fields and by the Anglo-Persian Oil Co. for its fields in Persia. Comprehensive plans for the unit operation of other oil fields may have been described publicly but no such descriptions have come to the attention of the writer. New fields are coming more and more into the hands of single operators or of a few who control large activities and who appreciate fully the need for cooperative action and are willing to forego the lure of a large quick profit from high flush production in order to secure the advantage of better stabilization in the industry and a larger though more deferred profit by operating the field as a unit. Much can be done toward efficient development of an oil field controlled by a few operators who are willing to cooperate for that purpose, but the best result can be obtained only by pooling their interests in the field

Jan 1, 1930

By A. A. Schweizer

A method to improve the quality of Magmont zinc concentrates to become acceptable feed to an electrolytic zinc refinery is described. The magnesia content of zinc concentrates produced was too high due to particle locking with sphalerite in coarse fractions. Regrinding the concentrates to a very fine particle size and then refloating the sphalerite was chosen to eliminate a sufficient amount of the magnesia to make the concentrates acceptable.

Jan 1, 1984

By Whitmell J. Smithwick, Charles E. Dandois

The first operating unit of the ring or annular shaft kiln as developed by Mr. Karl Beckenbach of West Germany was rated 185 tpd and was installed in 1962. Today, there are approximately 84 units in operation in Western Europe and Japan. Twenty-one additional units are under construction or on order. Sizes range from approximately 100-330 tpd, however, units of over 500 tons are in the design stage. The ring shaft kiln is a single vertical cylinder to which are attached the required service platforms, combustion chambers, injectors and distribution piping (Fig. 1). Auxiliaries such as recuperator, exhaust fan and dust collector are mounted on the appropriate service platform. The charging pan, feed conveyor, etc., are mounted at the kiln top and at the bottom of the kiln is the silo with a vibrator type discharger. Mounted separately is the required blower for injector air and fan for internal cooling.

Jan 4, 1973

(Under this heading will be published notes sent to the Secretary of, the Institute by members or other persons introduced by members.) Development and production. Member open for engagement. Past year in war mineral field work, operation and production. Ten years' thorough experience in both subordinate and executive positions, gold, silver and copper in the United States, Mexico, and South America. Age 37, married. Minimum salary $3600. Interview. South or East. A-577. Engineer and executive. Captain U. S. Army, age 36, expects discharge before July 1. Seven years' mining and metallurgical experience. Six years with large technical college as assistant professor of mining and directing extensive experimental work. Desires position as executive or research engineer with reliable company or as professor of mining with first-class college. A-909. Mining engineer. Twenty-five years' experience including mine and works operation, construction, plant installation, and mine examination. Speaks Spanish. A-1173. Metallurgical engineer. Twelve years' laboratory and operating experience, covering copper blast furnace, roasting, reverberatory smelting and latest Cottrell treater practice on copper dust and zinc dust. Technical graduate. 36 years of age, married. Highest recommendations. Open for immediate engagement. A-2354. Mining engineer. Junior Associate. At liberty about July 1. Captain Heavy Artillery. Single, age 24. Go anywhere. Best refer-ences. A-2843. Engineer. Age 26, single, graduate Missouri School of Mines, B. S. in Mis. Met. E. Desires position with oil or metal company in any capacity. Location immaterial. At present engaged, desires change. A-2844.

Jan 7, 1919

By Fred C. Bond, Jen-Tung Wang

Comminution energy is principally energy of deformation before break-age, which appears as heat. An empirical equation is presented which covers the entire comminution range. The new strain-energy theory considers comminution from the known principles of mechanics and the reduction ratio. Energy requirements according to the different theories are compared.

Jan 8, 1950

By Horace V. Winchell

This paper, embodying information acquired by the writer in his work in connection with the Geological Survey of Minnesota, is presented by permission of the State Geologist. Historical.—On November 16, 1890, the workmen of Captain J. A. Nichols, of Duluth, Minn., encountered in a test-pit on the northwest quarter of section 3, township 58, range 18, west of the fourth principal meridian, the body of soft ore now called the Mountain Iron mine. Hard ore, chiefly magnetic, had been known for many years on the Mesabi range, and explorations made by Mr. E. W. Griffin, of Minneapolis, near the falls of Prairie river in T. 56-24 and T. 56-25, and by John Mallmann, at the Mallmann explorations, T. 59-14, had revealed some hard hematite interbedded with quartzite and low-grade soft ore; but this was the first discovery of merchantable hematite on the range. Captain Nichols had been exploring more or less along the range for some two years. To him and to the Merritt brothers, of Duluth and Oneota, who, unshaken in Faith by the discouraging reports of explorers, miners, experts, and geologists, had persevered in the search for ore, great credit is due for the final success, and large rewards have accrued to them already.

Jan 1, 1893

By W. G. Matteson

The Oklahoma legislature recently passed a bill providing for "the creation of an oil and gas department under the jurisdiction of the Corporation Commission, authorizing the Corporation Commission to appoint a chief oil and gas conservation agent, and conferring exclusive jurisdiction on the Corporation Commission in reference to the conservation of oil and gas, and the inspection of gasoline and oil, the product of crude petroleum, and repealing all acts or parts of acts in conflict therewith and declaring an emergency." Some of the functions of the new bureau include the receiving and filing of all well logs, and the direction and supervision of plugging all abandoned oil and gas wells, under rules prescribed by the Corporation Commission. The two leading petroleum-producing States of the country, Oklahoma and California, have now established oil and gas bureaus with a staff of inspectors to see that the important rules relating to the conservation of oil and gas are thoroughly enforced. The economic significance and the value of well logs in the conservation work has been recognized, and the necessary legal action taken to insure and procure them. William B. Heroy, of the Government Land Classification Board, in a personal communication to the writer, says that the drilling of wells is also regulated by public authority in the Roswell artesian basin in southeastern New Mexico, where a permit must be obtained for the drilling of any well and a certified log of the well recorded with a county official. The method is said to give fairly satisfactory results. In a recent article1 a National instead of a State Bureau was suggested for collecting and filing well logs. In discussing the paper, L. L. Hutchison characterized such a plan as impractical because the average driller or contractor will often juggle or guess at the log and will not keep the record sufficiently close or accurate, making it necessary to maintain a special man at each well for the sole purpose of obtaining

Jan 1, 1918

By Arthur V. Abbott

During the past four years I have had occasion to make quite extensive use of steel castings in the manufacture of testing-machines and large scales for Messrs. Fairbanks & Co. The failure of some of these' castings at stresses much below those which were claimed for them by the makers, induced me to institute a series of experiments to determine the actual constructive value of the steel castings now to be obtained in this country. The art of steel-casting is rapidly improving, almost every issue of the scientific press bringing accounts of some new development; consequently, the results of the following experiments are only exponents of the value of steel castings as at present made. In order to make the examination as thorough as possible, ten sets of patterns were made and forwarded to as many different firms in the country who advertised to make steel castings. The first part of the accompanying table gives a list of these manufactures, together with the price per pound. The order accompanying the patterns simply requested the manufacturer to supply two castings from each pattern of his ordinary product of steel. These castings were sent to me and paid for in the usual manner, so that it is probable that the samples fairly represent the quality of the average of steel castings, and are free from the suspicion of being "special runs." Two patterns were sent to each maker, one being a straight

Jan 1, 1886

By Wilbur Stout

IN Ohio, the annual output of coke made from native coals has averaged not more than 70,000 tons, or about enough to run a 200-ton blast furnace. Raw coal locally mined from the Sharon, or No. 1, bed was used for iron smelting in Mahoning furnace at Lowellville, Mahoning Co., as early as 1846. This practice was continued in the Youngstown district until the coal became scarce and the Connellsville coke more popular. At present, the Sharon bed contributes a part of the fuel for the production of ferrosilicon iron at Jackson, Jackson Co. About one-third native coal and two-thirds soft coal are used. In this state, coke, on a commercial basis, was first made in Jefferson County probably about 1861 or 1862. The coals used were the Steubenville Shaft, or Lower Freeport, and the Strip Vein or Middle Kittanning. The practice, however, was discontinued before 1880 because of the competition of superior foreign cokes. Beehive ovens, later built at Leetonia, Columbiana Co., were operated for only a few years; the coal used at this place is the Lower Kittanning or No. 5. In a desultory way, slack from the Pittsburgh coal has been coked at a few places in eastern Ohio, and attempts, either for experimental or for commercial purposes, have been made in other parts of the State. Small quantities of coke were made from the Upper. Freeport coal at Salineville, Columbiana Co., and near Nelsonville, Hocking Co.; the results were poor. Tests were made of the Middle Kittanning coal near Zanesville, Muskingum Co., at Moxahala Furnace, Perry Co., and at Washington Furnace, Lawrence Co.; the cokes were all high in sulfur and ash. Attempts were made to coke the Clarion coal at Vinton Furnace, Vinton Co.; a small battery of molding ovens and a pile of high-sulfur coke yet remain to tell the story. The Pittsburgh coal was coked on a commercial scale at Utley and at Lathrop, Athens Co.; but the operations were not successful and were soon abandoned.

Jan 9, 1919

By M. L. Rudee, R. A. Huggins

Samples of iron containing nitrogen or carbon have been given treatments similar to those used in cold-work peak (CWP) measurements and examined by transmission electron microscopy. It was observed that the unusual and nonreproducible behavior of the carbon CWP can be explained by a strong tendency for carbon to form grain boundary precipitates at temperatures below those used for CWP measurements. These precipitates dissolved at the temperatures used in the CWP measurements. There was no evidence for nitrogen precipitation at grain boundaries. There was no indication of precipitation along dislocations in either carburized or nitrided samples given treatments similar to those of CWP measurements. Although it is possible that subelectron-microscopic clustering had occurred, this observation supports the theories of the CWP that are based on continuous atmospheres rather than on individual precipitates. In an earlier paper,' the present authors developed a new distribution function to predict the occupation of sites for interstitial impurity atoms around a dislocation. When this distribution was applied to the case of carbon and nitrogen in iron, it predicted that, if the temperature dependence of the concentration of solute atoms in the matrix was controlled by the presence of equilibrium carbide or nitride precipitates, the tendency for nitrogen to segregate to dislocations would be greater than that for carbon even though their binding energies to dislocations are identical. The cold-work internal-friction peak (CWP) is considered by most authors to be produced by the interaction of interstitial impurities with dislocations. Many investigators have studied the CWP in iron containing carbon and nitrogen and have observed a significant difference between its behavior in the two cases. In this paper a series of experiments will be reported that were initiated to determine whether the application of the new distribution function would explain the observed differences between the carbon and nitrogen CWP. Although it was found that the distribution function, pev se, did not explain the differences, the differences became clear, and some insight into the mechanism of the CWP was realized. Before reporting the present experiments, the literature pertaining to the differences between the carbon and nitrogen CWP in iron and the various mechanisms proposed for the CWP will be reviewed. LITERATURE REVIEW Snoek2 first observed the CWP in iron specimens containing nitrogen, but also reported a weak and unreliable peak in carburized samples. Later, Ke3 established that the CWP height was proportional to the degree of deformation. The presence of nitrogen alone would produce a peak of the same size as found in a sample containing both nitrogen and carbon, and KG concluded that the CWP was caused by nitrogen. In a discussion of G's paper it was reported that Dijkstra had investigated the CWP in samples that contained only carbon. He found it to be much smaller than the nitrogen peak and "unstable". KG et al.4 charged specimens of iron with both carbon and nitrogen. They observed that the carbon CWP was much smaller than that observed in nitrided samples, but that aging at 300°C caused the carbon peak to increase. A similar treatment produced no change in a nitrogen peak. Annealing at higher temperatures caused the height of the CWP in both the nitrogen and carbon samples to decrease. This behavior was also observed by Kamber et al. 5 who found that the activation energy for the annealing of the CWP was identical with the activation energy for the self-diffusion of iron. They concluded that the annihilation of dislocations by climb caused the reduction in the CWP height. Kamber et al. studied the "unstable" carbon peak in detail. They measured both the Snoek and CWP during various aging treatments. In carburized samples, aging at 100°C caused the Snoek peak to disappear, although the CWP peak remained small. However, a subsequent treatment for 5 hr at 240°C caused the CWP to reach a maximum. They proposed that an additional location for the carbon, other than whatever site produced the CWP, is present. In nitrided samples the CWP was completely developed as soon as a measurement was made; additional sites are not present. No explanation of either the additional site or the difference in the behavior of carbon and nitrogen was offered. petarra5 performed a systematic study of the effect of composition on the CWP. Using three kinds of "pure" iron, he showed that there was a residual CWP when the carbon and nitrogen concentrations had been reduced to less than that detectable by Snoek-peak measurements. He observed the same general annealing behavior and composition dependence as previous investigators, with the following exceptions. On first measuring the carbon CWP, it was found to be identical with the residual peak, and essentially independent of the carbon content. If the CWP was measured a second time in the same sample, it increased in size, but was still only about one-fourth the size of a CWP in a sample of the same iron nitrided to the same composition. On the other hand, a series of annealing experiments showed that the nitrogen CWP was not al-

Jan 1, 1967

By E. S. Moffat

Members of the Institute who have visited the works of the Lackawanna Iron and Coal Company at Scranton, will remember the exposure of a large vein of anthracite coal in the rocky bank on the south side of Roaring Brook, near the blast-furnace. The vein is quite flat, and is exposed to view for several hundred yards along the banks of the brook, a few feet above the surface of the water. It is some ten feet in thickness, and is known as the Big Vein. At a point just opposite the blast-furnace, much of the coal from this vein was mined out many years since, the usual pillars being left to support the overlying rock and drift, which are here some twentyfive to thirty feet in thickness. Over thirty pears ago fire was communicated from an ore-roasting pile on the surface of the ground at this point, through an old shaft, down to the refuse and pillars which had been left in the mine

Jan 1, 1887

By Arthur Connolly

WHEN scientific literature was lacking or meager, research necessarily meant laboratory investigation above all else. Today, scientific literature has attained tremendous proportions, and the volume increases at a much faster rate than it is digested and efficiently utilized. For that reason the present-day research worker should spend much more time in the library, and correspondingly less in the laboratory, than is the general custom. Library research would overcome two serious errors often made by scientists: duplication of work described completely and failure to appreciate inventions described almost verbatim in the literature. To emphasize these failings that often occur in present-day research, consider a hypothetical scientist as he conducts his search from inception to the stage where it is made available to the public by patent or other publication.

Jan 1, 1942

By Louis D. Huntoon

CANADIAN gold production is forging ahead annually and the prospects are that it will continue to do so for many years. Table 1 shows recent annual increases. Production for 1933 will probably reach $70,000,000, and further increases are likely in 1934 and 1935. (Data for November and December, 1932, are estimated throughout this article.) The depression sent many prospectors to the woods so during the last two years many new gold areas have been discovered and are attracting real capital for exploration and development. Several mills came into production in 1932 and mills now under construction will start production in 1933. The offices of mining lawyers are busy. Capital for this new work is obtained from well financed mining companies, syndicates, and individuals who were fortunate enough to invest in the dividend-paying gold mines of the north country in the early days. Prospectors and capital are cooperating. An interest is always retained by the prospector or vender and usually a small amount of real money is given the prospector.

Jan 1, 1933

By R. I. Jaffee, E. S. Bartlett, D. N. Williams

The oxidation resistance and fabricability of molybdenum powder-metallurgy alloys containing up to 20 wt pct nickel in the form of a fine dispersion were studied. The effects of dispersion distribution and of amount and type (pure nickel or nickel compounds) of additive were considered. A definite improvement in oxidation resistance was observed, but the amount of improvement fell far short of requirements for an oxidation-resistant alloy. Fabricability by hot-rolling was limited. INVESTIGATIONS at Ohio State university1 and Battelle Memorial institute2 have indicated that the attainment of a truly oxidation-resistant molybdenum-base alloy for high-temperature service, with the coincident retention of high-temperature strength and toughness, will be a difficult, if not impossible, feat. Among the most promising alloy systems studied was the molybdenum-nickel system shown in Fig. 1. Alloys in this system show good oxidation resistance at temperatures well above the normal melting point of molybdenum trioxide because of the regenerative formation of protective nickel-molyb-date (NiMoO4) on the surface of the alloy during exposure at high temperatures. Unfortunately, the required alloy content to obtain oxidation resistant molybdenum-nickel alloys far exceeds the limits of the narrow terminal solid-solution boundary, and closely approaches the peri-tectic composition involving the brittle intermetal-lic compound, MoNi. Because of the peritectic reaction, fusion alloys are characteristically brittle, since the MoNi phase, being the last to form, tends to occur as a continuous grain-boundary network around each molybdenum grain. An added problem with this system is that the protective nickel-molybdate layer formed at high temperatures is unstable, undergoing one or more allotropic modifications upon cooling. The volume changes associated with this modification during cooling are such as to cause violent expulsion of the protective molybdate coating from the surface of the piece. This is, of course, quite detrimental in material exposed to cyclic temperature during service. The research reported here resulted from an attempt to overcome the aforementioned problems associated with the molybdenum-nickel alloys primarily by controlling the amount, size, and location of the MoNi phase. By using powder-metallurgy techniques of alloy preparation and sintering the blended molybdenum-nickel powder mixtures at a temperature below the peritectic reaction temperature, molybdenum-nickel alloys with a randomly dispersed MoNi phase were produced. MATERIALS The molybdenum powder used in the preparation of alloys for this study was commercial hydrogen reduced, minus 325-mesh (Tyler) material. Master alloys, by which nickel was added, consisted of elemental carbonyl nickel powder (12 average particle size), an alloy of 50 wt pct Ni-50 wt pct Cr, and compounds of MoNi, Ni,Si, and Ni2B. The nickel-chromium powder was prepared by filing a vacuum-arc-melted ingot, separating impurities magnetically, and screening to minus 200-mesh. The MoNi powder was prepared by pulverizing a hydrogen-sintered powder-metallurgy compact to minus 325-mesh material. Further sizing of this powder for study of effects of dispersion distribution was accomplished by air classification of the minus 325-mesh powder. The Ni2Si and Ni2B powders were prepared by crushing vacuum-sintered powder-metallurgy compacts to minus 200-mesh material. EXPERIMENTAL PROCEDURE Specimen Preparation—The general procedure followed in the preparation of alloys for testing is described as follows: 1) Blending. Either hand-blending of the powders in a ceramic mortar and pestle for X 1/2 or mechanical blending was used. Hand-blending seemed preferable for optimum homogeneity. 2) Compacting. Most of the blended powders were pressed to green compacts at pressures of 15 tons per sq in. in a single-action die, although some were pressed at 80 tons per sq in. A 1 X 11/4 X 1/4-in. green compact was the standard size for oxidation test material, and 7 X 1/2 X 1/4-in. compacts were used for fabricability test specimens. 3) Sintering. All green compacts were sinteredat

Jan 1, 1959

By AIME AIME

EDWIN W. KEMMERER, professor of international finance at Princeton, in a speech before a banking conference at Urbana, Ill., on Nov. 26, stated that the increase in the store of gold held by the United States is not so alarming as it appears on the surface. Excerpts from his address, as reported by The New York Times, follow: "It is significant . . . that the value of gold as expressed in its purchasing power in the United States during the last half-dozen years has been higher than at any other equivalent period since our records began 140 years ago. Our so-called 59-cent dollar today buys about 25 per cent more goods at wholesale than did our old dollar in the prosperous year 1926, and an ounce of gold will now buy considerably more than twice what it did then. This present high value of gold is one reason for its recent large production.

Jan 1, 1941

By AIME AIME

PERHAPS the most interesting paper of the subsidence session on Monday morning was that by Roland D. Parks entitled "Yieldable Metal Props for Underground Support." This paper described the development of a telescoping prop made from two pieces of pipe. The lower and larger in diameter has cast in it a soft metallic alloy which is slowly extruded through an orifice in the upper and smaller piece of pipe. In this way, the length of the prop decreases gradually as the load from the roof increases. The stress-strain diagram for these props, as tested in the laboratory, is almost ideal, and can be duplicated satisfactorily in successive tests. They have not yet been tested underground. Another paper of much interest was presented by Prof. P. B. Bucky. It is an addition to his series on structural models as applied to mining and was entitled "Effect of Approximately Vertical Cracks in the Behavior of Hori¬zontally Lying Roof Strata." It was illustrated by motion pictures of a model under test. After explaining the un¬derlying theory, the apparatus and the mode of testing, Prof. Bucky set forth the effect of vertical cracks in a mine roof, as follows: (a) the wider the crack, the weaker the roof; (b) where the sides of the crack are in juxtaposition, there is little weakening of the roof; (c) grouting cracks whose sides are not in contact restores the strength of the roof until it may be as strong as, or stronger than the uncracked roof. Small paper props helped sustain the roof. Both the nature of the material and its bonding affect its behavior under stress.

Jan 1, 1933