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By O. P. Arora, M. Metzger, G. R. Ramagopal

Single-phase aluminum containing 0.0001 to 0.06 pct Cu was studied in strong acid, mainly through observations of hydrogen evolution. The strong influence of copper was exerted almost entirely through the imposition after a certain delay time of an auto-catalytic localized-corrosiott reaction. Additions of cupric ion to the acid produced lower accelerations. The significance of the quantity and distribution of copper was discussed, and the implications for intergranular corrosion and neutral chloride pitting were indicated. AN investigation of intergranular corrosion in single-phase high purity aluminum exposed to hydrochloric acid indicated the copper content of the metal to have an influence on corrosion at lower levels than previously suspected.&apos; The work reported here was a closer examination of the action of copper but dealt with general corrosion to gain the advantage of having a continuous measure of corrosion through the volume of hydrogen evolved, the reduction of hydrogen ion to hydrogen gas being the principal or only cathode reaction in strong hydrochloric acid. Previous work on the hydrochloric acid corrosion of aluminum was sometimes insufficiently structure-conscious and the need for care in evaluating it arises from the low solubility of the iron impurity,&apos; and of some alloying elements, and the known or possible presence in many of the compositions studied of second phases leading to greatly increased corrosion rates.3 These increases are attributed to the presence of low hydrogen-overvoltage cathodes provided by the second phase.3&apos;4 For the present single-phase work, a few studies which used high-purity base material and small copper additions5-&apos; provide the essential information most unambiguously. The corrosion rate was shown to be increased markedly by the introduction into the acid of small quantities of the ions of copper (and of certain other metals) which cement on the aluminum and provide cathodes of low overvoltage.5 When there was sufficient copper in the aluminum, the same result was produced during the course of corrosion leading to a rate which increased with time as the reaction was stimulated by one of its products (autocatalytic reaction). In 2N (7pct) HC1, an accelerating rate was observed at 0.1 pct Cu but not at 0.01 pct.5,7 The present work dealt with corrosion rate and morphology and their correlation with the quantity and distribution of copper catalyst for copper contents from 0.0001 to 0.06 pct. PROCEDURE A lot of high-purity aluminum containing 0.0021 pct Cu, 0.001 pct Fe and 0.003 pct Si (Alloy A) was alloyed with copper to yield aluminum containing 0.014 pct Cu (B) and 0.06 pct Cu (C). Later it was found necessary to include the lower copper Alloy K which contained 0.0001 pct Cu, 0.0004 pct Fe and 0.0004 pct Si. The upper limit for any other element can be confidently estimated as 0.0005 pct. No element other than copper appears to be present in quantities sufficient to have an effect on general corrosion as great as the observed effect of the copper in A, B, and C. The only other heavy metal detected by spectrographic examination was silver (< 0.0001 pct). The acid was made up from a selected lot of 37 1/2 pct CP hydrochloric acid containing 0.1 ppm heavy metals (mainly Pb), 0.05 ppm Fe, and < 0.008 ppm As and from water distilled from 1 megohm-cm demineralized water and believed to have contained negligible quantities of heavy metals influencing corrosion. Acid strength was adjusted to within 0.05 pct HCl of the stated value by using precision specific gravity measurements. Test blanks 10 by 41 mm were sheared from 1.65-mm cold-rolled sheet. Edges were finished by filing. The blanks were annealed in air at 645°C for 24 hr in alundum boats and rapidly water quenched. The anneal is thought to have produced a substantially homogeneous solid solution—for iron, copper, or silicon, for example, the annealing temperature was 200°C or more above the solvus-and the quench is considered to have preserved the high-temperature structure except for the condensation of lattice vacancies into dislocation loops.&apos; The 0.06 pct Cu alloy did not appear unstable in respect to slow precipitation reactions at room temperature since two pairs of tests failed to show significant differences between specimens heat treated 3 1/2 years earlier and specimens heat treated 1 or 2 days before.

Jan 1, 1962

By W. A. Oates, J. A. Lambert, P. T. GaIIagher

Monte Carlo methods have been used to compute the arrangements of interstitial atoms dissolved in tetrahedral sites in bcc lattices. It is assumed that the presence of an interstitial atom "blocks " a certain number of neighboring sites and prevents their occupancy. Sites "blocked" by more than one filled site are allowed for. The computed values of. the mean occupation number (defined as the ratio of the total number of sites blocked to the number of solute atoms are used to calculate the configurational entropies of the solutions. These entropies are compared with those resulting from previous theoretical studies of this problem and also with available experin~ental data for the p Zr-H, Nb-H, V-H, and Ta-H systems. Evidence is also given that the "blocking" explanation of low limiting compositions in these systems, rather than this being due to initial limitations on the number of sites available, is probably correct. THE ideal partial configurational entropy of mixing of an interstitial solute in a metal is given by: where p is the number of interstitial sites per metal atom and Xi is the atomic fraction of the interstitial. For the bcc lattice. which we shall be concerned with in this paper, the interstitial positions are shown in Fig. 1. It can be seen that for the tetrahedral sites, p=6. whereas for the octahedral sites, p = 3. Different emphasis has been placed on the relative importance of energy and entropy effects in determining deviations from ideality in interstitial solid solutions. In some cases the same system, e.g., Fe-C, has been described by the contradictory regular and athermal solution models indicating that the enthalpy and entropy functions, derived from equilibrium data, are frequently not accu.rate enough to differentiate between these treatments. However, for certain metal-hydrogen solutions the equilibrium data is available over sufficiently wide ranges of temperature and composition to permit a reasonably accurate determination of the compositional variation of the heats and entropies. Hoch&apos; has attempted to interpret the results of interstitial solid solutions in terms of a regular solution model. In the case of the Ta-H system where 13 = 6, this model entails fitting the experimental relative partial entropies of solution, asH, to the equation: where ASgs is the relative partial excess entropy of solution of hydrogen. Hoch found that the results of Mallett and Koeh1 could be fitted to this equation with an approximately constant value of AF up to XH = 0.25. However, it is apparent from the solubility isotherms in this system which become asymptotic to the composition TaH that, since (Xh /6 - ~Xh ) becomes infinite only at TaH6, it is necessary that AS<&apos; tends to infinity at TaH. In other words, the low saturation composition of TaH, instead of the anticipated TaH,, eliminates the possibility of applying regular solution theory to such systems. Rather large negative excess configurational entropies must exist at higher hydrogen concentrations in order to explain the lower saturation values. To account for these low limiting compositions and excess entropies two distinctly different approaches have been followed. Rees and many others1-l2 have assumed that not all interstitial sites are crystallographically equivalent with respect to the interstitial addition; that is, in Eq. [I] p is less than the value anticipated from geometrical considerations. To describe, say, a bcc metal-hydrogen system with a limiting composition of MH by this approach one would consider that p = 1 in the first instance instead of p = 6.&apos;j3 In some cases, nonintegral values of B have been taken in order to improve the fit with the experimental data over limited ranges of composition. The other approach which has been used to explain the low saturation compositions is to assume that, although all sites are available for occupancy, strong repulsive interactions exist between the neighboring interstitial atoms, and hence occupancy of any site excludes or blocks a certain number of neighboring sites from being occupied. Earliest treatments of this concept considered the exclusion of an integral number, of nearest-neighbor sites from being occupied at all concentrations. In this case, the partial configurational entropy is given by: These early treatments failed to allow for the overlap of the blocked sites which will arise at all but the very lowest concentrations. More recently attempts have been made to calculate the effect of this decrease in the number of blocked sites on the configurational entropy. Using the quasichemical treatment of interstitial solid solutions as given by Lacher and assuming that an infinite repulsive interaction energy existed between the solute atoms. atom obtained an approximate configurational entropy applicable to the blocking with overlap case:

Jan 1, 1970

By E. Buehler, H. J. Levinstein

The temperature ranges in which the three inter-metallic phases in the Nb-Sn system form have been determined and the composition and structure of two of the three phases has been established. The kinetics of the formation of Nb3Sn in cored wire samples has been studied in the temperature range of 800° to 1050°C. From 800°to 950°C the rate of formation increases by four orders of magnitude. The rate-controlling step for the formation process in this temperature range appears to be the diffilsion of tin through NbSn. At higher temperatu~es a change occurs in the mechanism of the formation process such that up to a temperature of 1050°C the rate of formation of Nb3Sn does not increase above the rate observed at 950°C. For temperatures helow 950°C the current-carrying capacity of the wire increases with increased percent reaction reaching a maximum value when the formation process is 90 to 95 pct complete. The maximum current-carrying capacity obtainable in this temperature range is independent of the temperature. Above 950°C tlze current-carrying capacity obtainable in the wire decreases with increasing temperature of formation. A model is proposed which accounts for the ohserved behavior. RECENTLY, Buehler et a1.l reported the results of an investigation of the process variables which influence the superconducting properties of Nb3Sn-cored wire. These results indicated that at least four variables affect the properties of the manufactured wire. These include composition, particle size of the starting powder mix, temperature of heat treatment, and time of heat treatment. In order to understand completely the role of these variables, it is necessary to have an accurate knowledge of the phase equilibria in the Nb-Sn system. At the present time, phase-equilibrium diagrams for the Nb-Sn system have been published by a number of investigators.2-5 The diagrams differ as to the number of phases present, the composition of the phases, and the temperature range of stability of the phases. The present investigation was undertaken in order to resolve these differences. Since the investigation of Buehler et al. demon- strated that the length of time at the temperature of heat treatment affected the superconducting properties of Nb3Sn, it is apparent that it is necessary to understand the kinetics of the formation process as well as the equilibrium conditions before a complete understanding of the system is possible. As a result, the kinetics of formation of the various phases in the system were also studied in this investigation. EXPEFUMENTAL PROCEDURE Diffusion couples and sintered powdered compacts were employed in the phase-diagram investigation. The diffusion couples were made by filling 1/8-in.-ID monel-sheathed niobium tubes with tin. The monel sheath was employed to facilitate drawing.&apos; The tubes were then drawn to a tin-core diameter of 32 mils. Samples approximately 3 in. long were then cut from the drawn composite. The tin was drilled out of the ends to a depth of 1/4 in. and niobium-wire plugs were inserted into the ends and peened over. The monel was removed by etching in concentrated nitric acid, after which the samples were sealed in evacuated quartz bulbs and heat-treated in a resistance-wound tube furnace. The samples were quenched into ice water upon removal from the furnace. The diffusion couple samples were examined metallographically employing a chemical etching solution consisting of 10 ml of saturated chromic acid per g of NaF. In addition, two anodizing solutions were used for phase-identification purposes. The first was the picklesimer7 solution; the second consisted of equal parts by volume of 30 pct H2O2 and concentrated NH4OH to which 1 g of NaF was added per 25 ml of solution. The anodizing conditions for the second solution were 2 v and 100 ma with a tin cathode. The powdered compacts were made by pressing previously mixed powders of 99.9 pct pure Sn and 99.6 pct pure Nb supplied by the United Mineral Co. into cylinders 3/8 in. in diameter by 1/2 in. long. The cylinders were then sealed in quartz tubes and heat-treated in the same manner as the diffusion couples. The samples were examined metallographically and by X-ray diffraction techniques. Since it was desirable to be able to correlate the kinetic data with current-carrying capacity, the type of specimen chosen for this part of the investigation had to be a compromise between the optimum system for studying kinetics and one which was suitable for making current-carrying capacity

Jan 1, 1964

By T. G. Digges, C. L. Vold, M. R. Achter

A study was made of the effect of the growth conditions on the perfection of single crystals of niobium (columbium). Dislocation densities, determined by means of double-crystal diffractometer measurements , were not greatly affected by the method of crystal preparation but could be reduced by annealing treatments. However, the size, sharpness, and tilt angles of the substructures, observed with X-ray reflection macrograph, were sensitive to variations in growth procedures as well as to subsequent thermal treatments. Although the dislocation density was the same in both types, there were more low-angle bound-aries in crystals grown by zone melting than in those prepared by strain anneal. Mechanisms to account for these observations are discussed in terms of dislocation movements. A planned study of the structure-sensitive properties of refractory metals required the use of single crystals of a high degree of structural perfection and, for ease of handling, of large cross section. It appeared that the strain-anneal technique could satisfy both of these requirements. First, crystals grown in the solid state have been reported to be more perfect than those obtained from the melt.&apos; Second, the diameters of rods which may be produced by zone melting should have a theoretical limit determined by specific gravity, thermal conductivity, and surface tension, while the diameter of strain-annealed rods is limited only by practical considerations. Previously it was shown that niobium (columbium) single crystals of 1 in. diam2 may be grown by strain anneal, compared to the 0.5 in. maximum diameter achieved by zone melting, as reported for molybdenum by Belk.3 The current research was undertaken to investigate and optimize the effect of various process variables on the perfection of 1/4 and 1/2-in.-diam niobium single crystals grown by strain annealing and to compare their perfection to those grown by zone melting. Characterization of these crystals was more conveniently accomplished by means of X-ray than by metallo-graphic techniques. EXPERIMENTAL PROCEDURE Specimen Preparation. Zone-melted crystals of 1/4 in. diam were produced by the standard electron-beam zone-melting technique. The swaged and cleaned rods were outgassed, in the solid state at a temperature near its melting point, at a rate of 12 in. per hr, and single crystals were grown by making two molten passes at 2 in. per hr. By maintaining a zone length of 4 to % in., very uniform single crystals several inches long were obtained. For the strain-annealed crystals, an induction heater was used, in preference to other types of heating, to take advantage of the good penetration of large sections. A five-turn coil, 1 in. long, operating at 10 kc and powered by a motor generator, was contained in a vacuum chamber. The rod, suspended from the upper end, was raised through the coil for both recrystallization and crystal growth. In preliminary work single crystals of the same material were also grown with single and multiturn coils powered by a 450-kc generator. A vacuum of 2 X 10-6 Torr was maintained at temperatures up to 2400°C. Starting with electron-beam-melted ingots of 21/2 in. diam, the analysis for which is given in Table I, the material was cold-swaged to the desired cross section of 1/4 and 1/2 in. diam and then recrystallized. The rods were then strained in a tensile machine and converted to single crystals by passing through the induction coil. As with zone melting, control of orientation is possible by the use of special procedures. Other investigators, see for example Williamson and smallman,4 have reported that orientation control may be achieved by a bending technique. In the present work the strained rod is partially lowered through the coil to start the growth of the crystal. Then it is removed and bent at a point in the poly crystalline portion. Finally, it is returned to the chamber and growth is continued "around the corner". This procedure has certain limitations. If the bending operation exceeds the critical strain, recrystallization may take place. Also, the amount of bending which can be imparted to the rod is limited by coil geometry, and up to now has been 10 deg. However, by repeating the bending and growing operations it should be possible to attain any desired orientation. In preparation for X-ray examination, single crystals were sectioned and planed by means of the spark-erosion technique. To obtain the maximum reflected intensity, the (110) plane was exposed for examination. They were then etched 3 to 5 min in a mixture of con-

Jan 1, 1967

By C. J. Guntner, R. P. Reed

A commercial 18Cr-8Ni iron alloy (AISI 304L) was examined in tension at 300°, 76°, 20°, and 4°K. Continuous stress-strain recordings were made, X-ray analyses at periodic stress (strain) intervals were obtained, and the magnetic measurements were taken. From this data the percentage of martensitic products [bcc(a) and hcp (E)] was computed as a function of stress (strain). It was found thatup to 15 pct E phase forms at low temperntures. The amount of E formed increases to a maximum at about 5 pct strain, then decreases. This decrease indicates the additional transformation of E to a&apos;. The total amount of E and a&apos; was suppressed at constant stress (strain) at 4°K as compared to 76°K. It is proposed that the suppression of E and a&apos; is associated with the decreased mobility of extended dislocations at very low temperatures. The yield strength decreased as the temperature was depressed below room temperature and then increased rapidly near 4°K. SOME ferrous alloys which are austenitic (fcc ?) at room temperature appear to be unique in that two martensitic products (hcp e and bcc a&apos;) may form on cooling to lower temperatures or on application of mechanical stress. The most common room-temperature austenitic ferrous alloys are 18Cr, 8Ni stainless steels. Most aspects of the spontaneous transformations have been previously described for these steels.&apos; Several previous papers have described special aspects of the stress-induced transformations at low temperatures for the stainless steels, such as the existence of the hcp phase (c) after straining at 76oK,2-7 the morphology after straining using electron microscopy,7 and the decrease in E at higher strains at 76oK.4 However, for a complete representation, one must know the stress-strain characteristics and the dependence of both martensitic products on applied stress and temperature. It is the intention of this paper to provide that documentation. To accomplish this, continuous stress vs strain recordings were made at four temperatures: 300°, 76", 20°, and 4°K for annealed AISI 304L (a commercial 18Cr-8Ni alloy). At periodic stress intervals at each temperature the integrated X-ray line intensity of a selected peak for each phase (y, E, and a&apos;) was measured. In addition, photomicrographs of the strained surfaces were taken and magnetic measurements were made. The magnetic readings can be directly converted into percent a&apos;.&apos;,e With these measurements the percentage of each phase may be plotted as a function of stress (or strain) and test temperature. It was found that up to 15 pct E phase forms upon stressing the AISI 304L alloy at low temperatures. The E percentage increases abruptly after the alloy yields, but then decreases gradually at higher stresses. The rapid increase in e at 76°K is associated with an "easy-glide" portion of the stress-strain curve. The total amount of a&apos; + .G is suppressed below 76°K at a constant stress or strain. The yield strength decreases down to 76°K but increases rapidly below 20°K. EXPERIMENTAL PROCEDURE Tensile test specimens were cut parallel to the rolling direction from 0.1-in.-thick sheet. Continuous stress vs strain recordings were obtained at each test temperature (300°, 76o, 20°, and 4°K) using equipment and methods described elsewhere.&apos; The specimens which were used in the X-ray analysis were stressed to successive increments of strain at each temperature, analyzed at room temperature, then restressed at the test temperature. This procedure was repeated until approximately ten X-ray analyses had been performed with approximately 1.0 pct strain increments. The specimens had a reduced section 1 in. long, 1.2 in. wide, and 0.1 in. thick. They were electro polished prior to testing and after each strain increment. Table I lists the chemical composition, grain size, and hardness for the alloy which was used. This is the same alloy for which extensive mechanical-property tests3 and morphological studies of the spontaneous transformations&apos; have previously been made. For the low-temperature tests (76o and 4°K) below the Ms temperature the specimens were initially cooled to the test temperature, held for 1/2 hr, then warmed and X-rayed at room temperature. The results are listed in Table 11. From earlier work8 it was known that additional transformation on the second cycle would be considerably less (-0.1 pct

Jan 1, 1964

By H. S. Geismer

INTRODUCTION. THERE are three general methods available for obtaining commercial brown iron-ore : hand-screening; washing; and washing and concentrating. Hand-screening has produced a large tonnage of ore in the past, but is rapidly falling into disuse, except as a preliminary step, largely because modern furnace-practice requires all foreign material to be separated from ores before they are delivered to the furnace, and hand-screened ores can rarely be made to fulfill that requirement. Another argument against hand-screening is, that the waste-pile often contains as much ore as the screen recovers. The operation known as hand-screening consists of throwing the ore-bearing material against a stationary inclined screen of 0.5- to 0.75-in. mesh, similar in construction to the screens employed in sand-pits. The recently-prospected brown-ore deposits of Cuba seem to offer possibilities for hand-screening not possessed by the average American deposit, since these ores are not associated with worthless clays. Washing, and washing and concentrating, may be discussed together, since concentrating is never practical on brown iron-ore, except to treat ores that have already been washed. (Strictly speaking, washing might be classed as concentrating, but it is never so designated by brown-ore men.) The various steps of removing ore-bearing material and converting it into ore suitable for blast-furnace use, may be grouped under five heads: loading for transportation ; transporting ; feeding into the washer; washing; and concentrating. These five subjects will be considered in consecutive order. Each of these successive steps may be accomplished in a number of different ways, the choice depending entirely upon the character of the ore-bearing material to be treated.

Aug 1, 1911

mean to say that these explosions are mechanical, but that the ejectment of the stock, throwing out of tops, etc., are mechanical. I see no reason at present, although I have had almost no experience in the use of large quantities of Mesabi ore, to change my ideas on the subject. That these explosions should follow irregular working or slipping in the furnace, I think can be explained. I have noticed that immediately following slips there is little or no settling of the stock on top, although there is no lessening of the volume of gas passing into the stoves and boilers. Supposing that, after a slip of 3 or 4 feet, the filling continues, but for some distance from the &apos;top the stock fails to move: there would be a much better chance for the deposited carbon to clog interstices in the stock, and for the additional effect in the same direction of the fine ore in the charge, than if the stock were properly settling. Under such conditions it is easily supposable that the openings would be entirely closed, or closed so tightly that the pressure below the obstruction would be raised to a point approaching the blast-pressure, or to a point high enough to force a passage or an enlargement of the small passages which may remain. When this occurs, gas from below under pressure carries with it large quantities of deposited carbon and fine ore; if the case is aggravated, coke, stone, bell, etc. As soon as the red-hot deposited carbon meets the air there are perfect conditions for a dust explosion, which naturally follows, the same as in a coal-mine or flour-mill.

Jan 1, 1899

"The Southern Cross mining district was discovered during the early rush of gold seekers over Montana following the discovery of gold in 1861. Placers were worked near the Atlantic Cable mine in 1866, and soon attention was turned to quartz lode mining. High grade ores were discovered in the North Atlantic claim, adjoining the present Southern Cross group. The early metallurgical treat¬ment of these ores was by means of arrastres, a crude form of amalgamating mill, illustrated on the page opposite. This old arrastre located by the roadside on Warm Springs creek, was built by Barker Bros. in 1879. Further discoveries overtaxed the capacity of this plant, and in 1875 Thomas' Stuart employed a contractor named Jeptha J. Corner to convert the old Wilson & Fifer sawmill located at the Big Spring into an up-to-date gold quartz mill. 'For this trans¬formation Corner received the sum of $1,400.00. The illustrations give a good idea of the nature of its construction. Practically no iron was used in the mill, excepting for the stamps, dies and cams and cam shafts. Whether or not the saving attained reached the limits of present day perfection is not known. There being no steam boilers available, the early prospectors believed in the principle of conservation of fire wood, water power was therefore used, generated by a ""direct-connected"" over-shot wheel. Water for power purposes was supplied by the nearby spring. History fails to record the tonnage treated in this relic of early Montana milling practice.The ores of the Southern Cross district have not proved readily amenable to mill treatment, but being largely composed of iron oxides, they are most desirable fluxing ores for smelter operations. The B. A. & P. Ry. extends into the district. Electric power is furnished by the Flint Creek 'station, three miles distant."

Jan 1, 1913

By J. L. Jones

1. Brinell tests at progressively increasing temperatures are given for a representative lead-base and a representative tin-base babbitt, showing that the former has superior resistance to deformation at the working temperatures of bearings. 2. Small squares of bearing bronze, tinned and then babbitted with a representative lead-base babbitt and a representative tin-base babbitt were subjected to compressive loading. The lead-base babbitt showed less average compression than the tin-base babbitt. Compression did not materially increase the Brinell hardness of the babbitts. 3. A process and a tool are described for giving smoother and more accurate surfaces to bearings than has heretofore been possible. The following experiments have recently been carried out in the chemical laboratory of the Westinghouse Electric and Manufacturing Co., Pittsburgh, Pa. While the work is incomplete, it is described at the present time because data on the comparative merits of lead-base and tin-base babbitts are of interest in connection with the present shortage of tin. BRinell Habdness of Babbitt at Increasing Temperatures Bearings fail because of wiping, or deformation. Hence tenacity is desirable in a bearing metal, especially tenacity at high temperatures. The Brinell test is commonly regarded as a measure of tenacity. In fact, it has recently been proposed to substitute for Brinell hardness number the expression " tenacity number."l It seemed, therefore, that the Brinell test was especially adapted for the tests described. Disks, 4 in. (101 mm.) in diameter and 1.5 in. (38 mm.) thick, were made of the babbitts to be studied, designated A, B, C. They were poured into metal molds, pyrometer leads being soldered in the center of each disk. The composition of the babbitts was as follows:

Jan 1, 1919

By H. A. Bedworth, W. H. Bassett

The amount of oxygen present in refined copper bears an important relation to the effects of various impurities on physical properties of copper, as well as the effects of reducing gases at higher temperatures. It seems fitting at this time, when the effects of reducing gases on copper are being discussed, to describe methods that have proved satisfactory for the determination of oxygen and sulfur, and to present some results obtained by investigation of these methods in the authors&apos; laboratory. The procedure for the determination of sulfur is closely interrelated with that for oxygen and has, therefore, been included. It was first proposed by Hampe1 that oxides in copper could be accurately determined by the loss in weight sustained by finely divided copper when reduced at red heat in pure hydrogen, or by the weight of water produced. Hampe&apos;s method was later modified by Archbutt,2 who established the accuracy of the method and demonstrated that equally accurate results were obtained by noting the loss in weight or by weighing the water formed. The determination of oxygen by heating in carbon monoxide has been proposed by West.3 In our hands this method has given slightly lower results than obtained by heating in hydrogen. Heath4 found that the loss in weight after heating in hydrogen did not represent the true oxygen as cuprous oxide but included also gases derived by the metal from the fuel and refining in the furnace, and any trace of mechanically held moisture. He found, further, that the copper after ignition retained hydrogen equivalent to about 0.01 per cent. Heath proposed to determine the amount of occluded gases by preliminary ignition for 20 min. in pure carbon dioxide—and to correct the error caused by absorbed hydrogen by subsequent ignition and cooling in carbon dioxide, finally replacing this gas with air.

Jan 1, 1926

For convenience, we tabulate below the weight systems contained in the Probierbüchlein: [Pound and centner weights used by merchants for ore, lead, and copper I frother = 20 or 50 centners (depending on locality) I centner (Stolberg & Eisleben) = 112 pounds. I centner (Nuremberg) =100 pounds I pound =2 marks =32 lot =128 quintlein-512 pennyweights =1024 beller I mark -16 lot -.64 quintlein =256 pennyweights = 512 beller 1 lot= 4 quintlein= 16 pennyweights= 32 beller I quintlein = 4 pennyweights= 8 beller I pennyweight = 2 beller Netherlands mintmasters&apos; weights for silver I mark =12 pennyweights=288 grains I pennyweight - 24 grains Assay weights for gold I mark= 24 carats 96 carat-grains. I carat = 4 carat-grains] The assayer&apos;s weights were miniature copies of the legal weights of his locality, intended, like the modern assay ton, to eliminate calculation. Each assayer made his own, not usually bothering about a given proportion between the true weights and the assay set, but maintaining the correct ratio between all the weights in any one set. The weights were quite small, to permit the use of less sample, but the exact size is nowhere stated in the Probierbüchlein. Even the legal pound varied considerably from place to place, depending on locality, and assayers would use different factors depending on the sensitivity of their balances, among other things. Agricola makes the assay centner equal to one actual drachma, by which term he means the German quintlein, or 1/12,800 of the full weight of the 100-pound centner. Schreittmann says that the 100-pound centner on the assay scale should be less than half a quintlein, i.e., the factor should be at least 25,600. Biringuccio says the assay centner might

Jan 1, 1949

John R. Lucas was born Apr. 15, 1866, at St. Louis, Mo. From his 19th year until his death on his 51st birthday anniversary, he was engaged in the mining industry, in which, however, he made his beginning and achieved his progress after a somewhat unusual fashion. Presumably without previous training as a mining engineer, he became in April, 1885, and remained until the end of 1892, bookkeeper of the Granite Metal Mining Co. at its St. Louis office. Then for a year he served as bookkeeper of the same company at its mine in Montana. This official of a mining company is at the very heart of its operations; and if he possesses ambition and intelligence, may learn the business thoroughly. It is not surprising, therefore, that Mr. Lucas, being that kind of man, assumed, in 1894, a position with the Hope Mining Co., another St. Louis corporation operating in Montana, which he retained for eight years, serving not only in the office, but becoming also successively mill foreman and assayer. This varied practical experience prepared him for important administrative functions. From April, 1902, he was for many years the business agent of the Goodhope Mining Co. In 1903, he became also the assistant superintendent of the Granite Bi-metallic Consolidated Mining Co., and subsequently its superintendent-a position which he retained until his health failed at the end of 1916. In addition to the other Granite Bi-metallic properties, he had charge of the sapphire mines in the west fork of Rock Creek, Mont., the Basin Gulch placer mines, the claims of the former Hope Co., etc., all of which he managed with skill, integrity and recognized business ability.

Jan 6, 1918

DURING the month of March there was some lifting of the veil, revealing somewhat of the maelstrom in the economics and politics of the world. Great Britain was in throes of political controversy, with threats of resignation by Lloyd George and a general election to ensue. Ireland was uneasy with internecine squabbles. The leaders of the opposing sides have been summoned to London for a conference which Parlia-ment believes offers the only hope of a solution of the present difficulties. France, awakening more and more to grim realities, learned of a budget for 1922 calling for more than 50 billion francs, or nearly one-third of the estimated national production, with the prospect that after this deduction is made there will be nothing left over what is required for the immediate support of the, people, and that on a reduced scale. Germany, although hard at work, found itself coming closer and closer to financial collapse and repeated its intimations that it would be unable to keep up with the provisional payments of 31 million gold marks to the Reparations Commission every 10 days as arranged at Cannes. Russia suffered more acutely from the famine and there were evidences of political insubordination among the Ukrainians. Egypt was in trouble arising from determination to win independence. About the middle of March the complete independence of Egypt was established and that country passed into somewhat the same relation-ship toward Great Britain that Panama has to the United States. At the head of the Adriatic, Fiume came into notice again with disorders threatening to produce conflict between Italy and Jugoslavia. In the Near East there were forebodings of trouble through resumption this spring. of the war between Greece and Turkey.

Jan 4, 1922

By W. S. Ayres

I AM well aware that this subject is not strictly in the line of mining engineering, yet as it is a subject with which mining engineers at times have something to do, I have thought, perhaps, it might not be wholly out of place to communicate to the Institute something of the method used in determining deflection, and of its final issue. Having felt a need of some simple formula for determining the deflection of girders of uniform cross-section under any load, I have been led through the counsel of Mr. Frederick J. Slade, to whom I am indebted for many suggestions, to undertake a labor of which I shall in this paper give only some of the most important features. The results arrived at agree with those obtainable from the received formula; of Weisbach, Rankine, and others, but the expressions given by these authors, and by all others that I have at hand, are of such a form that they are not easily applied by those whose higher mathematics have become rusty from disuse, and they require, moreover, too much labor in their application to be of practical value. The general formula that I have adopted is similar to that given by Rankine, and is deflection = [mWl3 -El], in which l is the span, W the total load, E the modulus of elasticity, I the moment of inertia of the uniform cross-section of the girder, and m a factor depending for its value on the mode of distribution of the load. The problem then is to find the value of this factor m in the formula, and for some distributions of the load it leads to a number of mathematical difficulties. In this place I shall consider first the girder to be loaded symmet-

Jan 1, 1877

By A. B. Parsons

PUBLICATION of this little volume is a luxury that the Institute itself could scarcely afford. In truth, no engineer nor geologist, no assayer nor metallurgist would be likely to enhance his knowledge, improve his technique, or cut his own operating costs by reading this excellent translation of two booklets first published circa A.D. 1520. It is doubtful if the present enterprise would, in a practical or tangible way, "promote the arts and sciences connected with the economic production of the useful minerals and metals." And such, is the prescribed purpose for which the funds of the Institute should be spent. Fortunately for the Institute, the Seeley W. Mudd Memorial Fund is not so circumscribed; and the Fund Committee enjoys, greater liberty of action. The sponsorship by the Mudd Fund in 1942 of the publication of The Pirotechnia of Vannoccio Biringuccio, as translated by Dr. Smith and Mrs. Gnudi, was an innovation-indeed something of an experiment. Not only was the content of the volume significant mainly for its "cultural" and "scholarly" attributes; -but the format, an outstanding example of the fascinating art of bookmaking, bore no resemblance to the ordinary technical book. The Committee, frankly, was surprised at the enthusiastic reception accorded the volume. When a second edition was required, the Committee became convinced that the publication of material of this type, particularly if printed and bound in attractive form, was an appropriate avenue for utilizing a moderate proportion of the monies available from the Fund. The Bergbüchlein and the Probierbüchlein antedate by some years the first publication of De la Pirotechnia and of De re Metallica; but Georgius Agricola, the author of the latter work, made good use of the material in the earlier volumes. As pointed out in the Introduction, both

Jan 1, 1949

ON July 2 the Krupp plant in Essen was occupied by the French. The City of Frankfurt, on the edge of the Mayence Bridgehead was surrounded by the French. French infantry and cavalry occupied some more towns in the Ruhr. These moves were apparently in the way of reprisals. The Bank of England on July 5 raised its discount rate from three per cent. to four, per, cent., the lower rate having previously prevailed for almost exactly a year.. The advance appears to have been inspired by the reserve ratio, but especially owing to the fact that the low rate in the London market had led to the out-flow of funds from there to other markets. Philip Snowden brought up again in the British .Parliament his motion in favor of the condemnation of the capitalistic system and the substitution of socialism. The motion was put to vote and was defeated by large majority, only the members of the Labor party voting for it. The Allies and the Turks finally came to an agree-ment at Lausanne, the Turks getting about all for which they asked. It would be tiresome to record the details. The main fact is that the Turks, after having been ejected from Europe in 1918, are now going to return. Russia agreed to the settlement respecting the Straits. The Soviet Government of Russia formulated and adopted, subject to ratification, a constitution for the United States of Russia, which appears to be patterned after the constitution of the United States of America and the unwritten constitution of Great Britain. The important thing about this seems to be that it definitely reunites the constituent parts of the old Empire, the semi-independence of the Ukraine being surrendered.

Jan 7, 1923

By Robert E. Hochscheid

The subject article appears in the February, 1978, edition of Mining Engineering, and on page 190 carries the statement, "As most operators know, in a Water-Only cyclone, ability to adjust the vortex finder is quite important due to the sensitivity of this type of operations to variance in feed conditions and having to take them apart to make this adjustment is always a nuisance." Our experience as a manufacturer and supplier of Water Only cyclones does not agree with the above statement, and we offer the following brief discussion. Our company finds that the sensitivity of the Water-Only cyclone is a function of the fineness of the coal being washed, with the sensitivity to vortex finder length being greatest for coals coarser than 3/4-in. and virtually insensitive to raw coal finer than 1 mm. For coals finer than 1 mm, we find that we can use the shortest standard vortex finder in either our 10- or 15- in. Water Only cyclone without exception. For coals 5/8-in. x 1 mm ceramic vortex finders of fixed length have been satisfactory in all cases following an initial testing period in which the length was determined. Coals coarser that 5/8-in. are more sensitive to the vortex finder length, and two installations handling coals coarser than 1-in. continued to experiment with vortex finders of various lengths long after the initial startup period. For coals of all sizes, final adjustment of product quality has been achieved by determining the optimum size of apex orifice, which is accessible and readily changed, if necessary. Comments above assume no unusual change in the coal being washed or the required quality of clean coal.

Jan 1, 1979

By C. Max Bauer

THE most important development in the petroleum industry in Montana, during 1924, was the bringing in of the Hepp well on May 12, by the Midwest Refining Co. This followed three years of active prospecting and drilling in the state by this company. The well is located 35 miles west of Billings, in Stillwater County, and makes a high-grade paraffin oil from the Dakota sand at a. depth of 3825 ft. After flowing for several months at the rate of 150 bbl. per day, the well has been shut in for lack of storage, awaiting further development in the field. TABLE 1. Production Cat Creek and Kevin-Sunburst Fields Month Kevin-Sunburst Pipe- Estimated Cat Creek Pipeline Estimated line Runs Fuel Oil Used Runs Fuel Used January 3,214 0 133,400 140 February 3,250 0 134,248 490 March 11,989 595 163,129 910 April 116,897 1,155 125,918 980 May 179,726 2,310 152,179 770 June 126,131 2,697 122,270 910 July 132,173 2,170 118,034 770 August 202,001 2,695 142,313 1,120 September 187,201 2,135 110,012 350 October 162,589 1,995 121,683 350 November 130,392 2,520 139,900 350 December 107,465 1,780 124,169 0 Total 1,363,028 20,052 1,581,255 .7,140 There are two producing oilfields in the state-the Cat Creek and the Kevin-Sunburst, which produced a total of 2,971,475 bbl. in 1924. The only other field of proved value is Soap Creek, which contains a heavy black oil and is shut in for lack of marketing facilities. Gas is produced for local use at Havre, Chinook, and Baker, and a carbon-black plant is located at Baker.

Jan 3, 1925

Data about production are very meager. In this county from the earliest days until after the Civil War, the amount of coal used locally greatly exceeded that shipped on account of the iron produced; for many years the furnaces used raw coal for melting the ore. In 1846 it was stated that in this county one ton of iron required three tons of iron ore and three tons of local coal used raw.1 In 1864, eleven furnaces in Pennsylvania using 102,230 tons of raw coal produced 44,671 tons of iron, or 2.3 tons raw coal per ton of pig iron .2 This was probably as good a record as was made, as nearly all furnaces changed to coke some years later. Neither of these figures include the coal used for steam and other purposes around an iron plant. The Beaver and Erie Canal was opened in 1845 and the shipments shown from then to 1865, inclusive, are of coal received by the canal at Erie, and do not include any used at local points along the canal. From the completion of the Erie and Pittsburgh Railroad in 1864 the tonnage shipped by canal decreased. rapidly, and, while the canal shipments after 1864 are supposed to be those received at Erie by canal only, they may include some rail tonnages. Tonnages on Erie and Pittsburgh Railroad may, and probably do, include some used locally; those on the Jamestown & Franklin Railroad do not. It is likely that both canal and Erie and Pittsburgh Railroad figures include some coal originating in Lawrence County, and possibly a little from Beaver County. These tonnages are not duplicated in the data for either of the other counties. Not all of the railroad reports can be found now.

Jan 1, 1942

W. H. LINNEY, Chairman, OSCAR LACHMUND, Vice-Chairman LYNDON K. ARMSTRONG, Secretary-Treasurer, P. O. Drawer 2154; Spokane, Wash. STANLY A. EASTON, S. SHEDD. Mining camps from Mexico to Alaska and from the Pacific coast to the Atlantic were represented by delegates at the 5th Annual Northwest Mining Convention which was held in Spokane, Wash., Feb. 19-24, 1917. About 300 delegates from outlying regions were present, this being fully 100 more than have been counted at any previous mining convention in Spokane. Graham B. Dennis, president of the Northwest Mining Association, made the address of welcome. In part, he said: "Heaven has made us the possessors of an area great enough for an empire, varied enough in climate and possibilities to compass the whole complex field of modern industry. In the development of this broad heritage, we are not only actors for today, but trustees for future ages. "It is to foster this spirit of unity; to create and maintain strong bonds of mutual good will and confidence, that we founded the Northwest Mining Association. Wee support it because we believe it will give us strength; because we believe we shall learn from each other; because, in industry as in every other walk of life, personal contact and establishment of ties of friendship enrich and round out the characters of men." One of the interesting lectures of the week was that on "Alaskan and Russian Gravel Mining," by Dr.&apos; Henry Mace Payne, consulting engineer for the Russian government and Consolidated Goldfields of South Africa. Dr. Payne&apos;s illustrations showed the different appliances in use in the countries mentioned. The Resolutions Committee reported back to the Convention six of the seven resolutions that had been presented to it. These were adopted as submitted, with some minor changes.

Jan 5, 1917