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By E. E. Bach

STATEMENT OF THE PROBLEM THE administration of industrial organization today embraces more than the cost of production and selling prices. Competition is deeper seated than mechanical devices, overhead charges, and a shrewd manipulation of the markets. Despite the "down-to-the-minute" equipment and the "last word in organization," it is quite evident that "capacity production" will be an unknown quantity until the workman is considered as a producer, in relation to his home, as he is now considered in relation to industry. Whether or not a man shall do an honest day's work is as much a psychological condition as it is a matter of physical strength or skill. His attitude toward his work each morning is determined, to a large degree, by the environment of his home. Whether this attitude, good or bad, obtains the day through will depend entirely upon the one fact as to whether the corporation which employs him does or does not differentiate between the mechanical factor and the human factor in industry. To be more specific, sociological work, under whatever name, should be of such a character as to influence the life of a workman in such a manner as to establish a cooperative interest in his work, foster within him a spirit of contentment in his home, lead him-so to employ his leisure time that he will not lower his efficiency as a workman, destroy his domestic happiness, or endanger his standing in the community as a citizen. While no fixed rules of procedure can well be formulated for the development of the work, yet definite lines of activities will readily present themselves as applicable to the individual needs of a community. This is especially true where community influences and agencies pertaining to general welfare are easily correlated.

Jan 2, 1918

By F. A. Hames, D. S. Eppelsheimer

The ferromagnetic copper-manganese-aluminum and copper-manganese-tin alloys (Heusler alloys) owe their ferromagnetism to the beta phases (body-centered cubic structure) in their respective systems.l,2,3 The ternary beta phase regions in these systems are extensions of the beta fields of the binary copper-aluminum and copper-tin systems into the ternary models of the copper-manganese-aluminum and copper-manganese-tin systems respectively. X ray analysis has indicated the presence of long-range order in the more strongly magnetic alloys.3,4,5 The ideal ordered structure is obtained in alloys of compositions Cu2MnAl and Cu2MnSn; the copper atoms occupy positions at cube centers while the aluminum (tin) and manganese atoms alternate at cube corners. This atomic arrangement is illustrated in Fig 1. The compositions Cu2MnAl and Cu2MnSn are also those that show maximum magnetic saturation moment. 3,4,6,7 Departures from these compositions result in a decrease in the degree of order attainable and a decrease in magnetic saturation moment. In view of the chemical similarities of aluminum, tin, indium, and gallium, and the existence of beta phases in the binary systems copper-indium and copper-gallium, it may be suspected that ternary beta phases exist in the systems copper-manganese-indium and copper-manganese-gallium, and that these are ferromagnetic. The purpose of this investigation was to determine whether ferromagnetic beta phases exist in the systems copper-manganese-indium and copper-manganese-gallium analogous to the ferromagnetic beta phases in the systems copper-manganese-aluminum and copper-manganese-tin. Previous Work At the time this investigation was started no information could be found regarding the constitution of copper-manganese-indium and copper-manganese-gallium alloys, nor of the binary manganese-indium and man-

Jan 1, 1950

By Peter Nalle

12.3-1. Reporting. NEED. It seems almost unnecessary to comment on the need for reporting research and development results and activities, and yet much of the difficulty and misunderstanding surrounding a Research and Development (R&D) group results from poor or nonexistent reporting. Certainly no evaluation can be made without reports of results or plans. It is as important to report accurately and fully for the department's own use as it is for external use. Research unreported might as well be considered research undone. This section will discuss, in part, the need for reporting, the general types of reports which may be generated to satisfy the need, and finally, the evaluation of a project as judged by various commonly used standards. PURPOSE. Some specific observations might be appropriate concerning the reporting of R&D results. The requirements and background of the group receiving the report must be considered. A particular report is usually directed towards the background of a particular group, such as ((technical," "operational," "financial," or "marketing." It is essential that the emphasis and coverage be geared to the training of people receiving the report. It should be obvious that the financial department will be less interested in the technical details of the process and more interested in the capital funds and tax implications involved in the project. Operating personnel will be greatly interested in the effects of a new method on mining plans, and so on. This does not mean that the reporting in any way should slight pertinent details, nor should a patronizing attitude be assumed by the writer. However, it is essential that the needs of the reader be recognized. For reports that might have large and varied distribution, it is often feasible to group, either as sections or appendixes, the special details and information of interest only to certain functions within the organization. A

Jan 1, 1968

By K. D. Eigenbrod

A case history is presented of a landslide that occurred adjacent to a highway in the valley of the North Saskatchewan River, about 12 miles upstream of Edmonton, Alberta. The slide took place in the late fall of 1965 following excavations associated with highway improvements that deepened the slope and cut it back to 20º. The slide occurred in the Upper Cretaceous Edmonton Formation. Till covers the bedrock at the location. The bedrock consists of interbedded mudstone, claystone, and sandstone with layers of bentonite and coal. The field investigation consisted of a series of pits at the toe of the slide and seven boreholes around it. Undisturbed samples were taken with a Pitcher Sampler and piezometers were installed at various depths in the section. The slide had taken place on a horizontal bentonitic clay layer and it crossed softened mudstone in the back slope. Three piezometric levels were detected but no water pressures were found along the horizontal portion of the slip surface because it was in contact with a free-draining coal layer. Borehole evidence revealed that the bentonitic clay layer was sheared in place beyond the confines of the slide zone. Although this slide was a first-time occurrence, it was part of a much larger slide block that moved presumably when the valley was being formed. Laboratory tests were carried out to determine the shear strength parameters of the bentonitic clay and the back slope material. These parameters together with the observed water pressure distribution in the slide area gave a factor of safety of 1.01 in a non-circular limiting equilibrium analysis. The case history is particularly instructive in indicating the care that must be taken to obtain representative information for stability analysis when geological and groundwater conditions are non-uniform. The origin of the sheared clay is discussed.

Jan 1, 1972

By James Norman

DIATOMACEOUS earth occurs in deposits widely distributed throughout the nation. The chief producing areas are in the Western States, where many high-grade deposits are known. Eastern deposits of diatomite are unsatisfactory for many purposes either because of impurity or because of the extremely fine particle size. Eastern users of diatomite, on the whole, must pay for transportation of the material from the west coast. The freight rate is necessarily high because of the great bulk of the diatomite. A satisfactory process of purifying the diatomaceous earths of Maryland and Virginia, which are unsuited for wide use only because of impurities, should be of value to eastern users. In the past, benefication of diatomite by wet processes has been limited to classification or sedimentation for the removal of sand from diatoms. Calcination with salt is used to produce a white diatomite when iron is present in the impurities, and small amounts of clay are rendered inactive in the process. No treatment has been developed whereby a large proportion of clay can be removed from a low-grade diatomaceous earth to give a diatomite of very high purity. In August 1937 the Federal Bureau of Mines, in cooperation with Dr. R. C. Williams, of Baltimore, undertook the problem of purifying low-grade Maryland diatomite by froth flotation. Work was done at the Eastern Experiment Station, College Park. Unless otherwise stated, the crude diatomite used was from the Patuxent River deposits near Dunkirk. This material, consisting of roughly one-third each of clay, quartz sand and diatoms, was representative of the usual low-grade marine diatomite found in the Coastal Plain Miocene beds of Maryland and Virginia and sporadically in other Atlantic coast states. As received, it contained 50 to 60 per cent moisture and probably had been wet since its formation.

Jan 1, 1940

By C. S. Roberts, S. L. Couling

PLASTIC strain in polycrystalline metal as a result of bulk movement of one grain with respect to another along grain boundaries is not new. Rosenhain and Humphrey observed such effects shortly after the turn of the century.' Since then, observations of grain boundary deformation have been made on several metals. In recent years, intensive studies of the deformation at grain boundaries have been performed on polycrystalline metal and bicrystals.14-20 Aluminum or its alloys have been used in these latter studies. The subjects of controversy at present appear to be not whether grain boundary deformation exists, but 1) how quantitatively important it can be in polycrystalline metal, and 2) what its detailed mechanism is. Some investigators have concluded that such de- formation is minor in importance while others have concluded that it is a major consideration. Some have concluded that it involves shear of one grain over another at the interface while others have concluded that it operates by crystallographic deformation within the grains near ,the boundary. A categorical statement for electrolytic magnesium cannot be made on either of -these points. When polycrystalline magnesium is deformed in creep under conditions of high strain rate and low temperature, grain boundary deformation is relatively slight." Under these conditions, much deformation occurs within the grains and boundary contours change to a higher-energy jagged form. The result is shown in Fig. 1, where boundary jaggedness is pronounced upon polishing and etching after a plastic strain of approximately 6 .pct at 300°F and 3000 psi. No migration of the boundaries has been detected in this process. When the same metal is deformed the same amount at 600°F and 300 psi, resulting in a much lower strain rate, the boundaries migrate toward a lower energy configuration, where

Jan 1, 1958

By John C. Calhoun, F. W. Gooch, J. P. Everett

The results of two sets of displacement experiments are reported. In the first set of experiments various solutions of sugar in water were displaced by other solutions of sugar in water. In the second set oils were displaced by water. Each set of experiments was performed on a linear system made of cemented silica sand grains. These displacement tests were made to evaluate the behavior when the ratio of fluid viscosities between the displacing and displaced phases was varied. A further consequence of the test results is a comparison between displacement behavior when the displaced and displacing phases are miscible as with sugar solutions and when they are immiscible as with oil and water. INTRODUCTION Buckley and Leverett1 have presented a theory for the displacement of oil by gas or water based upon the relative permeability concept. This theory presents the displacement of oil as occurring in two phases, an initial or primary phase preceding the breakthrough of the displacing phase and a subordinate or secondary phase during which both oil and the displacing phase flow simultaneously through the same porous section. These authors gave the results of calculations to show that the percentage of oil displaced during the primary phase by water drive would be dependent upon the ratio of the viscosity of the oil to that of the water. No experimental evidence was reported by these authors to substantiate their theory. Qualitatively, however, it has been found to be in agreement with many observed field results. Laboratory investigators have been in general agreement in reporting for air or gas drive2,3 a small primary phase of production and a large secondary phase. Reported investigations on water drive3,4,5 have shown instances where both primary

Jan 1, 1950

By D. V. Carter, Dan C. Williams, Franklin M. Hackbusch

During 1939 little of consequence happened in East and East Central Texas in the way of oil discoveries. At the end of the year, there were 47 oil and gas fields in the district. Twelve other fields, 11 oil and one gas, have been abandoned. The ranking fields in order of the number of completions for the year were East Texas, Talco, and Rodessa (Texas portion). There were 511 oil wells (distillate wells included), 32 gas wells, and 257 dry holes completed in the district. Exploration, Discoveries and Extensions During the year, 113 exploratory wells were drilled, the same number as in 1938; four oil fields and one gas-distillate field were discovered. Perhaps the most important discovery, which has been named Barron field, was that of M. Samuel et al., No. 1 Barron in Limestone County. The wells in this field are of the gas-distillate type. Other than the Talco and Sulphur Bluff fields, which produce oil from the Paluxy sand (Upper Trinity), this is the first field on the Corsicana-Mexia fault zone to obtain commercial production from deeper Trinity strata. This "pay" is the Petit lime of the Lower Glen Rose of the Trinity group. The four oil discoveries were: Redland, Angelina County; Bazette, Henderson County; Rowe and Baker, Henderson County; and Marion County Shallow in Marion County. It is believed that the Bazette field, Navarro County, represents an extension of the Flag Lake field. For details concerning discoveries, extensions and important wildcat wells drilled during 1939 see Table 2. Production and Proration The district produced 175,053,729 bbl. of oil (distillate production included) which is a decrease of 4.0 per cent from the 182,369,484 bbl. (distillate production included) produced during 1938. The district's production for the year 1937 was 208,594,453 bbl. The East Texas

Jan 1, 1940

By C. Erb Wuensch

The Eagle mine is situated in the Kerber Creek mining district, Bonanza, Saguache County, Colo. The climate and topography of this district arc similar to those of mining camps of the Rocky Mountain region that lie 9000 to 12,000 ft. above sea level. The district is at the northeasterly edge of the San Juan volcanic region, in which successive Tertiary lavas have built up a high plateau resting upon earlier sedimentary formations, or the underlying pre-Cambrian complex. The latter was exposed in places by erosion previous to the eruptions. In the Bonanza district, proper, only volcanic formations, andesites and latites, are found. Dr. H. B. Patton,1 in his survey of the district, discriminates between several varieties of lavas and maps these as distinct flows. They are local variations within the same lava and it is impossible to determine any distinct line of demarkation between them. Structurally they are members of the same flow. There are three general types of vein occurrences: 1. Lead-zinc-copper-silver-gold veins in well-defined fissures with a quartz gangue; ill these, the various sulfides show a zonal arrangement. 2. Massive gray copper ores high in silver, in irregular fractures in the form of small lenses and pockets, in which little or no quartz is found. 3. Manganiferous quartz veins very low in silver and gold at the surface which, with depth, become important silver veins containing subordinate amounts of gold. These veins have a quartz gangue with an abundance of Phodochrosite. The silver is associated with small amounts of sphalerite, galena, and pyrite; fluorite also is present. The Eagle is the only mine that has been developed in the manganiferous quartz type of vein. It was discovered ill the fall of 1582, but little more than assessment work was done on the property for a number of

Jan 1, 1923

By J. E. Pogue

It is the purpose of this paper to attempt to establish three theses which may be stated in advance as follows: 1. The crude oil potential is the accumulation of surplus initial production. 2. The crude oil potential is a semi-inventory and therefore is a causal factor in the price of crude petroleum. 3. The price of crude petroleum no longer correlates with above-ground inventories but does correlate with corrected inventories (i. e., above-ground storage plus the inventory equivalent of the crude oil potential). The factors and principles set forth in this study are thought to yield an approximate answer to a number of questions of active interest in the petroleum industry today, to wit: (a) How long would be required to eliminate the potential if all drilling ceased? (b) What would be the indicated crude oil production of the United States in 1931 if proration were abandoned? (c) What economic change would be necessary to warrant a higher price for crude oil? Definitions For the purposes of this study the following definitions may be stated: The crude oil potential in the United States is the quantity of oil that all the oil wells would make the first 24 hr. if permitted to flow unrestricted. The surplus potential is the above-mentioned quantity minus the volume currently produced. Initial production is the first day's unrestricted flow of an oil well. Aggregate initial production is the sum of the initials of all wells completed during a year. Surplus initial is the initial not needed to bring production into balance with demand. The surplus initial is equal to the crude oil potential minus the current rate of production. The annual production-equivalent of the crude oil potential is the volume of oil that would be produced in one year if all wells were permitted

Jan 1, 1931

By Samuel S. Arentz, Dorsey A. Lyon

Introduction % •................. 789 The Present Sources of Zinc ..:.......... 791 Zinc Ores.................. 791 Lead-Zinc Ores................. 793 Loss oF Zinc at the Mine.............. 793 Present Method oF Extracting Zinc From Ores....... 795 Class oF Ores Suited to Zinc Retort Smelting....... 795 Concentration Processes Used for Treating Zinc Ores .... 795 Hydro-Mechanical Processes............. 795 Electro-Mechanical Processes............. 796 Flotation Processes............... 797 Losses of Zinc in Lead and Copper Blast-Furnace Smelting .. 798 Possible Future Sources oF Zinc Supply.......... 800 The Problem oF the Metallurgist and the Present Status of New Processes................. 801 Introduction A great deal of attention has recently been given to the metallurgy of zinc, and much of that which has been said and written on this subject has been in the nature of a criticism. For instance, we are quite accustomed to hearing it said that the metallurgy of zinc has stood still, that it is antiquahed, out of date, etc. We are, however, inclined to agree with George C. Stone1 when he says that, although there have been no such spectacular and radical changes as were worked in the metallurgy of copper and iron by the introduction of converters, there has nevertheless been a decided and marked progress in the metallurgy of zinc, and especially during recent years. However, it must be admitted that, due to the fact that the chemistry of zinc is so different from that of the other metals, the retort process is the only process by which zinc is produced commercially; and, moreover, that losses which occur in the zinc industry— that is, in the mining, milling, and smelting of zinc ore—are very great, for it is stated2 that probably less than 50 per cent. of the zinc mined, even

Jan 1, 1915

By Willard S. Morse

The purpose of this paper is to record the results obtained in the use of the Russell process at Aspen, Colo., covering a period of fourteen months, from November, 1891, to December, 1892, during which time over 30,000 tons of ore, purchased outright, on sample and assay, were treated. No explanation of results will be attempted, nor will the chemistry of the process be discussed. The plant was designed by C. A. Stetefeldt, of San Francisco, and built by the owners by day-labor. The entire plant is run by water-power, supplied by a flume 3600 feet long, and a pipe-line 2200 feet long, with a head of 170 feet. A Pelton water-wheel, 8 feet in diameter, is used, from which power is transmitted by wire-rope to the main counter-shaft in the mill, a distance of about 250 feet. From the mill to the samplingworks, about 150 feet, power is also transmitted by a wirerope. A Pelton water-wheel, 3 feet in diameter, supplies power to the dynamo for lighting the plant. The works are located adjoining the Santa Fe railroad tracks, and all ore and supplies are unloaded directly from the cars to the works. The sampling-works are provided with crushers and rolls, the latter being used only on samples, and not on the entire ore. The Cornish hand-quartering method is used in sampling ore for purchase. After crushing and sampling, the ore goes to the bedding-floor, where it is made up into mixtures suitable for the mill. The drying-plant consists of four Stetefeldt double shelfdryers, six shelves high, and is provided with dust-chambers and a stack 65 feet high for draft. These dryers are fired with gas

Jan 1, 1896

By Edward Keller

In a paper, entitled A Uniform Method for the Assay of 'Copper Material for Gold and Silver,' A. R. Ledoux invited the assayers of this country to contribute to a symposium, in which the results of their assays of given samples of copper-matte and metallic copper would be made comparable. This symposiun 2 appeared about one year thereafter; and through it and its discussion, first became generally known the fact that the gold-yield by the all-fire method of assaying is usually higher than by the so-called combination (wet and dry) method, in which nitric acid is employed as a solvent for the copper. In the publication alluded to, the supposed cause of gold-losses in the latter method was declared to be the solvent action of copper nitrate, or of the reduction-products of the nitric acid, upon the gold. Up to a very recent date, gold has been held to be insoluble in pure nitric acid. (The solvent action of any chlorine present in the nitric acid must here properly be disregarded as belonging in the realm of carelessness.) Among later allusions to this topic, W. R. Van Liew3 ascribes the solution of the gold in the combination-assay entirely to the action of nitrous acid at the high reaction-temperature of copper and nitric acid; F. B. Flinn4 believes the low result in gold to be due exclusively to mechanical losses—finely-divided gold penetrating through the filter-paper—but presents no experimental data confirmative of this belief; and 0. Pufah]5 attributes the solubility of' the gold in some coppers to the presence of selenium—a view which appears to be shared by many as-

Jan 1, 1913

By J. E. Burke

THE origin of so-called annealing or recrystalli-zation twins in face-centered-cubic metals continues to be a matter for speculation, and in the present report an attempt is made to explain their origin and to account for at least a majority of the observations concerning their behavior. The fact that annealing twins are prominent only The speelmen was deformed 8 pet in compression and then indented over the lower left-hand corner in a Rockwell in-denter, and then annealed to cause partial recrystallization. Note intense twinning in heavily deformed part and slight twinning in less deformed part. The upper right-hand corner is unrecrystalized. Area reduced approximately 25 pot for reproduction. after recrystallization suggests that deformation may be necessary for their formation. In 1926, Mathewson1 reported the observation by Phillips that annealing twins are frequently parallel to strain markings which delineate octahedral planes in the deformed (and partially recrystallized) matrix, and suggested that strain markings are mechanical twins which grow into annealing twins during recrystallization. Later work by Burke and Barrett' has shown that strain markings are traces of planes upon which slip has occurred, and that there is no evidence for the formation of mechanical twins of microscopically resolvable width in face-centered-cubic metals. Mathewson3 has pointed out, however, that slip may produce twin faults, and later modifications of this hypothesis have assumed that twin faults rather than true mechanical twins serve as the nuclei for annealing twins. Carpenter and Tamura5 suggested, also in 1926, that annealing twins might form by accidents of growth. A close-packed layer of atoms can be added to the octahedral plane of a face-centered-cubic metal in two possible positions, the right position

Jan 1, 1951

By Homer Staley

THE casting alloy 88 copper, 10 tin, 2 zinc, commonly known in England as Admiralty metal and in this country as Government bronze, gun metal, or Naval Department composition G, has, at its best, many valuable properties. However, its physical properties are known to vary widely with slight changes in method of manufacture of the castings, such as slight variations in composition, variation in pouring temperature, kind of mold used, method of pouring and gating of molds, size and shape of castings, amount and kind of heat treatment., and so forth.1 The microstructure of castings made from this alloy is influenced by slight variations of composition, rate of cooling, and kind and length of heat treatment. This is best understood by reference to the equilibrium diagram. The part of the diagram in which we are interested and the effect of the thermal equilibrium relations on the physical properties of the alloy 88 copper, 10 tin, 2 zinc, have been discussed by Hoyt, Camp-bell, Primrose, and Rawdon.2 In Fig. 1 is given the equilibrium diagram of the copper-tin alloys. Briefly stated, the relations of composition and temperature changes are as follows. Compositions between A and a consist of but one constituent-the a bronze, which is a, solid solution of copper and tin, rich in copper. On cooling from the molten state these compositions gradually crystallize, at temperatures above 790°, into a mass of interwoven tree-like crystals or dendrites. The cores of the dendrites are rich in copper and the percentage of tin gradually increases as the surfaces are approached. As cooling progresses, after all the metal has crystallized, no further changes occur, in the crystals other than diffusion within the crys-

Jan 9, 1919

By Robert R. Abbott

The influence of various elements in retarding or accelerating the absorption of carbon during the process of carburization is fairly well known. In general those elements which form carbides accelerate the absorption, while those which do not retard it. It has sometimes been wrongly stated that those elements which raise the temperature of the critical range increase the absorption, while those which lower this temperature decrease it. Silicon is a notable exception to this rule, for its influence is to raise the critical range but to lower the absorption of carbon. Some elements which do not form carbides have no apparent influence upon the absorption rate. Carbon itself retards the absorption rate. With a view to obtaining more exact data upon the subject the following experiments were undertaken: 208 steels of different chemical composition were selected to represent most of the types of modern constructional steels. Specimens 2 in. in diameter and 9 in. in length were weighed to milligrams. They were then packed in the special carburizing box shown in Fig. 1, and kept in the furnace for 10 hours at a temperature of 900' C. A duplicate experiment was conducted at 1,000° C. At equal intervals of time the box was rotated in the furnace so that two complete revolutions were made in the 10 hours. This precaution was taken to neutralize as much as possible any effect of unequal heating. At the end of the 10 hours the box was allowed to cool in the furnace with the doors open. The specimens were then weighed again and the increased weight (carbon) determined. In the following table are given the analyses of the various steels, together with the increased weight of carbon expressed in milligrams.

Jan 1, 1914

By Harold L. Bare, Frank R. Barnako

Coal mining historically has been a. hazardous occupation but, in recent years, tremendous progress has been made in reducing accidental coal mine deaths and injuries. The purpose of this chapter is to discuss the basic principles of accident prevention as they are related to coal mining. Accident prevention fundamentals are no different for coal mining than for any other type of work. The fundamentals apply to all industries. Construction workers may be struck by falling tools and materials, and miners may be struck by falling slate and coal. Sailors may be trapped by shipboard fires, and miners may be trapped by mine fires. Railroad brakemen may lose hands and fingers positioning couplers, and miners may lose hands and fingers positioning couplers. Many other examples could be cited, but the point is that accidents that happen in coal mines are basically similar to accidents that happen in other industries. Thus, the basic principles for preventing accidents apply in coal mining as they do in any other type of work. COAL MINE ACCIDENT EXPERIENCE The US Mine Safety and Health Administration (MSHA) is the main source for accident experience data in coal mines. Coal mine operators are required, by law, to forward to MSHA monthly the number of fatal and disabling injuries, man-hours worked, and tons of coal mined. This information is compiled and published quarterly, with annual summaries, by MSHA. Trends in the number of fatalities and fatal injury rates are shown in Fig. 1. Major coal mine disasters, with number of miners killed, and dates of coal mine safety legislation are shown in Table 1. The fatal and disabling injury frequency rates for the coal industry are shown in Fig. 2.

Jan 1, 1981

By George Sachs, J. Spretnak

The process of recrystallization has not as yet been explained satisfactorily. Some definite conclusions could be drawn from recent investigations, such as, for example, that recrystallization is a process of nucleus formation and crystal growth1 and that the orientations of the nuclei correspond to some fragments of the original crystals, which have been considerably distorted during deformation.2 There are, however, a number of metals and alloys crystallizing in the face-centered cubic system, which form a particularly simple orientation if recrystallized as a sheet.3 Such a shect is almost a single crystal with the cubic axes parallel to the rolling, transverse, and normal directions of the sheet. This preferred cubic or (100) orientation of the recrystallized sheet has been considered to be very different from the rolling structure of the same metals,4 but there are two reasons why this last supposition remains open to controversial discussion. The first reason is academic: In practically all cases except the one mentioned above, close correlations and similarities between rolling and annealing orientations have been observed; for instance, in iron and steel sheet.6 Secondly, no deformed metal actually forms a simple orientation. In any thoroughly investigated case a number of different orientations and considerable scattering or deviations from the ideal orientations have been found.6 It is generally true that investigations on single crystals have shown that a definite orientation is approached in stretching or in compression of an originally undisturbed crystal.7 In the special cases, however, where the initial orientation was close to an important crystallographic direction that differed from the final "ideal" orientation, the resulting orientation changed very little by deformation, staying somewhere in the vicinity of the initial orientation.8 Such deviations

Jan 1, 1940

By W. A. Mudge, Paul D. Merica

One of the most prominent features of our present-day industrial development is the ever-increasing demand put upon materials of construction. Engineering ingenuity, within the past 25 years, has been unusually active, and in some fields at least engineers frankly say that engineering design has progressed as far as the limitations imposed by the properties of the present materials of construction will permit. Consequently, they are today demanding improvement in their working materials and seeking new ones, through the aid of which the present limitations of design may be overcome. The activity of this search is evident in all fields, but it is particularly so in that of structural materials required to be resistant to corrosion. The corrosion resistance of metals and alloys is never absolute and all-inclusive; a particular alloy will withstand some corrosive conditions well and fail utterly under others. Furthermore, other properties, physical and mechanical, required in conjunction with corrosion resistance vary considerably for different commercial applications. One wants a soft, ductile sheet metal resistant to atmospheric corrosion; another, a high-strength alloy resistant to sulfuric acid. The last decade has witnessed active and definite progress in the development of high-strength, corrosion-resisting alloys. In June, 1924, a symposium by the American Society for Testing Materials, on Corrosion-resistant, Heat-resistant and Electrical-resistance Alloys, disclosed no less than 60 commercial alloys the properties of which were described as being suitable for industrial service where corrosion resistance was a feature. Today the number of these alloys has been doubled, at least. In addition, economy in design and construction through decreased weight has given considerable impetus to the improvement of alloys of which the mechanical propprties may be improved by heat-treatment.

Jan 1, 1935

FREQUENTLY the careful engineer puts the word porphyry in quotation marks or precedes it with "so-called," when he writes of the Porphyry Copper mines. This is done by way of serving notice that he is aware that the term is not a precise one, though no one who is informed on the subject would in any event misinterpret it. The name originated from the fact that the rock containing the copper at Utah Copper, Morenci, Nevada Consolidated, and Braden-the first four to be developed-was in each instance known as porphyry. The term was convenient; and when Ray, Miami, and inspiration came along they fell into the Porphyry category even though the ore consisted essentially of a rock called schist instead of porphyry. The word is not inclusive enough; nor as a matter of fact is it sufficiently exclusive. Numerous copper deposits occur in porphyry rocks that are not Porphyry Coppers, paradoxical as it may seem. Desiring to be more accurate and at the same time to use a word that is in some degree descriptive, various engineers have adopted the expression "disseminated copper deposits." This alludes to the characteristic scattering of grains or specks of copper minerals more or less uniformly throughout the mass of the rock. Yet here again the implication is not entirely accurate, for the following reason: in some of the ores, the proportion of copper minerals "peppered" in the rock is small, compared with that which coats the walls of cracks and minute fissures; and that which is found as veinlets along planes of fracture. Many geologists have extended their interpretation of the term disseminated to include both types of mineral occurrence. One of the most striking features of the Porphyry ores is the intense shattering and fracturing that the rock underwent at some period or periods prior to the deposition of the copper

Jan 1, 1933