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By E. M. Wise

THE practice of dentistry, particularly the construction of artificial dentures and "bridges," involves a unique and difficult application of the precious-metal alloys. Appliances used in the mouth are continuously exposed to corrosive agencies which can hardly be described as mild, and must remain free from tarnish and be substantially immune to corrosion. Limitations with respect to space and weight demand high physical properties, while complexity of form requires ease of working. The high corrosion resistance required necessitates the use of alloys of high precious metal content. The usual expedient of resorting to mechanical working to produce the requisite strength and stiffness cannot be utilized because of the frequency of annealing and soldering operations. To meet these difficult conditions manufacturers of dental goods were early led, unknowingly perhaps, to the production of precipitation-hardening or temperable alloys. The excellent properties of iridium-platinum may have suggested the addition of platinum metals to the conventional gold-silver-copper alloys to produce greater strength and hardness. It was found that such quarternary alloys retained their high physical properties after passing through the usual soldering process; i, e., heating to 7500 to 8000 C. and cooling naturally in the air. Later it was discovered that they could be softened and rendered more ductile by heating to the same temperature and quenching, in water. These early examples of precipitation hardening, for years the common knowledge, of dental practitioners and laboratory technicians, escaped the attention of the scientific world and discovery of the transformation which was responsible for this hardening was discovered by the Russian investigators of the system Au-Cu, Kurnakow, Schemtschushny and Zasedatelev,(1) § although the optimum conditions for securing good properties in aged alloys were not given attention.

Jan 1, 1932

By F. A. Jerabek, H. L. Hartman

This study presents results of investigations in a small model of segregation in discharged fill slurry, the quantity of solids escaping in the drain liquid, and the relationship of solids to slurry concentration and discharge rate. Compressibilities of fine fill material, in dry and wet states and individual size fractions, are compared. Two terms are frequently used in describing the hydraulic placement of fill material underground: hydraulic stowing is mostly associated with the underground flushing of coarse-sized fill material, such as coal washery refuse; while hydraulic backfilling refers to placement of small-sized fill material, e.g., sand or classified mill tailings, mainly in metal mines. Characteristically, in backfilling, only a few hours may elapse between the time the material is hoisted as ore and redeposited as fill underground. Hydraulic filling was first used about 100 years ago to control subsidence in coal mines. It was subsequently adopted in many mining operations all over the world, but its basic concepts have never been adequately studied and analyzed. This is not surprising, when one considers the number of variables involved in the hydraulic backfilling operation. Recently, much work has been done on the problems of transportation of slurries in pipes. Comparatively less research work has been done concerning the physical properties of fill material (compressibility, cementation, permeability, etc.). Very little work has been done on the problems of fill placing, distribution, and segregation of fill material discharged in the mine void. It is the purpose of this paper to explore two of the basic, lesser known aspects of filling: segregation and compressibility in discharged fill slurry. Difficulties in observing the behavior of hydraulic fill slurry during the pouring operation underground, and insufficient knowledge to conduct any kind of meaningful theoretical analysis, suggest experimental model studies. The tests described in the following sections were conducted in the Rock Mechanics Laboratory of the Department of Mining at Penn State.

Jan 1, 1965

By John P. Bryant

Plant nutrients are obtained by plants from both the air and the soil. Carbon dioxide, a gaseous form of carbon and oxygen, supplies the carbon which usually makes up 50% or more of plant structure. Plants are capable of absorbing carbon dioxide directly from the air. Most of this nutrient comes from the air, although some carbon dioxide is absorbed by soil water and taken into the plant as liquid. Growing plants use more water than any other substance. Plant nutrients in the soil dissolve in soil water; soil water entering the plant carries nutrients into the plant structure. Water is then given off into the air as the plant breathes or transpires. The inorganic or mineral portion of the nutrients which plants require comes from the soil. Inorganic or mineral composition of plants is usually less than 5% of their weight, and this mineral requirement, usually lacking in the soil, must be provided by fertilizers. Proper fertilization of a soil to improve its mineral level and productivity is the basis for the fertilizer industry (Thomas, 1960). There are 13 essential plant nutrients which often must be added to soils or plants and are generally considered as fertilizer minerals. These nutrients are divided into the categories: primary minerals (nitrogen, phosphorus, potassium); secondary minerals (calcium, magnesium, sulfur); and micro or trace minerals (boron, iron, manganese, copper, zinc, molybdenum, chlorine). Further, cobalt is often added to fertilizers. Although it is not considered to be an essential plant nutrient, it is essential to animal health and is often applied to forages as a fertilizer constituent. One point of major significance to the fertilizer industry is that not all nutrient carriers supply that nutrient in a chemical form which will be available to the plant. Thus, a product which may be considered a fertilizer mineral may require substantial processing or treatment before it becomes useful as a nutrient carrier. Fertilizer Industry Scope Until about 1900 demands for higher crop yields were met simply by bringing new agricultural lands into cultivation. Since that time great progress has been made in increasing yields through fertilization and improved varieties and cultural practices. The importance of the fertilizer industry to the economy and welfare of the U.S. is widely recognized. [Fig. 1] illustrates the relationship of lime and fertilizers to crop yields. In terms of tons of fertilizer products, the growth of the industry has been phenomenal, particularly between 1950 and 1970. Table 1 shows the increase in fertilizer usage. Primary Plant Nutrients in Fertilizers Primary minerals (nitrogen, phosphorus, potassium) are designated as such because of their significance to plant growth. Practically all soils are deficient in both nitrogen and phosphorus, and most of them are also deficient in potassium. Consequently, these nutrients

Jan 1, 1975

The entire War Minerals Relief Commission heard the case of the Chas. T. Pyrites & Chemical Company of Georgia on April 15 and 16. The Commission insisted on great detail with regard to the entire enterprise, although the main questions seemed to be of the amount involved. It is considered by the Commission that this claim comes unquestionably under the Act, it is one of the best examples that has been brought to the attention of the Government thus far. Testimony showed that operations were done on the property late in 1916 without request from the Government. Preparations were made to work the pyrites deposit on a comparatively small scale but , following a visit from a representative of the Secretary of Interior and a personal interview of the principal owner of the property and Secretary Lane, operations on a much larger scale were begun. The amounts expended prior to this interview were carefully separated from the expenditures thereafter. Testimony showed that it was the intention of the owners to transport their product by motor truck to the railroad-13 mi. away. This limited shipments to about 50 tons daily. Under the enlarged plan taken against the better business judgment of the owners, a railroad spur at a cost f nearly $200,000 was built to the mine. The operation included a concentrating mill with a capacity f 600 tons daily and an expensive dam to make possible the use of waterpower. With these improvements, the company was just beginning, operation under its enlarged program when the armistice was signed. This resulted in a greatly decreased demand and consequently lower prices, with all prospects indicating that the property could not operate profitably when Spanish pyrites begin to move.

Jan 6, 1919

By P. B. Liebermann

1. Haulage Tests on Coal-mine Cars THE haulage of coal from the face to the tipple is an important enough link in the production of coal to deserve its full share of study and care. In order to obtain a better understanding of mine haulage conditions, a series of tests and investigations has been made which promises to hasten the improvement of present conditions. For hauling coal through the mine and on the surface, locomotives are required, the size and power consumption of which depend on the resistance to motion offered by the mine cars. This resistance is principally caused by gravity and hearing friction. The effect of gravity can be reduced to a minimum by a suitable layout of the haulageways; that is, by arranging the grades in favor of the loaded trips, and by fixing the percentage of grade to that value which gives the lowest power consumption for loaded and empty trains. The bearing friction, which is considerably greater than is generally realized, can be easily reduced to a negligible quantity by the installation of a suitable anti-friction bearing that will stand the rough use and abuse of coal-mine service. The present investigation will deal with flexible roller bearings in comparison with ordinary plain bearings.

Jan 7, 1917

By W. H. Moore, E. T. Powell

IN the early days of mining in the Anthracite field, only the thicker and better seams of coal were mined, because of the limited mining and coal-cleaning facilities, therefore many of the thinner and less productive seams were permitted to remain unmined. With improvements in mining methods, the introduction of modem preparation plants, and the increased market demand for small-size coal, the thinner and more laminated seams have now become assets. In many instances these seams overlie the mined-out beds of the thicker and better seams, from which all recoverable coal was removed by the conventional breast-and-pillar method of mining. Some collieries in certain sections of the Anthracite field are now relying on these thinner and laminated seams. For the purpose of illustration, a large area in the Hickory Swamp-Ridge Basin of the western middle coal field has been selected, where as early as 1898 the No. 4, or Little Buck Mountain, seam was mined and pillars removed. The No. 5, or Buck Mountain, seam lying on a comparatively light pitch and with intervening strata of but 55 ft. of rock was not mined until 1935. Farther east, in the same basin the Nos. 8 and 9 seams, which are two splits of the Mammoth seam, have been mined and robbed and the workings have been abandoned since 1896. The overlying No. 9 ¾ seam, or the upper split of the Mammoth, and the No. 9 ¾ or 4-ft. seam remained virgin, with only an interval of 50 ft. of rock separating them, and with 40 to 50 ft. of rock strata separating the No. 9 ½ seam from the completely mined area of the Nos. 8 and 9 seams. These seams lie on a pitch of 45° on the south side of the basin and on 75° on the north side of the basin. Mining has been carried on in the 9 ½ and 9 ¾ seams for 3 years on both dips of the basin, for a distance of 3500 ft. In some sections the overlying strata of the thicker seams previously mined have settled without any apparent breaks in the upper strata, as indications have shown in the top split of the Mammoth; while in other areas the roof and bottom of this top split of the Mammoth have settled unevenly, thereby causing the bottom and roof to break into blocks. In attempting to mine over a large area of the No. 5 or Buck Mountain seam, a similar settlement has been encountered; the roof of the seam has been broken and a considerable amount of timbering has been necessary in order to make the mining of the seam possible. The conventional breast-and-pillar method, using shaker conveyors, has been used in the No. 5 seam, and a slant-breast method in the mining of Nos. 9 ½ and 9 ¾ seams. MINING OF LIGHT-PITCH SEAMS The No. 4 seam was mined and robbed by the conventional breast-and-pillar system. In this area the seam pitched from 5° to 25° on the north dip, averaged 8 ft. in thickness and had a slate bottom and a

Jan 1, 1941

MAY 17-The last bit of verbal sod had hardly come to rest on the grave of the coal industry-which grave was being eagerly dug with typewriters and microphones by administration hangers-on and even an operator or two-when its leaders gathered for the 1950 Coal Convention of the AMC in Cincinnati on April 24. Surprisingly, mourning clothes were not being worn but the boys had on their diggers preparatory to digging their way out from under the muck. High costs created by wage and welfare demands, together with work stoppages, have caused markets to shrink, but even so, an optimistic air still prevailed as new techniques were disclosed at technical sessions. The administration, however, came in for its share of knocks.

Jan 6, 1950

By Max Heberlein, R. P. E. Hermsdorf

The electrolytic refining of metals for the removal of undesirable impurities has become a recognized necessity in the nonferrous field. Copper, lead, zinc, nickel, silver and gold have been produced in this manner for years. The United States Metals Refining Co., realizing that considerable quantities of lead and tin could be made available to the trade if a satisfactory method of purification of these metals could be established, decided to investigate the possibilities of electrolytic solder. In cooperation with Dr. Edward F. Kern, of the School of Mines at Columbia University, the company developed a process of electrolytic refining of lead-tin alloys using a tin-lead fluosilicate electrolyte. A pilot plant was installed in November 1927, and the commercial unit was put in October 1929. Since that time thousands of tons of electrolytic solder have been produced in this plant and consumed by all branches of industry that use solder. Older Methods of Producing Solder In the early days practically all solder was made by melting together virgin lead and tin in the proper proportions to meet specifications; then the solder was cast into the commercial shapes required. Today the base of most solders comes from scrap or secondary materials. Ordinarily solder is produced from secondary materials either by sweating solder-bearing scrap or by smelting lead and tin-bearing drosses, residues and similar materials. When solder is produced from scrap by sweating, clear solder is collected directly. It is then given some kind of kettle refining and usually blended to specification with virgin metals before it is cast into finished shapes. In producing solder from drosses and residues, the materials are usually first given a reducing smelting treatment from which a crude solder is obtained. This crude solder may be refined in several ways, but usually the first step is a furnace liquation to remove the bulk of the copper, which is followed by one of the more or less complicated methods for the removal of antimony and other impurities.

Jan 1, 1937

THE twenty-first birthday of the Rocky Mountain Club will be celebrated on April 11 by the Last Round-up; for, as announced at the annual meet-ing of the American Institute of Mining Engineers in February, the Club and the Institute have voted to con-solidate and formal approval by the court alone re-mains to be secured. The Rocky Mountain Club was organized some years since "to create and maintain good fellowship between the Rocky Mountain members and to further the in-terests of the Rocky Mountain States." From the first, mining men dominated it, as was natural in view of the prominence of mining in the Rocky Mountain region. A series of brilliant annual dinners were held and a site purchased for a clubhouse. A fund was raised to provide a home for the Club. Just as success was as-sured the war came and the members of the Club con-sidered it would be unpatriotic to spend money for such purpose at that time. In a spirit of patriotism the Club funds were devoted to war purposes, especially the Commission for Relief in Belgium and the caring for soldiers going to and returning from the front. So much of the money was used that at the end of the war the project for a clubhouse was out of the question with-out raising a new fund, and since 1923, the Club has been inactive. There is now in its treasury a substan-tial sum. The assets are for the most part the result of contributions made by W. B. Thompson, John Hays Hammond, and Edward H. Clark, all members of the Institute and all of whom wished to see these funds applied in a manner to leave some lasting memorial of the spirit which animated the founders and at the same time perform some useful function in the development of the region in which the Club's interest centered. It was thought that this could best be done through affilia-tion of the Club with the Institute and both organiza-tions have voted for the merger. The Club members not already in the Institute are to have the privilege of a special Rocky Mountain life membership, and the property of the Club is to be used to endow a Rocky Mountain Club fund to be used for purposes in accord with those of both the Institute and the Club and with especial reference to benefiting the Rocky Mountain region.

Jan 4, 1928

By A. W. Ruff

The seismic wave produced by an explosive is very important in blasting. A true understanding of the wave is only important when considering possible structural damage to buildings located near the blast, but it is also of primary importance when considering rock fragmentation. Because of the importance of the seismic wave to fragmentation, a finda-mental study of the seismic wave and its effect was made at the Cananea Consolidated Copper Co.'s mine at Cananea, Sonora, Mexico. Strain gages were used to measure the strain in the rock when nearby explosive charges were detonated. The variance in the circuit voltage caused by changes in the resistance of the strain gage was measured with an oscilloscope and recorded with a Polaroid camera. CONFINED DRILLHOLE CHARGES To record the seismic wave from a confined drillhole explosive charge, a gage was cemented to the bottom of a 4-in diam drillhole. The horizontal gage hole and nine horizontal charge holes were drilled perpendicular to the center line of the 2-39 drift and 4 ft above the floor. The gage hole was 29 in. deep, and the charge holes were drilled so that each bottomed 1 in. deeper than the gage hole. The gage was installed with its axis horizontal and parallel to the 2-39 drift. The charge holes had the following horizontal distances from the gage: hole 3, 3 ft; hole 4, 4 ft; hole 5, 5 ft; hole 9, 9 ft; hole 10, 10 ft; hole 14, 14 ft; and hole 15, 15 ft. Figs. 1 and 2 show the relationships of the gage and the charge holes. Charges of 80 pct special gelatin, which weighed 50, 100, and 150 g were exploded in the charge holes and the seismic waves were recorded. All charges were stemmed with 200 g of mud and detonated with an electric blasting cap. Fig. 3 shows the recorded seismic waves. The reflected components of the waves were too weak to be objectional on these records. Table I shows the data taken from the wave forms. The approximate average velocity of a wave with a 9-ft travel distance was 12,900 fps. Since different charge weights were used, it was necessary to scale the data. The scaled maximum compress ion-strain data and the scaled maximum tens ion-strain data are shown in Figs. 4 and 5, respectively. Figs. 6 and 7 show the strain-distance data from Figs. 4 and 5 converted to a 1-lb charge. The results showed that the wave consisted of an initial compression pulse followed by a tension pulse. The amplitude of the tension pulse approached the amplitude of the compression pulse as the distance between the gage and the shot increased. The decay rate of the seismic wave is very important in the evaluation of the blasting characteristics of a rock. When high-amplitude stresses are produced, as in rock fragmentation, the rate of decay is much more rapid than when small amplitude stresses are produced. In underground mine blasting, the burdens are usually not greater than 6 ft and the decay is very rapid. The rapid seismic-wave decay rate in the fragmentation range means that in practice, if the minimum weight of powder is used to break a specified burden, only a very

Jan 1, 1961

Book Review MANAGEMENT AND MEN. By Meyer Bloomfield, Boston. The Century Co., New York, 1919, pp. 584, H.X. 5 1/2. $3.50. This hook is an exposition of English efforts to solve the problem of labor unrest in England. The first six chapters are reprinted from articles published in the Satur-day Evening Post, for whom the author went to England to study the problem at first hand. These articles deal with housing, increased production, eliminating the internal friction in the industrial machine and a chapter each devoted to the view-point of employer and employee. These chapters are written in the easily readable magazine style and give a complete general survey of the particular solution being tried. Perhaps their greatest., certainly not their least, worth lies in the fact that they form a vehicle for unusually voluminous appendices containing in full the famous Whitley Reports which are the basis of the new movement, together with various reports, which, except for this publication, would be largely inaccessible to those inter-ested in this country. The Whitley scheme considers each industry a unit and proposes to establish therein a Joint Standing Industrial Council composed of representatives of employers and employees to consider appropriate matters affecting the industry at large. There is to be a District Council for each industry which will, as its name implies, deal with the clatters pertaining to that interest in. the particular district. The third and last body in this scheme of Industrial Parliament is the Works Committee, which is com-posed of representatives of the management and of the workers employed in particu-lar plants or mines to act in close cooperation With the district quid national machinery. The Whitley or similar schemes have been tried in many communities in England and the book contains interesting comments on the result obtained, it being notable that most of the objections conic from plants which have not tried the scheme. Meyer Bloomfield, the author; is the specialist in industrial personnel problems who organized the industrial service activities of the United States Shipping Board, Emergency Fleet Corporation. P. E. B.

Jan 10, 1919

By B. A. Wilcox, A. H. Clauer

DURING the course of an investigation on the high-temperature creep behavior of TD Nickel* (Ni + 2) vol pct ThO2), it was observed that the creep fractures were similar in appearance to low-temperature ductile fibrous fractures and creep ruptures by cavitation. Microfractographs of fibrous ruptures are typically characterized by a dimpled appearance, with second-phase particles frequently found near the bottom of the dimples.'-4 These somewhat resemble creep ruptures by cavitation, in that fracture occurs by void formation, with the subsequent growth and final merging of the voids to form a complete fracture.' It is the purpose of this communication to describe the creep fracture of TD nickel and suggest a mechanism for the rupturing process. The discussion is relevant to material crept to fracture in vacuo at a constant stress of 18,000 psi, over the temperature range 900" to ll00°C. The material used in this investigation was 1/2-in.-diam bar stock supplied by Du Pont, contain- ing 2.3 vol pct Tho2. The final fabrication treatment consisted of -95 pct reduction by swaging followed by a 1-hr anneal at 1000°C. Transmission and replica electron microscopy revealed that the material had a fibered structure with a transverse grain size of -1 µ and a longitudinal grain size of 10 to 15 µ. Selected-area diffraction indicated that the fiber axis was parallel to (00l), in agreement with the results of Inman et a1.6 The thoria particle size varied from 80 to 1000Å, with an average size of 400Å, and the mean particle spacing was about 1200Å. The remarkable structural stability7 was confirmed by annealing for 6 hr at 1300°C (about ' 0.9 the absolute melting point). Transmission electron microscopy revealed that the only structural change was a slight decrease in dislocation density. Furthermore, recrystallization or grain growth during creep has not been observed. All specimens were annealed in vacuo at 1300°C for 3 hr prior to creep testing. The following times to rupture were obtained for vacuum creep tests at a constant stress of 18,000 psi: 900°C, 854 hr; 930°C,

Jan 1, 1965

Graham Macfarlane, Louisville, Ky. (communication to the Secretary*):—In the paper by S. Whinery under the above caption mention is made of the occurrence of Clinton iron-ore in Kentucky and Tennessee. I believe that this is really a ferruginous limestone in what the Tennessee Geological Survey calls the Fernvale formation. In Davidson and Sumner counties, Tennessee, this occurs at about the horizon stated by Mr. Whinery. The maximum thickness of the deposit is from 10 to 12 ft., but it averages between 6 and 8 ft., lying practically horizontal. The Red River Furnace Co., under my direction, opened a mine in the Fernvale " red rock" near Goodlettsville, Tenn., several years ago. When it was first found we assumed it to be Clinton ore, but the absence of the characteristic Clinton fossiliferous structure and other evidence satisfied us that it is really limestone saturated with iron oxide. I think the very low ratio of SiO2 and Al2o3 to iron content as compared with the usual ratio in the Clinton ore is also evidence in favor of its being the Fernvale. The Tennessee Geological Survey states that at outcrops where this ore has been leached it carries about 44 per cent. of iron; under cover, from 20 to 25 per cent. of iron and from 3 to 6 per cent. of silica, the remainder being chiefly calcium carbonate. Its phosphorus content is irregular and generally rather high for a foundry-iron mixture. Since it is more than self-fluxing, we have at times operated with a mixture of brown hematite and red ore with no limestone.

Jan 1, 1913

By Clifton W. Livingston

So many factors influence blasting results that theories and rules are usually dismissed as impractical; the practice prevailing today is arrived at by cut and try. Usually the first step is to experiment with drillhole patterns and spacing until an arrangement is found that gives best results. The next step is to experiment with different types of explosives and sequences of blasting until the most satisfactory degree of fragmentation is achieved and until no further reduction in cost is immediately apparent. Improved fragmentation is generally attributed to the type of powder used, the sequence in which the holes are blasted, or the use of millisecond delays. Various types of drill rounds have been evolved in tunneling operations, underground development headings, and stoping, and various patterns of blasting in open pit mines and quarries. These practices usually are carried from mine to mine or from district to district, and great skill is exercised by those experienced in the art of blasting.

Jan 1, 1960

By W. E. Ruder

IT has been pointed out by Stead 1 that grains of considerable coarseness may be developed in steels containing from 3 to 5 per cent. of silicon, and in a previous paper 2 the present author has shown that under the proper conditions of annealing single grains having an area of 50 sq. cm. may be obtained. It is the purpose of this paper to discuss in more detail the conditions, promoting the growth of these grains, in the hope that the experiments described may throw some additional light upon the general problem of grain growth in metals. These silicon steels lend themselves particularly well to such experiments because of the ease with which the change in structure may be followed and because of the fact that the effect of the carbon present is largely obliterated by the high percentage of silicon. This forms a solid solution with the iron, which acts very much like a pure metal. This alloy has been found to have but one critical point, viz., Are. This point, determined by Roberts-Austen for Hadfield's 4 per cent. Si alloy, was found to lie at 703° C. Vigouroux3, in working with pure Fe-Si alloys, finds this point to rise from 750° C. for 0.5 per cent. Si to 860° for 6 per cent alloy, with a flat region in the curve from 3 to 4 per cent. Si. No accurate determination of this point has been undertaken by the present author, but it has been roughly determined to lie between 730° and 750°.

Jan 12, 1913

By Louis A. Riley

I DESIRE to submit, for the consideration and information of the members of the Institute, the following data, drawings, and tables, showing what I believe will be interesting information with regard to the diamond drill, and its uses in developing mineral lands. I would first say that the results given have been obtained during the past two years by means of two drilling machines belonging to the Lehigh Valley Coal Company, operating on their coal lands in the Mahanoy, Lehigh, and Wyoming regions. 1st. A tabulated statement, giving location of borings, date, progress, total cost, itemized cost per foot, etc. 2d. Section showing strata bored in Nos. 5 and 10 holes at Mt. Carmel, see Plate VI. 3d. Section showing strata bored in No. 19 hole at Hazleton, see Plate VI. 4th. Photograph and description of drill No. 2. From the first it will be seen that the total number of test-holes bored up to May 1st of this year is 24; 9 of these are in the Mahanoy region, 6 in the Lehigh region, and 10 in the Wyoming region, in all of which cores have been taken for the whole distance. The total distance bored is 9902 feet. The majority of the holes have been put down for the purpose of proving the lower veins of the coal series, and have had to encounter the harder rocks of the coal formation. Much of the distance has been through the lower conglomerates, going in some cases through the coarse egg conglomerate, the foundation of the coal deposit, and to the green sandstone and red shale which underlie it. These lower sandrocks and conglomer¬ates are among the hardest known to geologists, and present a formidable resistance to the exploring drill. This fact must be taken into consideration in comparisons of cost of drilling, and when considered will still further improve the very favorable results I am able to show in my statement of costs. In illustration, I will cite the work of one bit when boring in the upper or softer rocks of the Wyoming region, where 280 feet were obtained without resetting, while in the Lehigh and Mahanoy regions, in the lower and harder rocks, bits set with the same quality of diamonds would only bore from 3 to 20 feet before being worn out. In this connection it may

Jan 1, 1877

By Harry H. Power

WHILE the attention of all engineering branches is focused today on changes and improvements in the several curricula, we are concerned here with the many questions arising in industry and college concerning the preparation for the petroleum engineering profession. The succession of problems confronting the petroleum engineer demands a degree of versatility not ordinarily encountered in other professions. As a consequence, the student cannot acquire mastery of all the several engineering branches represented in field practice, and as an alternative, he has learned to appreciate the value of thorough training in the basic or fundamental sciences as a preliminary foundation for professional work. While our attention is directed primarily to the training of engineers in educational institutions, it is necessary that the ultimate education of the professional engineer be kept in mind. It is apparent that his success as an engineer is limited not only by his educational and job experience, but by his native endowments: mentality, personality and health. The engineer's lack of job experiences often proves as much a handicap as the lack of adequate college training. If the final product proves to be satisfactory, both industry and technical institutions are to be congratulated. However, if the product is found wanting, the one most responsible should be apprehended. FITNESS FOR PROFESSION For the most part, students of engineering colleges have had their interests in applied science awakened at a relatively early age. Many of them entered college as a convenient means of acquiring a technical education, but undoubtedly would have had better prospects in a shorter program offered by institutions of noncollege grade. The activating motive of practical interest is also strong in students suitable for college training, but in many cases an intellectual interest must be awakened in order that it may survive graduation. Numerous engineers believe that this progressive process of selection and determination of career aims is one of the essential services rendered by the engineering colleges. Industrialists, who are more interested in quality than quantity of petroleum engineering graduates, have pointed out the good that should result if more emphasis were given to the work of eliminating the misfits. They also point out the protective measures that have been taken by other professions for the betterment of professional standards. Mention has been made of the beneficial results to be obtained by collective determination of the market for the products of engineering schools, particularly in that the students unsuited to the profession would have an opportunity to prepare themselves for employment more suited to their personalities and other qualifications. In the event that such a system of coordinated personnel direction is developed by the

Jan 1, 1941

By D. L. Wood, J. H. Westbrook

The tensile behaviors of the CsCl structure compound AgMg are extensively documented in terms of strain, strain rate, temperature, composition, and metallurgical processing treatment. The observations lend themselves to presentation in terns of three regimes of deformation behavior; 1) low temperatures where deformation is primarily by slip; 2) intermediate temperatures where the deformation mode is also slip but with the detailed behavior dominated by dislocation interactions with solute atoms; 3) high temperatures where defomation is primarily by diffusion controlled processes. Of all the material groups of potential interest as high-temperature structural materials, the inter-metallics have been the least studied, particularly with respect to their mechanical behavior. Moreover, the application and processing of intermetallics for uses which exploit their often unique physical properties have been impeded by a lack of understanding of their mechanical properties. Previous work in this area* has been largely *For a recent review, see Westbrook.' exploratory, aimed on the one hand at the direct empirical development of materials of engineering utility and ,on the other at identification of the important parameters affecting the mechanical behavior of inter metallics. As a consequence, there has not been available, heretofore—for any inter-metallic—data, sufficient in extent or precision to provide an adequate phenomenological description of the effects of metallurgical variables on deformation behavior. Such documentation is prerequisite to intelligent application or processing design and is also necessary for testing present and future theoretical analyses of mechanical behavior. It was therefore an objective of the present investigation to document the deformation behavior of a simple ordered intermetallic over as wide a range as possible of all the usual metallurgical variables. The compound AgMg was chosen as the subject of this investigation because it met all of a group of desired criteria, namely: 1) congruent but moderate melting point; 2) simple crystal structure; 3) ordered structure persisting to the melting point; 4) broad solubilities for the component elements. The first and last criteria were expected to aid in the preparation of homogeneous single-phase specimens: the second and third to help simplify the

Jan 1, 1962

By AIME AIME

DONALD K. CRAMPTON, present Chairman of the Institute of Metals Division, A.I.M..E., is well known by nonferrous metallurgists in all countries for his research work on the fabrication and properties of copper and its alloys including investigation of season- and stress- corrosion cracking. He is also well known, at least by many metallurgists in the United States for the proficiency with which be carries on his hobbies, in i:lrlditlg photography. gardening, and golf

Jan 1, 1941

By John H. G. Monypenny

The range of chromium content of stainless steel is, in most cases, included in the limits 11 to 14 per cent., or the middle part of the range, 9 to 16 per cent., specified by the discoverer. For some time after the steel was produced commercially, the carbon content was about 0.3 to 0.4 per cent. and occasionally higher; only rarely was material with 0.25 per cent. carbon or less produced. The reason for this is obvious from the nature of the alloys of chromium available for making such steels; as the lowest carbon content generally available was about 1 per cent., and this in conjunction with a chromium content of about 60 per cent., the production of a 12-per cent. chromium steel with less than 0.25 to 0.30 per cent. carbon was impossible. The advent, on a reasonable commercial scale, of carbonless ferrochromium has modified this condition, however, so that for the last three years stainless material containing 0.1 per cent. or less carbon and the normal amount of chromium has been on the market. As far as the author is aware, the material was first made on a commercial scale by the firm with which he is associated in June, 1920, when a 5- or 6-ton cast of material containing 0.07 per cent. carbon and 11.7 per cent. chromium was made and cast into 12-in. ingots. The necessity for using a totally different raw material, carbonless ferrochromium, instead of the ordinary low-carbon ferro (0.6 to 1.0 per cent. carbon) has led to the idea that stainless iron is a quite distinct product and quite different from stainless steel. While this may be true from a commercial aspect, it is wrong metallurgically. The name stainless iron is unfortunate as the material is a very mild stainless steel and forms the lowest carbon member of a series of steels of continuously varying content which are, in many respccts, the counterpart of the series of ordinary carbon steels ranging from "dead soft" to tool steels. In an article on stainless steel in the Journal of the Society of Chemical Industry, November, 1920, the author said "Just as in the far-off days 'steel' was regarded as a hard product of iron, and little or no attempt was made to grade it into harder or softer varieties, so at present stainless

Jan 1, 1924