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By Milton T. Pana

Computer techniques now have been applied to the solution of a wide variety of scientific and engineering problems in the mining industry, but generally not in great depth in any one area. In mining, the area covered in greatest depth and with the greatest success has probably been mine planning and to a lesser degree production scheduling. A rather comprehensive review of the literature related to mine planning and production scheduling indicates that contributions in these areas have been geographically, as well as organizationally, widespread. Of twenty-six papers reviewed, eleven were from industry, eight from educational institutions, four from computer vendors, two from the Bureau of Mines, and one from a private consultant. The conclusions that can be derived from the literature are: First, the-state-of-the art has advanced to the point that computing ore reserves and developing mining plans with the aid of the computer is now a routine practice; second, the application of the computer to mine planning problems has markedly improved our ability to estimate ore reserves, more accurately define pit limits, and determine an optimum mining sequence. MINE PLANNING The papers in this section deal essentially with the problem of determining the final pit limits of an orebody and the ore reserves associated with a given pit limit. The problem is probably best described by Soderberg25 and more recently by Reibell. 23. There are two techniques currently being applied to this problem by several mining companies: 1) the multiple-cone technique and 2) the Lerch-Grossman algorithm. The multiple-cone technique is the older of the two techniques and has the advantage of being more flexible, allowing an engineer to easily vary pit slopes in different sectors of the design. The technique can also be used to define intermediate pit contours. The Lerch-Grossman algorithm is appealing in that the final solution is given in the form of a true mathematical optimum. The technique is limited, however, in that the size of the blocks in the orebody model are a function of the desired

Jan 1, 1969

By Fred D. Gustafson

With the postwar emergency for new housing and for new industrial buildings, much research has been done on lightweight aggregates for use in concrete and plaster. The trend toward lighter weight aggregates to relieve the dead load on the higher, steel frame- work buildings started toward the end of the last century. Progressively the requirements be- came more stringent, crushed bank slag, weighing 80 lb per cu ft as com- pared to 100 lb for crushed rock, was supplemented in some sections by foamed slags and expanded shales weighing from 40 to 60 lb per cu ft. In other sections cinders were used weighing from 40 to 50 lb, including sand. Sections favored with more recent vulcanism turned to pumice weighing from 30 to 60 lb, whereas other localities made use of diatomite, from 28 to 40 lb. Exfoliated vermiculite weighing from only 6 to 10 lb per cu ft came into use. As the search for lighter weights in aggregates continued so did the search for other desirable properties such as nailability, ease of cutting or channeling, and good insulation to both sound and heat. This search eventually led to a widespread interest in the expansion of perlite, or similar volcanic glasses, with the result that in 1946, the Office of the Housing Expediter' listed eleven firms reporting the operation of processing plants either on pilot or commercial scale producing aggregates weighing from 2 to 16 lb per cu ft.

Jan 1, 1949

By M. H. Richman, W. D. Sproul

THE indexing of a field-ion micrograph is in many cases similar to the indexing of the poles of a stereo-graphic projection.* If one has a standard projection as a guide, the task of indexing is relatively simple. In this way, field-ion micrographs of bcc and fcc wires have been oriented from projections available in most any text on X-ray diffraction. These books always illustrate the projections for the bcc and fcc structures and even for a particular hcp structure. There is no "standard" hcp projection because the angles between planes depend on the c/o ratio of the unit cell. In order to index field-ion micrographs of hcp metals, one must compute the angles between various planes—a rather laborious task. In recent work,, we have had to identify the structure and index the orientation of field-ion micrographs of the compounds WC and W,C. To overcome the problem of computing angles by hand or calculator, a program was written in Fortran lV for use on the IBM 360, Model 50 which will compute all angles between planeswith indices (hlklll) and (17,k,l2) in the range from (447) to (444) for any given c/o ratio. The program, which is more specific than that of Camp and clum, was so written as to take advantage of the multiplicity of the hexagonal system, and, for the limits defined above, only 26,649 values out of a possible 265,721 values had to be computed. This is a 90 pct saving in time (and cost) and was accomplished in the following way. Because the lattice parameters of the hexagonal crystal system are defined such that: a = b * c [1] the I index does not enter into the multiplicity (i.e., it cannot be transposed with the h or k indices), and all possible values of h and I, from 4 to 4 must be used—a total of eighty-one combinations. The index h2 varies the most—it must assume values from - Ill,: to 3Ihl. The indices kl and k2 are always equal and vary

Jan 1, 1969

By R. R. Vandervoort

The creep behavior of Nb(Cb), Ta, Mo, and W was determined under conditions of constant atomic dif-fzisivity, constant stress to elastic modulus ratio, and nearly equivalent grain size, and the steady-state creep rates obtained from these tests were correlated with calculated stacking fault energies for the metals. These results, in conjunction with similar data for several fccMetals,13 suggest that stacking fault energy may influence the creep strength ofbcc metals. The interrelationship between steady-state creep rate, subgrain size, and stacking fault energy was examined. It was found that the subgrain size for a given creep stress, increased as stacking fault energy increased, but that this relationship did not cormpletely account for the effect of stacking fault energy on creep rate. The crystallography and energetics of stacking fault formation in bcc metals has been discussed by a num-ber of authors,1-5 and impurity stabilized stacking faults on (112) planes have been observed in Nb,6,7 w,8,9 Fe,] and V" by transmission electron microscopy. However, a crucial question is whether or not stack-ing faults influence the mechanical strength of bcc metals. Potentially, stacking faults could increase strength by reducing the mobility of the partial dis-locations bounding the fault, by acting as barriers to slip dislocations, and by retarding the climb of dislo-cations during high-temperature deformation. The objective of this study was to seek a correlation be-tween creep strength and stacking fault energy for several bcc metals; namely, Nb, Ta, Mo, and W. The creep behavior of most polycrystalline metals and alloys at high temperatures and moderate stresses can be described by the following relation:11,12 im=Af(s) where i, = minimum creep rate, A = constant, j(s) = a function involving metallurgical structure, a = applied stress, E = average elastic modulus at the test tempera-ture, w = constant (equal to 5 for most pure metals), D = diffusion coefficient. One factor in the structure function F(s) which sig- R. R. VANDERVOORT, Member AlME is Research Metallurgist, Process and Materials Development Division, Chemistry Department, Lawrence Radiation Laboratory, University of California, Livermore, Calif. Manuscript submitted February 28, 1969. IMD nificantly affects the creep resistance of fcc metals is stacking fault energy, and creep rate has been shown to vary directly with stacking fault energy to the 3.5 power." In the latter investigation, four fcc metals of widely different stacking fault energies (Ag, Cu, Ni, and Al) were creep tested at a constant stress to modulus ratio of 1.21 x 10-4, at a constant diffusivity of 2.7 x 10-12 sq cm per sec, and at nearly equivalent grain sizes of about 0.7 mm. The creep data were then correlated with stacking fault energies. In the present study, a similar procedure was followed. All materials used in this work were consolidated by powder metallurgy techniques. Impurity contents in the as-received materials are listed in Table I. Chemical analyses showed that no measurable contamination of the test specimens occurred during pretest annealing treatments or creep testing. Specimens with a gage section 0.75 by 0.125 by 0.050 in. were creep tested in tension in a vacuum of less than 10-9 torr. Deformation at temperature was measured by tracking fiducial marks on the gage section of the specimen with an optical comparator. Optical deformation measurements also permitted observation of the macroscopic characteristics of the deformation Table I. Typical Specimen Impurity Content, ppm Nb Ta Mo W C 45 10 155 6 O 185 30 4 10 N 30 6 3 2 H 5 I 1 <1 als 3 10 2 15 Ca <5 I3 5 Cr 5 <3 10 <5 Cu 10 50 2 15 Fc 10 10 150 35 Ni 2 150 20 <5 Si <I0 1 3 <10 Ta 100 Ti 10 8 1 Zi 15 50 1 3 Table II. Test Conditions for Constant Stress-Modulus Ratio of 6 X 10.&apos; and Constant Diffusivity of 2.7 X 10-12 sq cm per see, and Grain Size Values for the Given Pretest Annealing Treatments Literature references Pretest Annealing for E and D Treatment Stress, Temperature, ___"&apos;Values__ Grain Tempera-Metal psi "C E D Size, mm ture, .C Time hr Nb 745 1525 14 15 to 17 0.83 1650 I Ta 1220 1770 18 19.20 O.91 1800 I Mo 1975 1630 18 21 0.77 2200 I W 2140 2265 18 22 040 2400 5

Jan 1, 1970

By J. A. Fellows, Earnshaw Cook, H. S. Avery

THE increased use of heat-resistant alloys (26 per cent Cr, 12 per cent Ni; 16 per cent Cr, 35 per cent Ni; 12 per cent Cr, 60 per cent Ni; etc.) in recent years has been accompanied by continued demands by the consumer for improvement in properties. The manufacturers of these materials, of necessity, have resorted to more critical studies of the basic causes of variations in fundamental properties. To keep pace with the need for augmented information, previous techniques of investigation have been refined and new test methods and instruments created. It is the purpose of this paper to describe the apparatus, experimental technique and precision of measurement that were employed in the exploration of properties of heat-resistant alloy presented in a companion paper.? The detailed precautions in experimental procedure essential for attainment of accurate and comparable data at elevated temperatures cannot be too highly emphasized. THE CREEP TEST Since the fundamental concepts of creep testing have been recognized for the past 20 years, present interest is restricted to refinements in equipment and experimental procedure. The creep-test laboratory constructed for the American Brake Shoe and Foundry Co. is designed to permit 1000-hr. tests in the temperature range of 1200° to 2200°F. with a choice of applied stress extending from 50 to 50,000 lb. per sq. in. in increments of 50 lb. per sq. in. To simplify the calculation of weight combinations, the loading beams (Fig. I) are provided with counterweights to eliminate the tare. The precision of the knife-edges (10.1 ratio) is such that a 10-gram weight placed on the upper specimen grip will be exactly balanced by a 1-gram weight attached to the loading shackle. Check of the loading weights proved the maximum error to be 0.06 per cent. Axial alignment is provided by crossed knife-edges in the grip seats. The furnaces are similar in design to those of Crane and Company, Battelle Memorial Institute, and the U.S. Steel Corporation. An 80 per cent Pt, 20 per cent Rh No. 19 B. and S. gauge wire is used as the heating element. The details of construction are shown in the radiograph reproduced in Fig. 2. The windings are held in place on an alundum tube with alundum cement; the distribution of turns is adjusted to give a maximum temperature gradient of ± 1°F. over a 4-in. gauge length (Fig. 3). To avoid sharp temperature differentials at the ends of the test section, the length of the furnace is four times the gauge length. Sixteen-inch coupons are used to reduce the temperature of the threaded

Jan 1, 1942

By David Keys

THE object of this investigation was to determine with a vertical magnetic variometer the extent of the titaniferous ore deposit that occurs not far from Ivry in Terrebonne County, Quebec, about 70 miles north of Montreal. The Ivry mine, on lots 37 and 38 of range V, Beres-ford township, Quebec, is one of the largest and most accessible to transportation of the deposits of ilmenite in Quebec. The ore consists of an aggregate of ilmenite anhedra serving as host for numerous fine plaques of hematite. No magnetite is known from any occurrence near this lot, and in this way the deposit differs from many others that contain a large percentage of magnetite with the ilmenite. The deposit at Ivry thus has much lower magnetic susceptibility than those containing abun-dant magnetite, and a sensitive magnetometer was necessary for the work, although a body of magnetite with ilmenite about a mile from the Ivry mine was successfully prospected with a dip needle. The principal orebody is exposed in a quarry known as the Ivry mine, from which about 16,000 tons of ore have been shipped. Small exposures of ilmenite isolated by drift serve to show the presence at the surface of some of the bodies indicated by the magnetometer,- but most of the hill is covered with glacial till and second growth hardwood. At the lower levels the till gives place to fluvioglacial sands and gravels from which the forest has been cleared. The increasing thickness of the sand and gravel as the hill descends makes the tracing outward of the deposits from the rocky knob of anorthosite a difficult matter. Within the orebodies too, some masses of anorthosite persist, which may account for some local irregularities. Fig. 1 is a photomicrograph, taken by reflected light, of a typical specimen of the ore. The dark patches are hematite and the light parts are ilmenite. No trace of magnetite was found. Fig. 2 is a photo-micrograph of a thin section of the country rock showing the texture of the anorthosite. The mean of four analyses quoted by Robinson1 is: titanium, 19.26 per cent; iron 45:41 per cent.

Jan 1, 1936

By Frank G. Snyder, Paul E. Gerdemann

The Southeast Missouri lead district, located about 70 miles south of St. Louis, embraces four important sub-districts and several minor ones. The important sub-districts, in order of discovery, are Mine La Motte, the Old Lead Belt, Indian Creek, and the Viburnum Lead Belt. Descriptions that follow are of geology and ore deposits of the Old Lead Belt. The ore deposits are stratiform in character and are localized in a narrow carbonate bar and algal reef environment on the flanks of exposed Precambrian of the St. Francois Mountains. Ore structures include a variety of primary depositional features such as pinchout zones, disconformities, ridge structures, reefs, and submarine gravity slides. Faulting, prior to and during ore deposition, "prepared" the host rock and strongly fractured areas are mineralized much more intensively and extensively than unfractured parts of the same sedimentary structures. The deposits are epigenetic in character. Mineralization is believed to have occurred at the time that post-lower Ordovician faulting took place. The mineralizing solutions are believed to be concentrated brines from adjacent basins that moved out of the basins during faulting, uplift, and erosion of the St. Francois positive area.

Jan 1, 1968

THE Executive Board of The American Engineering Council met in Pittsburgh, May 26 and 27. Its actions on the licensing of engineers and on the Employment Bureau are printed at length elsewhere in this issue. The board announced plans purposing the solution of the national problems of water power and forestry, upon which "the industrial development of the nation and the standard of living of future generations largely depends. The whole Federal water-power situation is in so critical a condition that immediate constructive action by the Government to conserve the public interests, involving vast consequences of economic and Federal policy, is necessary. After a long discussion during which the water-power problem as it affects Government reorganization was reviewed and Henry Ford&apos;s Muscle Shoal&apos;s plan was discussed, the board decided to lay the entire question before President Harding. A national movement to conserve the nation&apos;s forests, in which engineers, the U. S. Forestry Service, the forestry services of the states, universities and technical schools, and other groups such as the farmers, the railroads, and lumbermen, shall pool their efforts, was set in motion by the engineers. The work will be in charge of a Reforestation Committee of the Council, headed by Charles H. MacDowell of Chicago. Mov-ing picture interests will be asked to aid. The board pledged its support to President Harding in his plan for Government reorganization. In adopting the report of its Committee on Public Affairs, headed by J. Parke Channing of New York, the Executive Board of the council determined, in the event of the failure of the President&apos;s efforts to bring about greater economy and ffieciency in national affairs by regrouping of Federal functions, to press independ-ently a nation-wide movement for the establishment of a Department of Public Works. Progress in a national survey of the two-shift day in American industries was reported by the Council&apos;s Committee on Work Periods in Continuous Industries. This survey, called the most extensive of its kind ever made, has been in progress for more than a year; and purposes an exposition of industrial conditions which shall form a basis for establishing the relative merits of three shifts of eight hours each and two shifts of twelve hours each.

Jan 7, 1922

By J. French Robinson

A review of production in the Eastern District for 1930 is necessarily brief. Drilling operations were curtailed, due to economic conditions, which in turn reduced production. However, in spite of these conditions, there have been a few outstanding developments which surpass any of recent years. The development of a field in Chautauqua and Cattaraugus counties, New York, has been rapid and probably reached its peak of production in 1930. The gas in this field comes from the White Medina Sand (Silurian), at an average depth of 2600 ft. Some of the wells had an open flow of 20,000,000 cu. ft. of gas per day,&apos; with an original rock pressure of 965 pounds2 per square inch. Another area developed during 1930 was the Tyrone field, in Tyrone Township, Schuyler County, New York. This field was discovered 2nd is practically controlled by the Belmont Quadrangle Drilling Corpn. of New York. The production is from the Oriskany Sand (Devonian), which is found at an average depth of 2100 ft. The field covers approximately 2000 acres, and to date has 14 producing gas wells. The largest well had an open flow of 15,000,000 cu. ft. and an original rock pressure of 740 Ib. The gas from this field is impregnated with sulfur, and requires washing before it is marketed. Because little is known of the Oriskany Sand, a brief description may be of interest. This sand outcrops at Oriskany Falls, New York, and has a thickness of 10 to 12 ft. Its texture is coarse grained, it is composed mostly of quartz and is a regularly bedded sandstone. At Yauger&apos;s Wood, in Cayuga County, New York, it is exposed and shows a thickness of 26 feet. The discovery of the Tyrone field led to much prospecting in the New York and the northern part of Pennsylvania, and as a result of this search, the Allegany Gas Co. struck a large gas well in Farmington Township, Tioga County, Pennsylvania, which created considerable excitement through the Eastern District. The gas was encountered at a depth of 4010 ft., and tested 20,000,000 cu. ft. open flow, with a shut-in pressure

Jan 1, 1931

By M. O. Holowaty, C. M. Squarcy

1750 to 1850: The scene shifts westward across the Alleghenys to the young town of Pittsburgh; charcoal gives way to mineral coal as furnaces grow larger and the blast is heated; above all, Pennsylvania iron is adding strength to the new Nation and building an empire in the West. TWO names are inseparably associated with the Pittsburgh iron industry-those of George Anschutz and John Hayden. The iron ore deposits of southeastern Pennsylvania were found and developed early in the 18th century, and several forges and furnaces were built and operated. It was only after the revolution that the iron men crossed the Susquehanna River, built furnaces in the neighborhood of ore deposits of Franklin County, then along the Juniata River and its valley. Juniata Iron found a ready market in the Pittsburgh area. However, difficulty in transporting it across the Allegheny Mountains induced iron mas¬ters to seek ore and plant locations in the Pittsburgh district. One of the first to reach this area was George Anschutz, who migrated to America in 1789 at the age of 36, reaching Pittsburgh in the fall of 1790. Anschutz immediately set out to organize an iron company in Pittsburgh, and was able to interest some residents in his project. After being informed of an iron ore deposit located only three miles out of town (on the site of the present 26th St. and the Allegheny River) he decided to build there his blast furnace and foundry plant. Total cost of the installation was $300. When the furnace was put in operation, Anschutz, now known as Red George, found that the ore deposit was only an insignificant one and would last no more than a few weeks. A new deposit was found on Roaring Run, in the southeastern corner of Armstrong County. Anschutz transported some of this ore to the mouth of Two Mile Run, where it was loaded on horse wagons and transported to the furnace. In this way, he operated off and on for several months, until the furnace was blown out in 1794. After working for a year as plant manager for John Probst at Langhorntown, he built the Hunting-

Jan 1, 1961

By J. D. Price, W. M. Bertholf

In preparing a paper on coal washing in Colorado and New Mexico, it is difficult to refrain from entering into a discussion of the historical aspects of this subject, for the story of coal washing in these states goes hack well into the last century. This phase of the subject could well make a complete paper in itself, and of necessity this present discussion must be limited to current operations. Therefore, we are taking into consideration only those washing plants which have operated for some period during the years of 1947 and 1948. Summary Of the eight million tons of coal mined in the two states in 1947. ap- proximately two million tons were washed in wet washing plants, using concentrating tables or jigs. The one table plant accounted for 70 pct of the output of washed coal, and two large Baum jig plants accounted for an additional 26 pct, leaving only a small residual tonnage to be accounted for by other types of jigs The necessity for washing coal is occasioned by the desire or necessity of reducing the ash content of the coals— sulphur is not a problem in this area. All washeries, except the table plant, are at or near the tipple, hence wash only one kind of coal. At the table plant a large number of different coals are washed. Only at the table plant is there any occasion for drying any considerable quantity of fine coal— other plants size and/or dewater on shaking screens. The results of washing at the smaller plants are judged by the number (or lack) of complaints about the quality of the washed coal. This is probably as good a system as can he devised for small, intermittent operations. The efficiency of the Baum jig ap-pears to be quite high. This is to be expected as long as the automatic control of the refuse gate operates properly. The efficiency of the concentrating table is not as high as that of the Baum jig, especially when the "difficulty" of washing is taken into consideration. When dealing with coals in which the "bone" is larger than the "coal," the table appears to be at a definite disadvantage, because of its sizing action.

Jan 1, 1950

By P. A. Beck, L. J. Demer

As reported in a previous publication,&apos; isothermal grain growth in high purity aluminum and in an aluminum alloy with 2 pct magnesium can be adequately described by means of the empirical relation: Here, D is the average gain size after an annealing period 1. The annealing period includes the time for complete recrystal-lization R, and the time for gain growth 1,. D, is the pain size as recrystallized, n is a parameter depending on the temperature and on the material. The effect of 2 pet magnesium in solid solution was to decrease D, and to increase R, A and n at a given temperature. The present work was undertaken in order to investigate the above listed-effects of magnesium in solid solution, as functions of the magnesium content. The work also includes the study of certain anomalous effects observed in the recrystal-lization and grain growth of the 2 pct magnesium alloy at 350°C. Experimental Procedure The method of producing the ingots used in this work was described in detail1 and need not be reproduced here. The materials used were high purity aluminum, furnished by the Aluminum Co. of America, of lot analysis shown in Table r and magnesium from a high purity distilled stock of magnesium crystals. Table i—Lot Analysis of High Purity Aluminum Per CeNt Si.................................... 0.00~ Fe.................................... 0.002 Cu................................... 0.002 Mg................................... 0.003 Mn................................... o. oox Ingots were prepared for a series of binary aluminum-magnesium alloys of increasing alloy content. The numbers used to designate these ingots and their magnesium contents by chemical analysis are given in Table 2. Table 2—Ingot Numbers and Magnesium Contents Ingot Number Pct oa Magnesium aI 2.05 22 1.80 24 0.12 26 0 02s The analyses showed no difference in composition between the top and the bottom of the ingots. Spectrographic analysis of the ingots for elements other than magnesium showed, within the limits of accuracy of the method, no increase in impurities over the amounts given in the lot analysis for the high purity aluminum in Table I. Careful microscopic study of ingot 21 in the as-cast condition, at magnifications up to I 500X, revealed a cer-

Jan 1, 1949

By L. S. Castleman, H. A. Froot

A study was made of the growth kinetics of B-brass layers in a-brass us y-brass diffusion couples in which both phases were saturated in the 6 phase. It was found that useful estimates can be made of the difhsion coefficients at the ß-phase interfaces from interface displacement data, which are relatively easy to measure experimentally; also, a useful estimate can be made of the mean heat of activation for diffusion from layer growth data. The effects of pressure on layer growth kinetics were explored and found to be consistent with a vacancy model for diffusion in 6 brass in both the disordered and ordered temperature range. 1 HE study of multiphase diffusion receives relatively little attention in comparison with that devoted to diffusion in homogeneous materials. Of the hundred or so papers on diffusion written each year,&apos; only a few are devoted to the subject, and it is the rare review article2,3 that devotes any space to multiphase diffusional phenomena. This is unfortunate, since the metallurgist frequently encounters practical situations involving cementation processes such as cladding, protective coating of metals, and so forth in which he needs guidance of a fundamental nature. The investigation of multiphase diffusion phenomena is complicated by the fact that one must consider reactions at phase interfaces as well as the migration of atoms within the individual phases; these reactions cause the interfaces to be displaced within the diffusion zone. The relative displacement of two adjacent interfaces corresponds to the growth of an intermetallic layer, and it is not difficult to determine experimentally the kinetics of layer growth. In the past few years it has been pointed out4,5 that valuable fundamental information may be gained about diffusion coefficients and the concentrations at interfaces through a study of their motion. Accordingly, it is the purpose of this paper to report the results of an investigation of interface motion in a simple multiphase binary system. In the work reported herein, attention was focussed on the growth of a 6 -brass layer in a diffusion couple prepared from a- and y-brass compositions saturated with respect to the 6 phase. This particular system was chosen for a number of reasons. First, the bcc ß-brass phase is disordered for all compositions at temperatures above 468°C and becomes increasingly long-range ordered for all compositions at temperatures below 454° C;6,7 thus, the effects of a variation in order on interface displacement could be determined. Second, diffusion coefficients have already been obtained as a function of temperature in the ß phase both in the ordered and disordered Re- and a theoretical picture of the mechanism of diffusion in this and other ordered solutions is emerging.11&apos;12 Third, some thermodynamic data are available for the a-, ß-, and ?-brass phases,13,4 and these data could be used to gain insight into questions of phase equilibria and concentrations at phase interfaces.

Jan 1, 1963

The Secretary : The work of Mr. A. E. Outerbridge, Jr., of Philadelphia, first made known in his paper on " The Mobility of Molecules of Cast-Iron," read at the Pittsburgh Meeting of the Institute, in February, 1896, has been reviewed by the Committee on Science and the Arts of the Franklin Institute, whose report, dated May 5, 1897, is accompanied with a table of tests made by the Committee, and amply confirming the statements of Mr. Outerbridge. Concerning the originality and novelty of his investigation, the Committee says: " The fact that a certain molecular change takes place in cast-iron in the course of time has been known and recognized by many persons for a long time, and that this change tends to relieve the internal strains and render the casting tougher has often been noticed and acted on, although in a very crude way; but, so far as the sub-committee has been able to learn, Mr. Outerbridge has been the first to make a careful study of this, and to note that the change may be hastened by impact, and the whole effect produced in a short time, and also to make a scientific study of the phenomenon. We believe great credit is due him for the initial observation and the careful work dependent thereon. The results were first given to the public in a paper read before the American Institute of Mining Engineers, on February 20, 1896. This aroused a wide-spread interest and discussion among users of cast-iron, and so far as the sub-committee has been able to determine, it has not been shown that anyone, either in this country or abroad, has antedated Mr. Outerbridge in his work in this line. The Franklin Institute therefore recommends the award to him of the John Scott Legacy Premium and Medal." This report has not been published, hut I have had the opportunity to read it in manuscript. The table of testa accompanying it comprises 91 tests of " rumbled" and an equal number of " not rumbled" companion-bars of cast-iron, 26 by 2 by

Jan 1, 1898

By Samuel S. Wyer

THE installation of the gas-producer power-plant in America has been so unusual that all engineers have viewed it with in¬terest; a large majority, however, regard it with a lack of con-fidence and many with positive distrust. Despite the fact that European engineers have usually been less inclined to take the initiative along experimental lines than are Americans, they have, nevertheless, developed the gas-producer plant to a very high state of efficiency to which they were forced by the neces¬sity of economy in fuel-consumption. The gas-producer power-plant is so common in Europe that engineers as well as the general public regard it with the same degree of confidence that is now universally placed in steam¬plants. Gas-engines, both small and large, are in general use there, and central stations, aggregating several thousand horse¬power, are quite numerous. The fact that gas-producer power-plants have received so little attention in America may be attributed to five conditions:-1&apos;, ignorance and prejudice; 2, newness of work; 3, in-

Mar 1, 1905

By C. E. Abbott

The Birmingham district, Alabama, is distinctive in the proximity to one another of its deposits of iron ore, coal and flux. These three basic requisites for the making of iron and steel are found within a radius of 10 miles. Both dolomite and limestone are produced, the former for blast-furnace flux and the latter for basic open-hearth operations. The Tennessee Coal, Iron and Railroad Co., a subsidiary of the United States Steel Corporation, operates a limestone mine at Muscoda, near Bessemer, 12 miles southwest of Birmingham, served by its own railroad transportation system. The mine has a capacity of 130 tons per hour. Average analyses of a recent month&apos;s production arc as follows: Fe²zO³ SiO² Al²O³ CaCO³ MgCO³ Lump, percent............................. 0.51 0.22 98.63 0.14 Crushed and washed, per cent,................ 0.70 0.26 98.36 0.18 Lump stone, 2 1/2 to 755 in., is used in open-hearth operations at Fairfield Steel Works. Fine crushed and washed stone, 1% to 0.063 in., is calcined at the lime-burning plant and used for lime charges at the Ensley open hearths. Geology The district&apos;s deposits of hematite ore occur in the Clinton formation, and the limestone beds mined are stratigraphically 330 ft. above the ore beds worked. A cross section on the center line of the mine is shown in Fig. 1. This limestone formation, 130 ft. thick, is in the Warsaw horizon of the Lower Mississippian. It lies above 100 ft. of Fort Payne chert, which is immediately above the Clinton formation, and is composcd of layers of chert and cherty limestone, approximately 50 per cent of the material being pure chert. The chert is extremely hard, and the cost of driving raises through it is very high. Both iron ore and limestone deposits lie on the southwest limb of the Jones Valley anticline, the formations dipping from 15&apos; to 32&apos; to the southeast. The iron-ore seam outcrops along the crest of Red Mountain, a ridge with northeast-southwest trend rising 200 to 300 ft. above Jones and Shades valleys at the

Jan 1, 1938

By C. E. Abbott

The Birmingham district, Alabama, is distinctive in the proximity to one another of its deposits of iron ore, coal and flux. These three basic requisites for the making of iron and steel are found within a radius of 10 miles. Both dolomite and limestone are produced, the former for blast-furnace flux and the latter for basic open-hearth operations. The Tennessee Coal, Iron and Railroad Co., a subsidiary of the United States Steel Corporation, operates a limestone mine at Muscoda, near Bessemer, 12 miles southwest of Birmingham, served by its own railroad transportation system. The mine has a capacity of 130 tons per hour. Average analyses of a recent month&apos;s production arc as follows: Fe²zO³ SiO² Al²O³ CaCO³ MgCO³ Lump, percent............................. 0.51 0.22 98.63 0.14 Crushed and washed, per cent,................ 0.70 0.26 98.36 0.18 Lump stone, 2 1/2 to 755 in., is used in open-hearth operations at Fairfield Steel Works. Fine crushed and washed stone, 1% to 0.063 in., is calcined at the lime-burning plant and used for lime charges at the Ensley open hearths. Geology The district&apos;s deposits of hematite ore occur in the Clinton formation, and the limestone beds mined are stratigraphically 330 ft. above the ore beds worked. A cross section on the center line of the mine is shown in Fig. 1. This limestone formation, 130 ft. thick, is in the Warsaw horizon of the Lower Mississippian. It lies above 100 ft. of Fort Payne chert, which is immediately above the Clinton formation, and is composcd of layers of chert and cherty limestone, approximately 50 per cent of the material being pure chert. The chert is extremely hard, and the cost of driving raises through it is very high. Both iron ore and limestone deposits lie on the southwest limb of the Jones Valley anticline, the formations dipping from 15&apos; to 32&apos; to the southeast. The iron-ore seam outcrops along the crest of Red Mountain, a ridge with northeast-southwest trend rising 200 to 300 ft. above Jones and Shades valleys at the

Jan 1, 1938

By A. L. Holley

The first session was held in the rooms of the American Philosophical Society, on Tuesday evening, February 26th. The President, Dr. T. Sterry Hunt, called the meeting to order, and after a few introductory remarks concerning the importance of theoretical and speculative science, which often involves principles of the highest economic value, and, more than all that, serves to enlarge our conceptions of the universe, and ennoble us, by the cultivation which it affords to our most exalted faculties, proceeded to discuss some points in the chemistry of the atmosphere. It is known that there is in the crust of the earth a great amount of oxidized carbon, not only in the shape of coal, but also in the graphite or plunlbago of the crystalline rocks, in the various bituminous shales or pyroschists, which are found in all succeeding rock-formations, and also in the forms of bitumen and petroleum. All the analogies of nature lead us to conclude that these various carbonaceous substances have had an organic origin, and have been generated by the deoxidation of carbonic acid, a process effected by the growing plant, and attended with the liberation of oxygen. He showed that the carbon of a layer of coal covering the whole earth&apos;s surface to the thickness of one meter, would, in its production from carbonic dioxide, liberate an amount of oxygen equal to that now present in our atmosphere. But bituminous coal contains also a large amount of hydrogen, derived from the deoxidation of water, which implies the liberation of a farther portion of oxygen. The amount from this latter source would equal, for the various coals and asphalts, from one-eighth to one-fourth, and, for the petroleums, onehalf of that set free in the deoxidation of the carbon which these hydrocarbonaceous bodies contain. From what we know of the composition of the stratified rocks, it is probable that they include an amount of deoxidized carbon and hydrogen many times greater than that contained in a layer of coal one meter in thickness, and, consequently, that the disengaged oxygen in past ages must have far exceeded that now present in our atmosphere. To this must be added

Jan 1, 1879

THE first session was held in the rooms of the American Philosophical Society, on Tuesday evening, February 26th. The President, Dr. T. Sterry Hunt, called the meeting to order, and after a few introductory remarks concerning the importance of theoretical and speculative science, which often involves principles of the highest economic value, and, more than all that, serves to enlarge our conceptions of the universe, and ennoble us, by the cultivation which it affords to our most exalted faculties, proceeded to discuss some points in the chemistry of the atmosphere. It is known that there is in the crust of the earth a great amount of oxidized carbon, not only in the shape of coal, but also in the graphite or plumbago of the crystalline rocks, in the various bituminous shales or pyroschists, which are found in all succeeding rock-formations, and also in the forms of bitumen and petroleum. All the analogies of nature lead us to conclude that these various carbonaceous substances have had an organic origin, and have been generated by the deoxidation of carbonic acid, a process effected by the growing plant, and attended with the liberation of oxygen. He showed that the carbon of a layer of coal covering the whole earth&apos;s surface to the thickness of one meter, would, in its production from carbonic dioxide, liberate an amount of oxygen equal to that now present in our atmosphere. But bituminous coal contains also a large amount of hydrogen, derived from the deoxidation of water, which implies the liberation of a farther portion of oxygen. The amount from this latter source would equal, for the various coals and asphalts, from one-eighth to one-fourth, and, for the petroleums, one-half of that set free in the deoxidation of the carbon which these hydrocarbonaceous bodies contain. From what we know of the composition of the stratified rocks, it is probable that they include an amount of deoxidized carbon and hydrogen many times greater than that contained in a layer of coal one meter in thickness, and, consequently, that the disengaged oxygen in past ages must have far exceeded that now present in our atmosphere. To this must be added

Jan 1, 1878

The first session was held in the rooms of the American Philosophical Society, on Tuesday evening, February 26th. The President, Dr. T. Sterry Hunt, called the meeting to order, and after a few introductory remarks concerning the importance of theoretical and speculative science, which often involves principles of the highest economic value, and, more than all that, serves to enlarge our conceptions of the universe, and ennoble us, by the cultivation which it affords to our most exalted faculties, proceeded to discuss some points in the chemistry of the atmosphere. It is known that there is in the crust of the earth a great amount of oxidized carbon, not only in the shape of coal, but also in the graphite or plunlbago of the crystalline rocks, in the various bituminous shales or pyroschists, which are found in all succeeding rock-formations, and also in the forms of bitumen and petroleum. All the analogies of nature lead us to conclude that these various carbonaceous substances have had an organic origin, and have been generated by the deoxidation of carbonic acid, a process effected by the growing plant, and attended with the liberation of oxygen. He showed that the carbon of a layer of coal covering the whole earth&apos;s surface to the thickness of one meter, would, in its production from carbonic dioxide, liberate an amount of oxygen equal to that now present in our atmosphere. But bituminous coal contains also a large amount of hydrogen, derived from the deoxidation of water, which implies the liberation of a farther portion of oxygen. The amount from this latter source would equal, for the various coals and asphalts, from one-eighth to one-fourth, and, for the petroleums, onehalf of that set free in the deoxidation of the carbon which these hydrocarbonaceous bodies contain. From what we know of the composition of the stratified rocks, it is probable that they include an amount of deoxidized carbon and hydrogen many times greater than that contained in a layer of coal one meter in thickness, and, consequently, that the disengaged oxygen in past ages must have far exceeded that now present in our atmosphere. To this must be added

Jan 1, 1879