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By I. R. Kramer, P. D. Gorsuch, D. L. Newhouse

Although many methods have been suggested for the calculation of tensile strength and yield point from chemical composition, their usefulness has been limited to a particular cooling rate or section size. Further limitations have been imposed by failure to take into account many of the alloying elements that exert a considerable influence on the tensile strength or yield point. These systems, nevertheless, have filled an important need in many instances. The value of a system for the calculation of the tensile properties from the chemical composition and cooling rate is that it permits the prediction of the effect of alloying elements and heat-treatment on the mechanical properties, so that more efficient use of alloying elements may be made. Furthermore, it aids in the choice of steel for a given application aid tends to decrease the number of steels that otherwise would have to be tested. It is the purpose of this work to present a method of calculating tensile strength and yield point from the chemical composition and to suggest a method of correlating the tensile-strength and yield-point factors and cooling rate. Steelmakers have been interested for many years in the calculation of the tensile strength of hot-rolled steels. Quest and Washburn' summarize several of the attempts that have been made to devise formulas. They show the inadequacy of each of these formulas and present one of their own. It is apparent from their work that a simple additive equation of the type TS = A + BX + Cy + DZ + . . . , where A, B, C, D, etc. are experimentally determined constants and x, y, z, etc., are the percentages of alloying elements present in the steel, is not adequate to analyze fully the situation encountered in the calculation of tensile strength. For example, it was found that the difference between the calculated and observed values became progressively greater as the carbon and manganese contents were increased. Therefore, the effect of manganese was given as a function of the carbon content. Grossmann, in his work on the harden-ability of quenched steels, and Walter, in his method of calculation of tensile strength of normalized steels, present two cases in which multiplying factors were successfully used to express the combined effect of alloying elements. The factors in both cases were obtained from the fractional increase in hardenability or tensile strength with increase of alloy content. Yield point often is more important in design than tensile strength. For quenched and tempered steels a linear correlation exists between yield 2nd tensile strength.4 This is not true, however, for normalized

Jan 1, 1948

By P. D. Gorsuch, I. R. Kramer, D. L. Newhouse

Although many methods have been suggested for the calculation of tensile strength and yield point from chemical composition, their usefulness has been limited to a particular cooling rate or section size. Further limitations have been imposed by failure to take into account many of the alloying elements that exert a considerable influence on the tensile strength or yield point. These systems, nevertheless, have filled an important need in many instances. The value of a system for the calculation of the tensile properties from the chemical composition and cooling rate is that it permits the prediction of the effect of alloying elements and heat-treatment on the mechanical properties, so that more efficient use of alloying elements may be made. Furthermore, it aids in the choice of steel for a given application aid tends to decrease the number of steels that otherwise would have to be tested. It is the purpose of this work to present a method of calculating tensile strength and yield point from the chemical composition and to suggest a method of correlating the tensile-strength and yield-point factors and cooling rate. Steelmakers have been interested for many years in the calculation of the tensile strength of hot-rolled steels. Quest and Washburn' summarize several of the attempts that have been made to devise formulas. They show the inadequacy of each of these formulas and present one of their own. It is apparent from their work that a simple additive equation of the type TS = A + BX + Cy + DZ + . . . , where A, B, C, D, etc. are experimentally determined constants and x, y, z, etc., are the percentages of alloying elements present in the steel, is not adequate to analyze fully the situation encountered in the calculation of tensile strength. For example, it was found that the difference between the calculated and observed values became progressively greater as the carbon and manganese contents were increased. Therefore, the effect of manganese was given as a function of the carbon content. Grossmann, in his work on the harden-ability of quenched steels, and Walter, in his method of calculation of tensile strength of normalized steels, present two cases in which multiplying factors were successfully used to express the combined effect of alloying elements. The factors in both cases were obtained from the fractional increase in hardenability or tensile strength with increase of alloy content. Yield point often is more important in design than tensile strength. For quenched and tempered steels a linear correlation exists between yield 2nd tensile strength.4 This is not true, however, for normalized

Jan 1, 1948

By P. D. Gorsuch, D. L. Newhouse, Irvin R. Kramer

ALTHOUGH many methods have been suggested for the calculation of tensile strength and yield point from chemical composition, their usefulness has been limited to a particular cooling rate or section size. Further limitations have been imposed by failure to take into account many of the alloying elements that exert a considerable influence on the tensile strength or yield point. These systems, nevertheless, have filled an important need in many instances. The value of a system for the calculation of the tensile properties from the chemical composition and cooling rate is that it permits the prediction of the effect of alloying elements and heat-treatment on the mechanical, properties, so that more efficient use of alloying elements may be made. Furthermore, it aids in the choice of steel for a given application and tends to decrease the number of steels that otherwise would have to be tested. It is the purpose of this work to present a method of calculating tensile strength and yield point from the chemical composition and to suggest a method of correlating the tensile-strength and yield-point factors and cooling rate. Steelmakers have been interested for many years in the calculation of the tensile strength of hot-rolled steels. Quest and Washburn' summarize several of the attempts that have been made to devise formulas. They show the inadequacy of each of these formulas and present one of their own. It is apparent from their work that a simple additive equation of the type TS = A + BX + Cy + DZ + ? ? ? , where A, B, C, D, etc. are experimentally determined constants and x, y, z, etc., are the percentages of alloying elements present in the steel, is not adequate to analyze fully the situation encountered in the calculation of tensile strength. For example, it was found that the difference between the calculated and observed values became progressively greater as the carbon and manganese contents were increased. Therefore, the effect of manganese was given as a function of the carbon content. Grossmann,2 in his work on the hardenability of quenched steels, and Walters,3 in his method of calculation of tensile strength of normalized steels, present two cases in which multiplying factors were successfully used to express the combined effect of alloying elements. The factors in both cases were obtained from the fractional increase in hardenability or tensile strength with increase of alloy content. Yield point often is more important in design than tensile strength. For quenched and tempered steels a linear correlation exists between yield and tensile strength .4 This is not true, however, for normalized

Jan 1, 1946

By Michael Tenenbaum

THE importance of semikilled steel as a high tonnage grade has long been recognized. The increasing severity of the applications for which semikilled steel is used makes it desirable to obtain further information regarding the features of open hearth practice and ingot structure that can affect steel performance in subsequent rolling and fabricating operations. Accordingly, an investigation is being carried out studying the structure of various types of semikilled steel ingots. This paper reviews some of the observations made and information gathered in this investigation. By definition, semikilled steel may be considered to include all nonrimming steels in which the natural shrinkage occurring during ingot solidification is offset to an appreciable degree by gas formation. Accordingly, this type of steel includes the entire range intermediate between rimmed and fully killed steel. The resultant ingot structures range from those of steels that have been capped to suppress a weak rimming action to those steels that have been killed in the furnace or ladle to the extent that no mold deoxidizer is required. A survey reported to the 1946 AIME Open Hearth Conference' reviewed the practices being used at 28 major plants for the deoxidation of semikilled steel. It was found that most plants divide the deoxidizing additions between the ladle and the mold many of the plants adding only minor amounts of deoxidizer to the bath or none at all. Silicon, aluminum and titanium were the only elements used for ladle and mold deoxidation. Mold deoxidizers were added as capping additions or as uniformly fed additions. Several practices were reported in which the steel was deoxidized in the ladle to the extent that little or no mold deoxidation was needed. No reference was made to grades capped by using special mold designs or special closures over the top of molds. Accordingly, specific examples of this type of practice will not be considered in this paper. It appeared from this survey of deoxidation practice that semikilled steel can be divided into three types, namely, capped semikilled, in which aluminum is added near the end of pour or after shut-off, intermediate semikilled steels, in which aluminum is fed uniformly throughout the pour, and semikilled steels requiring no mold deoxidation. In an attempt to cover the ingot structures obtained by the range of practices reported in the preceding survey, three series of experimental heats were made using increasing amounts of aluminum, silicon and titanium for ladle deoxidizers. The ladle deoxidizers were added as stick aluminum, 50 pct ferrosilicon and 20 pct ferrotitanium (4 pct carbon), respectively. Two methods of studying ingot structures were used. Ingots were removed from production, burned longitudinally and machined to allow observation of the central pipe and coarse blowholes. During the machining operation much of the finely porous subsurface structure was obliterated. Accordingly, observations were also made

Jan 1, 1947

By H. W. Mead, C. E. Birchenall

SELF-DIFFUSION in pure gold has been studied by Sagrubsky,1 McKay,2 Gatos and coworkers,3,4 and Okkerse.5 Sagrubsky used a sectioning technique but reported results far lower than any of the others. The work seems to be carefully done, and it appears that a factor of 60 must have been omitted in his calculations or the units misstated by an equivalent amount. McKay used a surface activity method, and Gatos and Kurtz, following Gatos and Azzam, applied autoradiography to the measurement of activity on an oblique section through the diffusion zone. These two investigations agree well with each other but give results below those reported here. Okkerse employed a very careful sectioning technique. Chemical interdiffusion in Au-Ag alloys has been measured under several concentration conditions. Average values of the diffusion coefficient for the range of 0 to 18 atomic pct Au were obtained by Braune.6 since the diffusion coefficient probably varies markedly over this range, the values may not be too useful. Also, a plot of these data suggests that grain boundary contributions may have been appreciable at the lowest temperature employed. Ebert and Trommsdorf7 give average values for 0 to 9 atomic pct Ag, and Johnson8 reports average values for 45 to 55 atomic pct Au. Johnson also measured silver and gold self-diffusion coefficients in 49.2 atomic pct Au alloys, and self-diffusion in pure silver. The self-diffusion of gold in pure silver has been determined by Jaumot and Sawatsky.10 Other measurements which do not cover a range of temperature or are of low precision are not mentioned in this account since a review by Kubaschewski is available." This contribution reports diffusion coefficients for self-diffusion in gold, self-diffusion of gold in Au-Ag alloys, and chemical diffusion in Au-Ag alloys. Although it had been intended to obtain silver self-diffusion data in the alloys it now appears unlikely that these measurements can be done soon, so a table has been worked out for a self-consistent scheme of diffusion coefficients which should not be too far from the true values. Experimental Details Experiments on pure metals were conducted using fine gold of 99.99+ pct Au and silver of the same purity. Alloys were prepared by melting the two metals together in a graphite crucible in vacuo and allowing the slug to solidify in the crucible. After machining to a cylinder about 0.85 in. diam each slug formed one half of a diffusion couple. Compositions were determined later by analyzing chips taken from the extremities of the diffusion zones. The gold used in the preparation of alloys was sometimes pure gold but was normally either in the form of clean pickled alloy from previous experiments or gold recovered by oxalic acid precipitation from warm aqueous solution. Chips from the various stages of experimentation were dissolved in aqua regia and the solution taken to low bulk, diluted with water, and again taken to low bulk before diluting for the precipitation. This precipitated gold contained a small amount of silver as the only impurity detectable by spectrographic analysis. Disks for use in diffusion couples had opposite plane faces abraded on emery paper as far as zero grit, were annealed for 12 hr at 900°C in argon, and had one face of each disk polished to 000 emery paper. Radioactive gold was plated at about 2 ma per sq cm from a small volume of cyanide solution containing 1 mg of inactive gold as a carrier. Specimens , were freshly abraded on 4/0 emery paper immediately prior to plating. In the case of the active couples disks of a similarly prepared but unplated alloy or pure metal were placed on top and welded to the active disk. With the concentration couples disks of different compositions were welded. Welding was performed after a pressure of 5,000 lb had been applied at

Jan 1, 1958

By B. M. Bird

ONE of the problems studied by the U. S. Bureau of Mines in cooperation with the University of Washington has been the re-treatment of table middlings. Hydraulic classification has given the best results. Instead of using the classifier to prepare the feed to the tables, as has been the practise for many years in ore dressing, it is used to separate part of a middling product that cannot be re-treated successfully on the table. Middlings are desirable in a table plant because the separation according to specific gravity is incomplete; that is, in the products of the table there is always an overlapping of free particles of coal and refuse that can be distinguished with heavy liquids such as are used in the float-and-sink test. The causes of this overlapping may be divided into two groups, those outside the table separation itself and those inherent in the table separation. The first of these groups includes, among other causes, the following: (1) poor adjustments of the table, (2) overloading or underloading the table, (3) irregularities in the quantity and quality of the feed, (4) irregularities in the power and water supply, and (5) a vertical danc-ing motion of the table deck due to weak foundations. These causes of overlapping are largely unnecessary in a properly designed and constructed plant; but whenever they are present they materially affect the character of the middling product, and hence the problem of re-treatment. The other group includes three additional causes: (6) small differences in specific gravity between coal and impurities, (7) a size-specific-gravity relationship of the coal and refuse particles in the table feed such that the sizing action of the table opposes the separation according to the specific gravity, and (8) shapes of particles that prevent a separation. The sixth, small differences in specific gravity, may be a very important reason for an incomplete separation. The change in specific gravity from coal to shale is always gradual and the designation of one part as coal and another part as refuse is arbitrary. If some specific gravity, such as 1.45, is chosen as the dividing point between washed coal and refuse,

Jan 1, 1928

By N. J. Grant, R. Nordheim

An extensive study was made of the aging characteristics of alloys based on the 80 pct Ni-20 pct Cr composition hardened with aluminum and/or titanium, each up to 4 pct. Aging was followed by means of hardness and hot electrical resistance measurements as well as by X-ray and microscopy. Stress rupture tests at 1500°F were utilized as a check on the predicted behavior. THE titanium and aluminum hardened Ni-Cr alloys, exemplified by Nimonic 80 and Inconel X, constitute one of the more important groups of alloys developed to meet the demand for materials retaining their strength at elevated temperatures. For service in the temperature range 1200" to 1500°F, these alloys offer high creep resistance. With increasing service temperature, however, the strength of the simpler Ni-Cr base alloys falls off rapidly so that above 1500°F there is a significant loss of strength. The present investigation was undertaken with the hope that a better understanding of the factors controlling the precipitation hardening of these alloys would make it possible to increase the useful service temperature range. Primarily this investigation involved the study of the effects of titanium and aluminum on the hardening and the subsequent softening at elevated temperatures. The titanium and aluminum contents were each varied between 0 and 4 pct by weight at a constant nickel to chromium weight ratio of about 4:1. (Except when otherwise stated, all compositions are expressed on a weight basis.) The major part of the investigation was confined to alloys with less than 0.06 pct C. Recently several papers dealing with the identity of the microconstituents in the titanium and aluminum hardened Ni-Cr alloys have been published. Using X-ray analysis of the residues from anodic dissolution, Rosenbauml was only able to identify carbides and nitrides in Nimonic 80 and Inconel X. However, since Rosenbaum worked with alloys in the hot rolled rather than in the aged condition, his results are inconclusive. Recently Hignett' reported that the hardening of Nimonic 80 was due to the controlled precipitation of Ni,(TiAl) having the cubic Ni3A1 structure. Taylor and Floydv-" published the results of an investigation of the nickel-rich corner of the Ni-Cr-Ti, Ni-Cr-Al, and Ni-Ti-A1 systems. In the Ni-Ti and the Ni-A1 systems the hexagonal Ni,Ti phase, 7, and the cubic Ni3A1 phase, -y', respectively, exist in equilibrium with the nickel-rich solid solution. The interatomic distances in the basal plane of Ni,Ti and the octahedral planes of the matrix are almost equal, thus explaining the Wid-manstaetten type structure formed when Ni,Ti precipitates from solid solution. When Ni:,Al precipitates from solid solution, it appears usually in globular form, often dispersed along rows corresponding to definite crystallographic directions. The 7 and phases are also the only intermetallic compounds which occur in the nickel ternary alloys with up to 25 pct Cr and 10 pct Ti or Al. Taylor and Floyd found that Ni,Ti takes practically no nickel, chromium, or aluminum into solution. Nial, on the other hand, dissolves a considerable amount of chromium and titanium and some nickel. Up to three out of every five aluminum atoms could be replaced by titanium in Ni,Al. This substitution caused a slight increase (less than 1 pct) in the lattice parameter. With respect to the effect of variation in the titanium and aluminum contents on the high temperature strength of Nimonic 80 type alloys, Pfeil, Allen, and Conway" reported that an 80 pct Ni-20 pct Cr alloy containing 0.20 to 0.30 pct A1 had the highest creep resistance when the titanium content was kept between 1.65 and 2.75 pct. Experimental Procedure The materials used for this investigation were electrolytic nickel, electrolytic or low carbon chromium, sponge titanium and 2s aluminum. The alloys were melted in an indirect carbon arc furnace under

Jan 1, 1955

By H. Y. Yancey, B. M. Bird

One of the problems studied by the U. S. Bureau of Mines in cooperation with the University of Washington has been the re-treatment of table middlings. Hydraulic classification has given the best results. Instead of using the classifier to prepare the feed to the tables, as has been the practice for many years in ore dressing, it is used to separate part of a middling product that cannot be re-treated successfully on the table. Middlings are desirable in a table plant because the separation according to specific gravity is incomplete; that is, in the products of the table there is always an overlapping of free particles of coal and refuse that can be distinguished with heavy liquids such as are used in the float-and-sink test. The causes of this overlapping may be divided into two groups, those outside the table separation itself and those inherent in the table separation. The first of these groups includes, among other causes, the following: (1) poor adjustments of the table, (2) overloading or underloading the table, (3) irregularities in the quantity and quality of the feed, (4) irregularities in the power and water supply, and (5) a vertical dancing motion of the table deck due to weak foundations. These causes of overlapping are largely unnecessary in a properly designed and constructed plant; but whenever they are present they materially affect the character of the middling product, and hence the problem of re-treatment. The other group includes three additional causes: (6) small differences in specific gravity between coal and impurities, (7) a size-specific-gravity relationship of the coal and refuse particles in the table feed such that the sizing action of the table opposes the separation according to the specific gravity, and (8) shapes of particles that prevent a separation. The sixth, small differences in specific gravity, may be a very important reason for an incomplete separation. The change in specific gravity from coal to shale is always gradual and the designation of one part as coal and another part as refuse is arbitrary. If some specific gravity, such as 1.45, is chosen as the dividing point between washed coal and refuse,

Jan 1, 1930

Abbey, Robert Graham, District Mgr.. The W. W. Sly Mfg. Co., 50 Church St.. New York, N. Y. '21 Abbott, A. N., Mines Supt., Mazapil Copper Co., LtdConcepcion del Oro, Zac., Mexico. '28 *Abbott, Argyle Campbell, Dev. Dept., E. I. du Pont de Nemours & Co., Wilmington, Del. '29 Abbott, Clarence E., V.P., Charge of Raw Materials, Tenn. Coal, Iron & R. R. Co., 1242 Brown-Marx Bldg.. Birmingham, Ala. '04 Abbott, Louis Benjamin, Chief Engr., Elkhorn Div., Consolidation Coal Co., Jenkins, Ky. '16 Abeel, George H., Jr., Cons. Min. Engr Box 427, Santa Monica, Cal. '18 Abel, Albert E., Asst. to Pres., Valley Mould & Iron Corp Hubbard, Ohio. '19 Abel, Raymond L., Asst. Prof., Dept. of Pet. Refin., Univ. of Pittsburgh Pittsburgh. Pa. '28 Abeel, Leo M., Research Engr., Sullivan Concentrator Chapman Camp, B. C., Canada. '31

Jan 1, 1929

By H. F. Haller

COLUMBIA-SOUTHERN'S Barberton limestone mine, 8 miles southwest of Akron, Ohio, is a million-ton-per-year producer from a depth of over 2200 ft in a district where other underground mining at this depth is unknown. Mining extracts 46 of the top 51 ft from a formation of Devonian limestone discovered by drilling in the 1890's. The same drilling revealed extensive salt deposits below the lime- stone, which led to the location of the chemical plant at Barberton as a division of the Pittsburgh Plate Glass Co. in 1899. Soda ash was the principal product of the plant, and as production increased the demand for limestone increased. Columbia's first attempt to secure a reliable all-weather source of stone was the development of a quarry at Zanesville, Ohio, in 1919. Zanesville production eliminated some of the stock- piling required by the use of Michigan stone, avail- able only during the lake shipping season. Stone from some Zanesville horizons, however, was found to be more suitable for cement production than for soda ash, and rail transportation remained an important factor. As demand continued to increase, plans were made to develop the Barberton deposit.

Jan 12, 1954

By JOHN A. MALONEY

AS noted in the February issue of MINING AND METALLURGY, an advisory committee to the Museum of Science and Industry of Chicago was authorized by the Institute's Board of Directors, with W. R. Wright of Chicago, former Director of the Institute, as chairman. Since that time the committee has been undergoing organization, and held its initial meeting at the Museum offices in Chicago on April 11 and 12. Functioning as consultants to the Geology and Mineral Industries branch of this new institution, the advisory committee is aiding in building an exhibit which will tell the story of geology, mining, and metallurgy to millions of visitors a year. Although patterned to some extent

Jan 1, 1932

By L. G. Marshall

WHILE surveying in a small Western mine, the following problem was encountered: Two traverses had to be connected by running a traverse line down the main hoisting shaft, which was the only connection between the two levels. The shaft was inclined at about 80 deg. from the horizontal and measured 8 by 10 ft. The distance between levels was about 110 ft., measured on one side of the shaft. The surveying equipment consisted of a transit, tripod, level rod, 100-ft. chain, and plumb bobs. There were no side or top the- scope attachments with which to take large, vertical angles. Therefore, we were confronted with the problem of taking readings between two points, one of which could not be seen through the instrument when set up under the other point, owing to the obstruction of the horizontal plate, and of measuring the distance between these points with a chain that was too short. The method of a line of plumb bobs down the shaft was impractical because a setup would be needed part way down the shaft, which would call a halt to all hoisting operations for some time. After considerable experimentation the following method was used.

Jan 1, 1936

By W. A. Boyer, A. W. Beck

At the Morning mine of American Smelting & Refining Co. it was particularly important that there be a means of signaling the engineer from the moving cage in the shaft. Because of the shifting ground in which the shaft was located, buckling timber made it extremely difficult to keep a continuous bell line serviceable. In 1930 engineers considered a moving contact pantograph arrangement between the cage and two stationary messenger wires strung on insulators in the shaft compartment next to the cage. The idea was abandoned because falling material in the shaft and speed of hoisting made it difficult to maintain communication. Later in 1934 a manufacturing company was consulted about the use of an electric eye or a radio signal. As the shaft was located in a return air stream of nearly 100 pct relative humidity, there was too much fog for the electric eye to be used. The radio signal was considered, and it was believed feasible to generate electric static on the cage, locating a radio receiver at the top of the shaft, but the manufacturing company's research department was too busy to work on it at that time.

Sep 1, 1955

By J. R. Campbell

It is the purpose of this paper to review somewhat in detail the literature on the subject that is extant, which ought to provoke considerable beneficial discussion. The value of 1 per cent. ash in blast-furnace practice was brought to the attention of the writer when he was connected with the U. S. Steel Corpn. Various groups of blast furnaces in the Pittsburgh district compiled a statement in which the average saving was about 6 c. per ton on pig iron for every 1 per cent. of ash reduction. Later, the same groups of furnaces, when materials had reached a higher price, compiled a statement in which there was a 30-cent saving on pig iron for every 4 per cent. ash reduction in the Pittsburgh district, which was equivalent to 7½ c. for every 1 per cent. ash reduction. In the Chicago district, on long freight hauls of coal and coke from the Pocahontas district, the set-up was 30 c. per ton of pig iron for every 2 per cent. ash reduction, or 15 c. for every 1 per cent. Some years ago, Ralph H. Sweetser, of the American Rolling Mill Co., presented a paper which provoked considerable comment.' To get the matter again before this body a résumé of his computations is given below: Comparison of Pig Iron Costs Ash in Coal. Ash in CoKe, Fixed Carbon in Coke peR Ton OB PIG Iron peN Day, Per Cent. PeR CeNt. Coke. Per Cent. PIG IRon. Lb. Tons 6.00 8.70 89.80 1800 365.0 7.00 10.15 88.35 1860 353.2 Coke with 8.70 Per Cent. Ash Ore mixture, 4144 It). = 1.85 tons @ $5.50.............................. $10.17 Coke, 1800 lb. = 0.90 ton @ $6.50..................................... 5.85 Limestone, 1000 lb. = 0.50 ton @ $1.50................................. 0.75 Labor, $365 per day on 365 tons....................................... 1.00 Supplies and service, $250 per day...................................... 0.68 Overhead, $200 per day............................................... 0.55 Reserve for relining and depreciation................................... 1.00 Total............................................................. $20.00

Jan 1, 1931

By Fred Jones

The Cripple Creek district is in Teller County, Colo., about 18 miles in an air line west of Colorado Springs and at an elevation of 10,000 It. A line drawn through Colorado Springs and Pikes Peak will, if continued, about pass through the district. The character of the country generally is rolling, with few trees and little snow fall. The annual precipitation is about 20 in. All the water used by the mines is supplied by the Altman Water Co., which pumps from the west slope of Pikes Peak. Gold was discovered in 1891, since which time the district has produced $411,000,000. The peak of production was reached in 1900 and amounted to $25,000,000. At present the production amounts to about $400,000 per month. Geology In general, the geology of the district is simple; ash veins and dikes traverse a volcanic plug of breccia. The ore occurs as enriched spots along these dikes and veins. The dikes represent the most recent extrusions and consist of basalt and phonolite. (For a complete geological description reference is made to Professional Paper 54, 1906, of the U. S. Geological Survey.) The ore consists of small parallel seams of high grade. In only a few cases is the gold disseminated through the rock; much of the gold in the broken ore is found in the fines. The wall rock is hard blocky granite or breccia. About 25 per cent. of the rock mined is shipped as ore to the Golden Cycle mill at Colorado Springs. The height of an ore deposit is usually several times its length. Few flat oreshoots have been found. The veins are all steep and have a dip of 70 to 80°. Development The claims are all 300 by 1500 ft. and are held by location or patent. All mining is done through shafts, one of which has reached a depth of 2600 ft. The main working shafts are 41/29 by 1335 It. and are made up of three compartments, each 4 by 41/2 ft. in the clear. They are timbered with 10-in. Oregon posts and plates and 8-in. spreaders. Two compart-

Jan 1, 1925

THE sessions of the Institute were opened on Tuesday evening, October 26th, at Garrett's Hall, by Mr. Charles A. Otis, Chairman of the Local Committee of Arrangements, who welcomed the Institute to Cleveland, and introduced Col. Charles Whittlesey, who ad¬dressed the Institute briefly on the coal deposits of Ohio. Col. Whittlesey described the situation and character of the coal-beds of the State, and gave a short history of the use of raw coal in the manufacture of pig-iron, and spoke of the excellent quality of metal produced. The aid that a body of scientific miners and metal¬lurgists were capable of giving in the development of coal and other mineral resources was dwelt upon, and the hope expressed that the visit of the Institute to Cleveland might be profitable as, well to its members as to the citizens of the State. The President, Mr. A. L. Holley, responded to the welcome of Mr. Otis and of Col. Whittlesey, and read an introductory address on Some Pressing Needs in the Iron and Steel Manufacture. The following members and associates, duly proposed and indorsed by the Council, were then elected MEMBERS. Alfred S. Bertolet, - Youngstown, Ohio. Henry Binnse, - Chicago, Ill. John Birkinbine, - Philadelphia. Andrew A. Blair, - Watertown Arsenal, Mass. Ogden Bolton, - Canton, Ohio. Lloyd Booth, - Youngstown, Ohio. E. Borda, - Philadelphia. N. P. Bowler, - Cleveland, Ohio. Alexander E. Brown, - Cleveland, Ohio. C. F. Brush, - Cleveland, Ohio. S. M. Carpenter, - Cleveland, Ohio. James Cartwright, - Youngstown, Ohio. Henry Chisbolm, - Cleveland, Ohio. Wilson B. Chisbolm, - Newburgh, Ohio. W. H. Clarke, - Millertown, Pa. James E. Clayton, - Ore Knob, N. C.

Jan 1, 1876

The sessions of the Institute were opened on Tuesday evening, October 26th, at Garrett's Hall, by Mr. Charles A. Otis, Chairman of the Local Committee of Arrangements, who welcomed the Institute to Cleveland, and introduced Col. Charles Whittlesey, who addressed the Institute briefly on the coal deposits of Ohio. Col. Whittlesey described the situation and character of the coalbeds of the State, and gave a short history of the use of raw coal in the manufacture of pig-iron, and spoke of the excellent quality of metal produced. The aid that a body of scientific miners and metallurgists were capable of giving in the development of coal and other mineral resources was dwelt upon, and the hope expressed that the visit of the Institute to Cleveland might be profitable as well to its members as to the citizens of the State. The President, Mr. A. L. Holley, responded to the welcome of Mr. Otis and of Col. Whittlesey, and read an introductory address on Some Pressing Needs in the Iron and Steel Manufacture. The following members and associates, duly proposed and indorsed by the Council, were then elected MEMBERS. Alfred S. Bertolet,.. .. . Youngstown, Ohio. Henry Binnse,. Chicago, Ill. John Birkinbine,.. .. . Philadelphia. Andrew A. Blair,. .. .. Watertown Arsenal, Mass. Ogden Bolton,. .. .. Canton, Ohio. Lloyd Booth,..Youngstown, Ohio. E. Borda,..Philadelphia. N. P. Bowler,.. .. . Cleveland, Ohio. Alexander E. Brown,.... Cleveland, Ohio. C. F. Brush,.. .. .Cleveland, Ohio. S. M. Carpenter,.. .. . Cleveland, Ohio. James Cartwright,.. .. . Youngstown, Ohio. Henry Chisholm,.. .. . Cleveland, Ohio. Wilson B. Chisholm,.. .. . Newburgh, Ohio. W. H. Clarke,.. .. . Millertown, Pa. James E. Clayton,. .. .. Ore Knob, N..C.

NEW MEMBERS The following list comprises the names of those persons who became members during the period Mar. 10 to Apr. 10, 1914. Members ADAMS, DANIEL T., Mining 1416 Westminster Bldg., Chicago, Ill. BLICKENSDERFER, FRANK CLEVELAND, Sampler Morenci, Ariz. CAVERS, THOMAS WILLARD, Met Copperhill, Tenn. CLAPP, CHARLES H., Geol Univ. of Arizona, Tucson, Ariz. CLARK, PATRICK T., Pres Bullwhacker Mine, Spokane, Wash. COMSTOCK, HARRY, Mining Mineville, Essex Co., New York. COOKE, JOSEPH H., Gen. Mgr Mono Dev. Co., Gisborn, Tooele Co., Utah. COOPER, DEXTER P., Civ. and Hyd. Engr 101 Park Ave., New York, N. Y. DEGOLYER, E. L., Geol Apartado 269, Tampico, Mexico. DESHAYES, ERNEST F., Mine Foreman Baldy, N. M. DOUGLASS, WILLIAM CRAWFORD, Min. Engr 107 Leonard Hotel, Butte, Mont.

Jan 5, 1914

By Sukune Takenouchi

Porphyry copper deposits in the southwestern Pacific region differ in some points of geologic features from those of the United States. The deposits distribute along old or active island arcs and are generally younger in age (1-16 m.y. B.P.). In Japan, however, no typical porphyry copper deposits are yet reported, though the geological situation of Japanese islands is similar to that of the southwestern Pacific. Fluid inclusions in some porphyry copper deposits In the southwestern Pacific region and those in igneous rocks genetically related to the ore deposits In Japan have been studied, and the genesis of ore-forming fluids from igneous rocks are discussed. From the results, the possibility of finding porphyry copper-type mineralization in Japan are considered.

Jan 1, 1976

NEW MEMBERS The following list comprises the names of those persons who became members during the period July 10 to Aug. 10, 1914: Members BAKER, FRED SHERMAN Tabowie, Unsan, Korea. BISSET, DANIEL GEORGE, Engr., 142 3d Ave., N. W., Edmonton So., Alberta, Canada.. BRANDT, MAURICE SHELDON, Chief Engr., White Eagle Mining & Milling Co., Box 298, Boulder, Colo. BROWNING, EDWARD, Min. Engr., Asst. to Supt., Cornwall Ore Bank Co., Cornwall, Pa. CASTLETON, WILLIAM ARTHUR, Mill Supt., East Butte Copper Mining Co., Butte, Mont. CHIDESTER, WALTER BARCLAY, Min. Engr., Care Mother Lode Mine, Greenwood, B. C., Canada. CLARK, EDWARD HARDY Mgr.,.Hearst Estate, 15 Broad St., New York, N. Y. CLARK, FREDERICK P., Chief Chem., International Lead Refining Co., East Chicago, Ind.

Jan 9, 1914