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By R. A. Bergman, C. J. B. Fincham

THERMODYNAMIC properties of many high-temperature systems containing sulfur, such as slags, metal sulfides, and solutions of sulfur in liquid metals, have been studied by means of equilibration with known gas mixtures.'" This method presupposes a complete and accurate knowledge of the thermodynamic data for all possible components of the gas phase at high temperatures. However, a survey of the data available up to 1952 on the thermodynamics of gaseous sulfur species and compounds, by Richardson and Jeffes,' showed that there was considerable uncertainty in the values of the free energies of formation of S, SO, HS, and CS. In many cases, this uncertainty made it impossible to decide whether or not these species would form a significant proportion of the sulfur present in the gas phase in any given system. After the review by Richardson and Jeffes had been published, St. Pierre and Chipman6 measured, by an indirect method, the free energy of formation of SO. This also enabled a clear choice to be made among the three possible spectroscopic values for the dissociation energy of S2 into atoms10 thereby determining the free energy of formation of S from S2, and fixing the free energy of formation of HS more accurately" The main purpose of the present investigation was to measure the free energy of formation of CS, which was still in considerable doubt. For example, at 1600°C, it could be estimated to be +6 +25 kcal per mole,* most of the uncertainty being in the * Based on the dissociation energles of CS6 and S2,5 the heat of sublimation of graphite, and, the assumption that the entropy of formation of CS is the same as that of CO. value of the dissociation energy." A secondary purpose of the investigation was to determine more accurately the equilibrium sulfur pressures over dilute solutions of sulfur in carbon-saturated liquid iron. General Method Dilute solutions of sulfur in liquid iron, saturated with carbon, were brought to equilibrium at 1600" and 1800°C, with known gas mixtures consisting, initially, of A and CS2. After equilibrium had been reached, the melts were quenched and analyzed for sulfur. In the high temperature region of the furnace, an equilibrium was set up between the various possible sulfur species and compounds in the gas phase; namely, CS2, CS, S2, and S. (It can be calculated that the amounts of S6 and S, are negligible at these temperatures:) Morris and Bueh17 and Kitchener, Bockris, and Libermana had previously studied the corresponding

Jan 1, 1958

By H. Hanemann

Discussion of the paper of H. HANEMANN and PAUL D. MERICA, presented at the New York meeting, February, 1916, and printed in Bulletin No. 108, December, 1915, pp. 2371 to 2385. JOHN A. MATHEWS, Syracuse, N. Y.-I should like to ask the authors if there is any evidence of chemical change resulting information of, alpha iron from the gamma crystals found in nickel steel of high nickel content when stressed beyond the elastic limit, similar to the effect produced by drastic cooling. Would the stresses mentioned and the drastic cooling both result in an increase in magnetic induction? I would also like to ask the authors if they have made a test of the hardness. It would be very interesting to see whether the hardness decreased under the conditions of stress, as might be the case if alpha iron were produced. PAUL D. MERICA, Washington, D. C.-While it is impossible to state absolutely, it is my belief that the effect of deformation is approximately the same as, that of -drastic cooling, but we did not make a test, of the hardness.

Jan 5, 1916

By W. R. Hamilton

The knowledge of the existence of petroleum in Southern California dates back to the days of the missions. The presence of asphaltum and semisolid bitumen was reported at Santa Barbara in 1792, but no serious attempt was made to develop oil until Professor Silliman's optimistic report in 1865 started California's first oil boom. Wells were drilled in many counties of the State, but the equipment was unsuitable and the drilling difficult and no production was obtained except in Ventura County. Even there the production was of little importance commercially, and not until the early '80s did it become sufficient to again attract attention. In 1888 the production for the State had reached a total of about 700,000 bbl. per year, practically all light oil produced in Ventura County, Pico Canyon, Los Angeles County and in the Puente Hills. The production of petroleum attained the dignity of an industry in 1895 when the Los Angeles City and Coalinga fields were discovered. The subsequent development has been remarkable, and in 20 years the production has increased from 1,000,000 to 100,000,000 bb1. per year. The refining industry has kept pace with the production of oil. The Pacific Coast Oil Co., the predecessor of the Standard Oil Co. of California, was the virtual pioneer refining company of the State, having built a refinery at Alameda about 1880. When purchased by the Standard, about 1902, it was dismantled and the refinery at Point Richmond was built. The Richmond refinery is now one of the largest in the world, having a capacity in excess of 60,000 bbl. per day. A small refinery was built by the Union Oil Co. at Santa Paula in the early days of the industry and later many asphalt refineries were in operation in Southern California. The Pacific Coast Oil Co. was then, as has been its successor, the Standard Oil Co. of California, the principal refiner and marketer of light products, the most valuable of which was kerosene. Before the opening of the twentieth century, gasoline of excellent quality was produced, though it was always a drug on the market and was produced for the simple reason that its presence rendered the flash and fire tests of the kerosene too low. The user of kerosene at the present

Jan 1, 1917

By J. N. Ong, J. P. Ratledge, J. H. Boyce

Since German operators opened the Tsumeb mine in the early 1900's, continuous operation has been interrupted only by enforced shutdowns during two world wars and the depression of the 1930's. Original metallurgical practice was blast furnace smelting. This was applicable only to low zinc ore, leaving large tonnages of high zinc ore to be stockpiled on the surface. A gravity concentrator using tables, buddles, and jigs operated for several years, but differential flotation of the ore did not get beyond the experimental stage. When the property was put up for sale by the South African Custodian of Enemy Property there was an estimated 434,000 tons of ore on surface dumps. The dump material, assaying 4.48 pct Cu, 15.8 pct Pb, and 10.9 pct Zn, had become highly oxidized during a stay of many years on the surface. But these dump ores had to be used in evaluating possible metallurgy because the shaft became flooded after the 1940 shutdown and underground ore was unavailable. Many companies examined Tsumeb but quickly lost enthusiasm because of the formidable metallurgical problems presented by the dump ore. However, on the basis of extensive test work, the present company decided that differential flotation would be successful and purchased the property after competitive bidding.

Jan 4, 1955

By D. D. Dunlop, J. R. Welker

The growing interest in the use of CO, in crude oil recovery increases the need for data on the effect of CO, on hydrocarbon physical properties. Data are presented on the solubility of CO, in various dead oils, the swelling changes in CO2-oil solutions and the effect of CO, on dead oil viscosity. This latter property shows the most pronounced effect, with viscosity reductions up to 98 per cent of the uncarbonated viscosities. An empirical method of estimating the viscosity of carbonated oils is presented. The apparatus and procedures used are described in sufficient detail to allow others to make similar studies. INTRODUCTION The effect of dissolved carbon dioxide on the swelling and viscosity reduction of specific hydrocarbon oils has been observed and recorded by a number of investigators.'- me object of this paper is to offer a means of predicting these effects for crude oils free from natural gas, using the dead state viscosity and gravity of the crude oils. The CO, solubility and swelling of numerous crude oils were determined in a visual cell at various pressure levels. The viscosity of the oils carbonated to various pressure levels was then determined by measuring the pressure drop across a capillary tube. From these data, the physical properties were correlated empirically. The resulting correlations allow the prediction of CO, solubility, swelling and viscosity reduction if the dead state gravity and viscosity of the oils are known. SOLUBILITY AND SWELLING MEASUREMENT EQUIPMENT AND PROCEDURE A high pressure visual cell was installed in a constant temperature cabinet. A test gauge was attached at the top of the cell for pressure measurement, and a line was run through the cabinet wall to a wet test meter which was used for volumetric measurement of the gas. The first step in making a test run was to put the oil in the cell up to a level about half to two-thirds of the total volume. This required about 50 to 65 ml of oil. carbon dioxide was then bubbled up through the oil for a time during which the pressure of CO2 in the cell was kept above 800 psia. Saturation of the oil with CO2 at this pressure and ambient temperature was confirmed by slowly bleeding CO2 through a valve to the atmosphere. If the oil was completely saturated with CO2, bubbles of gas would form in the oil at the first small decrease in pressure. If the oil was under-saturated, no bubbles formed until the pressure was decreased to the saturation pressure existing in the oil. If this saturation pressure was lower than that desired, more CO2 was bubbled through the oil until the desired level was reached. After saturation at ambient temperature was completed, the cabinet temperature was adjusted to the desired level and the cell was allowed to reach temperature equilibrium. After temperature equilibrium was reached, the pressure was again decreased slightly, and the oil again checked for full CO2 saturation at the cell pressure. The pressure now had changed because of the difference in solubility of the CO, in the oil at higher temperatures and the expansion of CO2 as the temperature increased. The outlet tube from the cell was then connected to the wet test meter and the CO2 was allowed to flow slowly out of the cell and through the wet test meter at ambient temperature and pressure. The water in the wet test meter had previously been saturated with CO2 at ambient temperature and pressure by allowing CO2 to flow continuously through it lor a period of several hours. The gas flow was stopped at several pressures during the run and the cell was allowed to come to equilibrium; this made possible the measurement of solubility and swelling data at the intermediate pressures. The volume of the oil in the cell was recorded at each of the equilibrium pressures in order to obtain swelling data. DATA AND RESULTS The solubility of CO2 in the oil was calculated by the relationship V — V, where R. = solubility of CO, in crude oil, cubic feet of CO, measured at 60F and 1.0 atm/ bbl of dead state oil at the temperature under which solubility was measured, V, = volume of gas released from the cell between the saturation pressure and zero pressure, corrected to 60F and 1.0 atm, cu ft, V, = volume of CO: contained in the gas space above the oil, corrected to 60F and 1.0 atm, cu ft, and V, = volume of the dead oil in the cell in bbl at the temperature of the run. The volumetric data of Sage and Lacey' were used to calculate V., from the volume of CO2 at high pressures. The swelling factor was calculated as where V, is the volume of the C0,-

By I. E. Puddington

The property of surface tension in liquids is said to have been known to Leonardo de Vinci in about 1500. Approximately'300 years later Thomas Young and others provided the ground rules relating surface tension to the wetting of solids and to the pressure drop across curved surfaces. In retrospect it seems remarkable that more than 100 additonal years were required for substantial technological use to be made of the-information. Thus super critical and freeze drying to avoid shrinkage of finely divided solids have only seen industrial use since the 1930's and doubtless additional possible applications will be equally slow in finding concurrence of conditions to make them attractive economically. The use of a second liquid phase that preferentially wets ,a suspended solid as a flocculant for that solid was pointed out in 1943 (1). Combining this phenomenon with mechanical energy to alter the morphology of the flocs or with surface chemistry to utilize it in the selective flocculation in mixed solids required more than an additional decade. A major stimulant in advancing surface energy based technology 'of suspensions was the report by D. I. Stock in 1952 (2) that mechanical agitation of a dry suspension of barium sulphate in benzene produced dense microspheres of the solid with highly desirable sedimentation characteristics. Investigation of this observation revealed that it resulted from small quantities of water in the system and mechanistically the phenomenon was identical with that reported in 1943.withthe addition of mechanical packing (3). Here then was a base from which to separate more efficiently suspended solids, to make small spheres from powders, to separate selected components from mixtures of finely divided solids or to break emulsions. Each of these possible branches of technology has been slow in developing on other than an experimental scale although considerable

Jan 1, 1979

By O. B. Harden

In working out the geological structure of a complicated district, where the problems are difficult to solve by the ordinary methods in use, a model, upon which all the geological and topographical data may be put, will be found of great value, bringing, as it does, all the facts in their proper relationship at once under the eye. In the teaching of structural geology, also, a model is of great value, since the student can thus have before him, in miniature, a representation of the rocks, as he would see them in place. Topographical models may often be useful in suits at law for damages in railroad accidents, or for trespass against mining companies, etc., in order

Jan 1, 1882

By S. W. Parr

FROM a study of sulfur with reference to its specific combination in coal, published as University of Illinois Bulletin No. 111, 1919, it is now possible to determine the various forms of this constituent with a good degree of accuracy. This fact suggests two questions: (1) Are the same analytic methods applicable to coke? (2) Is there any correlation between the forms of sulfur as it occurs in coal and the residual sulfur found in the finished coke? The answer to the second question might be helpful in answering a still further question as to what chemical route the sulfur travels during the carbonization process. While the special studies along these several lines are by no means complete, a few preliminary statements are herewith presented. They may, at least, prove suggestive of further possibilities from a continuation of research along these lines. There is no reason, chemically, why the analytic methods devised for coal should not apply to coke and a fair amount of experience in connection with such use affords confirmation of this statement. The procedure in the case of coal may be briefly outlined as follows; Combinations of sulfur as sulfate, or sulfides other than FeS2, are readily dissolved without disturbing either the pyrite sulfur or the sulfur that is in organic combination by means of dilute hydrochloric, acid-1 part of concentrated HC1 to 10 parts of water or approximately 3 per cent. acid. Digestion at 60° C. for 24 hr. insures the complete removal of the sulfur thus combined. In freshly mined coal the amount of such sulfur is very small; weathering processes, however, may very materially increase the amount of sulfate present.

Jan 9, 1919

By G. Stuart Jenkins

CONDITIONS at the properties of the Consolidated Coal Co. had reached a point where improvements were almost impractical. The mines, sunk years ago, had shafts and entries so small as to preclude the use of large mine cars. A radical change was necessary in the type of mining and also in the type of mine to accommodate such haulage units. After due consideration, the company decided to enter the field of trackless mining, utilizing belt conveyors and chain-flight conveyors, the belt conveyors to take the long haul, and the chain-flight conveyors to be used for gathering. It was decided not to sink a shaft, but to drive a slope on an inclination of 17 1/2°, which the company believes to be about the limit on which coal can be carried on a belt without rolling back unduly.

Jan 1, 1939

By Jack Fox

Three years ago we attended the V International Mining Congress in Moscow. This year we attended the VI International Mining Congress in Madrid. By almost any criterion, this was a most successful convention. There were 1717 registrants, not counting the ladies. I don't know how many of the latter there were, but they certainly made a welcome addition to the group. Once again, the International Organizing Committee put together a very impressive technical program which the Spanish National Committee backed up with a brand new Palacio de Congresos admirably equipped with simultaneous translation devices and an organization that provided an excellent social program, a tremendous set of post- meeting excursions, and very impressive opening ceremonies, entertainment and closing ceremonies. There was also an exhibit on the subject of Spanish and Spanish American mining history in the Palacio de Congresos.

Jan 1, 1970

Draftsman and transitman for coal mine work in Middle West. Salary $125 per month. No. 277. Technical graduate wanted for metallurgical work in experimental laboratory of large New England manufacturing concern. A knowledge of metallography of steel is essential. Practical experience is desirable but not required. No. 305. High-class man to install and take charge of a coal mining property. Must be experienced in handling labor and of good sound judgment. Work will require a man to be on the grounds practically all the time. The work is drift mining and is not gaseous. No. 306. Engineer familiar with the acid treatment and melting of cyanide precipitates; also a competent assayer. Applicant must be able to furnish good references. No. 307. Wanted-practical mining man, foreman, or superintendent for work in middle or southern Atlantic States. Salary $200 per month. No. 308.

Jan 5, 1918

1 Healthy and active Local Section organizations are vital factors in promoting the vigor and growth of the Institute 2 Activity on the part of Local Sections should be recognized and stimulated by appropriation of funds from the Institute's treasury, and these appropriations should be as large as is consistent with the relative needs for other activities 3 As between different Sections, the amount of such appropriations should be based primarily on the extent of activities as reflected in the number and character of meetings held and the attendance of the members at such meetings 4 In making a request for funds for any year, the officers of a Local Section should submit a report on the printed form approved by the Directors at their meeting on November 19, 1937 5 A standing Committee on Local See-

Jan 1, 1952

By E. Teghtsoonian, A. R. Causey

THE fact that the surface plays an important role in the plastic deformation of a single crystal has been demonstrated by several investigators. The surface conditions have been altered using oxide films,1'2 alloyed metal layers,3, 4 deposited metal films,' and polycrystalline layers.677° The resulting effects on the initiation and subsequent plastic deformation have been investigated extensively except for the case of a single crystal surrounded by a polycrystalline layer of the same material. The purpose of this paper is to describe an investigation of the effect of a polycrystalline surface layer on the yield stress, the critical resolved shear stress, and the work-hardening slope of tin single crystals. The tin single crystals used in this study were grown from the melt using material having an initial purity of approximately 99.999 + pet with lead and iron the major impurities. Fig. 1 shows the orientation of the (110)[001] slip system with respect to the crystal surfaces. The crystals had a 1/4 by 1/4 in. cross section and a gage length of 2 in. The polycrystalline surface layer was produced by abrading the single-crystal specimens with emery paper. Fig. 2 shows the broken Debye rings obtained from the deformed surface. The thickness of the layer was controlled by the number of passes on different grades of paper and was determined by electropolishing in dilute HC1, until the grains produced by the abrasion had all been removed. Metal-lographic examination showed that the grain size varied with depth, increasing from 10 µ right at the surface to 40 µ in the interior of the layer. The yield stress, critical resolved shear stress,

Jan 1, 1965

By AIME

IN the following pages are described the history and present operations of one of the country's great mining and metallurgical organizations-the United States Smelting Refining and Mining Company. Though the articles are largely of interest to the technical man, the success of the Company as a business enterprise should not be overlooked. Almost immediately following incorporation 42 years ago payment of dividends began and the total to date has been about $140,000,000, roughly half to preferred and half to common shareholders. Founders of the Company were Boston businessmen and financiers interested in such diverse enterprises as shoe machinery manufacture, banking, newspaper publications, and stock brokerage. The legal profession also was represented. The Company is one of the few, among the leaders in the mining industry, that has resisted the urge to move its home office to New York and has always remained in Boston. Perhaps for that reason it has been regarded as a "conservative" company. Conservative or not, it has certainly spread out geographically and it has certainly put its eggs in many baskets. In addition to the precious metals and the major nonferrous metals it has ventured into coal and recently in a small way into the field of oil and gas. It seems to have a predilection for the North American Continent; for in addition to Alaska, Canada, and Mexico it has had important operations in California, Arizona, Nevada, Colorado, New Mexico, and particularly in various districts in Utah.

Jan 1, 1948

By A. Rosen, P. Wynblatt, J. E. Dorn

The temperature, strain rate, and structure dependence of the flow stress in a poly crystalline Fe-2 pct Mn alloy was investigated between 77" and 370°K. It was possible to identify the low-temperature data from 77° to 160°K with Dorn and Rajnak's theory of the Peierls mechanism of plastic deformation. Above 160°K one or more thermally activated mechanisms must he operative; however, these were not identified in this investigation. The mechanistic basis for the rapid decrease in the flow stress of bcc metals with an increase in temperature over the low-temperature range is yet being debated. Various dislocation mechanisms have been suggested in the past but the agreement between the various proposed theories and the experimental results have not been definitive. In the present paper, the authors will demonstrate that the plastic behavior of polycrystalline iron containing 2 wt pct Mn plus interstitials agrees excellently with predictions based on the Peierls mechanism from 77" to 160°K whereas from 160" to about 370°K other as yet unidentified thermally activated mechanisms take over. Undoubtedly, the overlap of these mechanisms with the Peierls mechanism contributed to the difficulties of rationalizing the low-temperature behavior of iron and its alloys. I) EXPERIMENTAL TECHNIQUES AND RESULTS Although extensive data are now available on the effect of temperature and strain rate on the flow stress of various bcc metals and alloys, it was, nevertheless, deemed necessary for the objectives of the present study to obtain highly accurate data of the type most pertinent for checking the theories on a series of well-documented work-hardened states. Iron containing 2 wt pct Mn was used in this investigation in order to obtain a lower ductile to brittle transition temperature than that for iron.' The additional elements present were 0.004 pct C, 0.05 pct 0, 0.004 pct S, 0.003 pct P, 0.006 pct N, and 0.001 pct Si. The as-received 3/8 by 3/4 in. bars were cold-rolled to 0.100-in. thickness, recrystallized under argon for 30 min at 1073"~, further cold-rolled to 0.063-in. thickness, and finally recrystallized under argon for 30 min at 1000°K. This treatment gave a stable reproducible equiaxed grain structure having an average grain diameter of about 90 p. Prior to the final recrystallization treatment, the sheet was machined into tensile specimens 1/4 in. wide having a 1.625-in.-long gage section. All specimens were tested in controlled-temperature baths on an Instron Testing Machine. For convenience in the theoretical analyses the data will be given in terms of the shear stress for flow, 7, the shear strain rate, f, and the shear strain, y. A series of three standard strain-hardened states were obtained by prestraining specimens at 300°K and at a shear strain rate of 7.68 x lo-' per sec to three stress levels of 6.89 X l08, 10.3 X lo8, and 14.5 x 10' dynes per sq cm, respectively. Immediately following this prestrain the temperature bath was changed and each specimen was pulled in tension at either f = 7.68 X lo-' or f = 3.06 X 10"3 per sec. In terms of the accuracy that was achieved, the values obtained did not deviate more than *0.1 X 10' dynes per sq cm and * 1°K from the reported values of stress and temperature and not more than *5 pct in the reported values of the strain rate. The tensile stresses were converted to shear stresses using a factor of 1/2. The shear stress for the initiation of flow at the test temperature was determined by taking a y = 6.16 x 10'3 offset. from the modulus line at which point good accuracy could be achieved in determining y and the associated flow stress 7, with only a negligible increase in the pre-

Jan 1, 1965

By D. E. Swets, P. C. Frank, D. L. Fry

THE hydrogen-steel system has received considerable attention in the past several years. Recent experiments in this laboratory have shown that another group of operations, namely, sanding and grinding,' must be added to the already well-estab- lished list of phenomena that cause hydrogen to permeate steel. Qualitative tests which have been made with a very sensitive ion-gage type of detector similar to that used by Norton,' showed that sanding a steel surface caused hydrogen permeation. A metal type 6~6 vacuum tube was used as the ion gage with an electrometer to measure the ion c~rrent.~ The protective enamel coating was removed from the tube.

Jan 1, 1959

By V. S. Rood, J. A. Norden

The general system of workings at the Utah-Apex is similar to that found in many of the western metalliferous mines. There is a vertical three-compartment shaft extcnding to the surface, from which the various levels have been driven to the orebodies. The 1000-ft. (305-m.) level, about 3/4 mile long, was driven as a haulage and drain adit. Geology The formation is a flat north-dipping series of alternating limestone and quartzite beds. Extensive north-south faulting and fissuring have taken place, resulting in the formation of large replacement orebodies in the crushed zones in the limestone. The orebodies are irregular in shape and size, but follow closely the trend of the mineralizing fissures. The ore consists of galena, pyrite, sphalerite and small values in silver and gold. Large masses of non-commercial pyrite are frequently found in or adjacent to the orebodies, and more or less pyrite is found for some distance in the walls of the orebodies. Lenticular bodies of a black pyritic shale also occur in the zones where extensive faulting has taken place. Mining Methods and Condition of Workings Geological conditions, mentioned before, have made the ground extremely heavy. In mining above the 1000-ft. level, square-set and filling methods were used, but not altogether successfully. The crushing of timbers extended even into the filled portions of the stopes. The filling material itself, consisting of limestone, shale, and pyrite, possessed swelling qualities which added to the difficulty of maintaining

Jan 1, 1920

EXECUTIVE COMMITTEES OF LOCAL SECTIONS New York L. W. FRANCIS, Chairman. WILLARD S. MORSE, Vice-Chairman. . THOMAS T. READ, Secretary, Woolworth Bldg., New York, N. Y. P. A. MOSMAN, Treasurer. LOUIS D. HUNTOON, Boston HENRY L. SMYTH, Chairman. ALFRED C. LANE, Vice-Chairman. AUGUSTUS H. EUSTIS, Secretary-Treasurer, 131 State St., Boston, Mass. TIMOTHY W. SPRAGUE, HENRY A. WENTWORTH. Columbia F. A. THOMSON, Chairman. GEORGE W. RODDEWIG, Vice-Chairman. LYNDON K. ARMSTRONG, Secretary-Treasurer, P. O. Drawer 2154, Spokane, Wash. R. S. McCAFFERY, S. H. RICHARDSON.

Jan 6, 1914

With this issue of the Bulletin, the Institute puts into operation a plan which it has long had under consideration for enlarging its field of usefulness to its members. We refer to the Index to periodical literature bearing on mining, metallurgy, and related subjects, which will be found in the advertising section at the end of the Bulletin. The Index is printed on alternate pages so that anyone who desires to compile a card index can readily clip the items and paste them onto cards. By its affiliation with the Engineering Societies Library, the Institute possesses unexcelled facilities for the preparation of this Index, since practically every important engineering or technical paper published anywhere in the world is regularly received by the library. The items for publication in the Index are first selected by the library staff, but their final approval and their order of arrangement remains in the hands of the editor. A word should be said in explanation of the system of classification that has been adopted. It will be noted that the classification is extremely broad, no attempt having been made to gather the references into closely specialized groups. Our reason for breaking away from the modern tendency toward minute specialization is based upon the fact that the fundamental principles underlying all engineering are not by any means so diversified as has commonly been supposed. For example, it is not at, all unlikely that an engineer engaged in large-scale ore mining in the Southwest can profit by observing the methods employed by his colleagues in the Pennsylvania coal mines. It is notorious also how extensively the brotherhood of chemical engineers has profited by the. earlier experiences of the ore-dressing and metallurgical engineers. If the Index were minutely sub-divided, it would always be possible that the coal-mining engineer, for example, might fail to observe a most important paper because it happened to be listed tinder the head of iron mining. For this reason, mining practice in general is consolidated under one head. The same line of reasoning applies to other divisions as well. In order to make the Index of practical value to all members of the Institute, wherever they may be situated, the library will undertake to supply, for a nominal charge, an abstract, a translation, a typewritten copy, a photostat copy, or the original of any article in the Index. Requests for service of this character should be addressed directly to the Engineering Societies Library, 29 West 39th St., New York. Members are urged to cooperate toward the success of this new departure by sending us suggestions. Although every effort has been made to anticipate the wishes of the members, it is almost impossible to foretell what services may be most useful to our 7000 constituents. Furthermore, it is known that some men prefer one method of classification while others would find another method more convenient.

Jan 9, 1918

N/A

Jan 1, 1945