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Homestake's Bulldog Mountain Operation near Creede, Colorado, in the San Juan Mountains at an elevation of nearly 2,750 m (9,000 ft), is subjected to short summers and long cold winters. Creede’s history dates back to 1889 when silver ore was discovered; and by 1892 production of over a million dollars per month was being shipped from mines located along the Amethyst Fault. The Bulldog Mountain Fault remained relatively untouched by the early prospectors. The United States Geological Survey recognized the potential of this fault in 1960, which led to the staking of many claims over the structure. Homestake leased properties in 1963 and in mid- 1964 a tunnel was started at the 2,956 m (9,700 ft) level with encouraging mineralization being encountered. In 1968 a decision was reached to build a flotation mill of 318 mtpd (350 stpd) capacity. The erection of the mill was completed in early 1969, six years after the first exploration was begun. Since initial start-up, extensive drifting has been done on several separate levels. Two underground hoist installations serve the various levels and many thousand feet of vertical mining operations. Due to the unconsolidated nature of the vein, a new unique underhand cut-and- fill mining method was developed. This procedure is the reverse of the normal cut-and-fill and proceeds from the top down under cemented sand fill, which, while expensive, has greatly reduced s toping hazards. Prior to 1977, a considerable quantity of silver was lost in the slime fraction of the ores processed because of oxidation and other inherent characteristics of individual minerals. Due to Homestakefs favorable experience in treating the slime fraction of the Lead, South Dakota gold ores, experiments with leach methods to recover silver from the slimes by Carbon -In -Pulp offered' the potential for additional silver recovery. Work was begun on the Carbon-In-Pulp plant in April 1976 and completed in December of that year at a cost slightly exceeding $2 million. The C. I. P. plant was designed for 136 mtpd (150 stpd) of current plant slimes plus 227 mtpd (250 stpd) of slimes dredged from the old tailings during the summer season. The sand fraction of the flotation

Jan 1, 1981

By S. J. Hubbard, S. D. Michaelson, A. W. Last, B. H. Ensign

Of the seventeen western states, five-Arizona, Utah, New Mexico, Montana, and Nevada-produce about 90 pct of this country's primary copper. All seventeen of these states occupy 60 pct of the nation's land area but receive only 25 pct of the country's total precipitation. Seventy percent of this precipitation returns directly to the atmosphere through evaporation and transpiration, leaving very little for ground reservoir recharge or immediate domestic, agricultural, or industrial use. With so limited a supply available for all, competition for water rights among users is severe. The result does not always permit using the limited supply to produce the most valuable end product. Most of industry and much of agriculture can shop around for suitable operating locations. Where water is critical to their purposes, they can and do locate in areas where the needed amounts are available. Such is not the ordinary lot of the mining industry, which must locate in the area of the deposit it is planning to mine and concentrate. In the case of copper this happens to be, for the most part, right in the heart of the semi-arid regions of the West.

Jan 7, 1960

GENTLEMAN: The year 1928 was another in the history of the Institute which was marked by quiet growth and steady progress. The total membership as of December 31, 1928, was 8703 as compared with 8438 on December 31, in 1927. Again the main increase has been in Members and the number of Junior Associates is less. As will be seen also by the Treasurer's report, the increase is reflected in larger receipts for dues indicating that fewer have had to be dropped for non-payment. There has been a gratifying increase in the number applying for reinstatement and it seems clear that interest in and attachment to the Institute has notably increased. The year was signalized by the merging of the Rocky Mountain Club with the Institute which brought to our roll one hundred and forty who were not previously members from among the men who have made the West. It also brought to the Institute a strong tradition of good fellowship and a fund of over $100,000, the interest from which is to be expended so far as may be, for purposes beneficial to the Western states. The Endowment Committee expects to see other and similar funds entrusted to the Institute and the Board has already appointed a special committee to consider all projects for expenditure of the revenue from them. It is felt that with the organization and personnel available in the Institute even modest revenues can be made to yield large returns in the way of scientific and technical knowledge. Within the year also, a third great Division has been organized within the Institute, building on the foundation of the old Iron and Steel Committee. The new Division signalized its independence by joining the Lake Superior Mining Institute in a visit to the Menominee Range in September and by furnishing material for a special volume of 353 pages, "Iron and Steel" Technology in 1928," printed and distributed in December. The Institute of Metals Division held its fall meeting with good attendance as one feature of National Metal Week at Philadelphia in October, and published its volume of Proceedings, running to 836 pages, in August. "Petroleum Development and Technology in 1927," 844 pages, came out in June and recorded the work of the Petroleum Division. A most interesting Fall meeting was also held by the Division at Tulsa,

Jan 1, 1929

By H. F. McCullough

THE success of a coal-mining venture as relates to operations at the gob or break-line, such as the drawing of pillars or the working of long-faces, depends upon the control of face conditions. The measures required to control the latter are dependent upon the action of the coal seam, roof and floor at and in the vicinity of the faces, but the manner in which these will act is dependent upon the rate of face movement as well as upon the face characteristics and upon the forces exerted. Yet the merits of a method of working-the practicability of controlling face conditions and the means required for such control when applied to any particular case-are usually judged only upon a consideration of the characteristics of coal seam, roof and floor, and the manner in which they have been observed to act. Practically every coal-mining man knows that face conditions are influenced by the rate of face movement, but few have appreciated that this is as much of a factor in the control of face conditions as are the face characteristics and the forces exerted. Fewer yet have recognized or taken advantage of faster rates of face movement as one of the principal means of establishing control of face conditions or of securing more favorable face conditions. Seemingly inherent difficulties, particularly in the control of roof conditions, but also in the control of conditions of the coal seam and floor, are frequently mitigated or disappear when the rate of movement of the faces is sufficiently increased. The characteristics of the coal seam, roof and floor and the forces exerted upon them do determine the general trend or tendency of face action, but the manner in which the coal seam, roof and floor will act and be acted upon and the magnitude of the action during the time the site of mining operations remains at any particular point is very largely determined by the rate of movement of the faces.

Jan 10, 1926

By C. M. Means

Considering the hazard involved in mining operations, statistics show that a very small percentage of accidents is chargeable to electricity. These accidents do represent quite a large percentage of those that are preventable and they are the direct result of the introduction, for purely economical reasons, of a dangerous element. The introduction of electricity in mines should decrease the hazard, and in no case should electricity be applied to the mechanical operation of equipment if by so doing the dangers incidental to mining are increased. The greater number of accidents are the result of persons coming in contact with exposed conductors at potentials varying from 258 to 508 volts direct current. The use of alternating current at higher potentials than these is quite common in large mines, but it is very rare that an accident happens from this source. This is explained by the fact that where these high voltages are warranted, proper precautions are taken, and the installations are directed by those who fully appreciate the dangers incidental to the work. Direct current is in much more general use than alternating current because of its adaptability to haulage locomotives and the low cost of installation in small operations. We are, however, coming to a more extended application of alternating current for the operation of mechanical devices used in connection with mining. Our underground direct-current wiring system is an evolution from the surface trolley and feeder systems. This is probably due to the fact that our earlier successful applications were electric locomotives, which required the use of a trolley wire. The trolley current has been almost banished from industrial establishments on the surface because of the hazard involved, yet we use it indiscriminately underground, where the dangers from accidental contact or fire are infinitely greater., This does not mean that the underground trolley systems should be eliminated, but it does imply the proper safeguarding of such equipment as is necessarily a part of the trolley systems. It is a fact that the men now employed in the installation and maintenance of mining equipment may be in many cases incompetent or not thoroughly familiar with the work, but they are the men who must do the work and, in order to do it properly, it is necessary that they be educated

Jan 1, 1915

By J. M. Hartman

ONE of the most important subjects to the blast-furnace engineer is a thorough knowledge of the conditions affecting the temperature in the different portions of the furnace. All efforts to decrease the consumption of fuel and improve the working of the furnace must be based upon it, and I may, therefore, be permitted to place before you the results of my observations, and detail the conclusions to which they have led me. Tracing the thermic conditions from below upwards we have at the bottom of a blast furnace making No. 3 iron a temperature of 2900° F., which increases slightly to a point a little below the tuyeres. In the immediate vicinity of the tuyeres the temperature is somewhat lower, owing to the entering blast ; but a short distance above the tuyeres, where all the oxygen of the blast has been converted into carbonic acid, the highest temperature in the furnace must be attained. This carbonic acid is, however, almost as soon as formed, converted by the glowing coal into carbonic oxide, a process which absorbs heat, reduces the temperature, and provides the active agent for the reduction of the iron ores. In its ascent the hot carbonic oxide gradually parts with its heat, first melting the descending iron and earthy materials, which drop down to the hearth of the furnace. The limit of this zone of fusion is rather sharply defined, and the temperature above this zone suddenly decreases. In its further ascent the hot gas drives off the carbonic acid from the limestone, which causes a further absorption of heat, and finally the gas escapes at the top, at a temperature of about 250° F. if the furnace is working well. These changes of temperature 1 have attempted to represent graphically,

Jan 1, 1880

By F. V. Tideswell

COAL being essentially a complex conglomerate of plant remains that have undergone decay and interaction in varying degree, it is understandable that attack on the problem of its chemical constitution by normal chemical methods should have been attended by but slight success. The obvious method of fractionation by means of selective solvents has yielded a few results of some value. Thus it is known that from many, if not all, bituminous coals organic solvents extract small percentages of oxygenated compounds, which are generally assumed to have been derived from the original plant resins, though a more probable source would appear to be the glycerides and waxes of the plants. Organic solvents also extract small proportions of hydrocarbons, the origin of which is doubtful. Of more importance is the action of such pseudo solvents as pyridine, which, in addition to their specific solvent action, have the power of resolving and simplifying a portion of the coal substance in a manner analogous to that by which water can disperse a hydrogel. Early, work with pyridine indicated that coals are composed of two main classes of compounds: the one soluble in organic solvents, the other capable of being partly dispersed in pyridine. Recent work has shown that the dispersion is colloidal in character and that it may be accomplished by the use of solvents less active than pyridine, such as benzene or chloroform, provided that the temperature of extraction is raised or the coal has been suitably preheated. The action of reagents on coal has proved of little value in the past, but some insight into the constitution of coal has been given by regulated .destructive distillation. Thus, it has been shown that coals behave on distillation as though composed of two main classes of compounds: the one readily decomposable at moderate temperatures (yielding mainly the paraffins), the other undergoing a preliminary early decomposition (with evolution of oxides of carbon and water) and yielding a residue that at higher temperatures breaks down, yielding much hydrogen.

Jan 3, 1925

By C. M. Young

WHEREVER salt is extracted from the ground as an artificial brine produced by pumping down fresh water to dissolve the salt, subsidence of the overburden is a possibility, though apparently few cases of such subsidence have been noted and detailed records are wanting. This description is intended as a record of subsidence that may permit the forcasting of similar occurrences in other cases; the data were supplied largely by R. B. Lee, city engineer of Hutchinson, Kans. About eleven years ago, ground movement occurred at a neighboring salt plant, when the surface assumed the form of a shallow funnel. Movement was probably due to a flow of sand into a well through a poor seal or a broken casing. The salt deposit increases in thickness from the east until at Hutchinson, where the subsidence occurred, it is about 310 ft. think. The interbedded layers of shale vary in thickness from mere traces to about 7 ft. While knowledge of the shale content of the beds is not exact, the log of a shaft 3 miles east of Hutchinson indicates that shale forms about 25 per cent. of the total thickness. This shaft does not reach the bottom of the salt by about 60 ft., but there is no reason to think that the lower part of the bed is different from the upper. Logs of wells sunk to the bottom are not sufficiently detailed to be of much value. Above the salt is the shale of the well-known Red Beds. The thickness of this is variable, principally because of its eroded surface, but at the mine it is 340 ft. This shale is variable in character and strength, but contains no strong members of limestone or sandstone. If the support is removed, very probably it will subside. The Arkansas River flows across the salt district and Hutchinson is situated on the flood plain. Between the top soil, which is about 8 ft. thick, and the shale is 60 to 100 ft. of water-bearing sand and gravel.

Jan 2, 1926

By Arthur H. Redfield

The West Indies are the summits of a submerged mountain chain, the continuation of which must be sought in the mountains of central Honduras. In Haiti, the chain divides, one branch passing through Jamaica and the other through Cuba, the Cayman Islands, and the Misteriosa bank. Suess divides the West Indies into three zones: The first zone is entirely of volcanic origin and includes many recent volcanic cones. It includes the arcuate string of islands, which extends from Saba and St. Kitts to the Grenadines and Grenada. The western half of Guadeloupe belongs to this group. The second zone consists of a geanticline, of which the sedimentary rocks range from the Jurassic to the Quaternary, but consist chiefly of Lower Tertiary sediments. In the west it is broad, including the whole of the Greater Antilles; but in the east it is restricted to a narrow belt, which includes the Virgin Islands (except Anegada), Anguilla, St. Bartholomew, Antigua, the eastern part of Guadeloupe and part of Barbados. The islands that compose the third zone are flat and low. Like the second, this zone is broad in the west and narrow in the east; it includes the Bahamas, Anegada, Sombrero, Barbuda, and part of Barbados. Geologically, Florida and the plain of Yucatan may be regarded as belonging to it. Trinidad and Tobago, though geographically adjacent to the Lesser Antilles, are geologically a detached part of the South American continent. The crystalline complexes of northern Trinidad and of Barbados are a continuation, en echelon, of the crystalline axis of the promontory of Paria. The folded Cretaceous and Tertiary of the central and southern parts of Trinidad represent a continuation of the folded sedinlents of the Paria district of Venezuela. Possible Oil-bearing Areas The volcanic islands of the inner arc of the Lesser Antilles may be excluded from consideration; these include Saba, St. Kitts, Nevis,

Jan 1, 1923

By E. W. Mehal, R. H. Cox

A planar Gunn oscillator was developed for use in a monolithic microwave integrated circuit. The device was designed to operate in the frequency range of 20 to 30 GHz with a continuous wave output. Selective epitaxial deposition was used to form the n+n-n+ device structure in (111)-B semi-insuluting GaAs. The active n- region was about 5 µ thick and was doped to about 2 x 1015 electrons per cu cm by the reactor background. The mobility was -5000 sq cm v-1 sec-1. The n+ epitaxial deposits were doped to 1 x 10" electrons per cu cm using S2Cl2. Planarity of the three DURING the past few years, new microwave devices in discrete form have been developed utilizing GaAs. The next logical step is to combine these devices in a successive deposits was quite good; total overgrowth was less than 1 µ. Metal ohmic contacts were applied to the n+ or n- regions using a Ag-In-Ge alloy. The n+n-n+ devices had symmetric IV characteristics and could be operated C. W. for both directions of device bias. Metal ohmic contacts made directly to the n-region always Produced asymmetric devices. C. W. operation was obtained over the 22 to 28 GHz frequency range. The best performance obtained was 1.5 mw C. LV. output at 28 GHz. microwave integrated circuit. A potential application would be a radar receiver operating in the millimeter wavelength region. The key component in such an integrated circuit is a microwave oscillator, recently described by Gunn.1, 2 Under the influence of a large electric field, high-resistivity GaAs exhibits a bulk negative resistance, and high-frequency current oscillations result. Since relatively high voltage and

Jan 1, 1969

THE Joint Committee appointed to consider a Code of Ethics for Engineers recommends, after delib-erate consideration, that each participating Insti-tute or Society adopt the short simple Code of Ethics following this report. The Committee further recommends that the following method of interpreting and administering the Code be adopted by each participating Institute or Society after any necessary provisions have been, made in the Constitution and By-laws of the Organization. The President of each Society or Institute shall appoint a Standing Committee on Professional. Conduct, to administer the Code of Ethics. The duties of such a Committee shall be to interpret the Code and to render opinions on any cases of ques-tionable conduct on the part of members that may be submitted to the Committee. These interpretations shall be reported to the Executive Board of the Institute or Society who may approve these interpretations, or take such other action as may seem just and necessary. The reports of the Committee on Professional Conduct, when approved by the Executive Board, shall be printed in abstract and in anonymous form in the Institute's or Society's monthly journal for the instruction and guidance of fellow members. This Committee on Professional Conduct shall be appointed in each Institute or Society by the President holding office at the time of the adoption of this Code and shall consist of five member one appointed for five years, one for four years, a third for three years, a fourth for two years and a fifth member for one year only. Thereafter, the President then holding office shall appoint one member annually to serve for five years, and shall also fill any vacancies that may occur for the unexpired term of the member who has withdrawn. These appointments shall he made from among the older members of the Institute or. Society, so that advantage may be taken of their mature experi-ence and judgment. The Committee after appointment shall elect its own chairman and secretary. The Committee shall have power to secure evidence or other information in any particular case not only from the organization's own members, but if it should seem desirable, from men in other professions. The Committee may also appoint sub-committees to consider certain cases when deemed necessary.

Jan 3, 1922

By K. P. Anderko

INVESTIGATIONS of the constitution of the system Mg-Ba were first made by Grube and Dietrich1 between 0 and 47 atomic pct Ba and then by Klemm and Dincke1acker" ver the whole composition range. Klemm and Dinckelacker corroborated intermediate phases of the approximate formulas Mg9Ba and Mg4Ba, and showed a third compound to have the formula Mg2Ba, rather than Mg5Ba, as suggested by Grube and Dietrich. Mg2Ba had been previously recognized by Hellner and Laves3 s a MgZn2 (C14) type structure. The main discrepancies between the results of Grube and Dietrich and those of Klemm and Dinckelacker exist, however, in the liquidus temperatures and solidification equilibria of alloys containing more than about 10 atomic pct Ba. The liquidus temperatures measured by Grube and Dietrich, and the outline of the liquidus of Klemm and Dinckelacker are plotted in Fig. 1 on an enlarged scale. Although there are strong reasons to prefer the results of Klemm and Dinckelacker, it was considered worthwhile to remeasure liquidus temperatures of some alloys in the controversial composition range. The alloys, made up from sublimed magnesium and 99.5 wt pct pure barium, were melted in an Armco-iron crucible in a dynamic argon atmosphere. Thermal analyses were taken using a Speedomax auto- matic recorder. Careful stirring during the solidification process was required in order to avoid segregation. After thermal analysis some of the cast alloys were chemically analyzed. The intended and analyzed compositions of the ten alloys prepared are listed in Table I. Since standard barium determinations cannot differentiate between barium present as element and as oxide, both the barium and magnesium contents of the alloys were analyzed. The fact that the sum of barium and magnesium was close to 100 pct in each case was taken as evidence that no excessive oxidation had occurred. The liquidus temperatures measured are listed in Table I and plotted in Fig. 1. As can be seen, they are in good agreement with the liquidus found by Klemm and Dinckelacker. This leaves no doubt that the thermal results of Grube and Dietrich above 10 atomic pct Ba are incorrect. This work was performed under the sponsorship of the Pitman-Dunn Laboratories of Frankford Arsenal, Philadelphia, Contract No. DA-11-022-ORD-1975. Sponsorship and permission to publish by this organization are gratefully acknowledged.

Jan 1, 1958

By Junius D. Edwards, Cyril S. Taylor

Magnesium is the lightest metal used for structural purposes, for which reason perhaps more than usual interest is attached to measurements of its density. Although the density of solid magnesium has been det,ermined frequently, no measurements of the density of the liquid metal are available. Because of unusual experimental difficulties in measuring the density of the liquid, only a limited number of measurements of good precision were secured. The results, especially the value for the crystallization shrinkage, are of great interest in connection with the casting of the metal. A number of samples for these measurements were made available through the courtesy of the American Magnesium Corp. They were in the form of extruded bars 3/8 in- in diameter and several were of exceptional purity, as indicated by careful analyses. Table 1 gives the density values (at 20" C.) for magnesium of varying degrees of purity. The density was measured at room temperature by comparison of the weight in air, and when immersed in distilled water. The necessary buoyancy corrections were applied, so that the density could be expressed in absolute measure—grams per milliliter. The effect of the buoyancy of the immersed suspension and the surface-tension pull of the water upon the suspension were eliminated from the results by a preliminary weighing of the suspension immersed to the working depth. Great care was necessary to prevent the introduction of a significant error by the formation of gas bubbles upon the clean magnesium surfaces; these are sometimes very minute and easily escape observation. They may be detached by raising the specimen from the water and again immersing; this should be done just prior to completing the weighing. Their formation may be almost entirely prevented during a measurement by previously immersing the specimen in a solution of paraffin in petroleum ether. The thin film of paraffin remaining after the evaporation of the solvent prevents wetting of the magnesium surface by the water. In one such determination, the paraffin coating on a 22-gm. Specimen

Jan 1, 1923

By Shun-ichi Satoh

In the previous paper, the writer indicated that the arc welding of cast iron is practicable only when barium carbonate is used to retard the fusion of electrodes. Later, he tested the effects of 48 other elements, to discover the cause of their retarding action. Wrought-iron bars 33 cm. long and 0.53 cm. dia. were used as electrodes. The chemical analysis of the original electrode is given in Table 1. Table 1.—Analysis of Electrode Per Cent. Carbon.................................................. 0.045 Silicon................................................... 0.028 Manganese....................................... Trace Phosphorus.............................................. 0.047 Sulfur................................................... 0.008 Each of the bars was wound with a twine of asbestos (1 mm. dia., weighing 0.5 g.) and then was coated with a mixture of equal quantities of graphite and carborundum and one of the compounds listed in the second column of Table 2. The method used in coating was as follows: The mixtures were reduced to paste by adding to them a solution of water glass (1:3); they were next put in a glass tube of 8 mm. inner diameter, with funnel-shaped mouth (the same tube shown in the previous paper); then the bars were passed through the tube so that the mixtures were coated on them. The glass tube was used only as a means of making the diameters of all coated bars exactly 8 millimeters. The cast iron was deposited on the steel plates by connecting the electrodes first to the positive and then to the negative pole of the generator. The figures representing the time, voltage, amperes and energy required to melt each electrode are given in Table 2. They are arranged in the order of the atomic weights of the elements contained in the coatings. In Figs. 1 to 4, which show respectively the time, current, voltage and energy required in this operation, the abscissas indicate the atomic weights of the elements contained in the coatings, and the ordinates

Jan 1, 1929

By H. Ries

In the marketing of mineral products, it is always highly desirable for both the producer and the consumer to be able to discuss things in a common language, and this can only be done if there are standard methods for expressing the properties of the raw materials. Having developed such a form of expression, the next step would be the making of specifications, which may serve as a basis for selecting raw materials. Considering the large number of non-metallic minerals that are used, there are not a few for which there are no standard laboratory tests to be used in determining their properties, or even standard specifications on which grades or market price may be based. Indeed in many cases the consumer simply requests the producer to submit samples, and rejects or accepts them without any explanation. Could the producer know in advance just what the consumer needed, time and money might often be saved. It appears to the writer that it is of the highest importance to devise standard laboratory tests wherever possible, as this enables the consumer to state definitely what he needs, and is of great assistance to the producer. It should also work to reduce misunderstandings and disputes. In the case of sands, we find that they show a wide variation in their character, ranging from those that are so coarse as to be of gravelly nature to those that are so fine that they might be classed as silt; and from very clayey ones to those that are practically free from clay. For this wide range of sands, we have a corresponding variety of uses, which are based mainly on the physical properties of the sand, although these are not always very definitely stated. The chemical composition need rarely be considered, if the sand is of siliceous nature. To determine and express these properties there should be standard tests, which are to be followed in all cases where the material is tested in the laboratory. The use of sands for foundry work (making molds or cores) is old, and it has been recognized for some time that the important properties to be

Jan 1, 1926

By James Neale

FROM the beginning of its activities, the members of the National Production Committee have felt that the following points were essential to the success of its work: The operators must. feel that their operations were not 100 per cent. efficient; that they should be courteous and fair in their treatment of their employees; and that they should set an example of hard work and patriotic interest in increased production. Every move made must appeal to the sense of fairness of all parties concerned. The men must feel that in working more faithfully, and consequently producing more coal, they are rendering a distinct service to their Government in the time of its great need. As the workers feel that greater efficiency on their part results only in greater profits to the operators, the advantage to the operator should be lost sight of, as far as possible, and the advantage to the Government in fighting the war emphasized. Both operators and workers should know that the Government considered increased production an obligation, and opportunity for service, resting on both parties and not on the operators or the workers alone, and that both parties could very much better the efficiency of the pre-war period. Had the committee intimated that it thought the coal shortage was clue entirely to the idleness and inefficiency of the workers, its campaign would have failed, for the men would have resented the charge because only too frequently their efforts to produce more coal were thwarted by bad management; besides the operators would have lacked stimulus to better effort. On the other hand, had the impression been given that the committee thought that the coal shortage was clue entirely to bad management, the operators would have resented the charge because only too frequently their efforts to produce more coal were thwarted by the idleness and inefficiency of the workers; and the workers, having been thus indirectly pronounced 100 per cent. efficient and patriotic, would have lacked stimulus to better effort.

Jan 2, 1919

By Cyril Stanley Smith

The method of thermal analysis, so important in the development of metallographie science, has of recent years been falling into disuse owing to the development of other physical methods which give result's easier of interpretation and which can be used for the study of either equilibrium or transitional conditions because they do not require a continuously changing temperature. Nevertheless thermal analysis remains useful in the study of reactions that take place rapidly, and the simplicity of the experimental technique and the general availability of the apparatus involved are point's in its favor. Theoretically, thermal analysis is capable of giving specific and latent hat measurements and therefore should permit the study of reactions on a more fundamental basis than any other method. It is, however,difficult or impossible to obtain quantitative heat measurements from cooling curves obtained in the usual way. Even if the furnace containing the sample is cooled or heated at a linear rate, or if a gradient furnaec is employed to maintain a constant rate over a large range of temperature, the heat flow from or to the specimen depends on its previous history, for the difference of temperature between the specimen and its surroundings varies. The emissivity of the specimen surface, moreover, is unlikely to be constant. The able mathematical analysis by Russrll,1 although it prevent,s misinterpretat,ion of data, has an effect rather the reverse of that intended, and leaves the reader doubtful of the possibility of ever obtaining quantitative results from thermal curves. Nothing can be done to apply thermal analysis t'o the study of equilibrium conditions of reactions that arc not completed at rates of temperature change above about 1° C;. per minute, and this unfortunatetly excludes most solid transformations in alloys.† For the determination of liquidus

Jan 1, 1940

By Francis Donaldson

THE direct injection of cement grout into water-bearing fissures as a means of checking or stopping the flow of water into shafts and tunnels has been experimented with for a decade or longer and seems to have been first attempted in Europe. The earliest application of which the writer has found a record was at a shaft sunk by the Mining Society of Lens; this is described by C. Dinoire in the Transactions of the Institution of Mining Engineers.1. It is only lately, however, that the process has been entirely successful. This success has been accomplished on the Catskill Aqueduct, now under construction by the city of New York. This aqueduct includes a number of deep pressure tunnels, reached by shafts for both waterway and construction purposes. In portions of these shafts and tunnels considerable underground water was met. The contract for the first of these deep pressure tunnels was let to the T. A. Gillespie Co.; this section is known as the Rondout Siphon. It leads under the Rondout valley at a depth of from 400 to 800 ft. and is about 5 miles long. The engineers expected that considerable water would be encountered, but fortunately this was not the case except at one shaft, known as No. 4, which penetrated the rock at a junction between limestone and conglomerate. Water-bearing fissures were encountered almost immediately. At a depth of about 200 ft. a flow of 1,500 gal. per minute was struck. The shaft then contained as many pumps as could be used, and it seemed impossible to sink it further. After vain efforts had been made to proceed, John P. Hogan, a division engineer of the Board of Water Supply, suggested that cementation of the fissures be tried. The process was attempted for the first time in this country. Since the shaft was partly full of water it was necessary to drill grout holes with a diamond drill. Platforms were placed on the timbers at the water level, the diamond drill was installed and six 90-ft. holes were drilled in the bottom of the shaft. Several car loads of cement were pumped through these holes into the fissures, the drill casings being used for grout pipes. This largely cut off the flow of water from the bottom and sinking could then

Jan 1, 1914

By A. M. McQueen

Activity in the oil industry in Peru was somewhat above normal in 1928. Probably the most significant feature was the interest displayed in the oriental region in the northeast part of the country (Fig. 1). This region, though little known, has long been considered potentially rich in oil! gold, coal and other minerals, lacking only transportation to make it the country's most valuable source of income. The Standard Oil Co. of New Jersey, through its recently formed subsidiary the Standard Oil Co. of Peru, has acquired various tracts along the Maranon and Ucayali rivers in the neighborhood of the Brazilian border. Standard Oil Co. interests have had geological and surveying parties in this part of Peru since 1921, and as a result of the work done, we understand they have under lease at the present time some 2,500,000 acres of prospective oil lands. Development in the coastal region continued along normal lines during the past year. Production figures for both the International Petroleum Co. and Lobitos Oilfields show a small increase over the last few years. Total production figures since 1924 for the International Petroleum, Lobitos Oilfields and Zorritos companies, only in a minor degree estimated, are as follows: 1924, 7,924,700 bbl.; 1925, 9,138,042 bbl.; 1926, 10,750,676 bbl.; 1927, 10,110,696 bbl., and 1928, 11,969,677 barrels. International Petroleum Co., Ltd. Operations on the La Brea-Parinas Estate during 1928 continued with satisfactory results; nearly all branches showing improvement over the previous year. The average daily production for 1928 was 25,966 bbl., compared with 21,282 bbl. for 1927, an increase of 22 per cent. During the last two or three years, production methods on the company's property have been improved in line with the advance in scientific technique throughout the oil fields of the United States. Extensive investments were made in compressor equipment for handling surplus gas with the result that the gas-lift and repressuring operations are in no small way responsible for the increase in the 1928 production. In addition, the company's three casinghead plants produced 24,847,708 gal. of gasoline compared with 17,240,865 gal. in the previous year.

Jan 1, 1929

Gentlemen:-I herewith present a report on some of the more important activities of the Institute for the year 1921. The present incumbent took. over the active management of the Secretary's office on the first of July and his, work was facilitated, while becoming acquainted with the routine of the office, by the constant and., kindly assistance of the former, Secretary, Mr. Stoughton, during the following three months, and that no interruption occurred inn its regular and smooth operation is due to him and to the Assistant Secretary, who has always been ready to give the benefit of his experience and assistance. MINING AND METALLURGY Through the efforts of President Ludlow and the generous assistance of one of our members, coupled with the excellent work of Major Barbour, MINING AND METALLURGY has, during recent months, shown constant improvement, which could not have taken place, however, had it not been, for the support given by a number of our contributing members. We have every reason to feel encouraged with respect to the quality of the publication and its cost of production. For the year 1921, the net cost of MINING AND METALLURGY was about fifty cents per member, per annum. Occasional letters are received criticizing the Board for producing this publication, but they are more than offset by letters of approval. When the, full purpose of the publication is appreciated, criticism ceases. The elimination of MINING AND METALLURGY and reversion to free distribution of all papers to all members, whether desired or not, would mean such a heavy additional expense that the number of papers would have to be much curtailed. The generous cooperation of members in sending for only such papers as they particularly desired has saved, the Institute thousands of dollars. A plan is being worked out that will materially assist in securing a prompt distribution to members of all pamphlets dealing with subjects in which they are especially interested.

Jan 2, 1922