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By Eli T. Conner

WITH Thomas G. Fear, chairman of the Coal Di- vision, presiding, the coal miners opened their program Monday morning with a general session at which three papers were presented. The first, "The Classification of Coal for Stationary Steam Generation," was presented by the author, Thomas W. Harris, Jr. In discussion, H. T. Coates inquired if it would not be possible to pick out a geographical coal section, certain seams or a group of mines, which would rank high in a desired feature or features, perhaps giving different -- - local sections or different mines something to designate a rating ("good," "fair," and "poor"). This might be done relative to anti-clinkering, free-burning, ,anti-slagging, smokelessness, friability and grindability. These might be listed or arranged on a map or diagram so that the prospective customer could find a coal that rated particularly high in desired characteristics. C. A. Reed pointed out, in part, that coal producers and sellers have found a bad but necessarily present condition in the country, especially with the smaller user of coal. This is entirely due to the fact that the employer expects his purchasing representative to be a genius and have expert knowledge of everything he buys, coal included, whereas in the larger plants he has and uses expert knowledge from the active organization when necessary. J. B. Morrow said that size rating was important in classifying coal and he emphasized that it was impossible to come to a definite basis on analysis alone.

Jan 1, 1933

"Power is transmitted to Butte, a distance of 130 miles, over two separate lines running parallel on the same right of way.The transmission line embodies the most approved ideas in construction. The conductors are No. O. B. & S. gauge, hard drawn copper strand. The insulators are of the suspension type, each insulator consisting of six units, 10 inches in diameter. The insulators will stand a wet test of over 300,000 volts, and were selected after long and careful tests by the company's engineers. The wires are carried on steel towers of four-legged, single crossarm type, manufactured by Milliken Bros. The three conductors are suspended in a horizontal row from the crossarm, and there are no transpositions in either line. Above the power wires and symmetrically located are two galvanized steel strands, Vs-inch in diameter, grounded at each tower, which serve as a protection against lightning.The distance between towers in level country is 600 feet. In mountainous country, however, the spans are irregular in length and spans of 1,500 or 2,000 feet are common. The longest one in the line is that crossing- the Missouri River and is equal to 3,034 feet. The length of this span is such that a person standing at one end of it can sec the wires go off and vanish into space, while the tower at the other end is barely visible to the naked eye on a clear day. The towers at one end of this span arc shown in the accompanying photograph. The line starts at an elevation of 3,200 feet, rises to an elevation of 8,200 feet as it crosses the Continental Divide, and again descends to 6,100 feet, the elevation at Butte.Quantity of coppc1· in transmission line, 1,330,000 pounds.Number of towers, 2,-1-00.Steel used in construction, approximately, 2,-1-00 tons."

Jan 1, 1913

By R. W. Raymond

The various modifications of the art of photography have become within the last few years the indispensable allies of every art and science. But, before the introduction of the process which is the subject of this paper, there was, so far as I am aware, no satisfactory means by which certain photographic negatives could be made to yield, without the intervention of the skilled draughtsman, electrotypes suitable for surface-printing. I refer to negatives taken from originals, such as natural objects, or or lithographs, in which the lights and shadows are not represented exclusively by lines and dots, such as can be photo-engraved. The greater usefulness to engineers and manufacturers of electrotypes as compared with lithographs is evident. The electrotypes can be kept indefinitely and used in the production of many thousand copies. They can be duplicated at trifling cost. They can be placed for printing together with the " forms " of type, or included in these, upon an ordinary press. Finally, they are cheap, when made mechanically from a suitable original. Various methods have been adopted for the preparation of such a secondary original (as it might be called) in cases where the first original is unsuitable for photo-engraving. Thus, for instance, portraits have been produced in electrotype from ordinary photographs as follows: A large negative is made of the original (say a carle de visite of a person deceased), and a proof taken, but not " fixed." Over this proof a skilled artist draws the portrait with a pen, producing a picture which resembles a line-engraving. The photographic proof, which has served merely to guide the artist, is now obliterated, and the pen-and-ink drawing is photo-engraved. Electrotypes thus produced often retain the likeness in a wonderful degree, and give spirited and satisfactory pictures. 1 may instance, as examples, which many will recollect, the portraits of our deceased members,

Jan 1, 1887

By T. C. Shelton, W. M. Huang

One of the problems arising from the use of modern machines and systems in coal mining is increased emission of explosive gases into the mine passageways. Interest in degasification of coal seams has grown. The authors summarize the results of coal permeability tests done at Virginia Polytechnic Inst. on one of the fundamental aspects of the problem. There are undoubtedly many factors that affect the emission of gas from coal but the permeability of coal to gas flow would seem to be fundamental. However, there is very little information on coal permeability to gas flow available in the U.S. at the present time, despite the fact that such knowledge would appear to be significant in any degasification effort. Studies made recently in the mining engineering laboratories at Virginia Polytechnic Inst. have determined values of permeability on 1-in. cubes of selected coals. COAL PERMEABILITY The permeability values given in this paper are based on adaptations of Darcy's law formulated by Henry Darcy in I856 from experiments with fluid flow in porous media.' Using air as the gaseous fluid, they were obtained by employing similar methods as are used to dete1:mine the permeability of petroleum and gas reservoir rock specimens. Permeability is. a measure of the ease with which fluids flow through a porous substance, and it is governed by the connected pores within a porous medium. If a few large-sized pores, fractures or channels are present within the medium, the medium can have great permcnability without significant porosity. It is reasonable to assume, therefore, that the permeability of coal, due to its structure, is based on fractures connecting the pore space left as the result of some degree of devolatilization or other changes of the substance from which coal was formed. The results of this irvestigation tend to validate this assumption in that the values obtained indicate a close relationship between the rank and permeability of coal. COALS TESTED AND PROCEDURE The coals whose permeability values were determined in this investigation are given in Table I.

Jan 1, 1962

By T. V. Moore, H. D. Wilde

In many of the important problems of the petroleum engineer, it is necessary to know accurately the laws governing the flow of gas and liquid mixtures in vertical pipes. Although much work has been done along these lines, no satisfactory solution to the problem has been found. A good theoretical discussion of the energy balance in a gas-lift has been published by Versluys.1 One of the most important factors affecting the efficiency of the flow of oil and gas mixtures is slippage, and in most of the experimental work that has been done no provision has been made for the measurement of this quantity. As Versluys pointed out, since there is no method now known to estimate it from the data usually taken, slippage must be determined empirically. This paper presents the results of some work carried on to measure slippage in short experimental gas-lifts. As shown herein, slippage can be easily calculated in a vertical pipe carrying a mixture of oil and gas if the fractions of the pipe occupied by liquid and gas respectively are known. In this work, the fraction of the pipe occupied by the liquid was measured under a wide variety of conditions and the relationship between this fraction and other quantities, which are easily measured in ordinary work, was determined. It was hoped that the quantitative relationship obtained from this work could be used for making accurate calculations in flowing or gas-lift wells, but unfortunately it did not check satisfactorily when applied to actual wells. Apparently flow in long flow pipes is more efficient than in the short ones used for the experimental work. Nevertheless, it is felt that the data themselves arc of interest; that the method of attack may be of value in future work and that the relationship derived between slip and the relative velocities is a contribution toward the solution of the gas-lift problem.

Jan 1, 1931

By R. H. Maes, R. E. de Strycker, J. J. Jacobs

A simple method, based upow density measurements, has been perfected in order to determine the critical temperature of liquid miscibility gaps. Applied to the Pb-Cu system, it yielded a value of 980"C for the critical tempevature of the miscibility gap in this system. In the Pb-Cu-As system, the immiscibility between lead and coppev evolves towards a miscibility gap be-tween lead and copper arsenides; the liquation temperatures were determined joy different avsenic contents and values up to 1065°C were found. Combining these results with those given by the clzemical analysis of liquid samples taken at dqj.event temperatures, it has been possible to make a cowzplete determination of the liquid miscibility gap in this ternary system. In the Pb-Cu-Fe-As system, a ternary miscibility gap has been discovered; for some compositions, the molten and slowly cooled alloys separated into three layers: an Fe-As alloy, a Cu-As alloy, and a lead-rich layer. ThE Pb-Cu-Fe-As system is of interest for the study of the behavior of speiss or arsenical alloys in the lead blast furnace. The speisses produced in lead metallurgy generally have complex compositions, but they may be considered, in a simplified way, as a mixture of copper, iron, nickel, and cobalt arsenides; there is often an excess of metallic constituants, and lead is also present. Speisses liquate from lead at various temperatures according to their composition; according to industrial experience, iron speisses are already distinctly separated from lead bullion at temperatures of the order of 1100°C, whereas copper speisses only begin to liquate from lead at much lower temperatures, near their solidification points, which were never accurately determined until now. Besides these considerations of practical interest, the present study is of importance for the knowledge of liquid miscibility gaps. Particularly the data of the literature about critical temperatures of liquation are incomplete and present sometimes considerable disparities; a method has been perfected in the present work to determine these temperatures with accuracy. MISCIBILITY GAP OF THE LEAD-COPPER SYSTEM Review of Literature. The generally admitted outline of the Pb-Cu equilibrium diagram is shown by Fig. 1. This figure, with its numerical indications, is taken from the review of Hansen and ~nderko;' compositions are given in weight percent, as will be the case in the remainder of this paper. Between 36 and 87 pct Pb, Pb-Cu alloys separate into two layers, in the liquid state. The critical temperature of liquation has been much disputed in earlier studies, where values up to 1500°C were claimed; but a reliable study of ~ohnen,' based upon differential thermal analysis, gave a value of 990°C; this rather low value was verified by a recent study of Schiirmann and Kaune? based upon thermodynamical properties of the Pb-Cu alloys, which predicted a value of 1002°C. Liquid miscibility gaps were also studied by means of chemical analyses. Satisfactory results were generally obtained with the method consisting in taking samples of the two liquid layers in equilibrium and submitting them to chemical analysis; however, this method becomes delicate near the critical temperature. With this technique, Friedrich and waehlerts ob-

Jan 1, 1968

By C. P. Proctor

WESTERN Pennsylvania, eastern Ohio, and Illinois are carrying out experiments wherein much more slate and other impurities are loaded with the coal in the mine and hauled to the surface preparation plant for removal. In general everything is sent to the cleaning plant although there may be some gobbing in the mine. No conclusions have been announced as to the effect of such a mining system on clean coal costs. Such factors as ability of the surface plant to handle the impurities, land and facilities for disposing of the impurities, and the transportation facilities underground should be considered.

Jan 1, 1942

By C. S. Chang

Replacement of active groups in corn starch, as shown by results of the starch derivatives tested, impairs rather than improves the value of corn starch as a selective iron oxide depressant. Increased ability to depress iron oxides is generally accompanied by a parallel ability to depress quartz. PEARL starch, a corn starch prepared with a minimum of alteration, is a good selective depressant for iron oxide minerals.' From what is known of the complex chemistry of corn starch, there is evidence that it consists of a mixture of saturated giant polymeric molecules, both straight and branch-chained, the constituents consisting of glucose units with hydroxyl radicals as active or polar groups. To add to the existing knowledge of the chemistry of the flotation process, it is desirable to ascertain the effects on the corn starch as an iron oxide depres-

Jan 1, 1955

By E. P. Burtchaell

A method is presented for evaluating the effect of gravity drive upon the reservoir performance of a high relief pool. Conventional forms of reservoir analysis do not consider the alterations in the basic material balance data caused by gravity segregation of reservoir fluids. A procedure is outlined for structurally weighting physical and chemical data for use in the material balance equation. It is demonstrated how actual pool performance data can be utilized to evaluate the future reservoir performance of a gravity drive pool. INTRODUCTION Conventional reservoir engineering. procedure is inadequate for the analysis of an oil pool which has considerable structural relief, steep dips, and good permeability development. In, pools of this type, gravity drainage has an important part in the movement of oil to the wells and the effects of gravity on the overall pool performance should be included in any analysis of reservoir behavior. Many engineers have the opinion that the force of gravity in the movement of oil is not important until the later life of a pool.' Probably the basis for this belief is that gravitational effects may not be readily discernible until a pool is nearing depletion. This would be especially true for pools not having a high degree of structural relief and permeability development. Actually the effects of gravitational forces are at a maximum when the pool pressure is high, for during this period the hydrostatic head of the oil column is at a maximum and the viscosity of the oil is at a minimum. Oil recoveries from pools having favorable gravity drive characteristics may equal or even exceed recoveries which might be expected from water displacement. Field evidence indicates that in some reservoirs gravity drive has resulted in recoveries greater than that which could have been expected from gas expansion or water drive.'.3 Unfortunately, the possible effects of gravity drive on pool performance have been underestimated and other reasons have been sought to explain the high recoveries obtained. There are unquestionably many reservoirs to which the principles of gravity drainage can be effectively applied. It is the purpose of this paper to illustrate one method whereby gravity drive is included in the reservoir analysis of an oil pool. A hypothetical pool, typical of many California reservoirs, is used as an example. As used in this paper, "gravity drive" is defined as the overall effect of gravitational influences on the recovery of petroleum from the reservoir; "gravitational segregation" as the gravity separation of oil and gas within the reservoir; and "gravity drainage" as the downward movement of oil as caused by the force of gravity. SAND VOLUME DATA Fig. 1 presents a structural contour map of the pool under study. Maximum closure is 1950 feet with dips on the south flank approaching 45". The original gas-oil interface was set at -5200 feet. Average thickness of the producing sand was 200 feet. For use in subsequent calculations ill this paper, the pool was subdivided into 100-foot vertical increments and the sand-volume content of each increment was obtained. If the gross sand thickness is small, under 100 feet, the sand-volume content can be obtained by superimposing an isopachous map upon a structural contour map and planimetering the average thickness of each 100-foot increment. For sand thicknesses over 100 feet, one approacli would be to construct a sufficient number of cross-sections of the pool from which the weighted sand-volume of each 100-foot increment could be obtained. Variations in the sand body with depth, as determined by core data, can also be included in the above process. Table I presents a summary of sand-volume calculations, core data, and the original distribution of reservoir hydrocarbons in the pool. Fig. 2 illustrates the structural distribution of the sand-volume content. A total of 171,398 acre-feet is contained within the productive limits of the pool. Assuming an average porosity of 25% and an interstitial water content of 20%, the original hydrocarbon content was computed to be 227,075,000 barrels. DEPTH-PRESSURE DATA The determination of the initial vertical pressure arrangement in the pool is necessary for PVT and material balance calculations. Whenever sufficient data are available, a plot of pressure versus subsea depth of measurement should be made. From this plot a representative fluid pressure gradient can be established. Lacking sufficient initial pressure data, an initial pressure gradient may he estimated or calculated from avail-

Jan 1, 1949

By E. P. Burtchaell

A method is presented for evaluating the effect of gravity drive upon the reservoir performance of a high relief pool. Conventional forms of reservoir analysis do not consider the alterations in the basic material balance data caused by gravity segregation of reservoir fluids. A procedure is outlined for structurally weighting physical and chemical data for use in the material balance equation. It is demonstrated how actual pool performance data can be utilized to evaluate the future reservoir performance of a gravity drive pool. INTRODUCTION Conventional reservoir engineering. procedure is inadequate for the analysis of an oil pool which has considerable structural relief, steep dips, and good permeability development. In, pools of this type, gravity drainage has an important part in the movement of oil to the wells and the effects of gravity on the overall pool performance should be included in any analysis of reservoir behavior. Many engineers have the opinion that the force of gravity in the movement of oil is not important until the later life of a pool.' Probably the basis for this belief is that gravitational effects may not be readily discernible until a pool is nearing depletion. This would be especially true for pools not having a high degree of structural relief and permeability development. Actually the effects of gravitational forces are at a maximum when the pool pressure is high, for during this period the hydrostatic head of the oil column is at a maximum and the viscosity of the oil is at a minimum. Oil recoveries from pools having favorable gravity drive characteristics may equal or even exceed recoveries which might be expected from water displacement. Field evidence indicates that in some reservoirs gravity drive has resulted in recoveries greater than that which could have been expected from gas expansion or water drive.'.3 Unfortunately, the possible effects of gravity drive on pool performance have been underestimated and other reasons have been sought to explain the high recoveries obtained. There are unquestionably many reservoirs to which the principles of gravity drainage can be effectively applied. It is the purpose of this paper to illustrate one method whereby gravity drive is included in the reservoir analysis of an oil pool. A hypothetical pool, typical of many California reservoirs, is used as an example. As used in this paper, "gravity drive" is defined as the overall effect of gravitational influences on the recovery of petroleum from the reservoir; "gravitational segregation" as the gravity separation of oil and gas within the reservoir; and "gravity drainage" as the downward movement of oil as caused by the force of gravity. SAND VOLUME DATA Fig. 1 presents a structural contour map of the pool under study. Maximum closure is 1950 feet with dips on the south flank approaching 45". The original gas-oil interface was set at -5200 feet. Average thickness of the producing sand was 200 feet. For use in subsequent calculations ill this paper, the pool was subdivided into 100-foot vertical increments and the sand-volume content of each increment was obtained. If the gross sand thickness is small, under 100 feet, the sand-volume content can be obtained by superimposing an isopachous map upon a structural contour map and planimetering the average thickness of each 100-foot increment. For sand thicknesses over 100 feet, one approacli would be to construct a sufficient number of cross-sections of the pool from which the weighted sand-volume of each 100-foot increment could be obtained. Variations in the sand body with depth, as determined by core data, can also be included in the above process. Table I presents a summary of sand-volume calculations, core data, and the original distribution of reservoir hydrocarbons in the pool. Fig. 2 illustrates the structural distribution of the sand-volume content. A total of 171,398 acre-feet is contained within the productive limits of the pool. Assuming an average porosity of 25% and an interstitial water content of 20%, the original hydrocarbon content was computed to be 227,075,000 barrels. DEPTH-PRESSURE DATA The determination of the initial vertical pressure arrangement in the pool is necessary for PVT and material balance calculations. Whenever sufficient data are available, a plot of pressure versus subsea depth of measurement should be made. From this plot a representative fluid pressure gradient can be established. Lacking sufficient initial pressure data, an initial pressure gradient may he estimated or calculated from avail-

Jan 1, 1949

By J. Richard Lucas

The coal industry, one of the great basic industries in the nation, plays a major role in the American economy. Coal is the principal fuel used in generating tremendous quantities of low-cost power so necessary to the nation. Two-thirds of the electrical energy and one-fourth of all energy consumed in the nation is produced from coal. Large-scale production of steel, cement, and chemicals is vitally dependent upon this natural resource. Because of extensive reserves and low mining cost, it is one of the few natural resources in which the United States is a significant exporter. During 1965 in excess of 500 million tons of coal were produced, almost 10% over the previous year; more than 50 million tons were shipped to foreign markets. The utility market gained approximately 8% during the year for a total of 242 million tons.

Jan 2, 1966

By L. T. Sicka, H. N. Thomson

The Tooele plant of the Internationa1 Smelting & Refining Co. is situated at the mouth of Pine canyon, Tooele county, Utah. It is connected with the main line of the San Pedro, Los Angeles & Salt Lake railroad by the Tooele Valley railway, and is about 7 miles from Tooele Junction. Fig. 1 is a general view of the plant. The copper plant has been in operation since July, 1910, arid the first blast furnace at the lead plant was blown in on Feb. 29, 1912. The location of the plant was selected on sloping ground with the idea of using gravity to the fullest extent and thus keeping labor at a minimum. Practically the entire plant is constructed of steel, reinforced concrete, and brick. Bingham ores, both lead and copper, are received over the Utah Consolidated Aerial Tramway. The tram buckets, each containing

Jan 1, 1914

"Located on Missouri River 16 miles N. E. from Helena, 67 miles from Butte and 18 miles below Canyon Ferry. River drainage area 16,000 sq. miles.DAM: Built in 1907; rebuilt of concrete in 1911. Maximum height 129.3 ft., length over all 720 ft.; elevation of crest 3621; elevation of bridge 3640; normal head 60'; normal tail water elevation 3568.5.SPILLWAY: Length over all 491 ft.; clear opening in 24 sections; 445' flashboards, 14 high to elevation 3635, which is 3.5' above Canyon Ferry normal tail . water elevation.PENSTOCKS: 5 of steel, 12 ft. diam., about 75 ft. long from canal to main turbines, and 3 40-inch diam. from canal to exciters.WHEELS: 5 main pairs, horizontal, center discharge, 48-inch bronze turbines, 225 rev., 4,000 h-p. at 60 ft. head, made by S. Morgan Smith Co., direct coupled to generators, and--3 single, horizontal, 25-inch units, direct coupled to exciters.GENERATORS: 5 W. E. & M. Co. water wheel type, revolving field, 2,800 k-w., 2,400 v., 225 r. p. m., 3 phase, 60 cycle alternators.OPERATION: The plant has a larger water storage than Canyon Ferry and can also use stored water from Canyon Ferry storage. Separate transmission lines 13 miles long connect to lines from Canyon Ferry to Butte, and the Plant operates in parallel with the Canyon Ferry plant."

Jan 1, 1913

By R. W. Raymond

THE absence of a convenient glossary of terns connected with mining and metallurgy has long been felt by the general public. It is to meet this want, not to furnish a technical manual for experts, that the following glossary has been prepared. It originated in an attempt on my part to revise for publication the manuscript of a compilation prepared from the appendix of Yale's work on Mining Titles and one or two other sources, to serve as an appendix to a new work on mining law, about to be published by Mr. H. N. Copp, of Washington, D. C. This revision soon assumed, contrary to my original intention, the proportions of a reconstruction ; and with the consent of Mr. Copp, and for the purpose of receiving from my fellow-members valuable aid, I presented my still incomplete work as a paper at the Lake Superior meeting of the Institute, inviting from any quarter suggestions of new terms or better definitions to be incorporated in the glossary before its final publication. This invitation was so widely and generously responded to, that I cannot undertake to make in this place' individual acknowledgments to those members of the Institute, and professional colleagues outside of it, who hays favored me with ' assistance and advice. The labor bestowed upon this paper since its presentation, at the Lake Superior meeting has considerably exceeded that of its first preparation, as

Jan 1, 1881

By Maurice B. Dusseault, Edo Nyland

Numerous consistent seismic signals are being generated in a pilot fireflood in a 750 m deep high permeability unconsolidated channel sand in Eastern Alberta. The pilot has a central air injection well, eight production wells on artificial lift, and two internally placed observation wells. Surface seismometers and a 12-hydrophone downhole string were deployed to detect seismics signals. Date were collected for 22 hours employing signal-triggered event detectors recording on cassette tapes. Monitoring during twelve hours of steady air injection at 625m3/s yielded a clear event frequency of about 50 events/h. The events were mostly clear compressional wave arrivals originating in the vicinity of the firefront. Stopping air injection caused a gradual drop in event frequency, and the rate was reestablished when air injection was reinitiated. Spectral frequency analysis and knowledge of material properties indicate that the events are shears of a stick-slip nature associated with the strain-weakening behavior of the over-compacted reservoir sands. The event amplitude indicates small-scale shearing, and different amplitudes suggest that planes re-shear with lower energy release levels. The triggering mechanism for shear rupture is high shear stress created by thermal expansion in the area of highest ther- mal gradient. Other enhanced recovery techniques may also produce useful signals for process control. In particular, steam flooding, hydraulic fracturing, and high-pressure injection operations likely generate mappable microseismic events which can be applied directly to production/ injection strategy.

Jan 1, 1982

By A. T. Miesch

The purpose of this paper is to explore relations between the distribution and composition of uranium deposits on the Colorado Plateau and mineralogic, chemical, and lithologic aspects of their host rocks. The paper also appraises the host-rock sandstones as possible sources of elements in the uranium deposits. Other possible sources of elements are not discussed. Uranium deposits on the Colorado Plateau consist largely of sandstone and small amounts of mud-stone impregnated with uranium and vanadium miner- als and a suite of minor accessory minerals containing copper, lead, zinc, silver, iron, cobalt, nickel, yttrium, molybdenum, selenium, and arsenic, in addition to other elements locally. The deposits consist of clusters of closely spaced ore bodies which commonly aggregate several thousand tons, but range in size from less than one ton to several million tons. With only rare exception, the deposits show no close relation to fractures. The ore bodies are generally tabular in layers nearly parallel to the bedding in the host rocks, or they cross bedding at large angles to form roll structures. Absence of fracture control necessitates that the ore and associated elements were transported to the deposits by way of interstitial pore spaces in the sandstones. This points to the general process of lateral secretion as a possible mechanism of ore formation, and suggests the host-rock sandstones as a possible source of the metals. Roll structures in the ore

Jan 1, 1962

By Leonard Waldo

PROBABLY some of the views advanced in this paper will appear, from a metallurgical standpoint, little less than revolutionary. It is with considerable hesitancy that I venture to offer a few thoughts concerning what, seems to me to be perhaps the most important development of metallurgy since the introduction of Bessemer steel. Dr. John Percy, with that rare insight which characterizes the epoch-making man, described in a communication to the Royal Society, about 1855, an alloy of duminum and copper which he called aluminum-bronze. The name has "stuck." The term "bronze" has been so variously used that I confess I do not know exactly what constitutes a bronze; but I know that in the great materials of engineering simplicity of composition is a cardinal excellence; and I wish to venture the suggestion that aluminum-bronze is not an alloy of aluminum and copper in any such sense as the compounds of tin and zinc with copper (except the copper-tin compound SnCn3) are alloys. There are several reasons which lead me to this view. In the first place, if a series of bars be prepared containing varying percentages of aluminum and copper, and the electrical conductivity of these bars be carefully determined, a curve of conductivity will be obtained, as shown in Fig. 1, which represents the result of such experiments. While I am not sure, at this time, that the values of conductivity shown in this diagram are wholly dependent upon the percentage of aluminum added, the assumption is a probable one; and the curve indicates that an extremely small percentage of aluminum affects the conductivity in a ratio out of all proportion to the amount of that metal. Another reason is drawn directly from experience in the foundry. If we take from the furnace a crucible containing melted aluminum and one containing melted copper, both at a little more than a red heat, and pour them together, the reaction is so intense that the

Jan 1, 1895

By William Kent

THE dynamometer herein described is a modification of the one invented by Mr. Samuel Batchelder, of Boston, nearly forty years ago, a description of which may be found in the Journal of the Franklin Institute, 1843, vol. xxxii,.p. 277, and in the Scientific American of August 31st, 1878. The modification consists in providing a method of making an automatic record, and of indicating more minute variations of the power transmitted. The improved dynamometer was designed by the writer in 1877, and was built a few months since by the Class of 1879 of the Stevens Institute of Technology. The accompanying cut, taken from the Annual Announcement of the Stevens Institute, represents the dynamometer without the recording attachment. It consists, as shown, of two stout cast-iron frames, held together by bolts in bearings, in the top of which frames run two shafts, each carrying a pulley at its outer end and a bevel gear-wheel of 45' at its inner end. One of these shafts is the driving-shaft, connected by belt to the engine or other prime mover; the other is the driven shaft, connected by belt to the machine driven. The power is transmitted from one shaft to the other through two other bevel-wheels of 45' gearing with the first, the shaft common to them and on which they run freely being at right angles to the axis of the two shafts first mentioned, and carrying at one extremity a heavy pendulum. The bevel-wheels being connected, as shown, and the power being applied to the driving-wheel, the two intermediate wheels with their common shaft have a tendency to revolve around the driving-axis, which tendency is a measure of the force transmitted, and is resisted by the moment of the weight of the pendulum. In the Batchelder dynamometer the four bevel-wheels and their shafts are used, but

Jan 1, 1880

By William Bent

THE dynamometer herein described is a modification of the one invented by Mr. Samuel Batchelder, of Boston, nearly forty years ago, a description of which may be found in the Journal of the Franklin Institute, 1843, vol. xxxii, p. 277, and in the Scientific American of August 31st, 1878. The modification consists in providing a method of making an automatic record, and of indicating more minute variations of the power transmitted. The improved dynamometer was designed by the writer in 1877, and was built a few months since by the Class of 1879 of the Stevens Institute of Technology. The accompanying cut, taken from the Annual Announcement of the Stevens Institute, represents the dynamometer without the recording attachment. It consists, as shown, of two stout cast-iron frames, held together by bolts in bearings, in the top of which frames run two shafts, each carrying a pulley at its outer end and a bevel gear-wheel of 45° at its inner end. One of these shafts is the driving-shaft, connected by belt to the engine or other prime mover; the other is the driven shaft, connected by belt to the machine driven. The power is transmitted from one shaft to the other through two other bevel-wheels of 45° gearing with the first, the shaft common to them and on which they run freely being at right angles to the axis of the two shafts first mentioned, and carrying at one extremity a heavy pendulum. The bevel-wheels being connected, as shown, and the power being applied to the driving-wheel, the two intermediate wheels with their common shaft have a tendency to revolve around the driving-axis, which tendency is a measure of the force transmitted, and is resisted by the moment of the weight of the pendulum. In the Batchelder dynamometer the four bevel-wheels and their shafts are used, but

Jan 1, 1880

By Nicholas T. Camicia

A career in the coal mining industry today offers students one of the most interesting and challenging opportunities available in the industrialized world. As reserves of other fossil fuels dwindle in face of the world's demand for energy, it has become apparent that coal, once the king of energy sources, must be relied upon again as the major fuel for powering industrial growth in developed and developing nations. Centuries of coal supplies lie beneath the earth's surface, assuring the world of a steady, plentiful supply of energy until science and technology can produce a way to harness and efficiently use renewable sources, such as solar. The need to increase our use of coal during the last two decades of the 20th century is reason enough to believe that the future growth of the coal industry is assured. A major impediment to that growth might be backward national public policies that could restrict the full utilization of our coal reserves. These policies could result from overregulation and a failure of the public to recognize that coal use, with proper techno- logical safeguards, is compatible with our society's environmental-quality objectives. Communication of this problem and its solution is a major undertaking of the coal industry in the 1980s. At the end of the 1970s, the American coal industry was producing approximately 635 Mt/a (700 million stpy) of coal. To meet the nation's projected energy needs by 1985, the annual tonnage must be doubled. A similar scenario is predicted for the rest of the world. Such growth in the modern international business world will require huge additional amounts of capital, equipment, and people who know how to wisely raise and apply the capital; use the equipment productively; and deal with the many community, public, and governmental problems such expansion will create. Whether a student's interest is in actual mining operations, business administration, engineering, finance, law, industrial relations, marketing

Jan 1, 1981