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By W. E. Anderson, T. M. Brady

As part of a larger study to identify factors influencing the practical operating life of wire rope used on large draglines in surface coal mining, field trips to operating surface coal mines were made during late 1975. Wire rope performance information was obtained from personnel at 13 mine sites west of the Appalachians. Seventeen pieces of equipment, utilizing bucket sizes ranging from 30 to 220 cu yd (23 to 168 m), were documented. Draglines at large US surface coal mines can be represented as 120 machines having 60-cu yd (46-m3) buckets, moving 1.8 X 109 cu yd (1.4 x 109 m3) of overburden during 6650 hours of productive availability per year. Based on the limited field study, the calculated downtime resulting from rope-related causes averages 105.6 hours per year for each typical 60-cu yd (43-m3) dragline. The total loss in production from this source alone is thereby estimated at about 25 x 106 cu yd (19 x 106 m3) annually. Although study findings did not reveal anything about dragline rope life that wasn't known or practiced by one operator or another, most operators can expect improved rope life by periodic review of their practices and by adopting one or more life-improvement measures employed at other sites. Since rope productivity was found to vary by a factor of five among the sites studied, considerable improved average performance is possible. As little as 10% overall improvement would increase national productivity by 2 million cu yd (1.5 X 106 m3) of solid overburden removal. Associated savings in rope costs would be some $2 million annually, plus a large reduction of labor-related expenses. This report outlines preliminary findings which may prove useful to many operators in extending wire rope life. Some of these modifications or adjustments in maintenance/operating practices would not require capital investment. During the field survey, no company was found which had tried cost reductions by using presocketed dump ropes, or dump rope sheaves that opened like a snatch block, so these are suggested as possible improvements requiring modest capital input. Data Acquisition During the field visits, mine operators provided rope life information about their machines. Some of the rope life data consisted of gross averages; other data was in the form of detailed records, including rope construction and manufacturer, cutoff and resocketing periods, end-for-end switching, and downtime for rope change-out. Trends of average hoist rope life and average drag rope life determined from the field study are shown in [Fig. 1] as a function of bucket size. The three lines on the graph have slopes of 1, M, and 1/4. A comparison of the data shows that hoist ropes moved about twice as much material as drag ropes prior to retirement, although more than a two-to-one scatter within each category is evident. As expected, the larger machines with the larger buckets moved more total volume of material. The four pairs of solid symbols represent those data for which detailed rope life histories are presented in subsequent figures.

Jan 1, 1980

By AIME AIME

PLANS are now well advanced for the joint meeting of the Institute and over a dozen other engineering societies in Chicago during the week beginning June 26: Engineers' Week at A Century of Progress. All engineers planning to visit the Fair will find it to their advantage to be present at this time so far as the Chicago attractions are concerned, and Eastern members will also have the advantage of special transportation arrangements on June 24 and 25. The tentative program is given at the bottom of the next page. Monday morning, June 26, will be reserved for registration of members and guests and the Woman's Auxiliary at the Stevens Hotel, where special rooms will be provided. A luncheon will also be served there, and in the afternoon, a technical session on nonmetallics. Instead of having the big family dinner that evening at the Stevens, as at first proposed, the local committee has planned to have it at the Fair Grounds, where special facilities have been arranged. A meeting of the Board of Directors and a few invited guests will precede the dinner. All members and guests are likely to be interested in visiting the Museum of Science and Industry, so that will be the sole event on the program for Tuesday morning, June 27. The big attraction there at present is the model coal mine, the first operative coal mine ever built for exhibit purposes. It is based on the Deutsches Museum mine at Munich, but goes far beyond that in realism, and takes the visitor on an extended tour underground. It shows him in half an hour more types of modern mining machinery and coal geology than he would be likely to see in a week's underground study in the coal fields. The Institute members will be the first group to go through this mine.

Jan 1, 1933

By M. R. J. Wyllie, Michael A. Torcaso

With the continued deep drilling of today, increasing numbers of high pressure and high temperature gas-condensate reservoirs are being discovered. Correspondingly, the ranges of properties of gas-condensate reservoir fluids are also being increased. The literature1*'." contains several excellent reviews of the property ranges in presently known condensate reservoirs. When one examines these property ranges, it becomes apparent that the need for reliable data is great if the engineer is to evaluate properly or appraise a gas-condensate reservoir. It is the purpose of this paper to present phase-behavior data that will point out some of the important variables that influence recovery from gas-condensate reservoirs produced by pressure depletion. All these variables may be resolved into two major categories: the hydroc:arbon composition of the reservoir fluid and the physical properties of the reservoir. But the variables which we will consider are those which are usually determined from well tests shortly after discovery and are, consequently, readily available to the engineer. They are as follows: (1) the producing separator gas-stock-tank liquid ratio, (2) stock-tank liquid gravity, and (3) reservoir temperature. Laboratory depletion studies have been performed on several reservoir fluids to illustrate the effect of changes in the cronsidered variables upon ultimate recoveries. The deviation factors, Z, of a series of reservoir fluids were determined experimentally to illustrate their order of magnitude and their effect upon the calculation of in-place reserves existing at high pressurcs and temperatures. The procedures followed in conjunction with the performance of these studies and their associated calculations are illustrated in Fig. 1. For the purpose of this paper, the depletion recoveries are expressed only in terms of pcr cent of initial stock-tank liquid, with the abandonment pressure assumed to be 500 psig. VARIATION OF RECOVERY WITH INITIAL PRODUCING SEPARATOR GAS-STOCK-TANK LIQUID RATIO The producing separator gas-stock-tank liquid ratio has long been one of the principal criteria in assumptions and generalized correlations' used for the estimation of ultimate recovery from gas-condensate reservoirs. Fig. 2 presents a plot of the cumulative recovery of stock-tank liquid at abandonment as a function of the initial producing separator gas-stock-tank liquid ratio. The graphical illustration represents the results of 44 laboratory depletion studies performed on actual gas-condensate fluids. These data are presented not only to illustrate the general trend of ultimate recovery increase with initial producing ratio increase but to emphasize the considerable variation in possible recovery at any given producing ratio. Table 1 presents the properties of two actual reservoir fluids chosen to illustrate the approximate extremities of producing ratios for gas-condensate systems. The fluids designated as A and B exhibited initial producing ratios of 3,400 and 114,000 scf/bbl, respectively. Fig. 3 presents a graphical comparison of the cumulative stock-tank liquid recoveries, calculated from the well-stream compositions and produced volumes for each fluid during depletion. It is to be noted that Fluid A exhibited a recovery of only 16.5 per cent when produced to an assumed abandonment pressure of 500 psig while the corresponding recovery for Fluid B was calculated to be 62.2 per cent. This difference in recovery, which exemplifies the general trend of recovery increase with initial producing ratio increase, is readily explained by consid-

By N. R. Morrow, C. C. Harris

The experimental points which describe capillary pressure curves are determined at apparent equilibria which are observed after bydrodynamic flow has ceased. For most systems, the time required to obtain equalization of pressure throughout the discontinuous part of a phase is prohibitive. To permit experimental points to be described as equilibria, a model of capillary behavior is proposed where mass transfer is restricted to bulk fluid flow. Model capillary pressure curves follow if the path described by such points is independent of the rate at which the saturation was changed to attain a capillary pressure point. Aemodified suction potential technique is used to study cyclic relationships between capillary pressure and moisture content for a porous mass. The time taken to complete an experiment was greatly reduced by using small samples. INTRODUCTION Capillary retention of liquid by porous materials has been investigated in the fields of hydrology,l soil science,2 oil reservoir engineering,3 chemical engineering," soil mechanics,5 textiles: paper making: and building materials In studies of the immiscible displacement of one fluid by another within a porous bed, drainage columnsl and suction potential techniques2 have been used to obtain relationships between pressure deficiency and saturation (Fig. 1). Except where there is no hysteresis of contact angle and the solid is of simple geometry, such as a tube of uniform cross section, there is hysteresis in the relationship between capillary pressure and saturation.2 The relationship which has received most attention is displacement of fluid from an initially saturated bed (Fig. 1, Curve R2), the final condition being an irreducible minimum fluid saturation Swr. Imbibition (Fig. 1, Curve A), further desaturation (Fig. 1, Curve R), and intermediate scanning curves have been studied to a lesser but increasing extent.2 ,3,9-12 This paper first considers the nature of the experimental points tracing the capillary pressure curves with respect to the modes and rates of mass transfer which are operative during the course of measurement. There are clear indications that the experimental points which describe these curves are obtained at apparent equilibria which are observed when viscous fluid flow has ceased; and any further changes in the fluid distribution are the result of much slower mass transfer processes, such as diffusion. Unless stated otherwise, this discussion applies to a stable packing of equal, smooth, hydrophilic spheres supported by a suction plate5 with water as the wetting phase and air as the nonwetting phase. The discussion can also be applied, in many

Jan 1, 1966

By Wing L. Lew

LEAD, silver, and zinc, in quantities of economic importance are found in the Aguilar ore. The lead occurs as galena and the zinc as sphalerite and marmatite. The silver occurrence is more complex. Pyrargyrite and proustite have been identified only occasionally. Galena is silver-bearing and so are the various other sulphides, though to a lesser degree. The principal nonsulphide gangue minerals include calcite, quartz, wollastonite, rhodonite, and various calcium, aluminum, and iron silicates. A typical analysis of, the ore is: Pb, 11.2; Zn, 12.3; Fe, 4.4; Mn, 2.2; Cu, 0.15; S, 11.2; CaO. 7.6; "Insoluble," 50.1 percent; and Ag 263 g per ton. Crushing is done in three stages. The primary crusher at the mine is set to deliver about a 5-in. product. The crushed ore is then transported to the secondary crushing plant by a 3-km cableway where the general practice is to hold the product of the first Symons to about 1 in., and of the second Symons to about 1/2 in. When the ore is soft and rich the product of the first Symons is by-passed directly to the ball-mill bins. Dust control in the secondary crushing plant is effected by enclosing the dust-emanating sources and exhausting the enclosures with a Clarage No. 18 fan driven at 1300 rpm by a 20-hp motor. Use is also made of spray water at one or two critical places. Every effort is made to keep the air free from visible dust. Dust counts taken at the working places show dust concentrations of less than six million particles ner cu ft. The composition

Jan 1, 1947

By L. F. Elkins

In 1946 Littlefield, Gray and Godbold published a thorough geologic description of the West Edmond Hunton Lime reservoir, located in Central Oklahoma, and discussion of its early performance.l They stressed implications of the nature of the reservoir rock on performance to be expected with production both by natural means and by pressure maintenance with gas injection. The essence of their analysis was that presence of an extensive interconnected system of fractures and solution channels constituting about 10 percent of the total reservoir void space in otherwise very low permeability reservoir rock would result in severe channeling of naturally encroaching water or injected gas through the fractures with little or no benefit to ultimate recovery of oil. Considerations were in progress to unitize the reservoir for pressure maintenance by gas injection. Some other engineers involved in the project had considerably different opinions at the time regarding continuity of fractures and regarding effects of such fractures on performance. The field was unitized Oct. 1, 1947. Subsequently, pilot gas injection tests were conducted in four areas of the field; large scale waterflooding was conducted in two parts of the field in the Bois d'Arc or Upper Hunton; and pilot waterflooding was conducted in the Chimney Hill or Lower Hunton. Full scale water-flooding is now in progress in the Chimney Hill section where it is oil productive. The primary purpose of this paper is to divine some of the secrets of this reservoir through analysis of all aspects of its performance, with the hope that it will be of help to engineers and operators in developing and operating other low permeability fractured reservoirs. In part, this considers variance of actual performance from some widely used conventional reservoir engineering assumptions. For brevity, other aspects of unit operation and its benefits to the owners are not discussed. Oil and Gas in Place For unit participation, net pay in the Bois #Arc defined by the gross SP anomaly on electric logs totalled 2,100,000 acre-ft in the 30,000-acre reservoir. Development of West Edmond predated modem logging techniques that now would be used to determine "net" or "productive" pay. In Fig. 1 this log pick is compared with detailed core analysis and core descripfion by Littlefield et a1.l for one well identified as A on the index map in Fig. 2. Not all of the gross Bois #Arc section had oil staining, but all cores with measureable intergranular permeability were stained. (The committee selection of the Bois d'Arc SP interval also includes the Frisco section as identified from cores by Littlefield.) The Bois d'Arc is oil productive throughout the entire 600-ft monoclinal accumulation from the eastern upstructure erosional pinchout to the west-side oil-water contact. (See Littlefield et al.l and McGee and Jenkins for geologic detail.)

Jan 1, 1970

By W. A. Krivsky, R. Schuhmann

Jan 1, 1962

By U. C. Tainton

The paper reviews the evolution of electrolytic zinc, describing some of the major obstacles that have been encountered and overcome. The chief remaining limitations of present-day standard practice are: Difficulty of obtaining high extractions, especially from low-grade and complex ores; filtration troubles, if ores contain much soluble silica; and irregularities in electrolysis, if more than certain limited amounts of antimony, arsenic, cobalt; etc., are present in the ores. These factors dictate a relatively high-grade plant feed, thus subjecting the electroytic-zinc process to the same kind of limitations as the zinc smelter. The "high acid process," in which both acid strength and current density are raised to about four times the usual figures, is described. This system concentrates both plant and operations, allows a simple type of flow sheet, and. minimizes some of the difficulties above mentioned. The large-scale operation of the process is described. SOME time ago, at a meeting of the Institute Prof. J. W. Richards1 said, "I take exception to the statement that all the factors in the production of electrolytic zinc were known long ago. There is possible in my opinion an improvement of perhaps 50 per cent. in the new electrolytic processes." An examination of the literature of the subject will show the justness of Professor Richards' contention. The work of the earlier investigators was carried on in the shadow of difficulties that, today, are hardly more than memories. We seldom hear now of zinc sponge, that bête noir of the electrolytic-zinc pioneers. Zinc sponge, was the name given to a peculiar, soft, black, non-adherent form of zinc deposit that was utterly useless for melting into ingot form. At the big plant at Cockle Creek, New South Wales, in 1897, Edgar Ashcroft2 said that the solution in the plant would suddenly, and without ascertainable cause, go "bad" and begin to deposit spongy zinc. The most delicate, even spectroscopic, methods of analysis were unable to detect any difference between "good solution and "bad" solution; either form might change to the other on being kept for a while. When it is added that an outbreak of this insidious disease (which. appeared to

Jan 2, 1924

By G. Reinberg, C. D. Clarke

Most underground mining operations are dependent on pumping installations to keep the mine unwatered. The reliability of such installations is obviously of paramount importance. The volume of water to be handled is often considerable, and the total head is relatively high. In these cases, both capital cost and operating expense of the pumping installations will become significant factors in overall mining costs. To insure reliability and to keep efficiencies, and hence operating costs, within acceptable limits it goes without saying that mechanical maintenance of a mine pumping installation must receive scrupulous attention at all times. Large mine pumping installations today almost invariably use multistage centrifugal pumps, since positive-displacement units would not be economically competitive except under very unusual conditions of small volume combined with extremely high heads. Centrifugal pump maintenance, under ideal circumstances, would be confined to parts subject to normal running water, i.e., bearing surfaces, stuffing box packing, and shaft sleeves. Under adverse conditions, however, metal may be lost from the wetted surfaces of a pump by erosive or corrosive action of the pumped fluid, and maintenance costs can easily attain enormous proportions.

Aug 1, 1956

By R. W. Parsons

The over-all apparent single-phase permeability of fracture-rock systems was studied using two different two-dimensional models. In a strict sense the results are applicable only to these models, yet may give some insight into real reseruoir behavior. The regular fracture-matrix model can have any number of regular fracture sets. All fractures within each set have the same orientation, width and spacing. The gross behavior is amlytically equivalent to that of an anisotropic permeable medium. In the heterogeneous fracture systems, individual fracture conductivities vary within a two-dinensioml network pattern. A computer program calculates the overall permeability after the conductivities are randomly placed in the network. The calculated permeability depends upon the distribution of these conductivities and the particular fracture pattern into which they are placed. Although detailed information on actual reseruoir fracture systems is not available, this study shows how some of the possible variables may affect obserued gross reservoir characteristics. INTRODUCTION Characteristics of reservoir rocks are determined by direct (core analysis) or indirect (logging and production tests) examination. Both methods, singly and together, are widely used in reservoir evaluations. For fractured reservoirs a problem exists in relating characteristics of cores to the in situ reservoir properties. Knowing fracture characteristics can be of value in determining production mechanisms. Because of the limitations of observation, the intimate details of a fractured rock system will never be known. One approach in analyzing fractures is to study the behavior of some conceptually simple models. The two models analyzed contain features which may be realistic, yet are mathematically tractable. Flow is considered in two dimensions only, with the plane of interest at right angles with the fractures. This concept represents the horizontal flow in a reservoir system with the fractures oriented vertically. Only single-phase, laminar flow is considered. The regular fracture-rock system permeability is calculable from a simple analytical expression. The heterogeneous system requires a computer program for calculating overall permeability.

Jan 1, 1967

By R. S. Handy

AT THE TIME of my first visit to Bolivia in 1927 the tin-mining industry was prosperous, the tin price at London being more than £300 per long ton of tin, and the operators were making every effort to bring their plants up to the very highest point of capacity as well as of efficiency. Any device or piece of equipment or method that gave promise of increasing production was welcomed regardless of the cost, and the plants were being modernized as rapidly as human ingenuity could make it possible. At the time of my second visit in 1932, however, conditions had changed materially. The price of tin had fallen to a little over £100 but costs had not decreased anywhere in proportion and operators were at their wit's end to cut the operating losses that were everywhere prevalent. Charles L. Bradbury, manager of the Empresa Minera de Huanuni, at Huanuni, Bolivia, had been recently called from Mexico to make all analysis of the situation and to attempt to work out a remedy for the economic conditions that threatened to close the mine. His analysis brought out the following points:

Jan 1, 1938

By H. L. TERWILLIGER

THOSE of us who have been following rock drilling work for the last 15 or 20 years can recall some of the problems that were encountered with the old piston type of rock drill and the solid steel which it used. There was frequent trouble in keeping a straight hole in badly broken ground when using the ordinary four- point bit that had a flare on the wings of about 14". The drill steel, when pounding down its hole, would follow the line of least resistance and draw away from the desired line when it encountered a weak side in the ground through which it was drilling. Some would overcome the difficulty by making long winged bits to prevent the steel crowding over; this would relieve the troubles to a great extent. There was trouble with the rifling of drill holes and inability to drill round holes in some ground. The cure for these ills was to use the "X" bit, rather than the crossbit. The "2" bits were brought out in an effort to make it easier to drill a round hole in bad ground. Most of these troubles were before the days when the mechanical drill sharpener was in as common use as it is today. It was not until the introduction of the Leyner type of rock drill, requiring hollow steel that the users of rock drills found themselves confronted with more difficult prob- lems than they had ever encountered before with drill steel because the steel had to stand more severe service.

Jan 1, 1924

By Eugene McAuliffe

THE last obtainable figures of the value of the coal mining investment are those contained in the U. S. Census Reports, from data gathered in 1919. The values shown therein and set forth below cover lands and equipment and do not include distribution and marketing facilities. The working capital necessary to meet pay rolls to purchase material and supplies and workmen's compensation insurance are likewise excluded.

Jan 1, 1926

By Donald E. Cummings

Certain dusts are dangerous when inhaled, but most hazardous of all dusts are quartz or other forms of pure crystalline silica. The inhalation of dusts containing silica in combination with other elements gives rise to changes in the lung which differ from those produced by pure silica. As a generality, silicates are less dangerous than pure crystalline silica and vary greatly among themselves in harmfulness. Repeated analyses have shown that approximately 70 per cent of the total number of particles involved in any dust-producing operation are below 1 to 2 microns in diameter. (A micron is approximately 1/25,000 in.) Similar studies of dusts recovered from silicotic lungs post mortem have demonstrated essentially the same size frequency distribution, except that the upper limit of size retained in the air sacs is approximately 10 microns. Experiments carried on by Gardner and the author have further demonstrated that greater changes were produced by a fixed weight of very fine quartz particles (2 to 3 microns and smaller) than by the same weight of slightly larger particles (8 to 10 microns). Any attempt to control a dust hazard should therefore be directed toward the removal from the working atmosphere of particles less than 10 microns in size, and particularly those below 3 microns. All industrial hygienists agree on this matter, but there remains considerable dispute as to the lower limit of particle size capable of causing injury. It has been generally conceded, however, that particles of harmful dusts smaller than 1/4 to 1/2, micron are not essentially concerned in the development of pulmonary fibrosis. This opinion is partly substantiated by the existence of large numbers of these small particles in practically all atmospheres that are not associated with any known hazard. Such particles are so small that they have very little mass, fail to settle even in quiet air, and probably are not easily retained in the lung. Until further research proves that they are involved in the dangers provoked by the inhalation of certain dusts, engineers will generally agree that it is better to disregard them.

Jan 1, 1937

By J. Jones-Parra, R. S. Reytor

The porosities of fractured limestone reservoirs can be divided into two broad types in accordance with their effects on fluid distribution and fluid flow. In the coarse porosity, gravity segregation lakes place freely and the resistance to fluid flow is very small. In the fine porosity there is no segregation and a high resistance to flow, and it has relative permeability characteristics similar to tight sandstones. By analyzing the affect of the two porosities it is concluded that in some cases to recover the maximum amount of oil it is necessary to remove large quantities of gas from the reservoir by producing at high gas-oil ratios. In this manner the fine porosity is drained of its oil and the gas-oil contact drops slowly permitting higher production rates from the oil leg. Since this conclusion is contrary to widely accepted principles of conservation, a mathematical model (Fig. I) was constructed to duplicate the conditions desired. The behavior of the model indicates that under certain conditions it is possible to recover more oil by producing at high gas-oil ratios than by production at low gas-oil ratios, and that the rate of production is affected more by gas shut-offs than by the decrease in pressure (Figs. 2, 3, 4 and 5). INTRODUCTION It has been noted that certain limestone reservoirs behave in such a way as to indicate that there are two distinct types of porous spaces available for fluid storage and fluid flow. Regardless of the nature of these porous spaces the distinguishing characteristic is that in one type of porous space there is definite gravity segregation between the oil and the gas; while in the other, the gas evolved tends to remain distributed equally throughout the reservoir. For the sake of simplicity the porosity in which gravity segregation takes place at a fast enough rate to affect the behavior will be called "coarse po- rosity", while that in which this is not so will be termed "fine porosity". The behavior of a reservoir of this type would be different than that of a sandstone reservoir, especially if most of the oil is in the fine porosity. It has been observed that fluid flow to the wells takes place mostly through the coarse porosity. The large fractures which

By M. W. BERNEWITZ

IT is 27 years since I last visited Broken Hill, New South Wales, one of the world's greatest lead-silver-zinc districts. Then, the flota¬tion of ores was in its infancy. The Minerals Separation process had its birth as a practicability in the Central Mill, which is still operating and yielding high recoveries. The average Australian knows that Broken Hill is an important mining center in a "corner" of New South Wales, but he does not know what a factor it is in the lead, silver, and zinc production of the world. Nor does he realize that among the ramifications arising from metal production at Broken Hill are the great lead smelter at Port Pirie, South Australia, 254 miles southeast; the electrolytic zinc works at Risdon, and the limestone mine at Davenport, Tasmania; the acid works at Cockle Creek, New

Jan 1, 1935

By Alvinus Brown Wood

THE ancient copper-mines of Lake Superior, having been destroyed or covered by-modern mining-dumps, are not accessible to the present inhabitants of that region, and, since no more are likely to be found, some account of those already discovered, from one who has seen them, may be acceptable to the Institute. Early in May, 1855, 1 took a party of men to open an ancient pit on the Quincy mine-location. Mr. C. C. Douglas was the Agent.," as mine-managers were then called on Lake Superior. The Quincy Co. had previously done work on a fissure-vein, several hundred feet west of the Amygdaloid lode (afterwards called the Pewabic lode), on which was the ancient pit herein described. It was at this pit that the Quincy' main shaft was subsequently stink. The ancient pit showed an apparent depth of about 4 ft., but when cleaned out it was shown to be 14 ft. deep, having been filled up by the sliding-in of material composed largely of broken rock, taken out in sinking the ancient shaft, and left near its mouth. Midway of the shaft, and below water-level, was found a scaffolding, of white-birch poles,- which had been used as a landing, to assist in removing the excavated rock. The shaft was 7 ft. in diameter. The excavation had been done by first building fires in order to disintegrate the rock, as was proved by the abundance of charcoal found; then breaking the softened rock with hammers of diorite, such as is found in the greenstone range on Keweenaw point. These hammers had about. the size of large paving-stones. Only broken ones were found, the whole ones having been doubtless carried away for other work, such as could be traced on the lode for a hundred feet or more to the south. At the place where this shaft was stink, barrel-copper (i.e.,

Mar 1, 1906

By F. D. Richardson

STAFF: Editor, Gerhard Derge Carnegie lnstitute of Technology Schenley Park Pittsburgh, Pa. 15213 Editorial Assistant, M. A. Redmerski Production Editor, Otto T. Johnson THE METALLURGICAL SOCIETY: Jack H. Scoff, President; Richard C. Cole, Past-President; Harold 0. Emerick, President-Elect; Ralph L. Hennebach, Treasurer; Robert W. Shearman, Secretary; Donald A. Parks, Assistant Secretary; Leslie S. Wilcoxson, Assistant Secretary. PUBLICATIONS COMMITTEE OF THE METALLURGICAL SOCIETY: R. E. Lund, Chairman; T. E. Dancy, H. O. Emerick, P. R. Gouwens, R. E. Grace, J. H. Jackson, H. H. Johnson, A. E. Lee, Jr., R. R. Nosh, R. D. Pehlke, and Paul Queneau. Review and selection of manuscripts is under the supervision of the following Publications Committees: Extroctive Metallurgy Division: R. E. Grace, Choirmon; G. M. Bell, D. W. Bridges, J. M. Cigon, G. W. Heoly, T. A. Henrie, R. D. (Holli-doy, C. E. O'Neill, C. S. Somis, A. W. Schlech-ten, and Charles Shull. Iron and Steel Division: R. D. Pehlke, Choirmon; T. P. Floridis, Arnulf Muon, G. R. St. Pierre, E. T. Turkdogan, L. H.Von Vlock, and J. M. Uys. lnstitute of Metals Division: H. H. Johnson, Jr., Chairman; J. B. Clark, Vice Choirmon; M. R. Achter, G. F. Bolling. J. O. Brittoin, G. P. Conard, II, R. S. Davis, L. A. Girifolco, G. T. Hohn, J. P. Hirth, L. Himmel, G.T.horn, George Krauss, J. D. Livingston, R. D. Manning, H. M. Otte, S. V. Rodcliffe, R. E. Reed-Hill, H. C. Rogers, E. ScaIa, O. Sherby, M. T. Simnad, G. R. Speich, E. A. Steigerwald, R. A. Swolin, W. A. Tiller, W. R. Upthegrove, J. B. Wagner, Jr., Derek Wolton, H. W. Weart, W. W. Webb, and D. Published seven times yearly in February, March, April, June, August, October, and December by the American lnstitute of Mining, Metallurgical, and Petroleum Engineers, Inc., 345 East 47th Street New York, N. Y. 10017. Telephone PLAZA 2 -6800. Subscription $30 per year for non-AtME members m United States and North, South, and Central America; $32, foreign; $7.50 for AlME members Single copies, $6.00, single copier foreign, $6.50. The AiME is not responsible for any statement made or opinion expressed in its publications . . . Copyright 1964 by the American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc. . . . Registered cable address, AiME New York Indexed in Engineering Index, Industrial Arts Index, and Chemical Abstracts. Second dost postaas poid ot New York, N. Y.,ond Ann Arbor, Mich. Volume 230, Number 6.

Jan 1, 1964

F. W. Matthiessen, who, with E. C. Hegeler, of La Salle, was one of the creators of the zinc industry in the-United States, was born in Altona, Schleswig-Holstein, Germany, Mar. 5, 1835. He was one of a family of remarkable brothers, two of whom were long absociated in this country with the sugar and glucose industry. Mr. Matthiessen was educated at Freiberg, and came to this country in 1857 with Mr. E. C. Hegeler, after having, in company with that gentleman, visited the mining districts of Germany, Belgium, and England. They first went to Friedensville, near Bethlehem, Lehigh County, Penn., wherc attempts had already been made to produce zinc from the ore deposits found in that place. The ore was a he silicate but all attempts to extract zinc from it had failed. Mr. Matthiessen and Mr. Hegclcr were successful, but declined to invest their money in the zinc industry at Bethlehem because 01 certain local conditions. Hearing of the discovery of zinc -ore in the West, they visited both Wisconsin and Missouri and thought of settling in the coal region of East St. Louis. Finally La Salle, as being near to the Wisconsin fields and having much coal, was selected ae the site of the new smelting company, and on Dec. 24, 1858, the first shovelful of dirt was turned for the buildings of the new industry. The Civil War at first interfered with the manufacture of zinc, but afterward a lively demand for the metal arose and the future success of the institution was established. A large rolling mill was added in 1866, and in 1881 the manufacture of sulfuric acid as a byproduct was begun. Mr. Matthiessen also developed the Western Clock hlanufacturing Co. of La Salle, which manufactures the Big Ben alarm clock, from a small plant having 25 men to the present large institution which employs some 2000 workers. Mr. Matthiessen's affiliations with other metal industriefi have been numerous. But the contributions of the great zinc manufacturer to the causes of philanthropy and education have made his name known throughout the country, beyond industrial circles. He has given to the city of La Salle probably a sum total of $500,000 in various benefactions. Among the objects of his philanthropy were the La Salle-Peru Township High School, which he has made a model institution of secondary education for the entire United States; also the Tri-City Hygienic Institute of La Salle, Peru, and Oglesby, Ill., which he endowed for $200,000 This Hygienic Institute, which is unique in the United States, has a traincd staff of health officers, bacteriological laboratory, medical library, infant welfare station, milk station, free dental clinic, school nurse, and isolation hospital. Mr. Matthiessen was elected mayor of the City of La Salle three times and gave generously to the municipality of which he was the head. He also saved for the people of Illinois one of the great scenic districts of the state, Deer Park, with its cafions and natural beauties, which he con-verted into a model scenic resort, and the proceeds of which he gave to the charities of the Tri-Cities in which he lived. He died on Feb. 11, 1918.

Jan 1, 1920

BUMPS in No. 2 Mine, Springhill, N. S., furnished the main feature for discussion at the morning meeting* on Ground Movement and Subsidence on Feb. 18. Walter Herd, the author of the paper by which the discussion was introduced, not being well, was unable to be present. The paper was presented by T. L. McCall, who laid stress on the presence of sand- stone as the cause of bumps, on the value of retreating longwall in eliminating such phenomena at the coal face and on the advantage of wide headings with packs on either side, leaving space behind them for any coal that bumps might dislodge. George S. Rice, who presided, referred to his visits to the Nova Scotia mines and said that bumps usually occurred only where the coal was thick and strong and the roof and floor both more than usually hard. If any of the three were weak, bumps were not likely to occur. In the Nova Scotia mine, to which Mr. Herd referred, there was no material for packwalls and for this reason as well as for safety he had been convinced that long- wall retreating with a small percentage of pack walling was the most feasible plan.

Jan 1, 1929