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By D. W. Mitchell

J. H. Schlobohm (Joy Manufacturing Co., New York) —This paper has been read with a good deal of interest; however, there are several salient features which Mr. Mitchell has overlooked. The initial emphasis on selection should be placed on type of material to be loaded and method of mining involved. There is no possible connection in the comparison of scraper or Joy Lohite loaders with loaders of any other type. Neither can an operating comparison be made between "Rocker type" loaders and those equipped with loading head and gathering arms. Each unit has its application, but the application depends on material and the mining system involved. Mr. Mitchell's compilation of data on various loaders, while it represents a great many facts, does not represent true operational data, i.e. Table I, column heading "Max. Rated Capacity for 7 hr;" these figures are meaningless inasmuch as little or no time at all is allowed for tramming or switching or moving the loader from place to place. Table I, column heading, "Best Reported Field Shift," would be a better source of operational data, assuming of course that conditions, applicable to each class of loaders, were average to avoid enthusiastic performance figures. Table I, column heading, "Repair Parts Cost per Ton," is still another item which will not stand up under comparison unless the loaders involved are put into type classes, i.e., there are simply no means possible to show the repair costs of scraper loading versus a caterpillar mounted loader in abrasive material. The source of information here is also important. Actual field tests have proved that these costs are of a constant nature. Manufacturers are striving to hold them to a minimum and many interesting studies have been made. A fairly recent example of this in a large United States gold producer has proved that Joy HL-3 loaders can be consistently average, less than $0.025 per ton mucked. This cost represents repair labor and parts over a two year

Jan 1, 1952

By AIME AIME

NOT a few physical metallurgists started their profession- al careers as chemists or physicists, only to surrender later to the attractions of metallurgy. The present Institute of Metals Chairman varied this more usual sequence in hat his first love was electrical engineering, when as a recent graduate he served on the staff of the General Electric Co., of Schenectady. Soon turning to metallurgy as a more interesting field, he was metallurgist and then chief engineer of the Wads- worth Watch Case Co. from 1920 to 1927. Since 1927 he has been with the International Nickel Co. at the Bayonne, N. J., research laboratories where he is staff adviser.

Jan 1, 1940

By C. B. Dudley

In a work published in 1838, De Morgan, the author of the article on " Probabilities," in the Encyclopedia Metropolltimn, says: " The method of least squares is not yet introduced iutb the affairs of common life,.....that many thi~gs which are denlonstrable only by the higher branches of mathematics are looked upon as useless." And he mentions an instance in which "a method was suggested for estimating the relative importance of boroughs, by considering their population and ~wntributions to the revenue con)-

Jan 1, 1881

The Howe Memorial Lecture, in memory of Henry Marion Howe, Past President of the Institute, was authorized in April, 1923, as an annual address to be delivered by invitation under the auspices of the Institute by an individual of recognized and out- standing attainment in the science and practice of iron and steel metallurgy or metallography, chosen by the Board of Directors upon recommendation of the Iron and Steel Division. The following were the Howe lectures and lecturers for the years indicated: 1924 What is Steel? By Albert Sauveur.

Jan 1, 1932

By SAM A. LEWISOHN

IT is popular today to dramatize in a journalistic spirit, some particular factor among the causes of unemployment. Naturally the time chosen for such emphasis is usually when the factor in question is temporarily a particularly active one. A few months ago, in the unemployment then current, we saw largely the results of a healthy acceleration in changes in processes, greater efficiency, a more intensified use of labor-saving devices, perhaps also a change in products. So we have been hearing a great deal about the influence of mechanization on unemployment, the so-called technological unemployment. Many talk as if this kind of unemployment were a wholly new phenomenon, for- getting that it is a constant process in a growing industrialism, though it sometimes becomes more pronounced. At other times one would think that seasonal unemployment is the only type of unemployment, and then again the fashion changes and we hear .about nothing except cyclical unemployment. Every few years there seems to be a different fashion in labelling the germ supposed to be the cause of unemployment.

Jan 1, 1929

EVERY English-speaking mining, engineer or geologist knows that some terms used by his profession are not rigid but vary regionally; for example: what is called a vein by some, is called a lode by others and is known as a reef to their Australian colleagues. There are parallels in, the German language. Since, in addition, the meaning of some words may change considerably in 450 years-and other words may disappear completely-and not only the terminology but the concepts of a science are subject to drastic changes over such a long period of time, translating the Bergbüchlein posed some interesting problems. Old German texts and glossaries such as C. T. Delius' Anleitung zu der Bergbaukunst (1773), Minerophilus' Neues and Curieuses Bergwercks-Lexicon (1730), and H. Veith's Deutsches Bergwörterbuch (1871) proved useful sources of information when defini¬tions of obscure terms were needed. The task of translating was made even more challenging by the author's personality. As Ulrich Rülein von Kalbe was primarily a physician, his information must have been mostly secondhand. Since the nomenclature of the miners of Saxony, where he gathered his material on silver ores, undoubtedly varied from that of the German miners in Hungary, for instance, who probably supplied him with data on gold ores, it is not astonishing that he is not consistent in his use of some expressions. To give an example: there is every indication that Flöz and schwebender Gang (see footnote p. 21) are used interchangeably in spite of his occasional disapproval of such usage. It is obvious that he was an educated man with a questing and active mind and, although he apologizes-not wholly sincerely, one might suspect-for the simple

Jan 1, 1949

By John Henry Harden

IN 1874, with Mr. H. Y. Attrill, of Baltimore, Md., I made an examination of some property at Goderich with reference to sinking for and mining salt. With this end in view we visited all the wells in the neighborhood, but the information sought being of so unreliable a character I advised the putting down of a borehole on the property. This has since been done, the result of which has lately been published by Dr. T. Sterry Hunt in the Toronto Globe. From this there appears to have been passed through six beds of salt of an aggregate thickness of 123 feet. Rock-salt was known to exist, for, by the boring of existing wells, small crystals had been brought to the surface in the dirt, but no attempt had before been made to obtain a reliable sample or to prove the number and thickness of the beds. The question now remaining for discussion is, shall the present method of obtaining the salt be continued, or shall the beds be won by a shaft in a regular mining fashion, by which means the salt may be gotten in a condition almost ready for the market? The present mode of obtaining salt is by boreholes from 6 inches to 8 inches in diameter drilled to the beds, into which is inserted a pump. The "feeders" of fresh water intersected in drilling the well are allowed to descend on the outside of the pump-tube to the salt beds and there become saturated, when, on use of the pump, brine is obtained for evaporation. In the beginning brine can only be had in limited quantity, but by the daily application of the pump, and the gradual solution of the salt, a larger surface becomes exposed to the action of the fresh water, and a continuous supply of brine is obtained. It will then be understood that the supply of brine is dependent upon the feeders of fresh water intersected in boring the well, which, we are told, have never shown any sign of diminution, and this is the water that must be encountered in sinking a shaft. There are ten wells in operation at Goderich, the most important one to the present project being known as the Hawley Well, located at an elevation a few feet above Lake Huron at the mouth of the river Maitland, at a much lower level and nearer to the proposed shaft than any other well in the district. At this well the feeders

Jan 1, 1877

By John Henry Harden

IN 1874, with Mr. H. Y. Attrill, of Baltimore, Md., I made an examination of some property at Goderich with reference to sinking for and mining salt. With this end in view we visited all the wells in the neighborhood, but the information sought being of so unreliable a character I advised the putting down of a borehole on the property. This has since been done, the result of which has lately been published by Dr. T. Sterry Hunt in the Toronto Globe. From this there appears to have been passed through six beds of salt of an aggregate thickness of 125 feet. Rock-salt was known to exist, for, by the boring of existing wells, small crystals had been brought to the surface in the dirt, but no attempt had before been made to obtain a reliable sample or to prove the number and thickness of the beds. The question now remaining for discussion is, shall the present method of obtaining the salt be continued, or shall the beds be won by a shaft in a regular mining fashion, by which means the salt may be gotten in a condition almost ready for the market? The present mode of obtaining salt is by boreholes from 6 inches to 8 inches in diameter drilled to the beds, into which is inserted a pump. The "feeders" of fresh water intersected in drilling the well are allowed to descend on the outside of the pump-tube to the salt beds and there become saturated, when, on use of the pump, brine is obtained for evaporation. In the beginning brine can only be had in limited quantity, but by the daily application of the pump, and the gradual solution of the salt, a larger surface becomes exposed to the action of the fresh water, and a continuons supply of brine is obtained. It will then be understood that the supply of brine is dependent upon the feeders of fresh water intersected in boring the well, which, we are told, have never shown any sign of diminution, and this is the water that must be encountered in sinking a shaft. There are ten wells in operation at Goderich, the most important one to the present project being known as the Hawley Well, located at an elevation a few feet above Lake Huron at the mouth of the river Maitland, at, a much lower level and nearer to the proposed shaft than any other well in the district. At this well the feeders

By Jr. F. M. Perkins.

Capillary forces play a controlling role in water-drive displacement processes both in laboratory experiments and in actual reservoirs, but their quantitative importance may be quite different in the two cases. Because of the importance of conducting laboratory experiments which are representative of field conditions, it is necessary to understand exactly the role of capillary forces in the displacement process. Though a number of experimental investigations related to this subject are contained in the literature, there appears to be a lack of information pertaining to unsteady-state experiments in water-wet media. This experimental study was conducted to obtain additional laboratory data to clarify further the role of capillary forces in both the macroscopic and microscopic flow of oil and water in porous materials. THEORETICAL CONSlDERATlONS The capillary pressure is defined as the difference in pressure between a continuous oil phase and a continuous water phase in a porous material.' The magnitude of this pressure difference depends on the interfacial curvature and the interfacial tension. The interfacial curvature is determined by the geometry of the pore spaces, the wettability of the rock surfaces, and the quantity of cach phase present. Capillary forces are involved in a water-drive displacement process in that they exert a controlling influence on the microscopic fluid distribution which in turn is reflected in the saturation or macroscopic flow behavior. Microscopic Fluid Distribution Because of the microscopic nature of the displacement of oil by water, it is necessary to consider the flow and the fluid distribution in individual pores. On this microscopic scale the capillary Forces, which act over a distance of one or two sand grain diameters, control the distribution of oil and water under static equilibrium conditions. When an external force is applied to the fluids, such as in a water-injection experiment, the applied forces tend to distort the oil-water interfaces. However, in most fine-grained, water-wet sands, the applied pressure difference across one or two grain diameters is usually several orders of magnitude less than the capillary pressure difference. These con-siderations lead to the theory' that even during flow the capillary forces continue to control the microscopic distribution of oil and water within the pores of a porous material for all practical reservoir and laboratory flow rates. This concept of capillary forces controlling the microscopic distribution of fluids has been substantially verified by other investigators3-7 who have found a lack of dependence of relative permeability and residual oil saturation on rate of fluid injection. Macroscopic Distribution The microscopic influence of capillary forces cannot be observed easily and only the effect on the macroscopic or average saturation can be detected. The saturation, of course, is really the point of interest. During a water flood, large differences in saturation at the flood front cause large capillary pressure gradients. This, in turn, causes water to advance ahead of the flood front thereby reducing the capillary pressure gradient in this region. The result is that in homogeneous porous media capillary pressure gradients tend to cause a diffuse displacement front. At low rates in laboratory columns, the front may extend over the entire column length. When the advancing water first reaches the outflow face of a core, the water, which is the wetting phase, cannot be produced because the pressure in the water just inside the core is lower than the pressure in the oil-filled space around the outflow face. This difference in pressure is equal to the capillary pressure for the water saturation existing at the outflow face. Water, therefore, accumulates at the outflow end of the core which causes a reduction in the capillary pressure. Because the capillary pressure does not vanish except at the residual oil saturation,7,8,9 water will not be produced until the residual oil saturation exists at the outflow face. This entire effect,"' which is called the "boundary effect", results in a region of relatively high water saturation near the outflow face. At low rates of injection in a short column, this region of high water saturation may extend over a considerable portion of the column. The influence of capillary forces on the macroscopic flow of oil and water have been described by Leverett.10 For unidirectional, viscous flow in the absence of gravity segregation, the expression in dimensionless form for the fraction of water in the flowing stream, f, is

Jan 1, 1958

Recognizing the fact that the problems of the committee named by the Board to prepare the "official ticket" for officers ' and Directors of the Institute are various and difficult; and desiring to assist this committee by setting forth some of the principles that should guide the committee and some of the qualifications that should be required of candidates, the following instructions are formulated and the Secretary is directed to publish them in MINING AND METALLURGY concurrently with the publication of the names of each newly appointed Nominating Committee and to send a copy to each member of the Committee.

Jan 1, 1944

September steel production established a new record for a 30-day month with 9,034,000 tons. It was the highest of any month since March. Output of ingots and steel for castings was 535,000 tons more than was poured in August 1952, and 373,000 tons over the total for September 1951. Prime Minister Daniel F. Malan touched a gold button to start South Africa' a first uranium plant into production on the premises of the West Rand Consolidated Gold Mine, near Krugersdorp, Transvaal, 25 miles west of Johannesburg. Uranium oxide is being extracted from mine tailing after removal of the gold. Thirteen gold mines in the region are scheduled for uranium production. Defense Materials Procurement Agency signed an agreement-with the Bagdad Copper Corp., Bagdad. Ariz., for expansion of the firm's facilities to enable delivery of at least 27 million lb of copper a year and 91,0000 lb of molybdenite. It is said that the company will spend about E million on the expansion.

Jan 1, 1952

By Joseph W. Leonard

Seven formulas commonly used to evaluate industrial screening efficiency are investigated to determine if they are suitable for calculating the efficiency of rectangular-hole screens. Six formulas were found to be limited in application to square-hole screens. The seventh, although acceptable for evaluating rectangular-hole as well as square-hole screening efficiency, was found to be unwieldy. A new formula is developed based on the concept of misplaced sizes. This proposed formula permits the single step determination of efficiency and is applicable to all types of screening applications.

Jan 1, 1975

By P. Martignan

UNTIL quite recently, Alsace was the only district in France where petroleum could be found in somewhat industrial quantities. The Pechelbronn fields produce, however, only about 80,000 tons a year, which represent approximately one-eighth of the domestic consumption. Much research work has been done in Alsace to find the prolongation of the Pechelbronn fields, but instead of oil the drillings revealed the existence of large deposits of potash. This can, be easily explained when one remembers that the Pechelbronn oil is of the Oligocene period, and, that in the Alsatian stratification the Oligocene lies immediately on the Keuper, i. e., on the strata that originate from a period during which the largest salt and potash deposits were constituted. Before the war, and mostly at the end of the last century, some wells were drilled in various districts of France where some analogies could be found with the Alsatian geology, the borings being mainly made in the Triassic and Tertiary beds. They led to negative results. After the war, the growing importance of oil urged the necessity of resuming the explorations. But it is our belief. that this was greatly facilitated by the enacting of new legislation, which is embodied in the Mine Act of May 16, 1922.

Jan 3, 1925

By Howland Bancroft

THE writer has observed that some confusion is experienced by many mining engineers in making vertical sections of ore deposits in mining properties which they have examined. Having much examination work calling for the correct interpretation of vein structure and the subsequent platting of the same on sections, it has occurred to the writer that the accompanying diagram may be of use to others who at times may be called upon to prepare numerous sections. For example, a great mass of data on-strike and dip of ore bodies is collected underground in separate

Jan 7, 1914

By T. C. Mendenhall

All persons, actively engaged in your profession, must have a natural interest in the subject of weights and measures. All members of the engineering profession have to do with operations of weighing and measuring—some with measuring more than weighing, and some with weighing more than measuring—but all with both of these processes to a greater or less degree. Methods of weighing and measuring have improved constantly from the earliest times and have kept pace with the advance of other technical processes. It is, therefore, believed that you will be interested in a few remarks concerning some of the more recent advances in relation to the establishment of decimal standards of length and mass in this country. Before speaking of this, I will refer very briefly to some facts which may not be very generally known regarding our customary system of weights and measures. Although the yard is universally accepted as the unit of length, and the pound as the unit of mass, it is not generally understood, I believe, just in what respect the yard is the unit of length, or the pound the unit of mass. That is to say, it is not generally known in what degree these units have been legalized by Acts of congress. Doubtless, many of you are familiar with the facts which I will briefly recapitulate. The Constitution of the United States authorizes Congress to establish a system of weights, measures and coinage. The establishment of a system of coinage, as you know, was one of the first acts of the government, and the system then adopted is certainly one of the most perfect, if not the most perfect, that the world has yet seen. But, although Congress had the power to establish a system of weights and measures, it has never yet seen fit to exercise this power; that is to say, Congress has never yet

Jan 1, 1890

ERNST PROCHASKA, Bonne Terre, Mo. (written discussion*).-The special importance of this paper is the fact that it calls special attention to the existence of organic sulfur in coal. Many writers have denied the existence of a chemical compound of carbon with sulfur in coal, .but later investigations, and especially the paper by Fraser and Yancey, prove undeniably its existence. As we become more fully convinced of its existence and as the present methods of washing, either in a jig or on tables, are unable to separate the organic sulfur, it remains for an inven-tive genius to perfect a chemical washing process whereby the sulfur will be, dissolved out of the coal, or we must abandon entirely the washing of such coal.

Jan 11, 1919

By Jorge Munoz Reyes, Guillermo

The new entity, Yacimientos Petroliferos Fiscales Bolivianos, created in 1936 for the development and exploitation of all petroliferous zones of Bolivia, including those formerly belonging to the Standard Oil Co., is doing its utmost to bring about rapid development and by this means to create a new source of revenue for the State. With this in view, Y.P.F.B. has opened a new field in the Samaipata region, on the main road between Cochabamba and Santa Cruz. Installation of machinery has begun for the drilling of several wells on the five anticlines that occur in this region. Work has also begun in the Saipuru field, on the Santa Cruz-Charagua highway, which was discovered by the Standard Oil and temporarily abandoned. In this new field, a topping plant will be installed, to supply gasoline and kerosene to Santa Cruz. Explorations are also being made on the neighboring structures of Saipuru. At the end of 1937, the committee that is to study the region of the Chapare in the northeastern part of Cochabamba, was organized. The structures were studied 10 years ago by Kirtley Mather and other geologists. It is hoped that by March 1938 this camp will begin work, as this zone gives promise of being valuable. Development The capacity of the refinery at Camiri has been enlarged in order that it may supply all the needs of that region. In order that the supply of crude may be adequate, several wells that had been almost abandoned by the Standard Oil are being cleaned out. New wells have been located at this camp following the principal anticlinal structure, and during the first half of the year 1938 several wells will be drilled. The same program is being followed in Sanandita but on a greater scale, as the nearness of this district to the Argentine border, which is the best market for the Bolivian petroleum of the south, allows immediate sale of the petroleum. Possibly a new refinery will be installed at this camp, as the one now in existence is only a rudimentary distillery. At the Bermejo camp, which is farther south, intensive work is being done to bring the wells into production. The Standard Oil produced limited quantities several years ago, but since 1927 the wells of this dis-

Jan 1, 1938

By A. W. Ashbrook

There are many methods of analysis available for compounds similar to those used in solvent extraction processes. However, the majority of these methods are not directly applicable to the determination of solvent extraction reagents, especially in raffinates. The number which are applicable is further reduced if limited to the more simple methods suitable for process control purposes. Commercial extractants are complex mixtures. The complexity is increased by the addition of diluents and modifiers in two-phase systems containing metals. Raffinates from solvent extraction processes contain the more polar components of the extractants and the products of decomposition. Only a limited amount of information is provided by total organic carbon or spectrophotometric analysis. The complexities of the systems require a combination of methods.

Jan 1, 1978

By AIME AIME

ROBERT F. MEHL was born in Lancaster, Pa., March 30, 1898 and graduated from Franklin and Marshall College in 1919. He then went to Princeton and was granted his doctor's degree in physical chemistry in 1924. Two years as head of the department of chemistry at Juniata College, followed by a like period as National Research fellow at Harvard, working with T. W. Richards and Albert Sauveuir, satisfied Bob's immediate affections for college and university life and prepared him to turn temporarily to other fields.

Jan 1, 1938

The work of Americanism is getting under way slowly but surely. The purpose of the Auxiliary is to build for all time and it therefore wishes to lay its foundations securely, feeling that the true understanding and adoption of the ideals of Americanism are the safeguards of our country from the perils of anarchy, and the bond of union between labor, brains, and capital. We hope to have reports from several directors to print next month and here append the report of the Director for the New York Section, Mrs. W. Y. Westervelt.

Jan 5, 1919