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[ ] TEN FEET TALL and four feet wide, tire designed for Le Tourneau equipment is world's largest, and will operate with only 10 to 15 pounds air pressure. (15) SOIL SAMPLING: A complete collection of data about soil sampling techniques, accumulated during the past 33 years by the Acker Drill Co., is displayed in a 16-page bulletin. Modern sampling techniques are discussed along with recommendations as to correct tools and accessories best suited for economical recovery of samples. (16) GEAR MOTOR: U. S. Electrical Motors Inc. has a new bulletin on the type GW Syncrogear motor, showing phantom views of inner construction and operating detail. [ ] (17) SAFETY: A booklet containing an up-to-date list of American Safety Standards has been published by the American Standards Association. Comprehensive subject index and brief commentaries on the standards helps in selecting proper documents. Nearly all of the 160 American Safety Standards listed are widely used, and some have been adopted as a basic part of governmental codes.

Jan 1, 1952

PAUL D. FOOTE AND T. R. HARRISON, Washington, D. C. (written discussion *).-There are several methods for measuring the internal resistance of a battery, the line resistance in a circuit containing an e.m.f., or the true value of this e.m.f. The writers, however, were the first to em-ploy a simple principle whereby the total resistance of the circuit is ad-justed to a preassigned value for which the scale of the millivoltmeter is graduated, the only e.m.f. employed being that of the source measured. One of the simplest forms of these instruments is described on page 2842, September Bulletin. In papers now in the press we have described some twenty modifications of this simple design but all operating upon the same fundamentally new principle. The instrument devised by Mr. . Porter is of this general type but, unlike the designs we have recom-mended, is open to serious objections.

Jan 12, 1919

One item of general interest in MINING ENGINEERING Trends, May 1952 gives the wrong impression of the scale of the ilmenite operations in North Carolina It also implies there are known deposits of rutile which "guarantee self-sufficiency for many years" So far as we know this is not true At present, rutile is in such short supply in the United States that the Defense Mineral Authority is encouraging prospecting for new deposits So far none have been found of any consequence and our needs have to be met largely from the deposits near Jacksonville, Fla, and rutile imported from Australia JAY P WOOD VICE-PRESIDENT HUMPHREYS GOLD CORPORATION The reference to self-sufficiency was meant to apply to the ilmenite-bearing sands, not rutile, but improper phrasing failed to make this clear However, the press release that the Glidden Co circulated stated that this deposit of ilmenite was one of the largest in North America -Editor

Jan 1, 1952

By John W. Gruner

On account of the tremendous increase in the production of steel there has been much speculation as to the reserves of iron ore. A number of estimates of world scope have been published, which show that these reserves are definitely limited if a long range view is taken. There are, however, optimists who believe that in perhaps two generations the metallurgy of iron will have advanced to the point where any kind of iron mineral combination of perhaps 20 pct iron will be usable. This thinking has been particularly applied to the new taconite developments of the Mesabi Range, for here is an iron formation of such vast extent that its iron could almost last forever. Let us briefly examine this most favorable of all low grade ore reserves in North America. Nothing will be said about the 1,000 million long tons of material now classified as ore, for they will be largely gone in less than 20 years.

Jan 3, 1954

AN indication that Mesabi Range iron use companies may develop their own flotation processes for low grade iron ores is the report that Cleveland Cliffs Iron Co. is adopting a variation of one of the oldest known methods at its new Michigan treatment plant. Basically, the method involves using fatty acids and fuel oil reagents. The idea was developed many years ago and should be free of patent control. With other laboratories working on the same tack, it seems to be a pretty good bet that they will come up with their own processes. Any outside process will have to offer considerable advantage or low royalty rate to get consideration. Much of the appeal of the fatty acid process is the cheapness of the reagent. One source is pulp paper liquor in semi-refined form. With stream pollution legislation acting as a strong pressure, paper companies have been seeking ways to dispose of the material. Wisconsin has even attempted to use it for road binder.

Jan 5, 1953

By F. E. Luborsky, K. T. Aust

RECENT interest has been shown in utilizing solid-state techniques for obtaining large oriented grains in the Alnico Alloys.1-4 Unfortunately, due to the inherent brittleness of these materials it is difficult to introduce sufficient imperfections by deformation to support the nucleation and growth of new, recrystallized grains. As a result, recrystal-lization methods for obtaining large grains, such as the strain-anneal technique, do not appear to be feasible. Steinort et a1.2 used a combination of a thermal gradient and internal strains to obtain large single crystals of Alnico 5 from a poly crystalline casting by annealing at temperatures above 1200°C. It was suggested that the strains were the result of the precipitation of the y phase which exists between -850° and 1200°C. The purpose of the present study was to determine if the grain size of the cast Alnico alloys can be markedly increased by solid state techniques involv-

Jan 1, 1963

By Edmund E. Getzin

Of all the developments in the post-war history of Western Europe, none has been more remarkable in its aims and in the progress it has achieved than the movement toward European integration. It is not an exaggeration to say that this movement marks a virtual revolution, an about-face, in the long and complicated history of European states over the past three centuries. Although sporadic efforts to achieve European integration can be traced back for at least a 100 years, it remained for the breakdown of the European economies as a result of World War II and the subsequent Russian threat to give new impetus to the concept of broader economic and political integration. In fact, the economic integration of Europe following the end of the war was considered so essential that, in 1949, the administrator of the European Cooperation Administration, Paul Hoffman, spoke of the economic integration of Western Europe as an objective of American policy embodied in the Marshall Plan.

Jan 6, 1963

By Leroy W. Weeks, Peter B. Nalle

The rapid growth of the modern electronic computer industry during the past 15 years is, perhaps, the greatest phenomenon that has occurred in American business in this century. This growth is due in part to the new, and in some instances, revolutionary applications of computers instigated and developed by both the manufacturers of such equipment and their customers who search for easier, faster, more accurate methods of conducting their business operations. As in other industries, modern computers are becoming more common in the field of mining. The adaptation of computer analysis to the unique problems of mining companies is undergoing research and development by both electronic and mining companies. However, for those of us in mining who are interested in the possibilities of computer analysis and control, the basic question is Where can a computer system be of use in a mining operation today? Some ideas of such applications follow, as well as a specific example of computer control at the Riverside Cement Co.

Jan 9, 1960

By Harvey P. Knudsen, Young C. Kim, Edward Mueller

Abstract-This paper describes the results of a comparative study of the geostatistical ore reserve estimation method over three conventional methods; the polygon method, the inverse of the distance squared (IDS) method, and ELIP which is similar to IDS. Each method was evaluated on its ability to accurately predict individual block grades for one bench of the Pima mine, located near Tucson, Ariz. Results at the Pima mine indicate that the geostatistical method is no better or worse in predicting block grades and total tonnage than the ELIP or IDS methods. In contrast, the polygon method is clearly inferior. All of the methods would have given better results if geology had been included in the block model. At already producing mines ELIP or IDS may be good choices since they involve substantially less cost in computer time. For prospective or new properties the geostatistical model is more attractive due to its ability to construct confidence limits on the estimates.

Jan 1, 1978

By D. V. Fites

Criteria for deciding when rock should be ripped and what ripping equipment and techniques should be used in given situations are discussed in this article. The relation between ripper performance and seismic wave velocities in various types of rock is also discussed. The ripper is not a new tool. In fact, it dates back as far as the Roman Empire. The Roman's ripper-mounted on wheels and shaped something like a plow — was pulled by oxen and used to loosen the earth for the shovelers and basket carriers building the Appian Way. There are records of rippers being used in this country in railroad construction between 1860 and 1880. However, the ripper as we know it today did not appear until about 1930. Tractor-drawn models were in use in 1931 on the Hoover Dam project. At that time they weighed about 7500 lb and were pulled by tractors with about 75 flywheel hp and up to 30,000 Ib total weight. The chief shortcomings of trailed

Jan 1, 1969

By A. S. M’Creath, E. V. d’Invilliers

The rapid development of the southern coal and iron-ore fields during the past few years, and especially in the latter half of the year 1886, and the avidity with which everything relating to the industrial situation there is read and absorbed by the professional and non-professional public, has led to the preparation of a brief paper for the Institute upon a comparison of the raw materials available on or about January 1st, 1887, at three prominent centers of consumption. While disclaiming any originality or priority in the treatment of the resources of these districts, where so much valuable and interesting work has been performed in the past by several members of the Institute, we hope that the presentation of some analyses of samples personally secured by us in the several districts selected, and prepared for a comparative study of the character of the materials actually used and to be used by the furnaces of the "New

Jan 1, 1887

By F. M. F. Cazin

Some twenty years ago the author of a book,* by which, for the first time, molecular action was made to account for nearly all phenomena in hydrodynamics, began his preface as follows: " It is contrary to all experience, that any branch of science should suddenly cut short its own line of reasoning, and drop all connection with its past, and yet as quickly re-establish itself on an entirely new basis. It is, therefore, not without justification that this book should be met with caution and even distrust." When the newly-discovered natural facts and laws presented in this paper were, in 1891, first laid before the officers of the American Institute of Mining Engineers, they might have been preceded by a preface to the same effect; and the expression would have found its justification by the actual experience these facts and laws met with. Since then, as the result of their publication in one of the most prominent

Jan 1, 1895

Energy conservation has been the keyword in many plant expansions. Far many years, most of the phosphate industry has been dry grinding their phosphate rock. Agrico Chemical in Florida has recently been evaluating the wet grinding of phosphate rock, a process which eliminates a pre-dry stage for mill feed while allowing higher through- puts. This same company also plans to open a new phosphate facility in Louisiana that will use wet grinding in both ball mills. The Eveleth Expansion Co.'s Fairlane concentrator will have the largest rod and ball mills in the US mining industry. The plant will consist of three lines, each with one rod mill and one ball mill, and will process 464 ltph. The rod mills will be 15 x 20% ft, drawing 2035 hp. The ball mills will be 17 x 41½ ft, drawing 6900 hp and driven by dual 3000- hp motors. The plant is scheduled for startup in the fall of 1976.

Jan 2, 1975

By W. C. Elmore

THE magnetic powder method, long used for roughly mapping mag-netic fields, has recently been refined 1,2 for investigating the microscopic variations in the surface magnetization of ferromagnetic crystals. Bitter2 first discovered regular powder patterns connected with the crystal structure of such specimens. Several other investigators3 have used Bitter's original technique, with slight modifications, to study the varia-tion of the patterns with variations in the magnetizing field applied parallel to the surface, and their dependence upon the state of strain, of polish and of crystal cut. All of the explanations of these patterns on metallic ferromagnetics have been couched in general terms. In a preliminary report we have described an improvement in the powder technique which led us to the discovery of a new effect throwing con-siderable light on the magnetic secondary structure of alpha iron4 and of nickel5 single crystals. We now report additional evidence confirming the existence and stability of a magnetic block secondary structure.

Jan 1, 1936

By W. C. Elmore

THE magnetic powder method, long used. for roughly mapping mag-netic fields, has recently been refined 1,2 for investigating the microscopic variations in the surface magnetization of ferromagnetic crystals. Bitter2 first discovered regular powder patterns connected with the crystal structure of such specimens. Several other investigators3 have used Bitter's original technique, with slight modifications, to study the varia-tion of the patterns with variations in the magnetizing field applied parallel to the surface, and their dependence upon the state of strain, of polish and of crystal cut. All of the explanations of these patterns on metallic ferromagnetics have been couched in general terms. In a preliminary report we have described an improvement in the powder technique which led us to the discovery of a new effect throwing con-siderable light on the magnetic secondary structure of alpha iron4 and of nickels single crystals. We now report additional evidence confirming the existence and stability of a magnetic block secondary structure.

Jan 1, 1936

By W. C. Elmore

THE magnetic powder method, long used for roughly mapping mag-netic fields, has recently been refined 1,2 for investigating the microscopic variations in the surface magnetization of ferromagnetic crystals. Bitter2 first discovered regular powder patterns connected with the crystal structure of such specimens. Several other investigators3 have used Bitter's original technique, with slight modifications, to study the varia-tion of the patterns with variations in the magnetizing field applied parallel to the surface, and their dependence upon the state of strain, of polish and of crystal cut. All of the explanations-of these patterns on metallic ferromagnetics have been couched in general terms. In a preliminary report we have described an improvement in the powder technique which led us to the discovery of a new effect throwing con-siderable light on the magnetic secondary structure of alpha iron4 and of nickel5 single crystals. We now report additional evidence confirming the existence and stability of a magnetic block secondary structure.

Jan 1, 1935

By Leo Behr

RECENT years have seen important practical advances in the construction of recording instruments for use with thermocouples. The difficulties of the problem will be appreciated when it is remembered that a 10° F. change in temperature of a base-metal couple at 1500° means a change in the electromotive force of about 0.00035 volt. In a circuit having a resistance of 350 ohms, this means a change in the current of 0.00000,1 amp.; and despite this requirement of great sensitivity the instruments must be sufficiently robust to withstand the rough usage which is so often their lot. Two methods are in common use for the measurement of the electromotive force produced by a thermocouple: 1. The milliammeter method, in which the current produced by the thermocouple in a circuit of known resistance is measured and from. this the electromotive force is deduced by Ohm's law. 2. The potentiometer method in which a known potential difference is opposed to the thermocouple electromotive force. The use of thermocouple and milliammeter for measuring temperature introduces some possible sources of error, for the reading depends on a number of factors, including the following: (1) Electromotive force set up at the hot junction, (2) electromotive force set up at the cold junction, (3) resistance of the circuit including thermocouple, lead wires, and meter, (4) field strength of magnets, (5) strength of controlling springs in meter, (6) friction at pivots, of pointer on paper, etc. It is obviously necessary to so design and maintain the installation that the reading is independent of all the factors except the first. The electromotive force set up at the cold junction can easily be taken care of provided it is constant. This has been approximately accomplished by burying the cold junction in the ground or actually secured by locating it in a container, the temperature of which is kept constant by means of a thermostat.

Jan 9, 1919

By J. K. Edgar

For a number of years the production and use of super-purity aluminum (better than 99.99 pct) has been steadily increasing. High-grade lots of. such aluminum show certain outstanding characteristics not found in lower grades containing principally silicon, iron and copper as impurities. One such characteristic is the so-called "self annealing," that is, the re-crystallization of the heavily cold worked metal at room temperature.' Interest therefore is aroused as to the effects of the impurities. It is well known that the amounts of silicon and copper which occur in aluminum of better than 99.95 pct are completely soluble, at least at elevated temperatures (above 200°C). Iron, on the other hand, is known to be fairly insoluble in solid aluminum. Thus, a knowledge of the limits of this solubility would he of considerable use in studying the characteristics of the high purity metal. All investigators have agreed that iron has very low solubility in solid aluminum. Rosenhain, Archbutt and Hanson2 reported traces of an aluminum-iron phase in the "purest samples of aluminum obtainable." Gwyer and Phillips3 reported that an iron constituent was visible under the microscope in metal containing ".0088 per cent iron." Roth4 found that in the solid state the solubility of iron in high purity aluminum was 0.01, 0.01, 0.017 and 0.022 pct at 225, 320, 500 and 600°C respectively. Dix5 working with alloys containing less than 0.03 pct impurities, concluded from microscopic and chemical analyses of eutectic areas that the eutectic composition was close to 1.7 pct iron. Dix placed the eutectic temperature at 65s°C. Archer and Fink,6 using high purity aluminum-iron alloys, found that the hypoeutectic liquidus intersects the eutec-tic horizontal at 1.7 pct. This is in fair agreement with the investigation of the aluminum-iron system by Gwyer and Phillips who placed the eutectic at 1.89 pct iron with a freezing point of 653'C. Preparation and Chemical Analysis oP Alloys Electrolytically refined aluminum (99.991 pct aluminum) and a high purity alumi-num-iron alloy (11.45 Pet iron) were used in the preparation of the alloys for this investigation. To aid in controlling the iron content of the experimental alloys, an alloy of lower iron content was prepared first from these materials. The high purity aluminum was melted and heated to about 700°C in a plumbago crucible coated with alundum cement and the aluminum-iron alloy was then added. The alloy was thoroughly stirred, fluxed and skimmed and then chill-cast into notch bars. The aIlalyses of the three materials are given in Table I. The alloys for the determination of the solid solubility of iron in aluminum were prepared by melting 600 g total of the aluminum plus the required quantity of the aluminum-iron alloy (No. 92531). These

Jan 1, 1949

By Guilliaem Aertsen

The derivation of the word tire (or tyre, as it is spelled in England) is obscure. Some dictionaries suggest that it is the aphetic form for "attire, covering," so called as being the outside covering or band of a wheel; also as a corruption of "tier," the band which holds, or "ties," the rest of the wheel together. One dictionary states: "The supposed derivation of the word is that bands were first used on wheels in the City of Tyre, Syria." In the infancy of railroads, the tracks consisted of flat bars of iron, spiked or bolted to the upper surfaces of longitudinal timbers, which, in turn, rested upon masonry foundations. Stone blocks installed for this purpose on the old Germantown & Norristown Railroad, now the Chestnut Hill branch of the Philadelphia & Reading Railway, were to be seen for many years on the right-of-way, north of what is now Wayne Junction, Philadelphia, Pa. The "cornerstone" of the Baltimore & Ohio Railroad was laid Apr. 4, 1828, and the fist locomotive in America was built by Peter Cooper at the St. Clair Works, Baltimore, Md., in 1829 "to demonstrate its adaptability to a curved road." It is believed that the first successful locomotive was built in Philadelphia by Tyler & Baldwin in 1832 for the Germantown & Norristown Railroad. Rufus Tyler and Matthias Baldwin were brothers-in-law; the latter's name will be identified with American locomotives until locomotives are forgotten. The wheels on these first locomotives, designed to run on this primitive rail, mere shod with plain iron bands, bent and welded. The flanges consisted of separate iron bands, bent sidewise,welded, and bolted to the sides of the wooden fellies, or rims. Before many years had elapsed the tires were fabricated of iron bands, rolled in one piece with the flange projection on the side. The tire for each wheel was bent and welded and subsequently attached to the wheel center by shrinkage, bolts, rivets and various mechanical devices. Germany is generally given the credit for first making such tires of

Jan 1, 1917

For four years your Committee has been engaged in the study of problems connected with the educational preparation of professional geophysicists. The Present report represents the conclusions drawn from the investigations and deliberations undertaken since it was first organized. These studies have shown that the evolution of geophysics has proceeded along lines that differed from those marking the advance of classical geology. The latter science developed as a descriptive one, dealing with directly observable terrestrial phenomena, and the elementary, rational explanations that could be offered therefor. The fact that these phenomena were also chemical and physical in nature was seldom given more than passing acknowledgment. During the last half century, however, a new approach to problems of terrestrial phenomena has become of greater significance. This new attack has come through the sciences of physics and chemistry, as the people trained therein have investigated the facts of the earth as problems in their respective sciences. This development has been chiefly at the hands of European investigators, and European universities have long recognized it by establishing departments or institutions of geophysics. In the universities of North America, their arbitrary departmentalization into fields of physics, chemistry, astronomy, geology, etc., has prevented the academic recognition of such domains of science as geophysics and geochemistry. In consequence, the development of these subjects in the United States has been largely at the hands of nonacademic institutions, while the universities themselves are evidently in a state of confusion as to how the subject should be handled. In some places an attempt to teach geophysics is made in the physics department, in others in the geology department, in some in the engineering school, and occasionally as a cooperative effort; a Department of Geophysics is seldom found in North America. In some instances, proper academic plan. ning has been precluded by interdepart. mental jealousies, or by lack of appreciation of the significance of the subject. For the background upon which these conclusions are based, the reader is referred to reports previously issued or SPonsored by Your Committee. The "First Report of the A.I.M.E. Mineral Industry Education Division's Committee of Geophysics Education, 1939," summarizes the replies received to question-

Jan 1, 1946