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By James W. Lower

IN developing the orebody on lower levels of the Star mine at Burke, Idaho, Hecla Mining Co. is faced with a serious problem in driving raises. Levels are at 200-ft intervals. As a raise is being driven between levels, at points about 70 and 130 ft from the sill, heavy pressure arches develop and the raise becomes extremely hazardous. Eventually, following a blast, caving occurs, making it impossible to recover the raise. In February 1957 it was decided to attempt sinking a small winze on the vein from the 5500 to the 5700 level. This shaft (winze-raise No. 2) was to be used as a raise prior to stoping. It was assumed, and correctly, that the heavy ground pressure could be controlled by timbering close to the bottom after each advance.

Jan 7, 1958

By C. G. Dunn

With respect to theories of recrystalliza-tion in metals plastically deformed. it has been said that the present status of this subject is far from satisfactory.1 It may also be said that before any mechanism of recrystallization for metals and alloys can be set forth in a satisfactory manner, there must be made available considerable data on orientation changes that occur during the deformation and recrystallization processes. Although extensive data have been published on recrystallization in single crystals and in poly-crystalline specimens, more results of a type that can be classified according to simple orientation changes would be desirable in this complex field. It might even be said that before classifications are made according to types of orientation changes, it may be possible to classify a considerable amount of data into certain kinds of orientation states if groups of common or nearly common orientation occur. Methods for computing the probability of occurrence for various types of groups have been published2 and it has been pointed out in particular that it should be possible to analyze orientation data for high-order twin relationships between old and new grains even when agreement is not at all exact. In this connection, work on recrystallization in silicon ferrite reported in a paper concerned with complex groups of annealing twins3 indicated that some data were consistent with primary nucleation OCcurring according to a second-order or a third-order twin transformation. However, further work in this latter direction was definitely needed. It is, therefore, the purpose of the present paper to report data and analyses for primary nucleation in silicon ferrite following small deformations that have been carried Out at the Pittsfield Works' Laboratory of the General Electric Co. Analyses have been made with the aid of standard groups of twins that are reported elsewhere.4 PReparation oF Specimens and Experimental Procedure The material used in the present investigation was taken from the same heat of steel as that .used in a prior report.3 The finished strip in both cases was made by the Allegheny-Ludlum Steel Corporation according to methods that produce a high degree of preferred crystal orientation. Samples with large grains had the following composition: 3.45 per cent Si, 0.003 C, 0.008 P, 0.020 S, 0,075 Mn, 0.03I A1 and 0.072 Cu. Thickness of specimens was 0.012 inches. Plastic deformation was produced by cold-rolling the samples on a mill with 8-in. diameter rolls, the plane of the sample in each case coinciding with an XY plane (the plane of projection for the stereo-graphic plots) and the elongation occurring in the X direction. In general, elongations were held to about 3 or 4 per cent.

Jan 1, 1945

By B. K. Larkin

Solutions to the diffusion equation for a line source located anywhere in a region bounded by a circular discontinuity are presented. Such solutions follow automatically from the Green&apos;s function presented by Jaeger.4 Petroleum industry applications of this problem would include transient compressible fluid flow in porous media bounded by a discontinuity. Since several recent papers have treated the subject in less general form, it would appear that many workers in this area of the petroleum industry are not aware of Jaeger&apos;s work. STATEMENT OF THE PROBLEM In several trearments1,2,3 of the transient flow of compressible fluids in porous media it was convenient to consider a region to be bounded by a circular discontinuity. In such a region (Fig. I), the properties in Region 1, r < a, are constant but different from the properties in Region 2, r > a. Hurst, l using the Laplace transform, obtained solutions for a line source located in the center of such a porous medium. The purpose of this work is to point out that a much earlier paper by Jaeger4 presents the solution for a line source located anywhere inside the discontinuity. The assumption is made that a line source may be used to approximate a well. In the following material it is convenient to use the terms source and well as being equivalent; however, the reader should remember the distinction in applications. SOLUTIONS Jaeger presented the Green&apos;s function for a line source, or well, in the composite region shown in Fig. 1. In the most general form, the solution for a system of j wells in Region 1, each producing at a time varying rate, qi (t), is

By K. J. Miller, R. E. Hucko

The Coal Reparation Division of the Pittsburgh Mining Technology Center conducted an investigation to assess and compare the pyritic sulfur reduction potential of coal-pyrite flotation and high-gradient magnetic separation (HGMS). Tests were run on three coals - an Upper Freeport bed coal, a Lower Kittanning bed coal, and a Pittsburgh bed coal - to establish grade-recovery relationships characteristic of both processes. Representative portions of each coal sample were crushed to two top sizes-nominal - 500 pm (-35 mesh) and nominal - 149 pm (-100 mesh)-and subjected to conventional froth flotation. The froth product was then beneficiated by coal- pyrite flotation or HGMS, to provide a direct technical companion of the two processes. At - 500 pm (- 35 mesh), the size normally employed for coal flotation, both coal-pyrite flotation and HGMS effectively separated pyrite from coal, and the performance of the two processes was essentially the same. At a - 149 pm (- 100 mesh) sire, however, the performance of HGMS exceeded that of coal-pyrite flotation. The separation effected by HGMS were more efficient at - 149 pm (- 100 mesh) than at - 500 pm (- 35 mesh). On the other hand, it was concluded that either the effectiveness of coal-pyrite flotation decreases with diminishing top size or the process has not been optimized to treat material finer than 500 pm (35 mesh).

Jan 1, 1983

Under date of Sept. 30, the following open letter was addressed to the Members of the Colorado Section of the American Institute of Min-ing and Metallurgical Engineers by a Colorado Committee: At a meeting of the Colorado Section of the American Institute of Mining and Metallurgical Engineers, held on Friday, Sept. 19, a reso-lution was unanimously passed condemning the Engineers&apos; Licensing Bill passed at the last session of the State Legislature, and requesting the Chairman to appoint a Committee to act in conjunction with the other National Engineering Societies and the Colorado Metal Mining Associa-tion, with a view to securing its repeal at the extra session of the Legis-lature which the Governor has expressed his intention of calling. It may be within your knowledge that the bill in question was passed by the Legislature and signed by the Governor without the knowledge of any of the National Societies, and of few if any of their members. Under its provisions residents of other states cannot even come into this to examine a mine without securing a license, and aliens (among whom are many honored members of, the profession in Colorado) cannot obtain such a license at all. The mining industry in this state needs the coopera-tion of outside engineers, and we should welcome any assistance from them that will tend to develop our resources. To attempt to discourage the activity of visiting engineers will inevitably react on us, and brand the state as being hostile to brains and capital from outside. The difficulty of securing a license will prove a serious handicap to young engineers starting out in the independent practice of their profession. Moreover, a license issued to au engineer qualified in one branch will entitle him to practice in any other: so that the license is apt to mislead the public.

Jan 11, 1919

By S. F. Emmons

[The following notes of observations made during a visit of a few days in the month of October, 1886, which was cut short by a sudden summons East, are offered, in spite of their incomplete and tentative character, in the hope that they may aid the members of the Institute, in their coming visit to this region, to a clearer understanding of the general geological conditions under which the ore-bodies occur.] The Butte mining region lies in a sort of a depression in the mountains which is drained by Silver Bow creek and its various tributaries. On the east it is bounded by high north and south ridges of granite, and on the west by lower ridges, also running north and south, which, as far as examined, were found to consist of rhyolite. High mountains also inclose the depression on the north and south, but at a greater distance than the more immediate bounding ridges on the east and west, the distance between which is hardly more than six miles.

Jan 1, 1888

By Peter J. Lean

The introduction oE computer control in the grinding circuit of the New Broken Hill Consolidated Limited concentrator in the early 1970&apos;s gave smoother operation at optimum performance. The ore feedrate and water additions to the grinding circuit were controlled to operate each of the ball mill/ rake classifier grinding units at the upper limit of the circulating load while classifier overflow density was maintained to give a product size and pulp density suitable for flotation. An incremental expansion of the concentrator in 1981-82 included the installation of hydrocyclones in closed circuit with three of the four ball mills. Without the rake classifiers in circuit the previous control strategy could not be used and the complex interaction of hydrocyclone performance characteristics when classifying coarse grained sulphide ore resulted in the over-grinding of the lead mineral galena. Testwork aimed at optimising grinding circuit performance recognised the enhanced tendency of higher specific gravity minerals to report to the cyclone underflow. The data has been evaluated on an individual mineral basis and then used to develop a model For grinding circuit control. The development of the model which uses inputs of ore feedrate, metal content of the Feed and slurry density of the cyclone overflow to predict the size of the minerals in the grinding circuit product is described and model predictions are compared with plant performance.

Jan 1, 1984

By Robert G. Van Nostrand, John H. Henkel

TRANSIENT potentials obtained in resistivity prospecting can be separated into two classes. The first is electromagnetic, has a comparatively short time constant, and increases in relative amplitude as the electrode separation is increased. These electromagnetic transient potentials, of which an excellent theoretical treatment is given by Yost: are the result of changes in the current and can be classed as differentiated signals. The second class is electrochemical, has a comparatively long time constant, and decreases in relative amplitude as the electrode separation is increased. The electrochemical signals are generated by the current flow itself and can be classed as integrated signals. The transient potentials due to electrochemical factors are the subject of this article. The phenomenon is referred to as induced polarization. Schlumberger" was the first worker to observe induced polarization, but he was unsuccessful in attempts to apply the principles of induced polarization in electrochemical prospecting. Other workers, notably Bleil; have studied polarization and in some cases pointed out its possibilities, but no theory has been presented that describes polarization and its time dependence adequately. It is the purpose of this discussion to present the essence of a theory to geo-physicists and to show that it leads to results consistent with experimental evidence. The theory on which this analysis is based has existed in electrochemical circles since 1910."

Jan 1, 1958

By John M. Dale

Sulfur has attractive features as a base material for coating systems. It melts at 246ºF and can be applied as a liquid above this temperature. Its melting point is just above the environmental stress level, 180°F, for most coatings and yet it is low enough to be easy to work with in comparison to many hot melt systems. The viscosity characteristics are such that sulfur lends itself to spray applications. The oxidation rate of sulfur in the atmosphere is very low and sulfur has outstanding chemical resistance characteristics, particularly in acid environments. One of the greatest potentials for these coatings appears to be in the protection of other materials. At one time, most acid tanks and pits were constructed with acid- proof brick and sulfur based mortars. This type of construction is much more expensive than sulfur based spray coatings. An attractive sulfur based coating composed of sulfur, talc, milled glass fibers and dicyclopentadiene,1 developed by the Institute for the Bureau of Mines has excellent acid assistance and can be used to protect concrete from acid attack.

Jan 10, 1973

By William Garrett

I have heard it said that the late Mr. Holley made use of this remark: " There is an inherent, cussedness about rolls which, so far, no man has been able to find out." I think this can be safely claimed in reference to steel, as there are certain peculiarities about it that are pretty hard to account for. Previous to the introduction of the Bessemer process there was, as it were, a great chasm between iron and crucible steel; and, outside of what futile attempts had been made in puddling steel, nothing had been done to fill this gap. The Bessemer steel struck a medium between the two, the softest of it not being able to take the place of good iron, while the hardest was not suitable to encroach very far upon the crucible-steel trade. The open-hearth process made quite an inroad into the latter, but only for the lower and cheaper grades; and, beyond a doubt, for the finest grades of tool-steel, the cruciblesteel business has a long life before it. On the other side of the line comes the " basic " process, which brings us a step nearer iron ; but to fill up the gap completely, comes the Clapp-Griffiths process, which makes a grade of material—call it what you will—that is as soft as iron, welds as readily, and is in a fair way to supersede iron altogether. For fifteen years, I was in the employment of the Cleveland

Jan 1, 1886

By Charles Y. Clayton

A study of the literature shows that the greater part of research work on annealing of cold-worked iron has been for the purpose of studying the effect on grain-size and properties other than hardness. No reference has been found of experimental work of the same nature as that explained in this short paper. The material used throughout was Vismera iron, an iron containing 0.03 carbon and made several years ago by the Inland Steel Co. One-half inch stock was cut into cylinders % in. long. The cylinders were then compressed for 60 sec. in a Reihle testing machine under loads as indicated below: CoMPressiON, Average Length, Series Pounds Inches 1 10,000 0.693 2 15,000 .599 3 20,000 .501 4 25,000 .426 5 30,000 .378 6 35,000 .351 7 40,000 .311 Fig. 1 shows these cylinders after compression. Each series consisted of 17 specimens lettered 0, B, C, D, E, F, G, H, I, J, K, L, M, N, P, Q and R. One specimen of each series was reserved for study of the properties in the cold-worked condition. The other specimens were annealed in a Hump furnace for 1/2 hr. at the following temperatures: TEmpeRa- TempeRa- Letters tuRe,° C. LettERs tuRe °C. B............................... 250 J.............................. 650 C............................... 300 K............................. 700 D............................... 350 L.............................. 750 E............................... 400 M............................. 800 F................................ 450 N............................. 851 G............................... 500 0. . :........................... 900 H............................... 550 P.............................. 950 I................................ 600 Q............................. L000

Jan 1, 1926

By J. PARK

Discussion of the paper of J. PARSE CHANNING, presented at the New York meeting, February, 1915, and printed in Bulletin No. 99, March, 1915, pp. 529 to 538. FRED H. RINDGE, JR., * New York, N. Y.-It is interesting to note that although this movement was started only seven years ago at Yale, it has spread in that brief time to 200 colleges and technical schools, anti thousands of men are interested in it. There are 3,000 graduates who became acquainted with the movement in college days anti are now promoting the industrial betterment idea all over the country. Some of these men are employed entirely in this work, and the number of such workers is constantly increasing. We feel we are really doing a very fundamental thing in getting so many coming engineers and prospective employers of labor to interest themselves in these things which we have been discussing this morning; these things which are so vital to efficiency and success in any line of business or engineering to-clay. Of course the institutions located in our large industrial centers have the greatest opportunity for practical service. But I have just returned from one college, Pennsylvania State College, where 300 engineering students in three clays signed up as interested in this movement and as anxious to take active part in the work this summer. That is one of a number of colleges situated in towns where there are 110 industrial opportunities. Therefore, their field of service must be where they work

Jan 5, 1915

By Hiroshi Oikawa, A. G. Guy

Recent experimental evidence has shown that it is often incorrect to neglect the reactions occurring at an interface with respect to the diffusion reactions. By introducing reaction-rate constants and k for the transfer of components 1 and 2 between the a and b phases, a phenomenological description has been devised for the coupled processes of diffusion and in-terfacial reaction. An illustrative example has been analyzed with the aid of a suitable computer program. The results indicate that for kab values on the order of 10&apos;1 cm per sec and Ð values of about 10¯10 sq cm per sec, the interfacial reactions are significant during the first 10 2 to l0 6 sec of a diffusion experiment. Among the observable effects of the interfacial reactions in this case appear to be the burying Kirkendall markers and an anomaly in the initial shifting of these markers. THE study of diffusion between two phases is especially important because of its direct connection to phase transformations. For example, the transformation of austenite to ferrite involves diffusion in the a and ý phases and also an interfacial reaction (trans formation) at the a/? interface. If ferrite and aus-tenite are the two members in a diffusion couple, the same two reactions occur during the diffusion process. The numerical values obtained for the diffusion coefficients and interfacial-reaction constants from diffusion experiments can then be employed to predict phase-transformation behavior. Refinement of the calculations of phase transformation is also suggested by the present method for treating two-phase diffusion. In the recent paper by Nolfi et al.&apos; only the solute com ponent is considered in the interfacial reaction accompanying a phase transformation. The present analysis demonstrates that both components must be considered. It is generally recognized that reactions of some kind must occur at the interface in a two-phase diffusion couple, but usually it is assumed that the interface reaction occurs so rapidly that its effect on the overall process is unobservable because the slower diffusion process determines the kinetics of the process. However, Seith and Heumann 2 pointed out that effects of the interfacial reaction should always occur in the early stages of diffusion, and recently Eifert et al. 3 have shown that interfacial reactions influence the composition and motion of the interface in a/ß Al-Cu diffusion couples during the entire course of prolonged, high-temperature treatments. A general procedure for handling the combined processes of interfacial reaction and diffusion in a binary, two-phase system is to introduce kinetic coefficients for the interface reactions and to develop the system of equations governing the interlinked processes of diffusion and interface reaction. The resulting equations, although not amenable to solution in closed form, can be usefully manipulated by a digital computer. INTERFACIAL REACTIONS IN TWO-PHASE DIFFUSION Consider the general case of diffusion between two solid solutions, a and ß, which are adjacent phases in a binary system, Fig. 1. Two semiinfinite bars having compositions c1 and c0ß are jointed at x = 0. If concentrations are expressed in volume fraction,4

Jan 1, 1970

By Albert D. Brokaw

The accompanying charts are presented to extend and improve a chart published under the title "A Chart to Provide Approximate Correction for Temperature and Deviation from Boyle&apos;s Law."&apos; The applicability of this earlier chart was limited by the fact that it was based on the work of Burke and Keyes² and Kvalnes and Gaddy3 whose experiments were conducted with pure methane, the adjustments suggested for natural gases of higher specific gravity were unsatisfactory except within limited ranges of temperatures and pressures, and precise interpolation was difficult. The extensive work of G. G. Brown, D. L. Katz and their associates on the heavier natural gases has provided better bases for the needed corrections, and the present charts. which are based largely on their work, are intended to simplify the computations involved. The design of the charts has been changed by plotting temperatures as a function of pressure and correction factor, on a semilogarithmic or "ratio" grid, which gives fairly even spacing of the graphs and simplifies interpolation. Charts have been prepared for natural gas with specific gravities of .60, .65, .70, .75 and .80. The standard computation for use in estimating the quantity of gas in a reservoir may be expressed as follows: _ PA X 520 X VR ZT where: Q is the volume of gas at 60°F and one atmosphere pressure PA is the absolute formation pressure in atmospheres

Jan 1, 1949

By Walter Miller

Construction of new large refineries was small in 1937, but extensive modernization and expansion of existing plants were made, bearing out the observation of the Bureau of Mines that the trend is strongly toward fewer and larger refineries. Building the first large combination skimming and cracking unit of 20,000-bbl. capacity was a startling achievement four or five years ago, but it has been exceeded many times since, and at least four units with a capacity of 30,000 bbl. or more were contracted for during 1937, as well as many other units of smaller but still substantial capacity. Installation of polymerization plants for producing high-antiknock blending naphthas from refinery gases progressed at an accelerated rate in refineries affording sufficient raw gas to make the use of the process profitable. The total productive capacity of polymerization units built and contracted for in the United States is now about 25,000 bbl., equivalent to the gasoline production from approximately 55,000 bbl. of crude oil a day. Octane Fuels Also utilizing refinery gases—the butylene fractions in particular—the plants for manufacture of iso-octane increased in number to such an extent that the combined capacities will enable the air forces of the United States shortly to go entirely to the use of 100-octane fuel, indications being that the Army will reach that position in 1938, with the Navy not far behind. Commercial air-lines are expected to take advantage of the greater power of high-antiknock fuels to gain the increased power and increased pay loads possible with their use. Work done on producing fuels with octanes beyond the 100 point has recently been reported, and their production can be expected, although at high cost, when the economics of the situation justifies and engines capable of utilizing them efficiently are available. In the field of motor fuels, important work was reported to the A.P.I. at its annual meeting, on the effect of altitude on antiknock requirements

Jan 1, 1938

By Albert D. Brokaw

The accompanying charts are presented to extend and improve a chart published under the title "A Chart to Provide Approximate Correction for Temperature and Deviation from Boyle&apos;s Law."&apos; The applicability of this earlier chart was limited by the fact that it was based on the work of Burke and Keyes² and Kvalnes and Gaddy3 whose experiments were conducted with pure methane, the adjustments suggested for natural gases of higher specific gravity were unsatisfactory except within limited ranges of temperatures and pressures, and precise interpolation was difficult. The extensive work of G. G. Brown, D. L. Katz and their associates on the heavier natural gases has provided better bases for the needed corrections, and the present charts. which are based largely on their work, are intended to simplify the computations involved. The design of the charts has been changed by plotting temperatures as a function of pressure and correction factor, on a semilogarithmic or "ratio" grid, which gives fairly even spacing of the graphs and simplifies interpolation. Charts have been prepared for natural gas with specific gravities of .60, .65, .70, .75 and .80. The standard computation for use in estimating the quantity of gas in a reservoir may be expressed as follows: _ PA X 520 X VR ZT where: Q is the volume of gas at 60°F and one atmosphere pressure PA is the absolute formation pressure in atmospheres

Jan 1, 1949

By J. D. Audley Smith

Heine&apos;s " blue test" for copper, as described by the authorities generally, calls for a set of standard colors; and there has been some discussion concerning the relative superiority, for this purpose, of sulphate and nitrate solutions. The whole matter evidently hinges on the preservation of the standard colors in well-stoppered bottles. The apparatus described by Q. L. Heath* cannot be much improved, when very accurate readings are required. The following method was devised for the purpose of doing away with preserved sets of standard colors, by making a fresh standard for each batch of assays. The solutions are prepared in the usual way, each ammoniacal solution being filtered into its separate bottle, and then filled up to the containing-mark and thoroughly mixed. A similar color-bottle, with an " S " etched upon it, to distinguish it from the other bottles, which are numbered to correspond with the samples, is kept to run the standard. About 150 C.C. of water is put into it, and then the amount of acid (sulphuric or nitric) present in each determination, followed by 30 C.C. of ammonia (s. g. 0.90), which should make the mixture strongly ammoniacal. The liquid is now made up almost to the containing-mark (200 c.c.), say within 1 C.C. The lowest assay is selected first and placed alongside the standard, which, at the beginning, contains no copper. A copper-solution is then dropped into the standard from a burette ; and after each addition the bottle is well shaken and compared with the assay-sample. This operation is repeated until the two shades match exactly, when the burette is read and the assay-result is calculated. The assay next in order of depth of color is now taken and treated in the same way, and so on, until the batch is completed. It

Jan 1, 1901

An "international gold conference" was held at Spokane, Wash., on Sept. 5, 1918, under the auspices of the Northwest Mining Association, which was attended by a large number of engineers, mine operators, and bankers, representing the northwestern states, as well as Alaska and British Columbia. The principal subject under consideration was the doleful condition of the gold-mining industry, gripped between the diminished purchasing value of its product, and the increased cost of its operation. Two resolutions were adopted by the meeting. The first approved the resolution adopted Aug. 12 by the American Gold Conference, a permanent organization formed at Reno, Nev., in which it is stated that relief by the United States to the gold producers of this country should he made to correspond with the increased cost of production, the extent of the relief to be fixed from time to time to Meet changing conditions. The second resolution, adopted after serious and long-continued discussion, was introduced by F. A. Ross, mining engineer, of Spokane, and a member of the Institute, and was as follows: WHEREAS, it is now clearly understood and agreed by the allied nations that national gold reserves must be augmented without delay if rapidly expanding credits are to be secured; and WHEREAS, at this time, the production of gold is daily decreasing to an alarming extent because of well known conditions that, render the mining of gold-bearing ores unprofitable; and WHEREAS there is no way by which the mining of gold-bearing ores may be made profitable except by the direct&apos; aid and influence of the government; and WHEREAS the government has appealed to the mining industry for practical information and practicable suggestions upon this subject; therefore, be it

Jan 10, 1918

By Wayne S. Cavender

During the past year, geochemical prospecting appears to have come of age as an exploration method, and its acceptance by the mining industry is widespread. There is a growing recognition that applied geochemistry is a scientific tool and must be performed and interpreted by scientific personnel who are trained in its utilization. At present, most personnel training is done by geochemical departments in government organizations and industry groups. Most schools in the United States and Canada do not offer geochemical training, particularly at graduate levels, due to faculty limitations, lack of budgetary support and the erroneous impression that applied geochemistry is not sufficiently academic. As a result, some companies have found it expedient to send selected personnel to European schools for advanced training. A critical personnel shortage now exists will probably continue into the near future. Indications are that the rate of development of new geochemical techniques has levelled off, and the probability of new breakthroughs is not high. Present research is essentially limited to efforts by government agencies and a few private companies. Progress has been the most rapid in the development of analytical techniques, but the need remains for investigation into sampling technology and the development of more quantitative methods for the interpretation of geochemical results. Geochemists need a better understanding of the numerous physical and chemical factors which affect and control primary and secondary dispersion phenomena in all geologic environments. Detailed studies must be made of the relationship between geologic, geochemical and geophysical factors. With better interpretive techniques, the return on the geochemical exploration dollar will increase.

Jan 2, 1968

Some years ago it was my good fortune to inspect some coal properties in Germany, and the most striking impression I received on my trip was that in that country every one in the coal industry, miners and operators, was proud of the fact-not apologetic about it-and that industrially coal was looked upon as a King. The explanation, of course, was that at least 90 per cent of the entire mineral value produced in Germany was from coal, and that it was the very foundation of the nation&apos;s industrial life. The feeling was so different from that existing in the United States among those engaged in producing coal that it made a profound impression on me, and many times since then I have speculated about the reasons for the difference in opinion in the two countries. Here, of course, our units are much smaller and more numerous, there is not so large a proportion of technically trained men, and we have the American trait of depreciating the things we do at home; but among those not actively

Jan 1, 1939