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THOSE MARKED THUS * ARE MEMBERS, MARKED THUS ?ARE ASSOCIATES. THESE SIGNS DOUBLED INDICATE LIFE MEMBERS AND ASSOCIATES RESPECTIVELY. THE FIGURES AT THE END OF THE ADDRESS INDICATE THE YEAR OF ELECTION. HEAVY-FACED TYPE SIGNIFIES HONORARY MEMBERSHIP. *AARONS, J. BOYD, Vivian Gold Mining Co., Ltd., Harris, West. Australia. '05 *ABADIE, EMILE R., Cons. and Min. Engr., 214 Union Savings Bank Bldg., Oakland, Cal. '76 ?ABBÉ, MAX F., Prest., Abbé Engineering Co, 220 Broadway, New York, N.Y. '07 ? ABBÉ, PAULO., Secy.,Abbé Engineering Co., 220 Broadway, New York, N.Y. '07 *ABBOTT, CHARLES W., Min. Engr. Pioche, Nev. ?08 *ABBOTT, CLARENCE Chief EDgr., Iron Mines, Dic Tennessee Caol, Iron & R. R. Co., Bessemer, Ala. '04 *ABBOTT, JAMES W., Min. Engr: Ploche, Lincoln Co., Nev. '94 *ABE, MASAYOSHI, Prof. of Mining, Imperial University Kyoto, Japan. '05

Jan 1, 1910

By C. E. Birchenall, W. Batz, H. W. Mean

AT temperatures between 1095' and 1347ºC, 13 runs have been made on the diffusion of silicon in iron. In two of the runs the couple compositions were entirely within the loop of the Fe-Si system; the base alloys contained 0.0 and 1.0 wt pct Si. The other runs in which the couples consisted of a 2.3 wt pct Si alloy welded to a 3.7 pct Si alloy were a phase throughout. The alloys were made by melting electrolytic iron and commercially pure silicon. Trace impurities were not determined. The butt welded couples were diffused in an inert atmosphere of argon or hydrogen. After cooling, cuts of two mils or greater thickness were machined parallel to the weld interface. The chips were analyzed for silicon. When the concentration and distance data were examined on the conventional probability plot,' no marked variation of the diffusion coefficient with concentration was indicated over the narrow composition ranges employed. Therefore, a single diffusion coefficient is recorded for each run in Table I. The temperatures and atmospheres of the diffusion anneal are listed along with the compositions of the base alloys. For a iron the silicon diffusion coefficient is given by the equation: D = 0.44 e-48,000/RT where R is the gas Constant and T, the absolute temperature. However, since the scatter in the data is fairly large, the activation energy may be in error by as much as 6000 cal per g-atom. The two ? iron points do not permit estimation of the activation energy with any reasonable certainty. They do indicate that the coefficients reported by Smithells2 and Jost,3 based on the work of Fry,4 are much too high. Although very dilute solutions in iron of manganese,5 nickel,8 cobalt,7 and molybdenum8 give dif- fusion coefficients quite close to those obtained for self-diffusion in iron, the silicon values are considerably higher, though of the same order of magnitude. This seems to be consistent with the fact that the silicon atom is the only one of those listed here which is appreciably smaller than iron. The authors are grateful to the Office of Naval Research for their support of this work under Contract N6ori-47, Task order IV, Project NR 031-184, to J. K. Stanley and the Westinghouse Research Laboratories for the silicon alloys used, to several steel companies for the silicon analyses, and to C. Wells, of the Metals Research Laboratory, Carnegie Institute of Technology, for numerous suggestions during the course of the work. References 'C. Wells: Atom Movements (1951) Chapter 2. A.S.M. 2C. J. Smithells: Metals Reference Book (1949) p. 405. Interscience. Pub. Co. 3W. Jost: Diffusion (1952) p. 223. Academic Press. 4 A. Fry: Stahl und Eisen (1923) 43, p. 1039. T. Wells and R. F. Mehl: Trans. AIME (1941) 145, p. 315. "C. Wells and R. F. Mehl: Trans. AIME (1941) 145, p. 329. 7M. F. Hawkes and R. F. Mehl: Trans. AIME (1947) 172, p. 467; Metals Technology (August 1947). .J. L. Ham: Trans. A.S.M. (1945) 35, p. 331.

Jan 1, 1953

By B. C. Craft

Development and exploratory work in Mississippi during 1934 was rather active, resulting in the expansion of the proven area and the drilling of a number of important wildcat wells. Mississippi showed a decrease in drilling operations during 1934. There were 36 completions from 18 counties during this period compared with 58 completions from 22 counties during 1933. There was a considerable decrease in activity in the Jackson gas field in Hinds and Rankin counties with only 9 completions, resulting in 8 gas wells and 1 dry hole compared with 17 gas wells, 2 oil wells and 7 dry holes during 1933. Leasing and geophysical work was reported from several sections of Mississippi last year. Extensive exploration and drilling were carried on in Lamar, Hancock, Pearl River, Greene and Stone counties and on the flanks of the Jackson anticline. Exploration will be continued in these areas during 1935. Four important wildcats were completed during 1934, all of which were reported as being structurally high, but without having important shows of oil or gas. These tests were: Hix and Germany's, J. J. Newman Lumber Co. No. 1, sec. 21-4N.-15W., Lamar County, abandoned at 3520 it. in the Wilcox; United Gas Public Service Company's Davis No. 1, sec. 30-1N.-5W., Greene County, abandoned at 7439 ft.; Gulf Refining Company's May L. Williams No. 1, sec. 33-5S.-17W., Pearl River County, abandoned at 4800 ft.; and Clarke County Oil Company's S. B. Kirkland No. 1, sec. 10-2 N.-16E., abandoned at 4002 ft. in the Eutaw. Another interesting wildcat was Gulf Refining Company's Dantzler Lumber Co. No. 6, sec. 22-4S.-llW., Stone County, abandoned at 7700 ft. (according to reports below the Selma chalk). A total of 114 of the 132 gas wells completed in the Jackson gas field are still producing and have a combined open-flow capacity of 4,145,-696,000 cu. ft. Four of the abandoned gas producers were never connected to the lines. The open-flow capacity of three wells in the Amory field is approximately 1,000,000 cu. ft. Producing against a line pressure of 50 lb., the demand during December greatly exceeded the capacity.

Jan 1, 1935

By E. C. Pechin

THE attention of the members of the Institute of Mining Engineers is asked to a description of the minerals of Southwestern Pennsylvania, as representing the minerals of an enormous area, stretching continuously, with local variations, along the western slopes, and at the base of the Alleghany Mountains, through Western Pennsylvania, West Virginia, and Kentucky, and destined to play no mean part in the future of the iron trade of the country. The particular locality is at and near Dunbar, in Fayette County, where the most careful examinations and extensive developments have been made. The deep gorges cut by the Youghiogheny and Monongahela Rivers, in their passage through the mountains and lower lands, give admirable facilities for observing the measures lying between the sandstones of No. 11 and the upper coal measures. Apart from its varied mineral and agricultural resources this section of country has great historic interest attaching to it. It was down the Monongahela that Braddock led his ill-fated army to its defeat under the walls of Fort Duquesne, and it was up the Youghiogheny River and Dunbar Creek that the shattered remnants hastily fled to gain the camp of Colonel Dunbar, the second in command, who was entrenched upon a high knob, at the head of the creek which bears his name, and which is still known and visited as Dunbar's Camp. Numerous streams, runs, and localities preserve the names of the guides and pioneers who accompanied, in early colonial times, young George Washington, who was pushing his surveys into the trackless and hostile wilderness, and many of them taking up large tracts of

Jan 1, 1875

By D. S. Kingery, D. W. Mitchell

The authors attended the 11th International Conference of Directors of Safety in Mines Research held in France, July 1963. In addition to Conference discussions pertaining to control of coal dust they had the added assignment to study present European practices for neutralizing the coal-dust explosion hazard. Information was obtained through discussions with the Research Directors, by visits to testing stations and observations of operating mines in various countries. This paper tells what the current practice in this field is in Europe, and how effectively coal dust explosions are controlled. The method is rock dust barriers. CONTROL OF COAL DUST DISSEMINATION Experience in Europe indicates that the control of dust production and dissemination by water or foam systems is not successful except during undercutting. Cybulski, Dawes, and DeBraaf - respectively Director, Mines Research Establishment "Barbara", Katowice, Poland; Principal Scientific Officer, Safety in Mines Research Establishment, Sheffield, England; and Chief, Central Mines Research Establishment, Hoensbroek, Treebeek, The Netherlands - believe that wetted dust becomes readily dispersible and abatement measures should be considered only as a temporary means for reducing the health hazard. In an effort to reduce the health hazard, calcium chloride is used on the floor of main haulageways in Dutch mines and water infusion is practiced in Germany in mines where the coal is relatively porous. With respect to wet coal dust, the Belgians, British, Dutch, French, and Russians reportedly have accepted the results of research from the Polish and American experimental mines on the effectiveness of water as an inert in arresting explosion propagation. The Polish use the two test methods proposed by the U.S. Bureau of Mines1 for evaluation of the adequacy of wetness of mine dust; they require that water be added to the wet dust to maintain a minimum of 50% moisture by weight if dependence is placed on water alone. GENERALIZED ROCK DUSTING The general attitude with regard to protection against coal dust explosions throughout Europe is that generalized rock dusting is a vital primary step to inhibit initial ignitions but definite emphasis is also placed upon the efficiency of rock dust barriers. Those exceptions to generalized rock dusting are Germany and Austria where some rock dusting is done but principal reliance is placed upon rock dust barriers. The rock dust used in Belgium, Holland, Russia, and Poland is coarser than that used in the U. S.; 50% of the dust is through a No. 200 sieve (75 microns). Recent research by the Polish indicates that the portion finer than 20 microns is ineffective in arresting explosion propagation, and that the rock

Jan 1, 1964

By Thunaes, Arvid

Pilot plant test work in 1942 and 1943 showed that by a combination of desliming, fine-size classification, and Sullivan deck concentration it is possible to recover heavy minerals such as cassiterite at least as fine as 10 microns in size. This appreciable improvement in gravity concentration practice has been substantiated by several full-sized plants.

Jan 1, 1950

(Members are urged to send in for this column any notes of interest concerning themselves or their fellow-members) The following is a partial list of members and guests who called at Institute headquarters during the period Mar. 10, 1917, to Apr. 10, 1917. Frederick R. Ahbe, Athens, Pa. Frank M. Leland, San Francisco, Cal. J. L. W. Birkinbine, Philadelphia, Pa. Edwin Ludlow, Lansford, Pa. Samuel D. Bridge, Monterrey, Mex. E. P. Mathewson, Toronto, Canada. J. R. Buchanan, Pasadena, Cal. E. V. Matlack, Webster Grove, Mo. G. M. Colvocoresses, Humboldt, Ariz. E. C. Potter, Clearwater, Mont. F. G. Cottrell, Washington, D. C. R. B. Stanford, Bluefields, Nicaragua. H. N. Eavenson, Gary, W. Va. R. S. Ransom, Jr., Newark, N. J. H. T. Fisher, Englewood, N. J.. M. L. Requa, San Francisco, Cal. E. P. Fleming, Salt Lake City, Utah. John A. Rice, El Paso, Tex. F. L. Garrison, Philadelphia, Pa. W. E. Rice, Ringwood, N. J. W. M. Grant, So. Bethlehem, Pa. Lewis A. Riley, Philadelphia, Pa. J. F. Hanst, Negaunee, Mich. Hallet R. Robbins, Vancouver, B. C. H. D. Hibbard, Plainfield, N. J. Allen H. Rogers, Boston, Mass. B. B. Hood, Chrome, N. J. A. A. Stevenson, Philadelphia, Pa. Henry M. Howe, Bedford Hills, N. Y. Wm. Huff Wagner, Johnstown, Pa. Hennen Jennings, Washington, D. C. E. E. Watts, Denver, Colo. Oscar Lachmund, Greenwood, B. C. Samuel S. Wyer, Columbus, Ohio. H. W. Aldrich, after ten years of service with the Anaconda Copper Mining Co., at Anaconda, has resigned and accepted a position as general superintendent for the Ladysmith Smelting Works, at Ladysmith, B. C. Charles E. Bunker, formerly superintendent of the Keystone mine, has been appointed superintendent of the Bunker Hill mine near Amador City, Cal.

Jan 5, 1917

By John Gjers

Being on a visit to your great and prosperous country, and having been favored with an invitation to attend this meeting of your Institute, the author has been requested by your Secretary to give a short account of his invention of the " soaking-pit," which he has great pleasure in doing. The object of the soaking-pit is the rolling of steel ingots with their own initial heat, that is, to supply the missing link in that chain of metallurgical operations which Sir Henry Bessemer began in 1857, when he proved how it was possible to produce malleable iron or steel direct from the fluid cast-iron out of the blast-furnace, without any further direct use of fuel. The great Bessemer invention has revolutionized iron and steelmaking throughout the world; but it stopped short at producing the ingot, which, it was found, had afterwards to be heated in a furnace to enable it to be rolled or hammered; and it is only lately, twenty-five years after Mr. Bessemer's announcement, that the author of this paper has been able to show that furnacing can be dispensed with, and that it is practicable to roll a steel ingot into say a bloom, a rail, or a billet, with its own initial heat. It has no doubt suggested itself to many that there ought to be heat enough in the ingot just cast, for the purpose of rolling; and from time to time attempts have been made to utilize this heat; but such attempts always ending in failure, it became a settled opinion in the trade that it could not be done—an opinion which the author is aware that your late lamented countryman, Mr. Holley, than whom there was none more conversant with Bessemer steel-making, also entertained. But settled opinions sometimes prove to be great fallacies. As an instance, it is not many years since the opinion prevailed in the trade that steel ingots could not be rolled successfully, that is, so as to make good rails, unless they were first allowed to get quite cold, and afterwards heated. No greater boon was ever conferred on the

Jan 1, 1885

The election of the following officers of the Council for the fiscal year 1919-1920, was confirmed by the Council on June 12th, 1919. President, S. E. Doane; vice-president, Wm. J. Clark; general secretary, Clarence L. Law; treasurer, L. B. Marks; directors, E. C. Crittenden, F. E. Cady, R. B. Ely. The membership of the Council for 1919-1920 will therefore be as follows: S. E. Doane, G. H. Stickney, George A. Hoadley, Wm. J. Clark, H. A. Horror, Otis L. Johnson, H. K. Morrison, Clarence L. Law, L. B. Marks, Adolph Hertz, S. C. Roger, P. S. Young, John C. D. Clark, Evan J. Edwards, James J. Kirk, E. C. Crittenden, F. E. Cady, R. B. Ely.

Jan 7, 1919

LATEST estimates of Russian steel production for 1951 give rise to the belief that on at least one vital front, the Western bloc of nations has maintained a definite advantage. On the surface, we are outproducing the Eastern bloc by more than twice. The United Nations Economic Commission for Europe estimates Russian output at 31.30 million tons, a 15 pct increase over the previous year. Production for the entire Iron Curtain is figured at 40.93 million tons. Western Europe alone produced 17 pct. more steel during the same period. The figures are misleading in one sense. We have no precise idea of how much steel is being used for arms. The Western nations are still expending much of their production for consumer goods, and you cant throw washing machines in a shooting war. It is significant to note that Russian production is well, beyond estimates made by world authorities prior to the current international situation. INTERIOR Secretary Oscar L. Chapman warns that the United States must make use of the resources of other nations or face mineral impoverishment once the time of struggle is over. He pointed out that the present struggle between two ideologies can leave the United States in such a state as to preclude anything but political' victory-with an accomp anying economic loss that will be irreparable. Chapman scored the attitude whereby conservation programs are looked upon as a luxury, pointing out that the nation faces an ever increasing need for action on that front. He also announced that the Bureau of Mines doubled its facilities for producing pure zirconium during 1950-51 at the request of the Atomic Energy Commission. Zirconium may be an important structural metal for atomic power devices. The Interior Secretary also said that the AEC has provided the Bureau with funds for the study of radioactive minerals and to help test and evaluate about 9000 ore samples believed to contain uranium.

Jan 1, 1952

By A. Lubinski, C. R. Stewart, K. A. Blenkarn

Storage porosity has been considered one of the important pore geometry characteristics of heterogeneous-porosity limestones. Storage pores are only containers for fluids, in contrast to flow channel pores which both contain fluids and provide continuity for fluid flow. The concept of another geometry characteristic, "poro-striction", is presented as a second pertinent variable in describing limestone pore space. In simple terms, poro-striction is a measure of the flow resistance between storage and flow channel pores. Alternating-flow core-testing theory provides flow relationships which can be used to divide the pore space of heterogeneous-porosity media into flow channel and storage pores and to measure the "porostriction" of the latter. Experimental application of this theory to naturally occurring heterogeneous limestones shows that "porostriction" and the ratio of storage to flow channel pores can be estimated. Porostriction and porosity ratio are microscopic characteristics which should influence oil-recovery efficiencies during certain types of displacement processes. A knowledge of pore geometry should be valuable in designing or selecting the most effective oil-recovery process for heterogeneous limestones containing storage porosity. INTRODUCTION The primary and secondary recovery of oil from limestone (carbonate) reservoirs has been and will continue to be a major source of the world's supply of petroleum. Oil recovery from this type of formation is strongly influenced by the size, shape and arrangement of the pore spaces which hold the formation fluids. Therefore, it is expected that better knowledge of pore geometry would lead to design of more effective recovery processes. The concept of storage and flow channel pores has been presented as an important characteristic of limestone porosity.1 In this concept, storage pores are only containers for fluids, whereas flow channel pores are those pores which both contain and transmit the fluids. The work reported herein involves the concept of an additional pore characteristic called "porostriction". This characteristic can be visualized as the flow resistance between the storage and flow channel pores. This resistance is an important pore geometry characteristic because it determines how easily gas and oil can replenish fluids removed from the flow channel pores. Fatt and co-workers at the U. of California have studied the effect of storage porosity and a factor similar to porostriction on transient-flow response of models of porous media during a pressure build-up or drawdown test.55 These models consisted of porous sandstone cores with artificially simulated storage pores. It is the purpose of this paper to describe tests which permit the storage porosity and porostriction of actual reservoir core samples to be estimated. The tests used for this purpose involved not transient tests but, rather, an alternating-flow technique in which pressure and flow are varied according to a sine-wave relationship. This technique may offer advantages over transient methods. THE POROSTRICTION CONCEPT Before discussing alternating-flow (A.F.) tests in core samples, it is necessary to define the porostriction parameter. For this purpose attention is focused upon an elemental volume v representative of a porous medium having both flow channel pores and restricted-access storage pores. For such an elemental volume, it is considered that the storage porosity is combined to form a single pore and that the access into the storage porosity may be represented by a single capillary tube connecting the single pore to the flow channels of the elemental volume. Let the radius of the capillary tube be designated as Rc and its length as L,. When fluid flows into or out of the pore, the following equation (Poiseuille's law) relates flow rate q to pressure drop p, and the physical characteristics of the tube and the fluid of viscosity jx.

By E. P., Mathewson

THE most important improvements in copper metallurgy today are the advances in the art of leaching and electrical precipitation of copper from solution; the development of flotation processes; improvements in crushing and pulverizing machinery; the enlarged units of both reverberatory and .blast furnaces, together with the application of pulverized coal to both styles .of furnaces; the enlargement of' units for converting copper and the improving of the mechanical design of converter shells and equipment; the electrical precipitation of flue dust and fume from escaping gases.

Jan 1, 1921

By Paul Cook

THE ore deposit of the Buckhorn Mines Co., Buckhorn, Nev., is peculiar in being a shallow kaolinized mass of material with basalt walls, and having apparently no direct connection with any of the usual gold-bearing rocks. The average ore contains 16 per cent. waiter of hydration, and the cyaniding of this hydrous clayey material offered unusual difficulties as compared with the typical gold quartz ores of Nevada. The orebody was thoroughly developed; then the mill was built according to the latest cyanide .practice, with such changes as were thought to be demanded by the peculiar nature of this ore. Upon starting the mill, the ore proved more difficult to handle than had been anticipated. It is hoped that an account of how these difficulties were met may prove of interest to anyone having a clayey ore to handle and to the profession in general.

Jan 9, 1916

By William L. Russell

A new instrument for measuring bulk and grain vol-urnes is described, and compared in accuracy with two modifications of Nutting's method, All three methods are reasonably fast, and in all three the probable error in the determinations of bulk volume can be kept down to about 0.1 to 0.2 per cent. INTRODUCTION The new pycnometer described in this paper is designed to give speed without sacrificing accuracy. Some time ago Russell1 described a somewhat similar appa-ratus; however, the instrument described in the present paper is more accurate. Nutting' designed the pycnom-eter shown in Fig. 1 (A and B), and Pirson3 has shown points like those of Fig. 1-D. The procedure described in this paper for using Nutting's pycnometer has been modified from that used by Nutting. CHOICE OF LIQUIDS The best liquids for measuring grain volumes are hydrocarbons or chlorinated hydrocarbons which evaporate slowly. Trimethylbenzene or mesitylene, triethylben-zene, carbon tetrachloride, and tertalin have been used for this purpose. Any of these liquids or mercury may be used for measuring bulk volume. PREVENTING ERRORS DUE TO INVASION OF LIQUID Errors due to the invasion of the porous, permeable bulk samples by the liquid of measurement may be prevented or greatly reduced by using mercury, by applying an impervious coating, or by soaking the bulk samples in the liquid of measurement until bubbles cease issuing from them. Errors are produced only by the invasion of the samples which occurs between movement when the samples are weighed in air and the moment the weight of liquid displaced by the sample in the pycnometer is determined. No error is produced by varying degrees of filling of the pore space of the samples by the liquid of measurement. The excess liquid should be wiped from the samples immediately before the weight in air W1, is determined, and they should be placed in the pycnometers immediately. OPERATION OF NEW INSTRUMENT The new pycnometer is shown in Fig. 2. It consists of two glass parts which fit together at a ground glass joint. The spaces J and D are connected by fine glass tubes E, and the space J must be larger than the space D by at least the volume of the largest sample to be tested. The projections H afford a grip for twisting when the two parts tend to stick together. The position of the sample in mercury is shown by I, and in other liquids by M. F is a permanent mark on the glass, and G is a tem-Some marker. In order to determine the position at which G should be placed, invert the instrument so that A is at the bottom, and fill space D. Place the cub K

Jan 1, 1958

By Charles P. Williams

BY PROFESSOR CHARLES P. WILLIAMS, ROLLA, MISSOURI. During the fall of the year 1873, attention was redirected to the occurrence of lead ores in Southwestern Arkansas (chiefly in Sevier County), and somewhat extensive explorations of the deposits have since been made in the hope of finding the ores sufficiently argentiferous to be profitably worked. How far the expectations have been realized I am not authentically advised, but samples of the galena ore, yielding 62.09 per cent. of lead, gave on assay at the rate of 15 3-10 ounces of silver to the ton of ore. This was the highest result obtained by myself, though I am informed that higher yields have been obtained by others. Among the samples of ores from this locality, forwarded to me in January last, was one specimen which I at once recognized as stibnite, and, on notification, other specimens of the same from Sevier County were forwarded me. The first specimen of the several received contained 11.51 per cent. of gangue, 57.62 per cent. antimony, 4.57 of bismuth, with small amounts of arsenic and iron. The latest result from a portion of another hand specimen I append in full, with duplicate estimations of the arsenic, bismuth, and gangue. The analyses were all conducted by Mr. C. R. Winters, under my direction, and in the case of those given below the ore mas separated as closely as possible from the gangue before analysis. The results are for the mineral freed from hygroscopic moisture, and are as follows: I. 11. Mean. Sulphur,.. 28.618 .. . 28.518 Antimony,.68.576 .. . 68.676 Arsenic,..6 47 .474 .497 Bismuth,..521 .498 .509 Iron,.......762 .. ..762 Gangue,..944 .948 .946 99.868 99.808 This result indicates that the ore is stibnite.

By T. A. Rickard

Our Transactions contain two notable papers descriptive of the stamp-milling practice of the Black Hills and of Grass Valley, namely, the elaborate and complete treatise of Prof. H. 0. Hofman, on " Gold-Milling in the Black Hills,"" and the paper describing the North Star mill, by E. R. Abadie, its superintendent. Having visited and examined the stampmills of both localities, I venture to offer here such comment as more recent information or a different point of view has suggested.†

Jan 1, 1896

By J. V. Gluck

In the present paper," as in earlier publications, V1'2"1 the authors present experimentally obtained relations for the free energy of solution of oxygen in various metals as a function of temperature. The relations are linear and given in slope-intercept form. The authors give values for the "probable error" of the slope and intercept, citing Birge's method17 for obtaining these quantities. Birge discussed these methods as early as the period 1929-32.25726 In Ref. 25 the probable error is defined as "the numerical value which the true error is as likely to exceed as not", i.e., 50 pct probability. Ref. 26 is even more detailed and includes a lengthy discussion of the applicability of the Gaussian distribution to experimental data. However, the use of the "probable error" has come under some question. For example, Ezekiel'~ states that "the use of the probable error tends to make the results appear rather more accurate than the standard error". Moroney28 stated (in 1951) that "the term 'probable error' was used in former times to denote 0.67450 (50 pct confidence using the normal distribution)....the term, a poor one, is now very much obsolescent. It has been said that 'it is neither an error nor probable' ". Bennett and Franklin in 1954" in discussing statistical confidence levels mentioned that "the customary use of the 5 and 1 pct levels is not completely a matter of chance; these levels probably represent a balance between the desire to be correct and the desire to be specific. Also in most people's minds the borderline between something that could possibly happen and something that is not likely to happen is somewhere in this region. Certainly 5 or 1 pct confidence limits are to be preferred to limits such as the 'probable error' which has only a 50/50 chance of including the correct value." It may readily be seen that the 95 pct confidence level, which is given by 1.960 (assuming large sample size), thus corresponds to approximately three times the "probable error". Indeed, limits of one standard deviation correspond only to about 68 pct probability. Even if we triple the tolerances given by the authors in the equations of their Table 111, the deviations do not become excessive and would not detract from their excellent results. It could then be said with a high degree of confidence (95%) that the precision of the slope and intercept values is about *3-5 percent of their absolute levels rather than the 1-2 percent implied in Table 111. This is then compatible with an earlier suggestion of Gokcen~' of a probable accuracy of 5 pct in dissolved oxygen measurements by the technique employed. Alternatively, the authors could have

Jan 1, 1967

By John A. Church

In the year 1874, when the price of pig-iron was still high, that staple product became the subject of discussion in the newspapers and among those philosophers who are determined to know the "reason why" for all things. The object of the inquiry was to find out Why iron did not fall in price as much as some other things had fallen. Indeed, there seemed to be an impression that iron and gold ought to move on nearly parallel lines, for the fact was constantly brought forward that iron then cost twice as much as it did before the war, though gold had returned to within twelve or fifteen per cent. of its former value. After some time the papers, by what seemed to be nearly unanimous consent, reached the conclusion that the maintenance of high prices was the work of the furnace proprietors, who, as the result of their shrewdness, were pocketing enormous profits. No proof was given to support this opinion, and the figures of cost and sale that were produced were of the most general kind, and used in the most vague manner. Visiting the president of the Thomas Iron Company, whose great works at Hokendaqua and Catasauqua, in Pennsylvania, are so well known as the largest and among the best conducted in America, I found him quite willing to meet the vague suspicions of the newspaper wiseacres, by a publication of the figures contained in the furnace-books of his company. These were accordingly given to the world through the Engineering and Mining Journal, and attracted the general attention they so well deserve. Though my own name became connected with these statistics, from the fact that I used them as the basis for the first attempt ever made to calcalate the furnace economy of an American works, I can, without the suspicion of egotism, say that the statistics referred to are the most valuable contribution the literature of American blast-furnace work has yet received, for their interest is independent of personal considerations, and due entirely to the fact that they represent faithfully the details of practice in one of the most prominent American works. They are an exact transcript of the furnace-books, and form a body of accurate information of the greatest value to the metullurgical student. Their importance is shown by the fact that though the theoretical conclusions which I based upon them have been several times attacked, not one of my critics has made the slightest contribution to

By John A. Church

IN the year 1874, when the price of pig-iron was still high, that staple product became the subject of discussion in the newspapers and among those philosophers who are determined to know the "reason why" for all things. The object of the inquiry was to find out why iron did not fall in price as much as some other things had fallen. Indeed, there seemed to be an impression that iron and gold ought to move on nearly parallel lines, for the fact was constantly brought forward that iron then cost twice as much as it did before the war, though gold had returned to within twelve or fifteen per cent. of its former value. After some time the papers, by what seemed to be nearly unanimous consent, reached the conclusion that the maintenance of high prices was the work of the furnace proprietors, who, as the result of their shrewdness, were pocketing enormous profits. No proof was given to support this opinion, and the figures of cost and sale that were produced were of the most general kind, and used in the most vague manner. Visiting the president of the Thomas Iron Company, whose great works at Hokendaqua and Catasauqua, in Pennsylvania, are so well known as the largest and among the best conducted in America, I found him quite willing to meet the vague suspicions of the newspaper wiseacres, by a publication of the figures contained in the furnace-books of his company. These were accordingly given to the world through the Engineering and Mining Journal, and attracted the general attention they so well deserve. Though my own name became connected with these statistics, from the fact that I used them as the basis for the first attempt ever made to calculate the furnace economy of an American works, I can, without the suspicion of egotism, say that the statistics referred to are the most valuable contribution the literature of American blast-furnace work has yet received, for their interest is independent of personal considerations, and due entirely to the fact that they represent faithfully the details of practice in one of the most prominent American works. They are an exact transcript of the furnace-books, and form a body of accurate information of the greatest value to the metallurgical student. Their importance is shown by the fact that though the theoretical conclusions which I based upon them have been several times attacked, not one of my critics has made the slightest contribution to

Jan 1, 1876

By E. S. Moffat

Members of the Institute who have visited the works of the Lackawanna Iron and Coal Company at Scranton, will remember the exposure of a large vein of anthracite coal in the rocky bank on the south side of Roaring Brook, near the blast-furnace. The vein is quite flat, and is exposed to view for several hundred yards along the banks of the brook, a few feet above the surface of the water. It is some ten feet in thickness, and is known as the Big Vein. At a point just opposite the blast-furnace, much of the coal from this vein was mined out many years since, the usual pillars being left to support the overlying rock and drift, which are here some twentyfive to thirty feet in thickness. Over thirty pears ago fire was communicated from an ore-roasting pile on the surface of the ground at this point, through an old shaft, down to the refuse and pillars which had been left in the mine

Jan 1, 1887