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By R. K. Amankwah, E. K. Asiam

Changes in the thermal-oxidation behavior and other properties of gold-bearing waste activated carbon when milled in both a ball mill and a vibratory mill were investigated. It was found that significant changes occurred in the oxidation temperature of the vibration-milled waste carbon as a result of increases in surface area and mechano-chemical activation. The mechano-chemical action brought about modifications in the crystal structure of the waste carbon. As a result, the vibration-milled sample was completely oxidized at a temperature of 450°C. Thus, the study established that vibration milling is a better way of lowering the temperature of oxidation of the waste carbon. Furthermore, the gold was found to be concentrated in the ash and, when leached with cyanide for 20 hrs, the gold recoveries from a sample having a head grade of 2 kg/t was 99.5% for the vibration-milled sample and 82% for the ball-milled sample. The lower gold recovery for the ball-milled sample was attributed to sintering of the ash, which was caused by the higher temperature required for its oxidation.

Jan 1, 1997

By John V. Beall

If you will be patient, we will explain how our plans to research the fishing possibilities of the Buffalo River following the SME Fall Meeting turned out, in general, to be an extension of the main theme of that meeting and, in particular, to confirm an astute observation on research made by Australian T. R. A. Davey in his Award-acceptance address at the Pb-Zn Research Luncheon. Buffalo River State Park is reached via Yellville where we tried without success to find one Odie Tollett who had been recommended as a boat liveryman. However, Mrs. Leon Dodd, in the Park, outfitted us nicely with a 17-foot aluminum canoe. Rain had dominated the recent weather of the Ozarks in northwestern Arkansas. So, under a leaden sky and intermittent showers, we stood on the bank of the turgid Buffalo demonstrating to our spouse, Sylvia, how to cast. Of course, with the water up and the sediment, the outlook for catching fish was bad. Sylvia said, however, "Oh, I get it. Let me try. Umm, like this I got one!" Sylvia reeled in a pretty ten-inch brown trout. "The poor thing, let's throw him back."

Jan 1, 1970

By Herbert Haas

The following notes describe a laboratory for metallurgical chemistry and technical analysis which I built late in 1903, while engaged, as constructing engineer, in erecting a pyrite smelter at the Afterthought mine, Ingot, Shasta county, California. This design partly supplements the paper of Mr. C. H. White, which was presented at the Atlantic City Meeting of the Institute in February, 1904.' The work of a chemist at a busy smelting-plant differs radically from the work of a student, who takes all possible care to have his analysis exact within hundredths of a per cent., and has plenty of time to devote to the operation. The works-chemist, having the shortest time in which to make his determinations, should have a laboratory arranged as conveniently as possible to save time in carrying out his work. By a conveniently-arranged laboratory, I do not mean an elaborately furnished one; but rooms suitably fitted up and supplied with the necessary apparatus to do the work expected from the chemist within the requirements of technical analyses. It is not uncommon at large smelters to have the night ae-sayer prepare 30 or more samples for titration, in time for the

Jan 1, 1905

By Laurence Delisle

The aim of this paper is the description of a technique to be applied to the study of sections of metal powder particles, less than 20 microns in diam. with the electron microscope, by the replica method, using for replica a material such as formvar or parlodion. This work originated with the study of particles of tungsten powders. Such particles were too small to be examined in sufficient detail with the light microscope. On the other hand, examination with the electron microscope of the powders dispersed in the supporting film was not found satisfactory because: 1. It did not permit differentiating between single particles and aggregates. 2. It did not show the true outlines of the particles but only the projection of a whole surface. 3. No details appeared. For that reason it was attempted to make replicas of sections of the particles imbedded in a mounting material suitable for polishing and etching. The method proved satisfactory for the examination of tungsten powder and was then extended to car-bonyl nickel and carbonyl iron powders. Procedure Several mounting materials commonly used in ordinary metallography were investigated. The problem consisted in finding a mounting material

Jan 1, 1950

Some mqre facts and inferences are presented in amplification of a recent paper on the geology of the Kalgoorlie Golden Mile stressing the volcanic origin of its rich gold ores, some of which are considered tobe exhalites. Previously unpublished and largely unmapped pyroclastic features in carbonated and chloritized, but not in amphibolitic, country rock are brought to attention. This applies particularly to the main host, viz. the relatively coarse-grained quartz dolerite greenstone (Q. D. G.), i.e. Golden Mile Dolerite, and gives more credibility to the spatial association of the rich Green Leader and telluride ores with bodies of sediments and tuffites occurring within, or adjacent to, Q. D. G. There may be an intrusive relationship with contiguous mafic amphibolites of doleritic origin, but this is not certain and can only be resolved by morecomprehensive mapping than in the past. Volcanic features have always been recognized in CalC Schist, i.e. Paringa Basalt, more so recently in the shape of coarse volcanic breccia.Iu the subsequent deformation of the gold ores since their inital emplacement there appears to be a structural parallel with some Canadian base-metal deposits, most of them of volcanogenic origin.

Jan 1, 1976

By John L. Baum

Tests show that 50 times the earth's normal field can exist near stacked drill rods. Protection against the effect of these strong fields can be obtained by means of a removable sleeve of common iron pipe. GEOLOGISTS and engineers working around a diamond drill rig have often had the opportunity to observe the magnetic attraction of drill rods pulled out of the hole for core removal. This is sometimes an amusing pastime, but this same magnetic force inadvertently applied to a compass needle can cause it to lose its polarity entirely or to become reverse polarized when placed in the immediate vicinity of stacked rods. The first recommendation, of course, would be to avoid the rods, but in surveying an operating drillhole this is not always possible; therefore steps must be taken to neutralize the magnetic effect of the drill rods. Early in the summer of 1949 the geological department of the New Jersey Zinc Co. undertook at Franklin, N. J., an extensive program of surveying the course of deep diamond drillholes. The majority of the holes were surveyed while in the process of being drilled, and considerable difficulty was encountered. A pattern for the deviation of drillholes had been established for the district from surveys in holes from which the drill rig had been removed. It was observed that a certain operating deep drillhole being surveyed did not fit this pattern. In the resulting confusion of repeated surveys and cementing a plug for wedging operations, the lower 1800 ft of the hole was lost. Because of this incident studies were initiated to determine the source of the difficulties and to develop safeguards against recurrence of faulty surveys. Using a hand magnet easily shows that the polarity of a compass needle can be reversed if rotation of the needle is hindered through tilting of the compass or clamping of the mechanism. Such experiments are not recommended, especially in the case of the clockwork type of instruments. A magnetized hairspring in a clockwork instrument will cause the compass card to assume a periodic motion which will not stop until the clockwork runs down. Routine check readings of instrument north before and after each survey are not always sufficient to catch instances of reversed polarity of the compass needle. Although the majority of instances probably take place while the instrument is being removed from the hole with needle in fixed position, it is demonstrable that a 'luggish needle, weakened during a previous test, can be reverse polarized

Jan 1, 1955

By I. Fatt

This paper proposes the network of tubes as a model more closely representing real porous media than does the bundle of tubes. Capillary pressure curves are derived from network models and pore size distributions are calculated from these curves. In this way is shown the difference between the true and calculated pore size distributions when the capillary pressure curve is used to obtain pore size distribution for porous media. INTRODUCTION Despite the technological importance of the laws governing flow through porous media, many of these laws have not yet been clearly formulated. This is especially true of the laws governing multiphase flow. The static properties, such as the capillary pressure curve, are also not at present interpretable correctly in terms of the pore size distribution and other structural properties of porous media. In the absence of any well founded theoretical description of fluid flow through porous media, many empirical descriptions have been proposed. In addition to the strictly empirical flow equa- tions, some equations have been developed rigorously from simple geometrical models of the pore spaces. These equations are only as valid as is the model used in their development. The two models used in the past, the sphere pack and the bundle of tubes, have been too simple, and as a result, the equations derived from them have failed to predict the observed properties. Agreement between theory and observation has been achieved for these models by inserting parameters of doubtful physical significance. The work to be reported here was undertaken in the belief that the study of a model more closely resembling most real porous media than does the sphere pack or bundle of tubes would yield useful information concerning the structure of real porous media and the relation between structure and flow properties. There was no intention of developing any calculational procedures, as for example calculating relative permeability from capillary pressure data. The objective of the study was instead to develop a better qualitative understanding of the relation between the various measurable properties of porous media. The model chosen for study is the network of tubes in which each tube represents a pore space in the porous medium. Microscopic observations leave no doubt that sandstones and clastic carbonates are three-dimensional irregular networks of irregularly shaped pores. The irregularity of these structures makes any accurate theoretical study of their properties impossible. Results from an oversimplified model such as the bundle of tubes are worthless when applied to real systerns. The sphere pack model, on the other hand, not

Jan 1, 1957

By Whitman E. Brown, Louis J. Erck

The installation in 1948 of a Hum-phrey~ spiral concentrator section at the Hill-Trumbull plant of The Cleve-land-Cliffs Iron Co. is the latest commercial method on the Mesabi Range being used for the recovery of fine iron ore. In two stages of concentration 84 spirals treat approximately 120 long tons per hour of minus ? in. ore. These spirals augment the production of the heavy-density plant which recovers the plus 36 in. iron from the plant crude ore. Structure of the ore is such that, when crushed, about 50 pct of the plant crude is minus ? in. size. After de-sliming in a 66 in. Akins classifier, grinding the classifier product in a ball mill and again desliming in a 78 in. Akins classifier about 15 pct of the crude ore remains to be treated in the spiral plant. Overall recovery of the ball mill feed in the Hill-Trumbull spiral plant during the 1948 season was about 53 pct of the weight and 66 pct of the total iron content. Of the actual feed delivered to the spirals from the 78 in. classifier 64.9 pct of the weight was recovered containing 73.7 pct of the total iron. The average analysis of the spiral concentrate is 55.05 pct Fe and 14.83 pct SiO2. An average of mill assays during the 1948 season is given in Table 1. The Hill-Trumbull plants treat both wash ore and jig-type ore. During the 1948 season spirals were used only on the fine sizes of jig-type ore. At times the deslimed minus ? in. size is of sufficient grade to warrant bypassing the spirals but in the main the fine size is delivered to the 48 first stage spirals and thence to the 36 cleaner or second stage spirals. In the past several years numerous Mesabi Range ores in the fine size cate- gory have been tested by a wide variety of beneficiating equipment. The prodigious amount of research devoted to the recovery of values in the fine ore reflects the dire need of the iron industry to squeeze the last possible unit of iron from the mined ore and to develop suitable equipment and processes to satisfactorily concentrate the leaner horizons as they are encountered in the process of mining. Large governmental and private appropriations have been allotted, new laboratories built, research and technical staffs increased, and operator-manufacturer cooperative agreements applied to hasten the solution of the problem. The University of Minnesota, at its Eighth Annual Mining Symposium in January 1947, dedicated as its objective the bringing to light of technological developments in iron ore beneficiation. Papers were given at that time relating to processes being developed. Specifically, these papers reviewed flotation, Baum jig, selective media concentrator, Hardinge concentrator, Dorrco sizer, heavy media concentration, Hydrotator, and the Humphreys spiral. The Cleveland-Cliffs Iron Co., after encouraging results from tests in a small pilot plant using one full size spiral, made the first commercial installation of Humphreys spirals on the Mesabi Range at their Hill-Trumbull mine, Taconite, Minn. This company

Jan 1, 1950

By Ryan Redyke, Jared Redyke

The demolition of an old power plant boiler house in Parsons, Kansas calls for the use of some linear shaped charges. The steel is thick and the structure is heavy but gravity can be a blaster’s best friend. This entry did not win in a very competitive category. We thought it was worthy of coverage in the Journal of Explosives Engineering.

Jan 1, 2015

By Heinrich Ries

The manufacture of fire-brick represents one of the oldest branches of the clay-working industry in New Jersey, and is of more importance than is commonly imagined. The New Jersey clays were first used for fire-brick after the war of 1812, and one of the earliest records, according to Professor Cook, shows that clay was taken from Woodbridge to Boston in 1816, arid used for that purpose. The value of the clays of the Woodbridge district does not seem to have been well and widely recognized for some years, however, although in 1855 the statistics, given in the Geological Report, show that clay for making 50,000,000 fire-bricks was then taken annually from the pits at Woodbridge, Perth Amboy and South Amboy. Perhaps the oldest works in the State was that known as the Salamander works (no longer in existence), where brick were made as early as 1825. A little later, in 1836, John R. Watson established a factory at Perth Amboy, and in 1858 Sayre & Fisher began the manufacture of fire-brick at Washington. The works of W. H. Berry at Woodbridge began operations in 1845, and have continued up to the present clay, although in 1896 the name was changed to J. E. Berry. The works of Henry Maurer & Son were established in 1856, and those of M. D. Valentine & Brother in 1865. These latter were started for making bath brick; later, sewer-pipe, and, finally, fire-brick and other refractory shapes were produced. A branch-works, located at Valentine on the Central railroad of New Jersey, was started in 1887. Even in the last two years several works have begun the manufacture of fire-brick. These include factories erected by

Jan 1, 1904

By Jun Yuan

Kaolin clays from five different commercial deposits in Georgia were studied to understand the variations of zeta potential and related fundamental properties. The results suggest that higher negative zeta potential is related to exchangeable or soluble calcium ions in the clays.

Jan 1, 1997

By David White

In these days, when detailed investigations of stratigraphy, structure, and sand conditions so frequently result in the discovery of new oil fields, and applause from oil companies and the public, geologists do well to walk humbly, and punctiliously to admit that the geologic principles controlling the distribution of oil and gas have as yet been discovered only in part, and that what remains yet to be learned is probably vastly more than what is already known. The few experiments already attempted have been fragmentary, and somewhat desultory, and however positive each of us may be with respect to certain theoretical conclusions, many of the fundamental questions as to the origin and mode of occurrence of petroleum are subject to radical disagreement. Of the chemical changes attending the generation of petroleum from organic matter, little is actually known. Most of the postulated formulas are liable to be misleading, through ignorance of essential factors. Open-minded-ness is therefore a prime essential at the present stage of our science. Nevertheless, adopting the hypothesis that oil originates in some manner fundamentally connected with the organic theory, and in possible departure from such open-mindedness, the writer will pay no attention to the so-called inorganic theory, since every attempt to apply this theory to the study of old oil fields, or to the discovery of new ones, affords cumulative evidence of its inadequacy. In this paper, some of the factors affecting the occurrence of petroleum that the writer believes worthy of consideration by the prospector for oil in any new region will be discussed. Some of these, which arc less generaLly understood, will be considercd somewhat in detail. Other points, the significance of which cannot now be determined, require more field study, and for that reason are here brought to the attention of the field geologist. On the other hand, certain theoretical points which do not bear especially on the oil possibilities of a new region will be given little or no attention. The main topics that will be discussed are: (1) sufficiency of carbonaceous detritus and residues in the oil-forming rocks; (2) stage of carbonization of the organic matter in the oil-bearing formations; (3) folding of the strata; (4) thickness of sedimentary formations; (5) conditions of deposition.

Jan 1, 1921

By Charles S. Allbright

To develop a method for predicting the stability of a fuel during long-term storage from rapid aging tests at 200° F, the Bureau of Mines determined the stabilities of three gasoline base stocks and an alkylate blending stock in both sealed storage and aerated storage at 110° F for periods extending to 32 weeks. Stabilities of samples containing gasoline-additive compounds were compared by aging, using two methods--rapid aging in a bomb at 200° F for intervals up to 16 hours and storage at 110° F. The additives used were an uninhibited tetraethyllead motor mix, N,N'-di-sec-buty1-p-phenylenediamine and 2,6-di-tert-butyl-4-methylpheno1. Results were related by graphs that enable predictions of gum and sediment formation during storage from data obtained in bomb tests. A premium-gasoline base stock and the alkylate proved to be stable, but the two regular-grade gasoline base stocks were found to be unstable. Addition of the diamine antioxidant improved the stability of both of the regular gasoline base stocks, while the phenol antioxidant improved only one of them. The presence of the tetraethyllead decreased the storage stability of all four fuels, both with respect to formation of gum and precipitation of inorganic sediment. The rapid test at 200° F appears to offer promise as a basis for a method of predicting gasoline stability in long-term 110° F storage.

Jan 1, 1968

By C. Y. Sun

In this paper, the development of research and practice on the separation process of fine complex Cu-S ore at a Copper Mine in south of China, was discussed. Since early 1980s, various processes were used, such as the process of bulk flotation-separation, the process of selection flotation and the process of iso-flotation. Especially when the process of selective flotation was put into operation, further development was achieved in beneficiation results, but the difficulty in separation of chalcopyrite from pyrite has not been solved yet, so causing a poor quality of Cu concentrate. The author has successfully developed a new separation process characterized by the use of collector thionocarbamate and fast flotation. The selectivity of fine chalcopyrite and pyrite was greatly improved. This process supplied a new route for the treatment of fine complex Copper sulphide ores.

Jan 1, 2014

By Joseph G. Selmeczi

Lime and limestone-based SO2 scrubbing processes have demonstrated reasonably good success in removing low concentrations of SO2 from flue gases. While most of the operating problems experienced in the early days of scrubbing have been worked out, problems usually increase and removal efficiency drops with increased amounts of SO2 present in the gas stream. In order to overcome these difficulties, yet still taking advantage of lime and limestone as the lowest cost neutralizing agents, a host of so-called double- alkali systems were developed. These processes take advantage of cations such as Na+ and NH4+ capable of forming highly water soluble bases or basic salts, such as hydroxide, carbonate or sulfite, which having been neutralized or acidified by the absorbed SO2 can be regenerated with a lower cost base such as lime.

Jan 1, 1974

By John Hower, Frank J. Markewicz, William Lodding

Greensand, greensand marl, and green earth are names given to sediments rich in the bluish green to greenish black mineral known as glauconite by the mineralogist. The word glauconite is from the Greek word glaukos, meaning bluish green. The term "greensand" as a rock name for a glauconite-bearing sediment is more appropriate than "greensand marl," a term that has been doggedly perpetuated in the literature. Because of its potash and phosphate content, greensand was dug and marketed as a fertilizer and soil conditioner for more than 100 years. The advent of prepared fertilizers with adjustable nutrient ratios led to the decline of greensand for agricultural application. The material has since been recognized for use in water treatment. Unfortunately, in spite of large reserves and worldwide distribution, the mineral has not been utilized to any significant commercial extent because no major application has been found for a substance with its chemical composition and properties. This lack is probably due to a paucity of research on its potential commercial application. Extraction of potash received considerable attention during and just after World War I. Because of relatively high extraction costs and generally low potash content (up to 8% ), glauconite lost its appeal as a source of this commodity. Historical Background Greensand was used as a fertilizer in New Jersey in the latter part of the 1700s. During the early 1800s its use became more common; applications of up to 100 tons per acre were sometimes made, although recommendations for agricultural use suggested 20 to 50 tons per acre (Tedrow, 1957). Many crops, especially the forage type, were said to improve with greensand application; however, because of, slow release of potash, large quantities were required. Certain greensands that contain sulfur and sulfide minerals are harmful to plant growth, and these were classified as "poison," "burning," or "black marls." The availability of higher-grade potash salts from other mineral sources, and the manufacture of prepared fertilizers, displaced the agricultural use of greensand during the later 1800s. During the mid-1800s the domestic greensand industry, centered in a small section of the eastern United States, grossed more than $500,000 per year. Toward the end of the century, annual production had dwindled to less than $100,000. By 1910 there were only six or eight greensand producers, grossing less than $5000 (Tyler, 1934). There was a small revival in the industry during World War I because of the curtailment of foreign potash, especially from Germany. During the later 1940s and early 1950s greensand was again recommended as a food nutrient for plants and farm crops. Agronomic studies discussed its potential as a soil additive that gradually releases potash and many trace-element nutrients essential for plant growth (Tedrow, 1957). Greensand was sold with the idea that it would condition soil and absorb and hold water while its base-exchange properties would release trace elements. For a short time glauconite was utilized in certain parts of New Jersey as a binding additive in the brick industry, and in the 1800s for making green glass (Cook, 1868). In the early 1900s the base-exchange property of glauconite was recognized for water treatment, and the mineral gained acceptance as a water softener. Mansfield (1922) does not mention base-exchange; however, the base ex-

Jan 1, 1983

By Frank J. Markewicz, William Lodding

Greensand, greensand marl, and green earth are names given to sediments rich in the bluish green to greenish black mineral known as glauconite by the mineralogist. The word glauconite is from the Greek word glaukos, meaning bluish green. The term "greensand" as a rock name for a glauconite-bearing sediment is more appropriate than "greensand marl," a term that has been doggedly perpetuated in the literature. Because of its potash and phosphate content, greensand was dug and marketed as a fertilizer and soil conditioner for more than 100 years. The advent of prepared fertilizers with adjustable nutrient ratios led to the decline of green- sand for agricultural application. The material has since been recognized for use in water treatment. Unfortunately, in spite of large reserves and worldwide distribution, the mineral has not been utilized to any significant commercial extent because no major application has been found for a substance with its chemical composition and properties. This lack is probably due to a paucity of research on its potential commercial application. Extraction of potash received considerable attention during and just after World War I. Because of relatively high extraction costs and generally low potash content (up to 8%), glauconite lost its appeal as a source of this commodity. Historical Background Greensand was used as a fertilizer in New Jersey in the latter part of the 1700s. During the early 1800s its use became more common; applications of up to 100 tons per acre were sometimes made, although recommendations for agricultural use suggested 20 to 50 tons per acre (Tedrow, 1957). Many crops, especially the forage type, were said to improve with greensand application; however, because of slow release of potash, large quantities were required. Certain greensands that contain sulfur and sulfide minerals are harmful to plant growth, and these were classified as "poison," "burning," or "black marls." The availability of higher-grade potash salts from other mineral sources, and the manufacture of prepared fertilizers, displaced the agricultural use of green- sand during the later 1800s. During the mid-1800s the domestic greensand industry, centered in a small section of the eastern United States, grossed more than $500,000 per year. Toward the end of the century, annual production had dwindled to less than $100,000. By 1910 there were only six or eight greensand producers, grossing less than $5000 (Tyler, 1934). There was a small revival in the industry during World War I because of the curtailment of foreign potash, especially from Germany. During the later 1940s and early 1950s greensand was again recommended as a food nutrient for plants and farm crops. Agronomic studies discussed its potential as a soil additive that gradually releases potash and many trace- element nutrients essential for plant growth (Tedrow, 1957). Greensand was sold with the idea that it would condition soil and absorb and hold water while its base-exchange properties would release trace elements. For a short time glauconite was utilized in certain parts of New Jersey as a binding additive in the brick industry, and in the 1800s for making green glass (Cook, 1868). In the early 1900s the base-exchange property of glauconite was recognized for water treatment, and the mineral gained acceptance as a water softener. Mansfield ( 1922) does not mention base-exchange; however, the base ex-

Jan 1, 1975

By F. C. von der Weid

THE mining district of São Fidelis, in the northern part of the State of Rio de Janeiro, is situated on the Paraiba River, where it crosses the Serra do Mar (Mountain of the Sea), in the center of a mountainous country having numerous graphitic outcrops. For a long time, these outcrops were irregularly explored by local people, who had little means and no technical advice. A few years ago, the Cia. Brasileira de Mineração de Grafite took over the control of some of the more important outcrops and entrusted to me the task of studying the ores and establishing a flowsheet for a pilot plant to be situated in Sao Fidelis-the ore to be concentrated being mostly of a very high grade. MINERALIZATION AND ORES The rocks of the district are mostly gneiss and crystalline schists, with occasional interstratification of dolomitic limestone belonging to the Archean Brazilian Fundamental Complex. The general direction of the beds is roughly between 60° and 80°E., with variable dip, generally nearly vertical. Mostly, direction and dip of the graphitic outcrops is concordant with the embanking gneisses or schists. These outcrops seem to be aligned in two or three parallel zones (Pádua, São Fidelis, Macabú), the São Fidelis zone being the best known and the most important to date. Two outcrops of the São Fidelis zone, Saudade and São Benedito, are now being exploited. Mining has been carried out, so far, on a small scale. The mineralization consists of a vein of nearly massive graphite in a very compact, partially granitized gneiss, with vertical dip. The vein is most irregular, with nests and lenses irregularly distributed along the fracture plane. The ore consists chiefly (particularly in São Benedito) of massive graphite appearing and disappearing along the main direction of the vein, forming a succession of irregular lenses in a sort of rosary design. The average width is more or less one foot, with variations from zero to 6 feet. The lode minerals are quartz, a little feldspar and garnet (the latter having its origin perhaps in the embedding gneisses), with rare ferruginous clays on the outcrops. In Saudade a little pyrite, pyrrhotite and chalcopyrite is found occasionally, as well as a carbonaceous mineral, very light, black and shiny, with conchoidal fracture, looking like a sort of jet. The composition of this mineral has not yet been established, but it seems to be very complex. The mineralization seems to be hydrothermal at a rather low temperature, perhaps mesothermal. The paragenesis, according to samples from Saudade, seems to be as follows, the earlier minerals being listed first: pyrrhotite, pyrite, chalcopyrite, with quartz concomitant to the three and

Jan 1, 1946

By C. B. Dudley

bas shown us that the railroads of this country can save several milt liohs a par by adopting uniform rail sections, and as unfortunately for him, he cannot patent his idea, it only remains for the railroads to adopt it, and to thank him for his payer. Dr. C. B. Dudley, Altoona, Pa. : 111 rising to close this interestin~ discussion, I want, in the first place, to thank every one who has contributed to it for his full and open criticism. The work tvhich has been done on steel rails, and which has been diwu&e,l here Juring thee two days, was not done to establish any pet theories, nor to make out that any person was great or any person small, but with a sincere desire to get at what is the truth in regard to the wedring capacity of steel rails. There are enormous commercial coneiderations invoIved in this question, and, as I look at the matter, the more honest criticism and fair discussion there is, the Inore likely it is that the truth will appear. Ad first I would like to say that it seems to me very little has been said here upon the main conclusion of the paper, namely, that the softer rails give the better wear. All sorts of side issues have been discussed; but this poiat, which is really the principal one at issue, has been largely ignored, aid I cannot But feel that it still remains unshaken. Witb regard to ohemists end chemical work, there has been considerable said tending to throw discredib on chemists and their work; and while I believe that there have been in the past, are now, and may be in the futnre, a good many poor chemical analyses made, X also believe that chemists are, as a rule, as honest and competent as gentlemen who belong to other professiomc. There are chemisb who are chemists, and who are not chemists. The determination of -manganese has bee* called in question. Now I think the chemist at almost every steel works in the country will tell you that, in his experience, the manganese diffe1.s in different parts of the same ingot. Mr. T. T. Morrell, chemist of the Camhria Iron Company, whom I believe to be s thoroughly competent and hone6t chemist, tells me that he has often found different amounts of manganese in different parts of the same ingot. Come with me to Altoona, and I will take you into the machine shop where steel is king cut aud shaped, and I will show you that it is often necessary to stop the lathe or planer and take a cold chisel to cut oat a hard spot, or else ntn the risk of breaking the tool. This hard spot is simply a pttrt of the syiegel which was not thoraughiy mixed with the ma

Jan 1, 1881

By Thomas M. Drown

Theodore Dehon Rand was appointed Treasurer of the American Institute of Mining Engineers by the Council, at the Boston meeting of February, 1873, to fill a vacancy caused by the resignation of the treasurer who had been elected at the first meeting in Wilkes-Barre in May, 1871. He was elected by the Institute to this offce in the following May, and yearly thereafter until 1903. He often alluded with amusement to the abrupt way in which he was injected into this position, by my coming to his office and asking him to accept the appointment as Treasurer, on the ground that he was eminently fitted for the position by reason of his legal and business knowledge, his interest in geology and mineralogy, and more particularly because he was a neighbor of the person (to wit, myself) who was slated for the Secretaryship, and they could thus convenient.ly confer on Institute matters. He consented, on condition that the duties should not involve too.much additional work for him. This assurance was easily given, for the Institute then

Jan 1, 1904