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By Claude H. P. Lupis, John F. Elliott

The classic Siez~erts' technique has been employed to determine the solubility of oxygen in liquid pure silver and the effect on the oxygen solubility of solute metal additions to liquid silver. The results indicate that oxygen deviates slightly from Sieverts' law in pure silver as = 3.9. Gold, platinum, md palladium decrease the solubility of oxygen in silver. First-order free energy, enthalpy, md entropy interaction coefficients are determined from the data. An important aspect in the establishment of the formalisms to be applied to represent the thermody-namic behavior of components of solutions is the accuracy of the experimentally determined thermody-namic properties. Wagner developed the first-order free energy interaction coefficient.' Recent papers2'3 extend the treatment formally to other thermodynamic properties and define the second- and higher-order interaction coefficients. A current communication4 considers in some depth the requirements and limitations imposed because of experimental error on the use of several formalisms now under active consideration in the field. This communication reports the results of an experimental study of the behavior of oxygen in liquid silver alloys that was carried out concurrently with the development of Refs. 2 and 3 with the hope of providing sufficiently precise information so that enthalpy and entropy interaction coefficients could be determined. THE EXPERIMENTS The Sieverts technique was employed using an improved design of the reaction bulb over that developed originally by Humbert5 and subsequently improved by pehlke6 and Weinstein.7 The Vycor reaction bulb as shown in Fig. 1 was air-cooled and contained a port for the thermocouple angling off to one side and a vertical port for connections to the gas supply and

Jan 1, 1969

By W. C. Lilliendahl, H. W. Highriter

THE method developed and used in this laboratory for the production of metallic uranium of such purity that it is ductile and can be cold-worked to fine wire or thin sheet by rolling has already been described1. It consists, briefly, in the electrolysis of potassium uranous fluoride (KUF6) in a molten bath composed of equal parts of sodium and calcium chlorides. The bath is contained in a graphite crucible, electrically heated to about 775° C., the crucible serving as the anode for electrolysis. The uranium deposits in finely divided form mixed with salts upon a molybdenum cathode suspended axially in the crucible. Upon completion of the electrolysis the cathode is removed and cooled, the deposit broken and leached to remove salts. The metal powder is washed with water and dilute acetic acid and dried in vacuo to reduce oxidation. Suitable amounts are then pressed into pellets and heated in vacuo by high-frequency induction, using a thoria crucible. The uranium melts and flows away from the pellet, leaving a shell, which is largely oxide. In general, this method produced a satisfactory metal, although at times the uranium was not ductile. The investigations recorded here were made to find the cause of this embrittlement. It was known that the metal generally contained carbon, derived from disintegration of the graphite crucible in which electrolysis is conducted, in amounts dependent upon the thoroughness of washing the metal powder. Accordingly, analyses of several samples, both ductile and brittle, were made by combustion and absorption of CO2 in Ascarite, using air instead of oxygen to reduce the temperature and rate of oxidation. Several of these metals were made with special precautions to reduce carbon content. The results show no relationship between ductility and carbon content in the range investigated (Table 1).

Jan 1, 1935

By George B. Lee

DURING The Two Years In Which The New Reduction-Works Of The Copper Queen Consolidated Mining Co. Have Been In Operation At Douglas, Ariz., There Has Developed A Remarkable Condition In Regard To The Corrosive Action Of The Water Used To Cool The Jackets Of The Blast-Furnaces. Were It Not For The Many Contradictory Features, It Might Pass As One Of The Unavoidable Troubles Due To The Composition Of The Water. This Water, Obtained From Wells 600 Ft. Deep, Is Also Used In The Steam-Boilers, And Its Composition, As Shown By The Following Analysis, Does Not Indicate The Presence Of Any Ingredient Which Would Explain The Corrosion Grains Per U. S. Gal. Silica, 0.861 Iron Oxide And Alumina, 0.223 Calcium Carbonate, 0.2111 Calcium Sulphate, Magnesium Carbonate, Sodium And Potassium Sulphates, . 14.850 Sodium And Potassium Chlorides, 9.732 Sodium And Potassium Carbonate, 6.452 32.409 The Jackets Are Made Of Inner Plates 0.5 In. Thick And An Outer Plate I In. Thick, With 3-In. Stiffeners Between The Inner And Outer Plates. In From 10 To 12 Months The Inner Plates Have Been Reduced By Corrosion To A Thickness Of From 1/8 To 1/16 In., While The Outer Plate In The Same Time Is Reduced By Less Than 1/16 In., And The Stiffeners Show Very Little Corrosion. The Plates Are Pitted And Eaten Away In Some Places More Than In Others. There Is Practically No Scale Found On The Jackets, But When Cleaned Considerable Iron Oxide Is Found In The Bottoms. With An Action So Marked, Serious Trouble Would Be Expected In The Boilers, But, On The Contrary, A Recent Inspection By a

Mar 1, 1908

By T. P. Floridis

It was deemed desirable to obtain an understanding of the vacuum desulfurization process. McKechnie1 has reported that the sulfur content of nickel- and cobalt-base alloys is reduced in vacuo. Keverian and Taylor2 have observed that vacuum melting causes desulfurization of iron-carbon-silicon alloys. Garnyk and samarin3 have desulfurized transformer steel by vacuum treatment. Experiments were conducted in order to investigate the desulfurization of liquid iron under reduced pressures, and to establish the effect of some alloying elements, and various crucible materials. A vacuum-induction furnace of 50-lb capacity was used. The charge was Armco iron. Silicon was added as 90 pct ferrosilicon, carbon as electrode graphite, and aluminum as high-purity aluminum metal. Magnesia and silica crucibles were used, their inside diameters were 5 1/2 and 5 3/8 in., respectively. The temperature was measured with an optical pyrometer and it was held at 1600 1 15°C. Samples were withdrawn with quartz tubes of 6 mm ID, without disturbing the furnace atmosphere. Pressures were measured with an alphatron gage. The experimental results are shown in Fig. 1. They indicate that: 1) Sulfur can be removed from liquid iron alloys by vacuum treatment; 2) The desulfurization is enhanced by the presence of silicon, carbon, and aluminum, all these elements increase the activity of sulfur dissolved in liquid iron;4 3) The pronounced effect of silicon indicates that probably a volatile silicon sulfide is formed, Alcock and Richardson5 have observed a similar phenomenon; 4) The same rate of desulfurization was obtained when the metal was contained in either magnesia or silica crucibles. Dr. J. Keverian has contributed many discussions and recommendations. M. S. Sutliff has helped in conducting the heats. The permission of General Electric Co. for this publication is gratefully acknowledged.

Jan 1, 1960

By T. F. Witherbee

IN a paper read at the Lake Superior meeting, August, 1880, an account was given of the successful use of Rendrock and Monaky powder upon a scaffoldn and salamander in the furnace. On April 5th, 1881, the same trouble called for like treatment, which, though not so immediately. successful, was on the whole more instructive than the first trial, and points, I trust, to a reasonably sure remedy for all such difficulties. Up to December 4th, 1880, foundry and mill iron were made from Old Bed and New Bed magnetite, and Kearneyy red hematite, when a return was made to Bessemer iron, from an inferior quality of New Bed ore as compared with that used during first blast. January 18th, 1881, New Bed, Chateangay, and East-shaft, a newly-opened Bessemer deposit of Messrs. Witherbee, Sherman & Co., were first used, and continued up to February 13th, on a fuel charge of 80 per cent. anthracite and 20 per cent. coke, the product on the three ores being about 10 tons more per day than on New Bed alone. From this time until March 11th all coal was used, and New Bed, Chateangay, and East-shaft ores, up to February 22d, and from that date Chateangay and New Bed, the product falling off 9 6/10 tons per day as a result of not using coke. It is fair, however, to state that the furnace was not in good condition during' this period, being over-burdened, and the New Bed ore was, temporarily, uncommonly poor, for reasons of no particular interest here.. It required to properly flux it at least 140 per cent. of limestone; and 101 per cent was actually used. March 11th, all Chateangay ore and 80

Jan 1, 1882

By H. C. Doepken

Wrought Hadfield steel was tested in axial tension at from 100° to —196°C, to determine flow and fracture stresses as well as conventional properties. Ductility and related properties, such as fracture stress, decreased continuously with temperature. Peculiarities during straining indicated possible martensite formation or mechanical twinning. THE mechanical properties of austenitic manganese steel have been summarized by Avery and Day,' including the low temperature tensile properties reported by Hadfield and coworkers2,3 " These data show the material to be brittle at both liquid oxygen and liquid 'hydrogen temperatures. Avery and Day report considerable ductility measured by Charpy V-notch tests at —100°F (-73°C). Since the review of low temperature properties by Seigle and Brick' show face-centered cubic structures, other than Hadfield steel, to be ductile at low temperatures, it was felt that a study of tensile properties, between the reported intervals, should show whether the decrease in ductility was a gradual decline or an abrupt drop beginning at some intermediate point. X-ray examinations were made in an attempt to shed further light on the mechanism of work hardening of austenitic manganese steel. The presence of a magnetic constituent has been found by Hall" and by Avery, Homerberg, and Cook." Krivobok7 demonstrated the growth of magnetic constituents on reheating cold-worked specimens. Hadfield2,3 ' and Goss found no a iron. The steel from which the specimens were taken was commercial hot rolled % in. diam rod of electric furnace steel. The ladle analysis was as follows: C, 1.40 pct: Mn, 12.11; P, 0.060; S, 0.012; Si, 0.120; Ni, 0.080; and Cr, 0.090. Fifteen specimens, 6 in. long, were cut from a

Jan 1, 1953

By Walter L. Maxson, Fred C. Bond

There is more information contained in a screen analysis than is ordinarily recognized, and there is an increasing need for methods of making this additional information easily available. As more comprehensive studies of crushing and grinding are made, and as the possibilities of decreased expense and increased extraction through a closer control of grinding are explored, methods of interpreting screen analyses assume an importance which they have not had heretofore. The information commonly desired, which can be determined from a complete and carefully made screen analysis, includes: (1) the size distribution of the material passing the finest screen, (2) the presence of a hard grinding fraction, (3) the location of natural grain sizes, (4) the presence of different materials with markedly different grinding characteristics, (5) the presence and amount of finely divided material such as clay, which is merely unlocked in grinding, and (6) the total surface area of the ground product. It is necessary to know the fundamental law of size distribution of a homogeneous material in order to correctly resolve a screen-analysis curve, and to understand the variations and anomalies that a sample may exhibit when compared with the ideal curve. This fundamental law was developed by Gaudin,1 who showed that when the logarithm of the per cent weight retained on any screen and passing the next larger screen in the Tyler standard screen scale was plotted against the logarithm of the screen aperture the resulting curve for the finer sizes of a homogeneous crusher or grinding-mill product would be a straight line. Gross and Zimmerley2 experimentally confirmed Rittinger's law, which states that the useful work done in crushing a homogeneous material is directly proportional to the new surface area produced; and showed that in the larger screen sizes resulting from impact crushing a

Jan 1, 1935

By John L. Schroder

INTRODUCTION-SYSTEM DESIGN The design of an underground mining operation requires the integration of transportation, ventilation, ground control, and mining methods to form a system which provides the highest possible degree of safety for mine personnel; the lowest cost per ton of product ; the most suitable quality of final product, considering its intended use; the maximum percent recovery of the reserve, consistent with cost and subsidence rights ; and the minimum disturbance to the environment. The selection of mining method is generally the controlling factor in overall mine design. Some important considerations in the choice of mining method are: 1) Depth of cover over the coal seam. 2) Strength and thickness of rock strata in the overburden. 3) Characteristics of the coal seam, including thickness, nature and location of impurities or irregularities, dip (or pitch), nature and direction of cleavage, hardness, and structural strength of the coal. 4) Nature and strength of the immediate roof (top) over the coal seam. 5) Nature and strength of the floor (bottom) under the coal seam. 6) Presence and amount of explosive gas (methane). 7) Quantity of water likely to be encountered in the mining operation. 8) Any previous or concurrent mining in seams above or below the coal seam to be worked. 9) Any restrictions on recovery required for subsidence control. Topographical and geological reports and maps of the area are usually available from state and federal geological surveys, and contain excellent general information to guide more detailed investigations. Exploratory drilling, and the plotting and analysis of the information thus obtained, are essential steps in any development program, and aid in the correlation and evaluation of information gained by other means. Other good sources of information are operating coal mines that may be in the same

Jan 1, 1981

By Edward F. Divers

Face ventilation is generally the most critical area in the coal mine ventilation system. Various studies have repeatedly shown that good ventilation is by far the most effective and least costly method of controlling dust and gas problems created during face operations. The Bureau of Mines has recently developed and assisted in the development of several new concepts in face ventilation systems, and in methods to accurately evaluate these systems underground. A new type of scrubber and ventilation system design built into the auger support frame of a continu- ous miner was developed. The objective was to improve face ventilation and reduce respirable dust concentrations. With this arrangement, one scrubber is mounted into each side of the boom. Laboratory and underground tests of various scrubber discharge arrangements showed good to excellent dust and methane control. Combined face ventilation systems, using both blowing and exhaust curtain, potentially offer dust and gas control and deeper cutting. Bureau tests at a mine using a combined face ventilation system and remote- control-operated continuous miners showed excellent dust and methane control. The advancement of line curtain systems beyond permanent supports without exposing workmen to roof fall hazards can be accomplished only with specially designed extendable devices. Numerous concepts for line curtain extension have been developed and tested. For the past several years, the Bureau has been testing various types of extensible face ventilation systems. These extensible systems can generally be classified as floor-, roof-, machine-, and rib-mounted systems. In the past 6 years, approximately 40 systems have been evaluated for feasibility. From these, several have been selected as practical or innovative and are presented herein. A technique developed by the Bureau to accurately and safely evaluate the effectiveness of face ventilation is also presented.

Jan 1, 1982

THE problem of reaction rates in the open-hearth process is essentially that of trying to form a fairly clear picture of the "chemical mechanisms" in the bath. Quantitative data on reaction rates would not be very useful even if they were available; however, what few , approximate data there are, can be used in combination with data given in Chapters XVI and XVII to sketch a picture of the "chemical mechanics" of the open-hearth process that is consistent with essentially all the present available evidence. The result may later be found incorrect in many details but even so it will illustrate certain useful methods for obtaining a clearer understanding of the process. As discussed in the last portion of Chapter XIII chemical reactions in general involve the following factors: 1. The reacting molecules are mixed together in space in such fashion as to favor collisions among them. 2. A certain number of collisions occur per unit time among the reagent molecules, depending on their concentration and on temperature. 3. A certain percentage of these collisions result in reaction, these being the collisions between those molecules possessing at the moment energy levels above certain minimum values. The temperature factor enters mainly through (3), and its effect is very marked. (What is called temperature is really the mean energy content of all the molecules of the substance involved; at any one temperature a certain proportion of the molecules will have much higher energy content than the mean value.) Various reaction rates measured at around room temperatures have been found to be speeded from 1.6 to 4.0 times by an increase of only 15 to 20°F., simply because increasing temperature produces a rapidly increasing percentage of molecules with energy levels above the minimum needed to produce chemical reaction in a collision.

Jan 1, 1944

By H. M. Chance

RECENT research work has shown that coal can be produced, at reasonable cost, from almost all coal-mining districts containing not more than 3 to 8 per cent. of ash. From coal so produced, an abundant supply of coke, suitable for blast-furnace operation, can be made containing from 12 down to 6 per cent. or less of ash. These statements apply broadly to the Appalachian coal belt, including most of the mining districts in Pennsylvania, Ohio, West Virginia, Kentucky, Tennessee, and Alabama. The exceptions will generally be found among those coals carrying a prohibitive percentage of sulfur. Any gravimetric heavy fluid method of separation will effect a reduction in the percentage of sulfur, but this reduction may not be sufficient to produce, from coal unfit for metallurgic use, a product that can be so used. When a large part of the sulfur is in the form known as "organic sulfur, "or is present as very .finely disseminated and homogeneously distributed pyrite, possibly it cannot be eliminated from the low-ash coal produced. When the sulfur exists as pyrite in distinct layers, bands, or nodules, or when it is finely disseminated but is irregularly distributed, often a low-ash coal low enough in sulfur to make good metallurgic coke can be produced from relatively impure coals. It has generally been assumed that the quality of coke on which blast furnaces must be operated depends on the geographic location off the furnace, and that the grade of coke on which a blast furnace must operate is that produced from the best coal obtainable by careful mining; or if the coal is prepared by washing, hand picking, or other means by which the foreign impurities are removed, that the grade of coke on which the furnace must operate depends on what has been termed the "inherent ash" of the particular coal.

Jan 6, 1924

By W. H. Corbould

THE township of Cloncurry is situated in the northwestern part of Queensland, about latitude S. 20° 42' 53" and longitude E: 140° 30' 25". Townsville is the port through which all the trade passes and is about 470 miles east-northeast of Cloncurry township. The Cloncurry copper district covers an area about 200 miles long by 40 miles wide. Unfortunately the mines are very scattered over this area, there being no large groups of mines. Mount Elliott mine is situated about 70 miles south from the township of Cloncurry, and Mount Oxide mine about 150 miles north of Cloncurry. The district has been known for the last 35 years, and in the early stages a large amount of capital was expended with little to show for it; but within the last four years the railway has been extended from Townsville to Mount Elliott and about 40 miles north of Cloncurry, which has made possible the treatment of the ores of the mines on this extension. The Mount Elliott company within the last few years has smelted and converted on its mine 169,688 tons. of ore for 20,554 tons of blister copper, containing 20,377 tons of copper, 35,642 oz. of gold and 28,841 oz. of silver, at a cost of about £33 per ton of blister copper, f.o.b. Townsville. This cost included all ' development, wages, salaries, general management, office, agency, legal expenses, freight, etc. The gold and silver contents would practically pay for freight to Europe, refining, realization charges, etc. The costs of supplies are as follows: Firewood 15s., coke, 75s., mine timber, 54s., and coal, 60s. per long ton; explosives: dynamite and gelignite, 50s. and blasting gelatine, 65s. 6d. per case.

Jan 1, 1915

By Thomas L. Watson

The occurrence of zircon in pegmatites of acidic composition is recorded by many observers both in this country and abroad, and they form one of the most important geologic modes of occurrence of the minera1. As is well known, commercially the most important American locality for zircon is near Zirconia in Henderson County, North Carolina, where many tons of the mineral have been obtained from a kaolinized pegmatite dike 100 ft. wide and traced for 1 1/2 miles along the direction of strike N. 50" E. Zircon may be developed in pegmatites as inclusions in the principal rock-forming minerals, chiefly quartz and feldspar, and as a separate megascopic constituent in the form of grains and crystals not exceeding, as a rule, 2 in. in size, and usually smaller. In the Henderson County, North Carolina, pegmatite, zircon occurs in prismatic crystals with pyramidal terminations measuring up to 30 mm. in diameter, associated chiefly with the feldspar. In some of the apatite veins of Canada, which are closely allied to pogmatite dikes, zircon is reported in crystals upward of 6 in. in length and 2 in. and more in thickness. Zircon in large masses occurs in Virginia in the well-known pegmatites near Amelia in Amelia County, and near Gouldin in Hanover County. Both localities are in the middle eastern portion of the Piedmont Plateau province, and are separated by a distance of about 40 miles in a northeast-southwest direction. The rocks of both areas, including the pegmatite bodies, are in an advanced stage of decay, and the hard and moderately fresh rocks are concealed beneath a cover of variable thickness of rock decay derived by the normal processes of weathering. Exposures, there-

Jan 1, 1917

By F. E. Wood, H. W. Young, A. W. Buell

This paper summarizes the results of laboratory tests conducted to determine the properties of the paraffin or rod-wax encountered in the Salt Creek field, Wyoming. It also describes field tests and methods employed to cope with the paraffin problem. The conclusions to bo drawn from the laboratory work are: 1. Samples of Salt Creek paraffin range in consistency from soft lo hard, the melting points varying from 120" to 156" V. 2. Masses of soft paraffin are soluble to an appreciable extent in crude oil and its liquid fractions at temperatures somewhat below the melting point of the paraffin. Hard paraffin is very slightly soluble. under these conditions. 3. Agitation apparently increases the amount of paraffin that will go into solution. 4. Paraffin congeals from solutions upon cooling to the point of saturation ation, which is in all cnscs below thc melting point of the paraffin. 5. Crutltl oil is tlie most effective. of all the solvents for holding paraffin in solution. 6. Pressure alone does not appreciably affect the solubility of paraffin in crude oil nor does it aid materially in holding paraffin in solution when the temperature is reduced. 7. Natural gas in solution under pressure does not appreciably increase the solubility of paraffin in crude oil, hut is effective in holding paraffin in solution when the temperature is reduced. 8. A foreign body introduced into a solution of paraffin in oil is imrnediately coated with paraffin if the temperature of the solution is at or below the melting point of the paraffin, and the object is considerably cooler than the solution. It may not be entirely correct to ray that paraffin is taken into solution; it is impossible that the paraffin may be in suspension rather than in solution.

Jan 1, 1928

By M. Amsterdam, F. Rothwarf, L. Muldawer

SILVER-cadmium near the composition AgCd shows three equilibrium phases. As with 13 brass, the high temperature phase is disordered body-centered cubic (8) and the low temperature phase has the ordered CsCl structure . However, there is an intermediate temperature phase which is hexagonal close-packed ((). In a recent paper, Speich and Mack' report on a study of the Ag-Cd eutectoid near the AgCd composition. Unfortunately, the phase diagram upon which they base some of their conclusions is incorrect. That diagram is taken from the Metals Handbook' and the error is that the 0 and ( phases have been interchanged. The Handbook gives the low temperature phase as hexagonal (designated 5) and the intermediate temperature phase as cubic ordered (designated . The error may be typographical or it may be one of confusion resulting from the use of 5, ,, and 0 for the intermediate phase in various papers. A careful search of the literature reveals that a number of authors have indicated the correct relative positions of the 13, 5, and 0 phases. The comprehensive work of Fraenkel and Wolf clearly stated that the high and the low temperature phases are either identical or are very similar. olander,' on the basis of electrochemical measurements, showed that the 13 phase is disordered and the 1 phase (designated 8" in his paper and in refs. 3 and 5) is ordered. Further work by Durrant5 using thermal and metallographic analyses provided a more precise phase diagram. A summary of these works was given by Hansen6 and shows the correct relative positions of the phases. Owen, Rogers, and Guthrie7 located correctly the upper two phases by X-ray diffraction. Their failure to find the low tem-

Jan 1, 1954

By P. E. Demmler

The apparatus in which the process of bright annealing of copper wire was carried out consisted of a section of iron pipe, 6 ft. long and 3 ft. in diameter. The pipe was provided with flanges to which were bolted the end plates for sealing, also with inlet and outlet tubes to allow for the displacement of the air in the pipe by natural gas. After charging with copper wire, sealing and displacing the air, the pipe was heated to 350' C. (662" F.). It was expected that the natural gas would furnish a neutral atmosphere which would prevent oxidation and give a satisfactory bright-annealed product. It was found, however, that the outer layers of wire were discolored and not suited for the use for which they were mtended. To obtain an idea of what was taking place in the annealing furnace, skeins of the hard-drawn wire were placed in a glass tube so that all changes in appearance could be observed as they were heated to different temperatures and under varying conditions. The temperature in each case was determined by means of a thermocouple placed in the tube close to the wire. Following is a summary of the results of these experiments: 1. When the wire was heated for 1 hr. in a current of natural gas at a temperature of 350") 400") or 500" C. (662", 752", or 932" F., respectively), there was a marked darkening of the wire throughout the skein. 2. When heated for 1 hr. in natural gas at a temperature of 600" C. (1112' F.), there was no coloration, the wire remaining clean and bright. 3. When heated in natural gas to 350" C. until darkened and the treatment continued with the temperature raised to 600' C., the coloration disappeared and the wire became clean and bright.

Jan 1, 1923

By Robert Hunt

The American Institute of Mining and Metallurgical Engineers was the first American technical organization to consider steel-rail specifications and sections. If I am not mistaken, the first contribution on those subjects to the Proceedings of the Institute was presented by Prof. Thomas Egleston, in 1874, and was entitled "Investigations on Iron and Steel Rails made in Europe in the Year 1873.1" The next contribution was Dr. C. B. Dudley's report of his investigation for the Pennsylvania Railroad of the wear of steel rails in their tracks, in 1878, which contribution led to a very memorable discussion that extended through several meetings.2 In 1880, Mr. C. P. Sandberg3 presented an article on rail specifications and inspection and rail sections. This was followed, in 1881, by A. L. Holley,4 in his exhaustive report on the then used American rail sections. The next contribution, I believe, was made by myself' at the Buffalo meeting, in 1888, on steel-rail specifications, which I followed,6 in 1889, by a paper on steel-rail sections. Since that time there have been numerous contributions to the Transactions of the Institute in relation to the manufacture of steel rails. The American Society of Civil Engineers officially took up the investigation of the relation of rail sections to the wear of car wheels in 1888. In the prosecution of this work, the Society appointed a special committee, whose labors extended through several years and resulted in an exhaustive report to the Society in 1893.7 Later, another committee was appointed to consider specifications for the manufacture of steel rails; the labors of this committee extended over a period of several years, a final report8 being made in 1910. It was my fortune to be the secretary of both of those committees.

Jan 9, 1919

By P. E. Demmler

The apparatus in which the process of bright annealing of copper wire was carried out consisted of a section of iron pipe, 6 ft. long and 3 ft. in diameter. The pipe was provided with flanges to which were bolted the end plates for sealing, also with inlet and outlet tubes to allow for the displacement of the air in the pipe by natural gas. After charging with copper wire, sealing and displacing the air, the pipe was heated to 350' C. (662" F.). It was expected that the natural gas would furnish a neutral atmosphere which would prevent oxidation and give a satisfactory bright-annealed product. It was found, however, that the outer layers of wire were discolored and not suited for the use for which they were mtended. To obtain an idea of what was taking place in the annealing furnace, skeins of the hard-drawn wire were placed in a glass tube so that all changes in appearance could be observed as they were heated to different temperatures and under varying conditions. The temperature in each case was determined by means of a thermocouple placed in the tube close to the wire. Following is a summary of the results of these experiments: 1. When the wire was heated for 1 hr. in a current of natural gas at a temperature of 350") 400") or 500" C. (662", 752", or 932" F., respectively), there was a marked darkening of the wire throughout the skein. 2. When heated for 1 hr. in natural gas at a temperature of 600" C. (1112' F.), there was no coloration, the wire remaining clean and bright. 3. When heated in natural gas to 350" C. until darkened and the treatment continued with the temperature raised to 600' C., the coloration disappeared and the wire became clean and bright.

Jan 1, 1923

Charles R. Eeyes, Des Moines, Ia. (con~munication to the Secretary*):—It is not in a spirit of criticism that I offer a supplemental suggestion or two on the subjects covered by this valuable and highly instructive memoir. There are two points which, in my opinion, should have received greater emphasis in Mr. Emmons's excellent paper. One is the fundamental r6le played by the chlorides under certain conditions in ore-formation. The other is the possible establishment of geographic relationships among the four pheilomena of (1) excessive chlo-ridic content of mine-waters; (2) the abundance of chloridic compounds of the precious metals; (3) the presence of man-gancse oxides; and (4) the diminishing importance, in ore-genesis, of the metallic sulphates. Although Mr. Emmons's notes refer to gold alone, it may be pertinently asked whether the same principles do not hold good for silver and copper also, since these metals form, together with gold, a distinct and well-known chemical group. That the reactions involved apply equally well to the other two metals mentioned, is sbown by a number of recent observations and discussions. Chloridic ores of silver are, as I have lately endeavored to show, mainly worked in arid or desert regions only; and the great deposits of disseminated copper-ores are similarly characteristic of such regions, in which both classes doubtless owe their formation to the abundance of saline materials derived from desert dusts, and to the plentiful and almost universal presence of manganese oxide. Under these climatic conditions, silver is somewhat more abundantly deposited than copper and gold, because its chloride is so much less soluble. During volcanic emanations, the metallic chlorides perform at all times distinct functions; when these are

Jan 1, 1912

By T. F. Witherbee

ON the 22d of November, „1879, white iron unexpectedly appeared while working the Cedar Point Furnace, Port Henry, N Y., on the following burden, calculated to turn out mill and foundry iron: Anthracite coal, - 3000 pounds. Connellsville coke, - 1500 pounds. Total, - 4500 pounds. Old Bed ore, - 3750 pounds. New Bed fine ore, - 2000 pounds. New Bed chunk ore, - 1000 pounds. Kearnev hematite ore, - 750 pounds. Total, - 7500 pounds. Magnesian limestone, - 1865 pounds. Common limestone, - 885 pounds. Total, - 2500 pounds. The production per week since making mill iron-from September 1st, 1879, to date, seven weeks-was 412 gross tons. Ore was not immediately taken off, as nothing serious was looked for. The iron for the next week graded from No. 4 to white, and in. six days the make was 274 1/2 tons. At 10 P.M., Friday, the 28th, a slip of-..4 feet occurred, and on Saturday, at 5 A.M., another of 3 feet on the south side and. 7- feet on the north side took place. At this time it was found that the south side had been hanging for over a week--a fact which had not been reported. Throwing off the wind, to produce slips. and reduce pressure, had been tried with no effect. The stock, as seen through the tuyeres, seemed to consist almost entirely of coal, with just enough infusible cinder to cement it into a mass through which the blast could not be forced. At 3.50 A.M., Sunday, the 30th, the first cinder seen in seventeen hours came into tuyeres Nos. 1, 2, 3, and 6, At 9.30 A.M. No. 3 was taken out to see if the stock

Jan 1, 1881