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By J. Chipman, J. A. Cordier

Equilibrium in the reaction H2 (g) + 2 = H2S (g) was studied at 1600°C for sulphur dissolved in Fe-Ni alloys of 0 to 100 pct Ni. Within experimental accuracy, the equilibrium ratio pH2s/pH2 [pct S] is independent of the Fe-Ni ratio. Its variation with sulphur content is the same in nickel and the alloys as in iron. Recent data on dissociation of S2 into atomic sulphur are used to apply a small correction to earlier equilibrium data. Equations are presented which define the thermodynamic properties of sulphur in liquid Fe-Ni alloys. ACTIVITY of sulphur in liquid iron was determined by Sherman, Elvander, and Chipman.' The effects of a number of alloying elements on the activity of sulphur also have been determined, that of silicon by Morris and Williams,2 that of carbon by Morris and Buehl,8 and the effects of manganese, phosphorus, and aluminum by Sherman and Chip-man.' The data of Rosenqvist and Cox5 have been used to establish the effect of copper. A summary of all of these data is included in the paper by Sherman and Chipman. In each case, the experimental method depended upon the study of equilibruim in the reaction of sulphur in the liquid metal with hydrogen gas to form H,S. Despite wide differences in the design of apparatus used by the several investigators, all of the results are in excellent agreement. Experimental Study Since the experimental method has already been described,' it will be sufficient to mention its general

Jan 1, 1956

PENNSYLVANIA ANTHRACITE LOCAL SECTION On Saturday evening, Jan. 31, 1914, about 40 members of the Institute met at the Hotel Sterling, Wilkes Barre, Pa., for the purpose of discussing plans for the formation of a local section in the Pennsylvania anthracite region. President Rand; Prof. Joseph W. Richards, of the Board of Directors; Dr. H. M. Chance, Chairman of the Committee on Coal and Coke, and Secretary Stoughton were among the guests present. R. V. Norris acted as Master of Ceremonies, and the arrangements were all made in advance by a Committee under the leadership of Charles Enzian, to whom an enthusiastic vote of thanks was accorded at the dinner. An address was made by President Rand, followed by .Professor Richards, who outlined the procedure necessary for the formation of a Local Section. Addresses were then made by W. J. Richards, F. W. Chase,. C. F. Huber, R. J. Foster, F. A. Hill, H. M. Chance, Bradley Stoughton, and others, after which a rising vote was taken, and it was unanimously decided to petition the Board of. Directors for the establishment of the Pennsylvania -Anthracite Local Section. More than the required number of members then signed -the petition, and President Rand announced the appointment of a Committee to organize the Section and arrange for a meeting in accordance with their By-Laws, consisting of R. V. Norris, W. J. Richards, R. J. Foster, Edwin Ludlow, C. F. Huber, Charles Enzian, Douglas Bunting, F. A. Hill, and J. M. Humphrey.

Jan 2, 1914

By C. E. Wethered

THE Morning mine is operated through one main working adit, known as No. 6 or 800 tunnel level. At a distance of 10,000 ft. underground from the portal is the vertical four-compartment, main working shaft, which extends to the 3050 level, a distance of 2250 ft. below the collar, or 800 level. Shaft-stations are cut and levels opened every 200 ft. of depth and the ore is stoped to the next level above. The vein is nearly vertical and the ore is usually fairly massive and brittle. Both walls are soft and slabby and much difficulty is therefore experienced in holding them. Stopes are usually carried up in short sections, approximately 200 ft. in length, that are mined as rapidly as possible in order to avoid a too great replacement or repair of stope timbers. The four-compartment vertical shaft, 110 ft. in the footwall of the vein, is the sole medium of outlet for all ore mined below the adit level. Two compartments of this shaft are used exclusively for hoisting ore, except at the time of changing shifts, when one compartment is used to handle some of the men and timber. The third compartment is equipped for handling men, tim-ber and all general supplies and is operated by a Nord-berg 300-hp. electric hoist. This hoist has a lifting ca-pacity of 14,000 lb. with an average rope speed of 800 ft. per minute. The fourth compartment is used solely as a manway and pipeway.

Jan 7, 1927

By Jan M. Mutmansky

A knowledge of rock characteristics forms the foundation for the application of rock mechanics to engineering works. Hence, there has been an increased interest in the determination and proper utilization of rock properties data. Most numerical values quoted for rock properties are obtained from arbitrary tests and are not necessarily indicative of any intrinsic rock characteristics. Recent attempts to correlate these properties by statistical methods have attracted considerable attention, in the hope that these might give some clue to the fundamental properties. To date, correlation and regression techniques have been employed for this purpose. The use of statistics has also been deemed appropriate because of inhomogeneity and anisotropy in rocks. The problems have been further compounded by the lack of standardized methods of measuring rock properties. The various ASTM committees are still deliberating on these matters, but recommendations should be forthcoming in the near future. As more reliable data become available, the ability of geoscientists to find more meaningful relationships between rock properties will be greatly enhanced. The objective of this paper is to outline another statistical technique which might be useful in providing an insight into the relationships that exist between rock properties. This method does not attempt to predict rock characteristics, but rather compares the similarity or dissimilarity between properties. This enables rock properties to be classified into groups with similar intrinsic characteristics. The technique described is one form of factor analysis. It allows the results obtained to be depicted geometrically, so as to make ready visual examination possible.

Jan 1, 1968

Sulfuric Acid and Phosphate Industries at Anaconda Reduction Works. BY E L LARISON (Contribution 70-Preprint 4400 words) In 1915 a 135-ton chamber sulfuric acid plant was built at the Anaconda Reduction Works to supply acid for leaching sand tailing Sulfur dioxide was obtained by roasting copper table concentrate Soon after, the flotation process, using acid as a reagent, together with development of a leaching and electrolytic process for zinc recovery, necessitated building a second acid unit of 50 tons' per day capacity, completed in 1917 Within a few months the zinc process was so improved as to consume no added acid Mean¬while research work was in progress on production of phosphate fertilizers using sulfuric acid and Idaho phosphate rock In 1920 a pilot plant was put into operation which treated 50 tons per day of phosphate rock to produce treble superphosphate containing 45 per cent available P205 In 1922 the original plant and process for leaching of sand tailing were abandoned in favor of a combination leaching and flota¬tion process In 1923 the sand leaching plant was remodeled into a treble super¬phosphate plant designed to treat 160 tons per day of phosphate rock. In 1924 the copper flotation process was put on alkaline circuit and acid, has not since been used as a reagent Practically all the acid produced is now used for making phos¬phate products In 1931 the use of copper concentrate as a source of sulfur dioxide was abandoned and an iron concentrate, floated from the copper concentrator tail¬ing, substituted

Jan 1, 1935

By P. J. Conroy, E. A. Curth

INTRODUCTION In June 1962, the first attempt at longwall mining in Illinois was initiated by Old Ben Coal Company in their No. 21 Mine. Longwalling was continued intermittently using various supports until April 1970. During this period, longwall mining techniques were used on separate occasions at six faces within Mine No. 21. However, due to various problems that developed at each location the faces were eventually terminated. The most significant problems concerned the support systems and roof conditions that were present in the mine during each attempt. Between 1965 and 1972, similar conditions were met by Freeman Coal mining Company during four attempts at longwall mining in their Orient No. 5 and Orient No. 6 mines. In 1975, the U.S. Bureau of Mines and Old Ben Coal Company entered into a cost-sharing agreement to demonstrate the application of longwall mining in Illinois. The first phase of the demonstration was to conduct a premining investigation to review previous attempts at longwall mining, perform rock mechanics tests, and establish support requirements based on the lnvestigation results. The information obtained during the demonstration at Old Ben's No. 24 has been utilized to optimize subsequent face equipment and panel geometry. Mining of the first panel began in September 1976 and was successfully completed in May 1977, and two additional panels were mined under the cooperative agreement. Currently, Old Ben Coal Company is the only longwall mining operator in Illinois. In addition to the face in Mine No. 24, five longwall faces are being operated in four other mines.

Jan 1, 1981

By John W. Vanderwilt

THE fluorescence of scheelite has been an important aid in recent years in the discovery and development of scheelite deposits. The use of fluorescence of synthetic compounds in industry, particularly in advertising, also has expanded greatly during the past decade. As a result, a number of new and convenient units for producing ultraviolet energy have become available, which have led to a greater application of fluorescence in the study of minerals. Studies have shown that the fluorescent color of a mineral may vary: (I) with the kind and quantity of trace elements, and (2) with the particular wave length of ultraviolet energy used. The wave length is dependent first on the type of generating equipment used, and finally on the filter employed to remove the visible light that may be present. A number of so-called ultraviolet lamps are listed and described, together with suitable filters known to be available. Scheelite fluoresces brilliantly with wave lengths of 2200 to about 3000Å., but not with longer wave lengths. The most convenient and efficient sources of ultraviolet for scheelite fluorescence- are portable and laboratory units designed particularly for use with scheelite. So-called ultraviolet light globes of the photo-flood type emit wave lengths too long to cause scheelite to fluoresce. Attention is called to the minerals that fluoresce in a manner similar to scheelite, which necessitates a check test by means of characteristic physical properties. Chemical tests are the final authority both for identity and content of tungsten in scheelite ore.

Jan 1, 1946

THE Rocky MountainClub brought into the East the spirit of the West; the impulse to build, to develop, to accept unquestion-ingly the comradeship and help of any straight shooter who had it in him to accom-plish things and a will to work. That this was the spirit of the Club was due to its leaders. It was their spirit and they attracted around them men of the same stamp. Among those who made the Club what it was no one had larger in-low fluence than William Boyce Thompson, the vice-president and chief of financial staff. It was characteristic of him that the same financial genius that was employed in building up Nevada Consolidated, In-spiration, Magma, Texas Gulf, and as director of the Metro-politan Life and the Federal Reserve Bank, was freely placed at the service of the Club. It was equally char- acteristic that the generosity that financed the Red Cross Mission to Russia inspired the use of the Club funds for Belgian and war relief. "W. B.," as he is known to his many friends, was born at Virginia City in Alder Gulch, Mont., on May 13, 1869. His father, William Thompson, born at Cobourg, Ont., had drifted into the old Northwest and, hearing at Yankton of the gold strike at Bannack, crossed the plains on the Oregon trail in the summer of 1863, arriv-ing in Alder Gulch at the inception of a mining boom that lasted several years, during which something like $60,000,000 in gold was yielded by the placer diggings. His mother was a daughter of Maj. James R. Boyce, Sr., from Logan County, Ky., who had served under General Sterling Price of the Confederate Army. Major Boyce's ancestors were early settlers of the Old Dominion, and his grandfather had seen military service in the war for American independence. Major Boyce's mother was a descendant of the Marshall and Smith families of Westmoreland County, Va. When Thompson was eleven years old, the family moved to Butte, then a silver camp. He attended the public schools of Butte, but desiring a better education, entered Phillips Exeter Academy and later the Colum-bia School of Mines. Returning West, for a year or two he ran the Boulder Chief mine near Basin, Mont., which earned him a sobriquet, "Boulder Thompson." While here, some old ore sacks, oil-soaked, introduced him to flotation. He was also the first to leach some of the ore dumps of Butte.

Jan 4, 1928

At the University Club, New York, Jan. 23, Chairman George E. Hale and other officers of the National Research Council, gave a dinner to officers of the national engineering and other societies. About thirty persons were present, including officers of the National Research Council, the four Founder Societies, American Society for Testing Materials, Society of Automotive Engineers, Inc., Illuminating Engineering Society, United Engineering Society, and Engineering Foundation. Letters were received from the Western Society of Engineers, which also had been invited. Gano Dunn, vice-chairman of National Research Council, was toastmaster. The proposed permanent organization of the National Research Council and possible methods of connection with the national engineering societies, either directly or through Engineering Foundation, were outlined. It was suggested that not only the four Founder Societies be represented in the Engineering Division of National Research Council, but also that the other national engineering societies be admitted to membership. It was proposed that the Engineering Division should have a chairman who should be an engineer of wide reputation and of the highest professional attainments who should devote his whole time to the establishment and development of the Division. Methods of organizing industrial research were discussed. At a subsequent meeting of the National Research Council, an invitation was issued to each of the national societies to form a research committee encouraging that committee to become active in the promotion of research within its respective field. Due recognition is to be given each committee in the general organization of the National Research Council. Dr. H. M. Howe, in a very interesting and comprehensive address, told of much important work that had been clone by the various sections of the Research Council, as that of mechanical engineering in developing the often rather nebulous devices for helping win the war and putting them in such form that they could be of direct use to the military service. The section on metallurgy, till lately under Bradley Stoughton and now under G. H. Clevenger, did much valuable work in the improvement of helmets and body armor and made very extensive ballistic tests with refractory steels for this purpose. Important work was done in investigating the fatigue of metals and results of great moment were achieved. The committee on ferro-alloys, under J. E. Johnson, Jr., did important work in effecting economy of manganese in steel manufacture with a view to reducing the necessity for importation of manganese ore, thus releasing ships for other purposes. , The section on electric welding has accomplished valuable results in the development of electric welding for ships, a new branch of industry of very great promise.

Jan 3, 1919

The cut-and-fill mining methods in use in the mines of The International Nickel Company of Canada Limited, at Falconbridge Nickel Mines Limited, in the Sudbury District, and at McIntyre Porcupine Mines Limited in the Porcupine District, are typical of the general cut-and-fill practice in both the base-metal mines and the gold mines in the Province of Ontario. The following pages describe the methods in use. HORIZONTAL CUT-AND-FILL STOPING Horizontal cut-and-fill stoping, as practiced in the mines of The International Nickel Company of Canada Limited, falls into two main classifications: (I) transverse cut-and-fill stoping, where ground conditions or wide ore bodies make it necessary to establish narrow stopes and pillars across the width of the ore body; (2) longitudinal cut-and-fill stoping where ore body widths and ground conditions allow safe mining of the full width of the ore body. Transverse Cut-and-fill StopiNg General Stoping Layouts Stope and Pillar Widhs.—For transverse stoping, experience has indicated that narrow stopes and pillars, 27 ft. 6 in and 22 ft., respectively, are most satisfactory. These width are multiples of 5 ft. 6 in., which is the center to center dimension of a standard square set. Thus any stope, or block of stopes, can be readily converted from cut-and-fill to square set-and-fill if ground conditions should warrant such a change. Formerly, pillars were established 16 ft. 6 in. wide, the equivalent of the width of three square sets, with the intention of extracting the pillars by mining an overhand slice one set wide and an underhand slice two sets wide. However, subsequent experience proved that a two-set overhand slice is so much more efficiently mined than a one-set slice, and 22-ft. pillars have been made standard. Chutes.—The stope chutes are established on the longitudinal center line of the stopes and are spaced at 22-ft. centers from footwall to hanging wall. The footwall chute is usually from 5 to 10 ft. from the footwall of the stope. It is offset where necessary at an angle of 52° and vertical chutes are carried from the offset at 22-ft. centers. In sections of the ore body where a flat hanging wall would cut off hanging-wall chutes within a few cuts of the sill, it has proved to be more economical to use temporary chutes or slushers, or both, for these first few cuts, rather than to el permanent chutes at the hanging wall.

Jan 1, 1946

By M. Otogawa

TsunashiRo Wada, honorary member of the Institute, died at his residence, Ushigome, in Tokyo, on Dec. 20, 1920, at the age of sixty-four; he was born on March 15, 1856, at Obana in the province of Wakasa. An expert mineralogist, lithologist and geologist, he identified himself throughout his life with the development of the mining interest of this country. Perhaps the most noteworthy of his meritorious services in the public sense was the extension of the Imperial Steel Works at Yawata, anticipating the grim fate that hurled Japan. into a war with Russia in 1904. Educated in the Imperial University of Tokyo by foreign professors, he studied especially mineralogy, lithology and geology. In 1875 he was appointed assistant professor in the Imperial University of Tokyo, and in 1878 entered the service of the Home Department. From 1880 until 1893, Mr. Wada was Director of the Imperial Geological Survey of Japan, during which time he practically laid the foundation of the geological investigation work in Japan. In 1884, he made a trip to Europe by government order to attend the international Congress in Berlin, visiting en route several countries of Europe and America. While Director of the Survey, he was also, from 1880 to 1885, lecturer, and from 1885 to 1891, professor of mineralogy and lithology in the Imperial University, and, from 1889 to 1893, was Director of the Imperial Mining Bureau of Japan. In this capacity, he revised the mining laws of Japan, thus laying the foundation of Japan's mining administration. In 1894, he was again appointed lecturer in the Imperial University of Tokyo; in 1895, appointed Technical Adviser on Mines to the Imperial Household Department of Japan; and, in 1897, appointed President of the Imperial Steel Works, which was completed in 1900 with the expenditure of $10,000,000. In this capacity he did a great deal to promote the iron and. steel industry of this country. We owe him the ore-purchase contract with the Daiya iron mine in China, which remarkably facilitated the extension of the iron works in later days. The victory of the Russo-Japanese war must be said to be due to his merit in no small measure. He resigned the presidency of the Imperial Steel Works in 1901. In 1899, Mr. Wada visited America and several countries of Europe by government order; in 1902, he traveled through north and middle China doing exploration work and studying the geology of the country, accompanied by mining engineers and geologists. From 1896 to 1908, Mr. Wada was president and honorary member of

Jan 1, 1922

By M. Otogawa

TsunashiRo Wada, honorary member of the Institute, died at his residence, Ushigome, in Tokyo, on Dec. 20, 1920, at the age of sixty-four; he was born on March 15, 1856, at Obana in the province of Wakasa. An expert mineralogist, lithologist and geologist, he identified himself throughout his life with the development of the mining interest of this country. Perhaps the most noteworthy of his meritorious services in the public sense was the extension of the Imperial Steel Works at Yawata, anticipating the grim fate that hurled Japan. into a war with Russia in 1904. Educated in the Imperial University of Tokyo by foreign professors, he studied especially mineralogy, lithology and geology. In 1875 he was appointed assistant professor in the Imperial University of Tokyo, and in 1878 entered the service of the Home Department. From 1880 until 1893, Mr. Wada was Director of the Imperial Geological Survey of Japan, during which time he practically laid the foundation of the geological investigation work in Japan. In 1884, he made a trip to Europe by government order to attend the international Congress in Berlin, visiting en route several countries of Europe and America. While Director of the Survey, he was also, from 1880 to 1885, lecturer, and from 1885 to 1891, professor of mineralogy and lithology in the Imperial University, and, from 1889 to 1893, was Director of the Imperial Mining Bureau of Japan. In this capacity, he revised the mining laws of Japan, thus laying the foundation of Japan's mining administration. In 1894, he was again appointed lecturer in the Imperial University of Tokyo; in 1895, appointed Technical Adviser on Mines to the Imperial Household Department of Japan; and, in 1897, appointed President of the Imperial Steel Works, which was completed in 1900 with the expenditure of $10,000,000. In this capacity he did a great deal to promote the iron and. steel industry of this country. We owe him the ore-purchase contract with the Daiya iron mine in China, which remarkably facilitated the extension of the iron works in later days. The victory of the Russo-Japanese war must be said to be due to his merit in no small measure. He resigned the presidency of the Imperial Steel Works in 1901. In 1899, Mr. Wada visited America and several countries of Europe by government order; in 1902, he traveled through north and middle China doing exploration work and studying the geology of the country, accompanied by mining engineers and geologists. From 1896 to 1908, Mr. Wada was president and honorary member of

Jan 1, 1922

By E. P. Mathewson

DURING the past 35 years it has been my privilege to deal with hundreds of recent graduates from engineering schools all over the world. In consequence, I, feel that I have learned something about the training of, engineering students. In the first place, I believe that too great specializa-tion is a mistake. A student should receive general training in engineering for at least three out of the four years of the course, and any specializing that may be required should come in the fourth year. Too great emphasis can not be laid upon the fact that the four years' training does not make an engineer; on the contrary, the graduate is only fitted to enter the pro-fession. He becomes an engineer in the true sense of the word only after years of practice; the college train-ing merely shows him where to look for information and develops his intellectual powers. Some of our engineering schools have lengthened the term of study to five years and talk of increasing it still further. This, in my opinion, is a mistake. A young man who spends more than four years in college is apt to become too academic and theoretical. It is better to stiffen the matriculation examinations than to prolong the years of study in college. No matter how good the faculty may be and how carefully selected the course of study, the graduate can never become an engineer unless he has some natural qualifications for the vocation. There are one or two subjects in which most recent graduates seem to be weak; these are accounting, the command of English, and training in the writing of reports. A short course in general accounting should always be included in the curriculum. To this should be added instruction in the preparation of estimates and cost statements. In making reports it should be borne in mind that these reports are to be submitted to busy men,-and not to technical men. The busy man wants the gist of the report summarized on the front page of the report. He wants to know that if he expends a certain sum of money in a certain way, he will get certain results and make so much profit. This should be put clearly before him in short statements, free from technical terms. The details of the report can follow .at greater length; it should be remembered that the employer is not going to read these details, but will confine his attention to the summary.

Jan 1, 1923

By S. S. Clarke

THEN sufficient ore has been blocked out on a lease to warrant a shaft, the proposed. Location of the shaft should be carefully considered, as the old promoter's method of sinking wherever his hat landed is a sad mistake as some: of us have learned by trying to operate such mines. In some instances certain conditions exist, such as mill location, railroad right of way, etc., that necessitate a change of location from the. ideal, but under average conditions and with the knowledge of the formation gained from the drill logs and with the general trend of the orebody known, the shaft can be located from. the standpoint of its future relation to the mine with re-gard to hauling and' hoisting a maximum tonnage: at a minimum cost per ton, also taking into account the minimum amount of expense and trouble- in sinking. Quite a few shafts are located in the wall of a run or just in the thin edge of the orebody: As a general rule the formation here is solid and permits rapid and safe sinking, and the shaft pillars are left in practically valueless material. This permits the withdrawal of pillars and still keeps the shaft protected. By opening a shaft in thin ground, you are not tempted to cut it high, wide, and handsome, but to shape it up-with ample clearance for lay-bys and with more of an idea of permanency, as a few hundred extra dollars spent around the shafts for proper track installation will re-turn, a good rate of interest in ease of handling "cans," quick get-away; and fewer wrecks. Nearly all the shafts in this district are sunk on a contract basis, the con-tractors furnishing all labor and explosives, and the company building the sinking-derrick, dump-track, and furnishing, all equipment, material, and power. The following costs are the averages, for three shafts sunk through good solid formation, with no water to, contend with, and approximately 260 -ft., deep, having about-100 ft. of shale. The contract price was $9 per foot with the shale and $13 per foot in the solid, making a total of $2,980 paid to the contractor. The wages paid by the contractor were, $5 per shift for the hoist-man, who also sharpened steel, $6 for the lead shaft man, and $5 for the helper;, the cribbing was sawed on contract for 40c. per shaft: foot; about. 94 board feet. of cribbing was used per foot of staggered cribbing and 168 board feet per foot of solid cribbing.

Jan 8, 1928

By W. P. Blake

FORGING under the hydraulic press, which was introduced by Haswell in the year 1861, at the machine shops of the Imperial State Railway Company of Austria, has since been greatly improved, so that at the present time there are very few parts of machines which cannot be produced in this way, and at no greater cost than iron castings. The process is now used at Vienna chiefly for such parts of locomotives as cross-heads, link-bars, axle-box frames, etc., especially where the form is intricate, and there are many angles and projections. These objects weigh from 50 to 150 lb. or more, and it is claimed for them that they are not only much cheaper than ordinary forgings, but are much more regular in form and stronger. The results which Mr. Haswell has attained, after years of patient experimenting, were well shown in the Austrian Department of the Vienna Exhibition by a collection of the pressed objects in iron and steel, just as they left the moulds, with some of them cut asunder longitudinally and the surfaces etched, so as to show the internal structure or direction of the grain. Through the courtesy of Mr. Haswell and his son I saw the hydraulic presses in full operation at the works, drawing down large Bessemer ingots, cutting them up into blocks of convenient size, and forming various parts of locomotives. They have two large hydraulic presses in use; the largest, with a piston 24 inches diameter, gives 1200 tons pressure, and the second, with an 18-inch piston, gives 600 tons pressure. The pressure in the pumps is 600 atmospheres. The action is vertical ; the piston descends upon the work, and for forging ingots is armed with a hammer-like head. An ingot of No. 7 soft Bessemer steel, which was forged in my presence, weighed 2030 lbs. One end being placed upon the anvil, the piston is brought slowly down and crowded into the mass as if it were putty or dough, forcing it each way, but chiefly in the direction of the length of the ingot, this being the narrowest section of the anvil and hammer. The piston is then raised and the ingot is moved forward for a second squeeze, and so on, until the first half of the ingot has been reduced in thickness, when it is turned on edge and the operation is repeated. The ingot is then turned end for end and forged until the whole length has been re-

Jan 1, 1874

By Clarence Zener

IT has long been known that the density of a metal usually decreases with cold-work. Thus O'Neilll observed as early as 1861 that cold hammering of commercial hot-rolled copper is accompanied by a decrease of density of 0.2 per cent, and that subsequent annealing restores the original density. The origin of this density change, however, has remained obscure. In particular, experiment has not yet decided whether it is due to the presence of small cavities and an increase in inter-granular surface or to an actual expansion of the lattice itself. This uncertainty in the origin of the change in density is a reflection of our uncertainty as to the changes induced in a metal by cold-working. One school regards cold-working as a breaking up of the original grains into a large number of perfect crystallites somewhat randomly orientated with respect to one another.2 According to this viewpoint, the mere introduction of a large intercrystallite surface induces a net volume expansion. Another school regards cold-working primarily as a distortion of the grains. It is not obvious that this second viewpoint will lead to a net volume expansion. The purpose of the present paper is to show that this is indeed the case, and that this expansion is of the right order of magnitude to explain existing experimental data. The physical basis for the association of an expansion with distortion lies essentially in the variation of the elastic moduli with volume. This variation is considerable. Thus from Table I we see that a I per cent increase in volume for the case of copper will decrease the bulk modulus K by 10 per cent, the shearing modulus µ by 3.8 per cent. If we thus twist a rod through a given angle, we shall do less work upon it if it increases slightly in volume, thereby reducing the torsion modulus that involves as a factor the shearing modulus. A general principle3 in physics states that the rod will so adjust itself as to have a minimum potential energy consistent with the end restraints. It will therefore expand. In order to obtain a quantitative comparison with experiment, we follow Maier4 in comparing the lattice expansion with the latent energy of cold-work. This latent energy has been measured directly by Taylor and Quinney5 on copper rods subjected to torsion, and may amount to as much as 15 per cent of the total work done upon the specimens. We shall assume that this

Jan 1, 1942

By Clarence Zener

IT has long been known that the density of a metal usually decreases with cold-work. Thus O'Neilll observed as early as 1861 that cold hammering of commercial hot-rolled copper is accompanied by a decrease of density of 0.2 per cent, and that subsequent annealing restores the original density. The origin of this density change, however, has remained obscure. In particular, experiment has not yet decided whether it is due to the presence of small cavities and an increase in inter-granular surface or to an actual expansion of the lattice itself. This uncertainty in the origin of the change in density is a reflection of our uncertainty as to the changes induced in a metal by cold-working. One school regards cold-working as a breaking up of the original grains into a large number of perfect crystallites somewhat randomly orientated with respect to one another.2 According to this viewpoint, the mere introduction of a large intercrystallite surface induces a net volume expansion. Another school regards cold-working primarily as a distortion of the grains. It is not obvious that this second viewpoint will lead to a net volume expansion. The purpose of the present paper is to show that this is indeed the case, and that this expansion is of the right order of magnitude to explain existing experimental data. The physical basis for the association of an expansion with distortion lies essentially in the variation of the elastic moduli with volume. This variation is considerable. Thus from Table I we see that a I per cent increase in volume for the case of copper will decrease the bulk modulus K by 10 per cent, the shearing modulus µ by 3.8 per cent. If we thus twist a rod through a given angle, we shall do less work upon it if it increases slightly in volume, thereby reducing the torsion modulus that involves as a factor the shearing modulus. A general principle3 in physics states that the rod will so adjust itself as to have a minimum potential energy consistent with the end restraints. It will therefore expand. In order to obtain a quantitative comparison with experiment, we follow Maier4 in comparing the lattice expansion with the latent energy of cold-work. This latent energy has been measured directly by Taylor and Quinney5 on copper rods subjected to torsion, and may amount to as much as 15 per cent of the total work done upon the specimens. We shall assume that this

Jan 1, 1942

By R. W. Raymond

I HAVE the pleasure of exhibiting samples of the rock in which the South African diamonds are said to occur, for which I am in debted to Mr. Franz Groeger, of Vienna, formerly an assistant of the Royal Imperial Geological Institution, whose account of the general geology of Southern Africa was contained in a recent number of the proceedings of that Institution. The rock is apparently a sort of tufa, evidently of volcanic origin. Mr. Groeger assured me that it could be seen in situ, bounded by uplifted stratified rocks; and that diamonds had been mined from it, by means of shafts, some distance below the surface. Groeger calls it "greenstone-tufa," and says of it, in the proceedings of the Geological Institution, " it breaks through the younger members of Group III [lower Trias and Jura], . . .. and crops out in oval masses, filling fissures . . ..The occurrence of this tufa is not locally limited, but has been traced and proved already over a large territory." DR. HUNT remarked that the material looked like the trass of the Rhine region. He thought it a new occurrence for diamonds. He believed diamonds to belong to ancient crystalline rocks, although these materials might be brought tip by volcanic agency, and the diamonds remain unaltered. In the volcanic rocks of Auvergne, crystals of sapphire, zircon, and spinel are found; and yet no one supposes that these minerals have been generated by volcanic agency. He had had a conversation with Bertrand de Lom on this subject, who agreed with him that these minerals, being hard and resistant,

Jan 1, 1874

By L. B. Lindemuth

TO those who are in a position to carry the thought to a conclusion, I would like to present a theory of the cause of blisters in ' galvanized sheets. Blisters that are caused from piping and shrinkage cavities will not be considered, because the reason for their formation is entirely obvious. Blisters that periodically occur, with no apparent system of location, number, size or grouping, and then disappear with no apparent change in manufacturing method, are the ones to which this theory would apply. Examination of blisters of the latter type has shown that they contain hydrogen gas at atmospheric pres-sure, and that occasionally traces of oxide or sulfide are found on the inner surface of the blisters. These two characteristics have led to the rather general idea that hydrogen gas generated in pickling, and that iron oxide supposed to be inherent in the ingot and causing weak spots, were, in some manner, responsible for the development of blisters in galvanizing. The theory which I wish to advance is that these blisters are caused by moisture that has penetrated the steel after the annealing operation. This moisture comes from the atmosphere, or from pickling or wash-ing, and when it is suddenly expanded into superheated steam in galvanizing, the increase in volume is so great that it cannot escape with sufficient rapidity through the small opening which it entered as moisture. The pressure so generated forces the sheet apart along those lines of lamination that may be found in practically all flat sections of steel rolled comparatively cold.

Jan 5, 1927

By D. Harrington

TheRe has been, during the past year, a wealth of report data and discussion relating directly or indirectly to various phases of ventilation of metal mines, and many of the data are from foreign sources. The phase of the subject most generously accorded the attention of the technical press is that of cooling mine air, with much less attention to other fairly intimately associated features such as fan performance, friction factors, fires, mine gases, mine lighting, health of miners, and ventilation standards. Cooling Mine Air South Africa, with its very deep mining on the Rand and with fairly high working temperatures, 'contributes the most definite data on the subject of cooling mine air, and undoubtedly the most interesting issued are those from a paper by J. H. Dobson,' in which he gives a comprehensive review of the subject as gleaned largely by analyzing the data in three papers.2 Dr. Dobson's summation is decidedly interesting. In general it is recognized that the introducing into the mine and circulating to the working places of large volumes of pure air is the most effective method of giving deep, hot metal-mine workings reasonably efficient working conditions. A tabulation as to the cost of securing various amounts of cooling by circulating various volumes, from 230,000 to 760,000 cu. ft. per min., indicates that there are cost limits beyond which increase of quantity of air in circulation is impracticable, as the annual cost of circulating 230,000 cu. ft. of air per min. in a certain mine at a depth of

Jan 1, 1928