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By W. C. Elli, M. E. Fine

YOUNG'S modulus of elasticity in metals ordinarily decreases with rising temperature. The range of the thermoelastic coefficient at room tem- 1/E dE/dT perature (temperature coefficient of modulus, is illustrated1 by the values for tungsten and hard-drawn aluminum, —95 and —1220x10-6 eg C-1. However, a nearly zero thermoelastic coefficient is observed in some ferromagnetic alloys over a limited temperature range. In these alloys, as the temperature is raised, an increase in modulus arising from loss of ferromagnetism compensates the normal decrease. Iron-nickel alloys containing 36 to 52 pct Ni behave in this manner. In the present investiga- tion, the dependence of the modulus and thermo-elastic coefficient on cold working and annealing were studied in iron-nickel alloys in this range of nickel. Although these alloys, when fully annealed, have a coefficient near zero over a very small temperature interval, the temperature range of low coefficient can be extended greatly by straining and then stress-relief annealing. The modulus of face-centered cubic iron-nickel alloys annealed at 1000°C does not vary linearly with composition at room temperature but, as shown by the solid line of fig. 1, from Koster,' is minimum at 40 pct Ni and maximum at 87 pct Ni. The modulus increases with applied magnetic field but retains the minimum near 40 pct Ni. Schematic change of modulus with temperature for three compositions is shown in fig. 2.'. ' With increasing temperature, the slope becomes less negative, goes through zero (temperature of minimum modulus for the alloy), becomes positive, and resumes its normal negative value above the Curie

Jan 1, 1951

By W. S. Potter

THE proportions of manganese and carbon in manganese steel are familiar to all, because manganese-steel castings have been well known for a decade or more in this country. The same alloy has now become a commercial product in the wrought state, and, as not only rails and bars are rolled daily but a great variety of forged and otherwise fabricated shapes are appearing, it may be interesting to mark the progress and, perhaps, to look a little closely into the nature of this important material of engineering.

Jan 4, 1914

By C. K. Leith

CERTAIN ideas on iron and steel sanctions to follow originated in a series of conferences held under the joint auspices of the War Department and Brookings Institute in Washington last spring. The views presented may be regarded as those of substantial segments of the steel industry. In view of the fact that steelmaking capacity can be so quickly converted to the production of armament, any effective control must necessarily include the entire steel industry and not solely the parts devoted to the production of implements of war. It must also be exercised all the way from production and shipment of raw materials through their ultimate conversion into finished products and use. Control will be dis- cussed under two main headings: (I) control of raw materials at the source; (2) control of steel capacity within the Axis countries.

Jan 1, 1944

IN the early period of steelmaking, ingot structure and segregation were of no practical importance. Crucible melting required very small ingots that gave little segregation, and a small inserted hot top prevented pipe. As larger ingots were poured from bessemer converters and open-hearth furnaces, segrega- [ ] tion, piping, and gas evolution became increasingly important. The techniques of making semikilled and rimmed ingots were developed with little knowledge of the actual mechanism of the process. The first studies of solidification were made by the Brearleys1 and Gathmann,2- who used stearine to show the effects of shrinkage and mold shape. Fig 11-1 is a picture of a series of stearine ingots at various stages of solidification. These studies showed that the liquid solidifies at a nearly uniform rate from the sides and bottom of the mold and demonstrated the formation of

Jan 1, 1964

By C. E. McWhorter

IN underground mining recent trends toward mining large tonnages of low-grade ore have created, among other things, a need for cheaper and more flexible ore transport. A relatively new development has been the adaptation of shaker conveyors to meet this need. Although widely used in coal mining, only in the last few years have shaker conveyors been used in underground metal mining. The equipment consists of a driving engine, either electric or air powered, upon which is mounted a drive trough supported in ball-bearing frames. The trough line, or conveying medium, is made up of a number of sections, each section connected to another, usually with bolts. The length of each trough section is controlled by the length that can best be handled underground, but is usually from 9 to 13 ft over-all. The length of a complete conveyor line is determined by the character and weight of material to be handled as well as by the size of the ore body. Trough lines vary in lengths from 100 to 300 ft and the trough has a cross-section area of 127 sq in., and is 22 in. wide by 6 ½ in. deep.

Jan 1, 1948

By H. W. Young

DEVELOPMENT of high-tension outdoor substations during the past few years has been due primarily to economic reasons. The demand for power in small communities could not be met with the conventional and 1 FIG. 1.-33,000-VOLT STEP-UP OUTDOOR AIR-BREAK SWITCH AND SUBSTATION INSTALLATION OUTSIDE OF A POWERHOUSE GENERATING AT 2300 VOLTS STEPPING UP TO 33,000. TWENTY-ONE COAL MINES ARE SUPPLIED FROM LINES LEADING FROM THIS INSTALLATION. comparatively expensive indoor types unless the rate for service was materially increased. That the various problems incident to development have been solved successfully, it is only necessary to point to the

Jan 9, 1919

By Ogden B. Malin

In conducting the manufacture of extruded brass rods and brass forgings it has been noticed that there is considerable variation in the physical properties, particularly the machinability of different rods and forgings, even though the composition, working temperatures and method of manufacture remain the same. It is the purpose of this paper to attempt to establish the cause and extent of this variation, and also to determine whether variations in composition within certain defined limits influence hardness and machinability to any marked degree. The writer believes that this variation probably is due to the variation in grain size of the metal, therefore the microstructures of several compositions under various conditions of working were examined in an effort to establish this as a fact. Survey of Previous Work in Studying Extrusion Defects Very little has been published concerning defects in extruded and forged brass. In 1921, R. Genders1 $ delivered a paper before the British Institute of Metals, relative to a defect inherent in the extrusion process. This defect, commonly found in extruded brass rod, shows up in the form of a circle in a transverse section consisting of oxides and impurities, and is generally present in the last 25 to 30 per cent of the rod. Genders concluded that the defect is caused by the turning inward of the skin of the billet at the edge of the plunger because the inside of the billet is more plastic than the outside, which is in contact with the cooler container; the outside skin will lag behind to form the rear end of the rod. Genders suggested a movable die as a remedy, and while this met with fair success, it is not used in present practice. About the same time as Genders' experiments, Tucker2 and Rosen-hain3 conducted experiments using colored plasticene in the form of a billet, and found much the same defect as Genders. Dr. Rosenhain State College, Pa.

Jan 1, 1932

One of our members, in Colombia, has written the following interesting account of his experience in trying to remit his dues to the Institute. "Last year I was away at the end of the year and on my return I was unable to obtain a draft in Honda until April, I believe. To avoid delay this year I remitted cash, early in January, to a friend in Bogota who I imagined could sell or procure for me various small drafts to cover my annual subscriptions. After many weeks' delay, I was informed that he could not get them for me and was remitting the cash to Honda where they were obtainable. After another long delay, I was informed that no one in Honda would sell drafts or checks for small amounts. Eventually I found a friend who was willing to oblige me in the matter and at once forwarded the amount."

Jan 8, 1919

By Dorsey Hager

DORSEY HAGER, Tulsa, Okla.-I have been asked why the Dexter region is dry. I would like to know myself. I drilled two dry wells on that same anticline which has production to, the east and west and south and north. That same anticline has seven domes that have been drilled and only three have proven productive out of the seven. In other words, you have one well-defined anticline with seven domes along its length, all mappable, all checked carefully, and only three of those seven have produced. Now why the others did not produce, I do not know. L. L. HUTCHISON, Tulsa, Okla.-There is no appreciable difference in the character or structure of the sands? DORSEY HAGER.-NO, I have never .been able to see any appreciable difference in the sands where we got production and Where we did not get it. I will say that the deepest wells we drilled, in the vicinity of Dexter, had no sands at the point where they got the production farther north. I. N. -KNAPP, Ardmore, Pa.-I first went to the Kansas-Oklahoma field in 1895 and occasionally thereafter until 1899, when I began drilling; for oil. I started close to wells that were producing gas and which, when drilling, lead made good oil showings in a sand above the gas. I thought these showings were good enough evidence of an oil pool for me without looking for any anticline and I made a paying development in what' I was afterward told by geologists was probably a synclinal trough. If I remember correctly Dr. Orton's report on the lola gas pool (about 1898) he distinctly said that he found no evidence of anticlinal structure and concluded from the records of a large number of wells that there, was a terraced structure of the productive gas sands, of which there were no surface indications.

Jan 4, 1917

By W. C. Elmore

THE magnetic powder method, long used for roughly mapping mag-netic fields, has recently been refined 1,2 for investigating the microscopic variations in the surface magnetization of ferromagnetic crystals. Bitter2 first discovered regular powder patterns connected with the crystal structure of such specimens. Several other investigators3 have used Bitter's original technique, with slight modifications, to study the varia-tion of the patterns with variations in the magnetizing field applied parallel to the surface, and their dependence upon the state of strain, of polish and of crystal cut. All of the explanations-of these patterns on metallic ferromagnetics have been couched in general terms. In a preliminary report we have described an improvement in the powder technique which led us to the discovery of a new effect throwing con-siderable light on the magnetic secondary structure of alpha iron4 and of nickel5 single crystals. We now report additional evidence confirming the existence and stability of a magnetic block secondary structure.

Jan 1, 1935

By Roswell H. Johnson

What becomes of the water which must have filled the oil and gas sands at the time of deposition, has long puzzled students of oil and gas and has found expression in Munn's well-known article on the hydraulic theory. Both Munn and Clapp have pointed out that in the Appalachian field the deeper sands carry increasingly less proportionate amounts of water. It seems to me probable that the principal source of oil and gas has been in the shales in proximity to the sands which now contain these products. The sand spits which mark off the lagoons from the sea comply particularly with the requirements of a limited sand imbedded in shales rich in organic matter. Cunningham Craig has objected to this view that the rich organic muds of lagoons are found only at the surface. That such muds do extend to considerable depth 1 am assured by Prof. Douglas W. Johnson, who has made an extensive study of the Atlantic Coast marshes. As any particular sand body becomes weighted by a heavier and heavier overburden, the result of increasing deposition, a part of the very large percentage of water in the uncompacted sand and mud is forced out. The water percentage of freshly settled mud is vastly higher than that of the resultant shales, or even of a very porous sand. If beds of less compressible material meet or underlie the shales in question, there will frequently be a lateral motion along such beds to some point where the upward movement will be resumed. We find in our laboratory work here that oil, gas, and water have extremely slight capacity for gravitational sorting while in a state of rest, but when moving the gravitational sorting is readily accomplished. As the oil, gas, and water pass a body of larger pores, the gas, owing to its lack of capillary attraction, is retained in the large pores. This has been predicted by Washburne, Blatehley and others on the ground that the water has a higher capillarity and grips the finer pores in such a way that there will be a greater proportion of oil and gas in the large

Jan 1, 1915

By A. W. Schlechten, R. F. Doelling

Parkes' process crusts were vacuum distilled using a shortened Pidgeon retort. Zinc was effectively removed below 800°C and recovered as a zinc sheet easily stripped from the furnace liner. Lead dasdistillationazinc required about 950°C and the resulting lead condensate tillationtended to stick to the thin metal liner. Final purity of residue is limited only by nonvolatile metals such as copper. THE successful commercial application of vacuum distillation for the removal of zinc from lead, as described by W. T. Isbell,' raises the question of whether or not a similar method can be used for other metal separations. Preliminary laboratory experiments on the vacuum distillation of Parkes' crusts by one of the authors' gave such encouraging results that it was decided to make a series of tests with large scale equipment to determine the results that might be expected in plant operation. The pilot-plant test results are reported in this paper. The great advantages of vacuum dezincing are its simplicity, the relatively low temperature of operation, and the fact that the zinc is recovered in the metallic state ready for use again in the desilveriza-tion of lead bullion. These same advantages and others would be realized from the vacuum distillation of the zinc-lead-silver crusts made in the Parkes' process. Zinc readily will distill over at temperatures of 800" to 900 °C as contrasted with the 1200°C or more used in the Faber du Faur furnace. Furthermore, the recovery of zinc as metal is practically perfect since there is no loss by oxidation or fuming. If the vacuum distillation is continued and hastened by raising the temperature to around 1000°C, the lead will distill over at an appreciable rate and deposit in a warmer zone of the condenser. This lead will contain a small amount of silver, but it can be returned to the desilverizing kettles and there is not the chance of loss that there is in disposing of the rich litharge from cupelling. The lower temperatures required will mean a saving of fuel and less wear on the equipment. One further point is that the vacuum distillation could be run on a small scale practically continuously, so as to avoid the accumulation of large amounts of silver-rich material and the need of assembling a large crew for special cupellation runs. It should be pointed out here that the final purity of the silver residue will depend on the copper or iron content of the crusts, as these and other metals with low vapor pressure will not be eliminated. The idea of treating the silver-zinc-lead crusts from the desilverization of lead bullion by vacuum distillation is not a new one, but such experiments have not been reported, as far as can be determined. In 1912, T. Turner presented a paper3 before the Institute of Metals on the vacuum distillation of brass, and a member of the audience suggested that he try his method on Parkes' crusts. In 1935, W. J. Kroll, noted for his discovery of debismuthiz-ing lead by calcium additions, published a paper' on vacuum distillation of metals and pointed out possible applications in the lead industry. Principles of Separation The successful separation of two or more metals by distillation depends upon an appreciable difference in the effective vapor pressures of the metals in the alloy to be treated. The vapor pressures of the common metals have been determined with considerable accuracy; for example, at 800°C the vapor pressures of the individual metals which are of particular interest in this paper are about .as follows: Zn, 241 mm; Pb, 0.0553 mm; and Ag, 0.0000276 mm. Unfortunately,, data are not available on the activities of the components in the ternary system Zn-Pb-Ag, but it can be estimated that on the basis of the vapor pressures of the individual metals a good separation can be made by distillation. The preliminary laboratory tests previously mentioned' supported this assumption. The pilot-plant size vacuum distilling furnace is shown in Fig. 1. It consisted of an abbreviated Pidgeon retort, 5 ft long with an ID of 8 in., heated by six silicon carbide elements placed symmetrically

Jan 1, 1952

By J. D. Hanawalt

Significant strides were made in the year 1948 leading to further recognition of the place of magnesium as a common commercial metal, rather than as just a premium aircraft material. One of the factors contributing to this recognition was the price stability and, in many cases, price reduction of magnesium products in 1948. In contrast to most other metals, manufacturing advances in magnesium outweighed the effects of increased labor and other costs. At the present time, many magnesium extrusions, die castings, and permanent mold castings can be purchased as cheaply as their aluminum counterparts in these forums, though competitive prices for sheet still await the inauguration of a modern tandem rolling mill for magnesium, such as has already been demonstrated.

Jan 1, 1949

By C. F. Tolman

In February 1913, Prof. L. C. Graton and Dr. Joseph Murdochl presented to the American Institute of Mining Engineers a notable contribution to economic geology under the title The Sulphide Ores of Copper. The value of the work was recognized by mine operators, and Mr. Graton was assisted in his plan to extend his investigations, by the organization of a commission to undertake a "secondary enrichment investigation." In this work he secured the cooperation of the Geophysical Laboratory of the Carnegie Institution of Washington. The report2 on the chemical phascs of the investigation has just been published. Incidental to investigations3 carried on in our laboratory of Economic

Jan 1, 1916

By W. L. Saunders

THE world's greatest producing area is, geographically, in the midland region of North America about the Great Lakes. This area, with but one- third of the nation's population, produces, with the exception of tobacco and cotton, three-quarters of the principal staples. It provides the surplus or export grain, meats, dairy products, steel and leading minerals. The social and political condition of a nation is determined by its industrial efficiency, and the share of the commerce of the world obtained by a nation is fixed more by the economy of its transportation than by any other factor. It is an economic maxim that: The total cost is the cost of production plus transportation cost. The cost of carrying 1000 tons by water or 100 tons by rail is equal, over the same distance

Jan 1, 1921

By T. Carl Shelton

The coal industry of the United States in 1967 had reasons to be both exuberant and concerned about its present and future role in the economy of the country. Continuing a momentum that began in the early 1960's, the industry has moved ahead in providing competitive customized products to strengthen its long-term domestic and foreign commitments, and has maintained with steady progress its position as a major supplier of energy. On the other hand, the industry must overcome air- water pollution and conservation-reclamation problems that have been identified by 1967 legislation. Throughout the year, the industry was characterized as "progressive," "healthy" and "dynamic." To have been termed a "growth industry" in 1967, is an accolade the coal industry can accept with pride. Culminating its efforts throughout the decade, the industry has emerged with a competitive image that is representative of its future strength.

Jan 2, 1968

By Thomas T., Read

THROUGHOUT the Colonial era, Philadelphia was easily , the leading city of North America, and it still held that position at the end of the period, with a population of about 25,000, though closely pressed by Boston, which had slightly over 20,000, and New York, which had nearly as many. It was the center of a region in which mineral industry was important. Thomas Rutter's bloomery, built in the Schuylkill valley in 1716, was quickly followed by many others, and during the Colonial period at least 20 blast furnaces, 45 forges, and iron- works of other types were built in eastern Pennsylvania, which easily led all the other colonies in iron manufacture. During the Revolutionary period others were erected as far west as Fort Loudon, in the Cumberland c alley.^ After 1800 the rapid development of the anthracite mining industry profoundly affected Philadelphia's, development, since transportation of the coal was then necessarily by water, and the streams of the anthracite . regions mostly flowed into either the Schuylkill or the Delaware Rivers. With an abundant near-by supply of coal and iron, with the seat of government, which had been there since 1774, and with a National Bank established there in 1791, one would have seemed safe in prophesying, at the beginning of the nineteenth century, that Philadelphia would permanently remain the leading city of the United States. Education in Philadelphia was at first wholly in the hands of the Quakers, who had established a "Public School" there in 1689, but in November 1739 George Whitefield, who had created a sensation in England by his preaching, though only 24 years old, passed through Philadelphia on his way to Georgia to found an orphan school there. He preached a series of sermons in Christ Church that were so disturbing to the established church that on Nov. 25 the Rev..Richard Peters (who was also Provincial

Jan 1, 1941

By FREDERICK W. BRADLEY

MINING methods are evolved rather than devised; and the process is slow. The advance in no particular year is phenomenal, but progress is un- questionably being made constantly in several directions: (a) better adaptation to given conditions of various "systems" of mining; (b) better utilization of mechanical equipment ; (c) improvement in working conditions so as to promote the health, safety and efficiency of the workers. During the year 1930 operations were commenced at a number of important new mines. Methods adopted are not new, except in minor detail, but the fitting of methods to conditions is interesting, because, as the engineers presumably started from scratch, they have selected the methods that experience under similar conditions has indicated as being the best.

Jan 1, 1931

By H. M. Chance

STRETCHING from New York southwestwardly to Georgia is a great range of hills and mountains consisting of pre-Palaeozic schists, slates, and gneissic and granitoid rocks, known locally by many different names; in Pennsylvaniaa as the South mountains, the Berkshire or Durham and Reading hills, and in Virginia and farther south as the Blue ridge. To the northwest of this range lies the " Great Valley," underlain by Lower Silurian limestones, and known as the Lehigh valley, Cumberland valley, Shenandoah valley, valley of Eastern Tennessee and Georgia and by other local names, but all these are parts of one valley, geologically and geographically continuous from New Jersey to Georgia. Lying upon and along the northern flank of this range of mountains, and dipping northwestwardly under the limestone of the valley, is the Potsdam formation (Primal or No. 1 of the Pennsylvania Geological Survey), which consists of sandstone or conglomerate overlain by slates. The latter are sometimes arenaceous and occasionally are replaced in part by sandstone. This formation varies from a few feet to several hundred feet in thickness. At the outcrop the slates are completely decomposed, oxidized or disintegrated, forming a belt of clay several hundred feet wide occupying the interval between the outcroppings of the sandstone and limestone. This clay-belt includes a more or less continuous series of iron-ore (brown hematite) deposits, which have been, and still are, extensively worked. The belt is more or less continuously mineralized with iron throughout its length, and hundreds of large deposits of ore have been developed and worked, producing many millions of tons of ore.

Sep 1, 1908