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By T&apos Ke, ing-sui

THE subject of recrystallization and grain growth has been much studied and the literature on this subject is numerous. Such studies have been mostly carried out by metallographic examination of X ray methods. Since recrystallization and grain growth involve elementary atomic processes, their mechanism can best be elucidated by a study of some properties which can be readily traced back in terms of such atomic processes. Prior to a detailed quantitative study, however, it is necessary to explore first the possibility and practicability of utilizing any particular property for obtaining the desired information. We have pointed out in a preceding article' that the internal friction of cold-worked metals is extremely high during recrystallization and it drops abru~tlv once the recrystallization is complete. ~reviois work has also shown that the viscosity of grain boundaries in a recrystallized specimen at a given temperature is raised by grain growth.' It seems thus that the measurements of internal friction may furnish a useful tool for the study of the mechanism of recrystallization and grain growth in terms of elementary atomic processes. The purpose of this paper is to report results of a study along this line. We will demonstrate that the internal friction method does give results in agreement with those furnished by conventional metallographic examinations. Once such a correlation has been established, we will be in a position to take further steps to achieve new information which cannot be achieved by conventional methods. The measurements of internal friction were made using apparatus and procedures similar to those used in the preceding article. All the measurements were made under such a small stress level that the internal friction is independent of stress level. The frequency of vibration is, unless mentioned otherwise, about one cycle per second in all cases. Internal Friction and Recrystallization Complete Recrystallization Temperature: Fig. 1 shows the internal friction curve during annealing of a few metals: aluminum, alpha brass and iron. These curves were determined in the following manner. In the curve for aluminum, internal friction measurements were performed upon. 99.991 aluminum subjected to 95 pct reduction area. The internal friction was first measured at room temperature. The specimen was then annealed at 50°C

Jan 1, 1951

By C. T. Bischoff

This paper describes the results of testing with colorimetric methods, using "dithizone", soil samples taken over various known copper and zinc deposits covered by glacial till. Variation in results is shown for different depths and types of overburden as well as grade and type of deposit. Limiting factors for the practical application of this work are discussed. The method has proved successful for copper and zinc deposits under clay and fine sand with depths up to at least 30 ft but fails in coarse sand and gravel unless depths are very shallow. Swamps require penetration to the underlying subsoil for sample material. DURING the past few years geochemical testing for traces of heavy metals in water, soil, rock, and vegetation has aroused increasing interest. Various techniques for field and laboratory determinations have been described in the literature, as have some of the results of application. However, little information has been published regarding application to glacial terrain. Over 90 pct of the Canadian Shield is overburdened, resulting in high costs for mineral exploration once the outcropping ore deposits have been found. This has been largely responsible for the widespread application of mining geophysics in Canada, permitting concentration of effort on area or zones considered most favorable. However, geophysical interpretation has its limitations, since at least 90 pct of the structures indicated thereby contain no valuable minerals. A more direct approach is therefore highly desirable. If underlying base metal mineralization can be detected by sampling soil or vegetation at moderate cost this should prove of great help in locating new discoveries or extending known ones. A large proportion of Canadian ore deposits contain appreciable copper or zinc, even where these are not the principal economic metals. Consequently the field of application is a broad one. This paper deals with investigations along these lines with particular emphasis on soil sampling. The problems involved from the start were: 1—Which types of glacial soil, if any, would best lend themselves to testing, and conversely which types might be considered relatively hopeless? 2—Through what depths of overburden could significant mineralization be detected? 3—What sampling techniques would prove economically applicable? This included minimum depth of sample and maximum spacing that could be allowed.

Jan 1, 1955

By William B. Phillips

It is proposed in this paper to discuss some of the chemical and physical principles involved in the manufacture and use of this important by-product obtained in the manufacture of steel by the basic process. The name, " phosphate slag," is adopted as a sort of compromise between "Thomas slag" and "tetrabasic phosphate." By the first of these latter names, viz., " Thomas slag," it is known in Germany, Austria, France, and the other continental countries, and in England, and is more easily apprehended by those who have no special Knowledge of chemistry, while the name " tetrabasic phosphate," being descriptive of the nature of the slag, is perhaps the best. It is but seldom that a discovery of such moment to two great industries is to be chronicled in the history of technical science. On the one hand, the manufacture of iron and steel has been greatly benefited, while on the other hand, the effects already noticed, and still to follow, to the agriculturalist, are of scarcely less conseqnence. The great majority of iron ores in the world, perhaps 90 per cent. of then), are now available for the steel manufacturer, while the manufacturer, and more especially the consumer, of artificial manures is relieved from the fear of the exhaustion of the crude phosphates. We have in phosphate slag, therefore, a product of the highest importance to those who make and we steel and fertilizers. Two great industries, which heretofore have had but little in common, are thus brought into close connection with each other, and the results sure to follow, if one may judge from the history of the past ten years, cannot fail to be of great and increasing value. These results may be compared with those which followed the introduction of the cupriferous Spanish pyrites into England for the manufacture of sulphuric acid. The copper extracted greatly reduced the cost of the acid, hence that of artificial manures. Cheap manures meant better farming and cheaper farm products, and these meant better and cheaper living to nearly all classes of society. The amount of fertilizers now manufactured in the United States

Jan 1, 1889

By M. O. Holowaty, C. M. Squarcy

Blast furnaces are the tools of men, and it is men who have made them great. Here is presented the story of the Ironmakers-the men who first poured hot metal into what would someday be the sinews of a nation. W HEN the Jacobean merchant adventurers bade farewell to the first ship of colonists sailing for the new land, they instructed them to direct all their skill and energy to grow silk worms in Virginia. The adventurers felt sure that they could flood the market with highly priced and much desired goods like silk, sugar, tea, and indigo. They were also convinced that they would fill the needs of the mother country for iron. Early iron production in the colonies The merchants certainly had a wonderful imagination, for silk and indigo were just as exotic in Virginia as they were in England. The settlers found it more profitable to raise tobacco on the vast stretches of the free, fertile land. Thus the plans of settlers clashed with those of The Virginia Co.; and only point of agreement was the desire to produce iron. But, even there the motives of the settlers and those of The Virginia Co. of London were worlds apart. The settlers wanted to produce the tools badly needed in the colony, while the Company desired to cash in on the rising demand for iron which the home industry could not satisfy. Both the settlers and the Company lost no time trying to find iron ore. Locations of the early mines are not known. If, however, the reports of the Irishman, Francis Maguel, can be trusted, as early as 1609 a ship sailed for England with a load of 17 tons of crude iron which the East India Co. purchased at £ 4 per ton. The iron was of excellent quality and considered the best iron made of non-English ore that was ever purchased.

Jan 1, 1961

By Philip M. Mc Kenna

When a new material becomes available to industry, it is useful to describe its properties as a guide to its most effective application; and when the new material may be produced in compositions having a series of graded properties, tests to select the combination of properties best adapted for various uses are helpful. The class of materials to be considered in this paper are hard tool materials produced by processes of powder metallurgy from hard carbide constituents and various matrices of iron, nickel or cobalt, or alloys of them with tungsten, or tungsten and carbon. The customary use of carbide hard alloys is for metal-cutting tools; although wire-drawing dies, lathe centers, follow rests, grinding rests, burnishers, rolls, extrusion dies, measuring gauges and micrometers, and a number of other tools are also made with these hard alloys as the essential wear-resisting parts. The properties and tests to be considered are those affecting these uses. In the development of tool materials since the industrial revolution we have had carbon tool steels, Mushet steel, high-speed steels, stellites, and now cemented carbide compositions. For an understanding of the latter category of materials their properties and uses relative to the older and more familiar tool materials will be considered. Hardness has been the property of greatest practical interest in tool materials. The word "hardness" is a generalized term lacking definite-ness unless the specific test used is described. However, efforts to explain physical properties as a consequence of chemical bond, and distance between atoms in chemical compounds have been illuminating. This seems the most generalized attack on the problem, and is based upon the idea that atoms in a lattice are held together as the square of the valence and inversely as the square of the distance between the atoms. The compounds compared must all be of the same crystalline arrangement. 100 W2 It is interesting to note the values of the figure 7 A 3 /3for a number of

Jan 1, 1938

By Frank Feuille, Edward Schuster

As the time allotted is short, we can present only a general idea of the oil laws in the Latin-American republics, as a supplement to Bulletin 206 of the Department of the Interior compiled under the direction of J. W. Thompson of the Bureau of Mines and entitled "Petroleum Laws of All America." We shall not discuss the European colonies in Latin-America nor the island republics. As to the countries discussed, we shall attempt to give the main features of such special petroleum legislation as has been adopted prior to the early part of this year; where no special petroleum laws exist, we must look to the mining codes for light on the petroleum policy. As the laws and regulations for the extraction of the metals are often difficult of application to, and are lacking in many essentials for, the petroleum industry, it is best for persons or companies desiring to enter, on a large scale, into the petroleum exploration and development of countries not having special petroleum legislation, to obtain a concession contract from the executive of the country under consideration, and to have the concession approved by the congress. If this concession, which would then be a special law, contains nothing contrary to the constitution of that country and does not infringe on vested rights of third parties, it should be reasonably safe. If in such country there is some doubt as to whether the petroleum subsoil is owned by the nation or the private surface owner, only public lands should be covered with the concession. Guatemala is the only republic in the group that discriminates directly against foreigners. Bolivia, Ecuador, Mexico and Venezuela require waivers of diplomatic protection.' Colombia requires foreigners to agree to be bound by its alien law. In addition,Mexico makes it unlawful for foreigners to acquire direct ownership of real estate, including mines, within a zone of 50 km. along the coasts and one of 100 km. alongitsland

Jan 1, 1923

By G. W. Jarman

The purpose of this paper is to present briefly a description of some of the special methods of separation or concentration, either singly or in combination with others, and to give certain operating data and examples. Explanation of the usual methods of large-production mill treatment, such as flotation or wet tabling, or of chemically treating industrial minerals, is not included in the scope of this paper, although one of these methods might be, in certain instances, augmented by one or more of the special methods that will be enumerated herein. Description of these special methods will be centered on magnetic separators, electrostatic separators and air flotation or air tables. Magnetic Sepaeatohs In general, separation is achieved by exerting upon a particle some kind of force opposed to gravity, either directly or at an angle. For example, in the Wetherill or cross-belt type of magnetic separator some particles are lifted vertically from the others because they have been exposed to a force to which they respond more readily than particles of lesser magnetic susceptibility. Of course, there is a limitation to this vertical rise, for the particle must be of a high enough susceptibility to receive a magnetic force greater than the 980 dynes per gram of gravitational urge. To overcome this limitation, the induction type of magnetic separator was developed, so that it is only necessary to instill, say, 30 to 60 dynes per gram instead of the 080, to cause a deflection away from the vertical in falling, and that deflection can be used advantageously when falling by inserting a dividing knife-edge. The induction magnetic separator (Fig. 1) has become a fairly well known method of concentrating and purifying. For example, abrasive grain was among the materials that did not respond to the previously best known type of magnetic separator, such as the Wetherill type, and the development of the induction magnetic separator in the plant of a

Jan 1, 1942

By R. L. Templin

In treating a cast metal by any working process such as rolling, drawing or forging, variations in the conditions present in the remelting, casting, chilling and preheating of the initial ingot will certainly have some effect on the physical properties of the final product. In considering the effects of cold working on the physical properties of metals, however, it will be assumed that these factors, being controlled according to best practice, will remain constant and therefore may be neglected. Starting with such a uniform metal ingot, the next operation in the production of wrought metal involves hot working by rolling, forging or extrusion so as to produce a slab, billet or bloom. This working must be sufficient to produce substantial grain refinement and minimize any defects occurring in the initial ingot. Even such a hot-worked product is not suitable as a starting material for determining the effects of cold working because it contains internal strains analogous to those resulting from cold working. It is necessary, therefore, to supplement the hot working with a considerable amount of cold working, followed by a proper annealing in order to obtain a material suitable for use in defining the effects of cold working on the physical properties of a metal. That is, if the effects of cold working are to be evaluated accurately it is necessary to have other effects at least constant if not absent. Such material, unfortunately, cannot always be obtained in commercial practice but the requirements just indicated certainly represent the desired goal; this goal has been attained in the treatment of some metals, one being aluminum. Factors That Must Be Considered Simultaneously with Cold Working So many other factors affect the physical properties of a metal that it is necessary to consider these factors simultaneously with cold working; their effects vary in magnitude with the amount of cold work present. The most important of these factors are: (I) chemical composition, (2) structure, (3) temperature of working, (4) character of working, (5) rate of working, and (6) methods used for measuring results. For

Jan 1, 1930

By G. W. Jarman

THE purpose of this paper is to present briefly a description of some of the special methods of separation or concentration, either singly or in combination with others, and to give certain operating data and examples. Explanation of the usual methods of large-production mill treatment, such as flotation or wet tabling, or of chemically treating industrial minerals, is not included in the scope of this paper, although one of these methods might be, in certain instances, augmented by one or more of the special methods that will be enumerated herein. Description of these special methods will be centered on magnetic separators, electro- static separators and air flotation or air tables. MAGNETIC SEPERATORS In general, separating is achieved by exerting upon a particle some kind of force opposed to gravity, either directly or at an angle. For example, in the Wetherill or cross-belt type of magnetic separator some particles are lifted vertically from the others because they have been exposed to a force to which they respond more readily than particles of lesser magnetic susceptibility. Of course, there is a limitation to this vertical rise, for the particle must be of a high enough susceptibility to receive a magnetic force greater than the 980 dynes per gram of gravitational urge. To overcome this limitation, the induction type of magnetic separator was developed, so that it is only necessary to instill, say, 30 to 60 dynes per gram instead of the 980, to cause a deflection away from the vertical in falling, and that deflection can be used advantageously when falling by inserting a dividing knife-edge. The induction magnetic separator (Fig. 1) has become a fairly well known method of concentrating and purifying. For example, abrasive grain was among the materials that did not respond to the previously best known type of magnetic separator, such as the Wetherill type, and the development of the induction magnetic separator in the plant of a

Jan 1, 1938

By Linn Bradley

F. H. WILLCOX, Pittsburgh, Pa. (communication to the Secretary*). -We must keep in mind, in balancing the savings-to be anticipated by the most efficient combustion of gas, the best heat absorption by stoves or boilers, and by heat conservation of the thermal equivalent carried in. blast-furnace gas-against the cost in operation, maintenance, depreciation and interest charges of the equipment required to realize the savings, that in boilers and hot-blast stoves we are basing our economies upon two different, combustion phenomena. In a boiler, evaporating water at a heat efficiency of 70 per cent., approximately 47,550 B.t.u. is consumed per boiler horsepower. Taking the blast, furnace gas cited in the above paper, we are using about 38 ¾ lb. of cold-washed gas per boiler horsepower. Using the hot-cleaned gas, the same equivalent heat is furnished by 34 1b. of the gas , This leaves of the 38 ¾ lb. required in the case of cold-washed gas, 4 ¾ lb. or 6,650 B.t.u. available for raising more steam when dry-hot gas is used, which means that an equivalent amount of coal firing can be dispensed with. Per ton of iron, this figure 2/3 X 12,000/38.75 X 4.75 = 980 lb. gas or 1,372,000 B.t.u. or 100 lb. coal. At $1.50 per ton of coal, the net saving per ton of pig iron produced by the use of dry-hot over wet-cold cleaning will, therefore, be about $0.06 2/3. At a stove heating 8,500 lb. of air per toil iron from 150° F., one-quarter of the dry-hot cleaned gas, or 3,000 lb., would heat the air to 1,450° F. 3,000 X 1,400 X 0.70 = (8,500 X 0.255) = 1,300. The cold-wet gas would heat the same amount of air to 1,280° F. 3,000 X 1,225 X 0.70 = (8,500 X.0.255) = 1,130.

Jan 4, 1917

By Russell Franks

IN recent years a considerable tonnage of the 18 per cent chromium and 8 per cent nickel steels has been used in lightweight high-strength structures that must be resistant to deterioration under atmospheric conditions. These steels are austenitic in character and their strength can best be increased by cold-working. Although a marked increase in tensile strength is obtained, claims have been made that the cold-worked steels do not possess fully satisfactory elastic properties. Under certain conditions, however, this has caused no great concern, because, as explained by Ragsdale,1,2 the cold-rolled steels have been widely applied for construction of lightweight, high-strength trains using spot welding for joining purposes. Ffield3 agrees that the ease with which thin sections of the cold-rolled 18-8 steels can be joined by spot welding is greatly in their favor, but that they would be more satisfactory if higher elastic properties and a higher modulus of elasticity could be obtained. He states that, as far as the mechanical properties are concerned, the straight chromium stainless steel is superior to the cold-worked 18-8 steel, and in order to illustrate, he presented the data of Fig. 1, which also give a stress-strain curve for a low-carbon 13 per cent Cr steel. Ffield? pro-posed that columbium-bearing or titanium-bearing cold-rolled 18-8 steels be given a heat-treatment (preferably for 1 hr.) in the range 400° to 600°C. to precipitate carbides in order to obtain better mechani-cal properties. Discussions by Sutton,4,5 de Ganahl,6,7 8 Krivobok and Lincoln,9 Knerr,10 and Thaden11 have given further information on the properties of the cold-rolled 18-8 steels compared with other materials used in light-weight, high-strength structures. These investigators and others point out that the ultimate tensile strength of the cold-rolled 18-8 steel can be increased to 200,000 lb, per sq. in. or higher; Krivobok et al. indicate that

Jan 1, 1940

By Oliver Bowles

While vast quantities of limestone and dolomite are used in metallurgy, the estimated production in 1926 being 23,860,000 tons, there are many problems connected with their use which have not received adequate study. The literature of metallurgy is notably lacking in comprehensive discussions of fluxing or furnace stone. Approximately 900 lb. of limestone is used for every long ton of pig iron produced in the blast furnace, but this important constituent of the charge receives little atten. tion compared with the intensive study that has been applied to ores and fuels, the other important constituents of the charge. In an effort to elucidate some of the doubtful points, the writer has made a wide review of metallurgical literature, and has had the disappointing experience of finding not more than a paragraph or two on metallurgical stone for each two or three thousand pages of literature reviewed. Furthermore, the limited information supplied is in some instances contradictory and even absurd. For example, a correspondent in a reputable metallurgical magazine classifies magnesia and silica together as impurities in flux " that must be melted and run off as slag." From the furnace operator's viewpoint it is desirable that as complete knowledge as possible be obtained concerning the effects of chemical composition and physical character of the stone on its action in the furnace and on the quality of the metal produced. A better knowledge of these features is advantageous also to the quarry operator in that it enables him to work more intelligently in producing stone that will best satisfy the metallurgists' requirements. The following pages comprise a brief compilation of data now available. Much of the information is well established and probably acceptable to most metallurgists. On some points there is room for debate, and the chief purpose in presenting a paper at this time is to arouse discussion which will throw more light on controversial points and thus assist the author in preparing a more comprehensive and accurate discussion of metallurgical limestone problems.

By C. R. Austin

THE investigation described in this paper deals with the development of high-temperature alloys of the Konel series over a considerable period of time at the Research Laboratories of the Westinghouse Electric and Manufacturing Co. The word "Konel" has been coined to designate a class of alloys which are essentially nickel-cobalt-iron with other elements added, usually in small quantities. Most of these alloys contain titanium, usually about 2.5 percent. The main consideration related to strength at high temperatures but the thermionic characteristics of the alloys was also of considerable importance. It is, however, with the mechanical properties at elevated temperatures that we are herein concerned. Much attention has also been devoted to their age-hardening characteristics. There is little need to stress the utilitarian aspect of this subject, as it has been discussed frequently. Alloys exhibiting superior properties at normal or elevated temperatures rapidly find many suitable applications. There may be some question, however, as to what constitutes a "superior alloy, " or an alloy that may have good service possibilities at high temperatures. The problem is complex and various means have been employed to predict the useful life that may be expected of a material. In recent years the "creep limit" has been used as the best means of evaluation. Such tests necessarily are prolonged and hence collection of data is very slow. In a general survey of many alloys therefore the creep test is not desirable and recourse must be had to much shorter time tests in order more rapidly to select alloys which appear to show promise. For this reason the present survey has been made using the high-temperature tensile test and a bend' test developed by Howard Scott.1 In the tensile test the conditions have been standardized for all tests, so that values obtained are at least comparable, one alloy with another, although the absolute values recorded merely indicate the mechanical properties at the given temperature under a definite rate of loading.

Jan 1, 1931

Coal was known in this county before 1819, but there is no record of its use before that year. In that year a furnace, the first one built in the northwestern countries, was put in blast on Bear Creek; it was built to use coke and its first blast was with this fuel, which was made in heaps, but the blast was too weak and the furnace chilled after two or three tons of iron had been made. Charcoal was then substituted, and this use of coal ceased.1 In November of the same year a resolution was adopted urging state aid for a road from Kittanning to. Hamilton, New York: "that this road will increase the trade and industry of the whole county, between Pittsburgh and the New York line; and that our soil will in consequence be better tilled, our mines of coal, of iron and of salt, be better wrought, etc."2 In 1828 an advertisement of lands situated near Freeport on the Allegheny River and contiguous to the canal nearly completed between the Kiskiminitas and Pittsburgh stated that they contained "large and never failing springs, Coal in abundance, and a great deal of Fine Timber."3 In 1830 there were said to have been 24 salt wells in this county producing 327,000 bushels of salt, chiefly on the Kiski and Allegheny Rivers. In 1837 there were a number of wells in the vicinity of Freeport. As all the salt works on the Conemaugh River, were using coal long before 1830,4 it is safe to say that a considerable tonnage of coal was used for some years in these plants. In 1837 a tract of land in Clarion Township having a new saw mill and abounding "in Stone Coal" was offered for sale,5 and also one in Toby Township having "an abundance of the best quality of iron ore and stone coal."' In 1839 an advertisement in the Pittsburgh Mercury said

Jan 1, 1942

By Richard Pearce

I am deeply sensible of the honor you have conferred on me in electing me your president for this year. It is difficult to understand why I have merited such distinction at your hands, except that I may possibly have helped, in some small way, in the develop ment of metallurgical practice in the West. I fear, however, that I shall fall far shirt of the expectations you may have in regard to my fitness for such a position. The responsibility of preparing an address for this occasion has caused me considerable thought and anxiety. Unlike my predecessors in office, many of whom have dealt in their presidential addresses with subjects covering a wide field, which they could survey with the confidence born of their own extensive knowledge, I have been confined by my experience, during the last twenty-five years, almost wholly to that portion of metallurgical science which bears especially on the treatment of gold and silver. Yet perhaps some sort of general review of the progress of this branch of metallurgy in the West, besides being the contribution I feel myself best qualified to offer, may prove acceptable to many of the members of the Institute. Some few of the gentlemen present will remember the crude condition of metallurgical practice as it was conducted in Colorado only twenty-five years ago. My own personal experience covers a period of eighteen years; and during this comparatively short time I have seen the most astonishing changes in the conduct of metallurgical works. In all probability the marked progress which this country has exhibited could hardly be reached anywhere else, and this result has been achieved mainly by the activity and enterprise so characteristic of the men of the West. The first little successful attempt at smelting made at Black Hawk, in 1867, by Ex-Senator N. P. Hill, representing the Boston and Colorado Smelting Company, proved a great boon to the miners,

Jan 1, 1890

By R. C. Allen, Ralph Arnold

The writers have no new system and no new principle of taxation to propose. The general subject of taxation is as old as governments are and as familiar to taxpaying Americans as the general thesis on the inalienable rights of man. We believe, therefore, following the committee of the National Tax Association, that improvement in the general conditions of taxation, including mine taxation, maybe brought about mainly through a better adjustment of known and tried principles and methods of taxing to modern complex forms of property and income, and that not much is to be expected from abandonment of experience for new ways and means, methods and principles, should anything new be discovered, which in our opinion is very doubtful. The committee referred to has constructed the general framework of its Model System of State and Local Taxation1 on familiar forms of taxing, by eliminating some that ' have proved bad, suggesting improvements in others, and adopting the best, leaving plenty of room for the accommodation of the general plan to the varying conditions of taxation in the several states. Unfortunately, the taxation of mines is dismissed by the committee with the statement that the subject has been reassigned for further investigation and report by a special sub-committee, frankly recognizing that the peculiar difficulties of this phase of the subject require special study and investigation. Much may be hoped for from the labor of this sub-committee if the problem is approached from the viewpoint of recommendations already published. In this paper, the writers state their opinion on some of the broader aspects of mine taxation with too little attention to the grounds on which they rest. Contrary to inclination space requirements compel them to resort to summary statements without adequate discussion for a satisfactory presentation of the whole subject. All they can do is to qualify the witnesses and record the testimony. The senior writer was introduced to the practical aspects of the subject of this paper in 1913, when, as State Geologist of Michigan, he was

Jan 1, 1920

By C. D. Young

IN an effort to employ cast steel of a stronger structure than that found in the annealed steel castings, the possibilities of heat treatment which will increase the strength without materially decreasing the ductility may be resorted to. The following abstracted report (which is a brief outline of what has already been clone by the Pennsylvania Railroad Co. at its shops and Test Laboratories at Altoona, Pa.) is of material interest, as it indicates what may be done with steel castings when properly treated, thereby permitting in railway service greater strength of cast steel parts without any increase in weight or space. The question of the heat treatment of alloy steel castings is not taken up in this paper. The obscurity formerly surrounding the heat treatment of steel has been for the most part removed by the development of our knowledge of the critical points of steel, pyrometers, furnace construction, and the testing of the finished product. The operations of the heat treatment proper will be taken up under the heads of (1) heating for quenching; (2) quenching; (3) drawing. (1) Heating for Quenching.-Heating for quenching is best conducted slowly, especially in the case of castings of variable thickness. Cracks may occur either in heating or in cooling, clue to different temperatures at different points of the casting. The castings should be thoroughly soaked at the maximum temperature (generally 1,500° to 1,600° F.), 1 hr. being sufficient for sections 1 ft. in thickness. The minimum temperature which will produce the desired hardening effect will, in all cases, be found to be the most satisfactory, as the grain coarsens when the critical range is exceeded to too great an extent. All temperatures should be governed by a checked pyrometer with the hot junction to the heated object, and with several couples in a large furnace to insure a uniform temperature.

Jan 2, 1914

By John C. Branner

Within a couple of years I have received many inquiries in regard to the manganese-mines of Brazil. These inquiries were doubtless directed to mc because I had lived and traveled in Brazil for more than eight years, and was therefore supposed to be pretty well acquainted with its geology and mineral resources. Somewhat to my chagrin, I not only knew nothing of manganese-mines in that country, but I had never before heard of the mineral having been found here in quantity, and I did not even know in what State the mines were located. The present summer found me in Brazil again, trying to finish up some of my early geological investigations along the northeast coast, and I have used the occasion to find out something about the manganese-deposits. Very little is known of these mines, even in Brazil. While at Pernambuco I was told that they were in the distant interior of the State of Bahia. In August I reached Bahia, and there I found out, concerning the mines and their geology, enough to be worth telling for the benefit of those interested in the mining or using of this mineral. Thus far, all the manganese-ore shipped from this State has come from two mines, the principal one of which is known as the Pedras Pretas mine. This was the first mine opened, is the best developed, and was the original discovery; the second one is on an adjoining tract, and the general geology and natural conditions are about the same in both. The Pedras Pretas mine is on the Nazareth-Amargosa railway, twenty-six kilometers west of the town of Nazareth, which is on tide-water, at the head of navigation, and is reached from the city of Bahia by a small side-wheel steamer that runs across the bay of Bahia and up the Rio Jaguaripe

Jan 1, 1900

By Howard N. Eavenson

The information contained in the following paper was collected at the request of the U. S. Coal Commission, and is published with the permission of that body and of the various companies furnishing the data. For obvious reasons, the names of the companies are not given. No data were obtained from states south of Virginia or west of the Mississippi River. The data about the amount of labor, in man-hours, required in producing a ton of bituminous coal have been collected with the idea of showing what is being done at some well-managed plants, and not to show the average amount required by all mines, which undoubtedly is considerably higher than the average of the figures shown.* Almost all of the figures were supplied by the various companies in reply to a questionnaire; when they were obtained from other sources the company was asked to verify them. On account of the amount of work required, the data were only requested for one or two months for each plant, and the figures represent in each case a month when the car supply was good and the work was practically steady. In the case of most of the West Virginia and Kentucky mines, these conditions were best met in May and June, 1922. The mines for which the figures are given are arranged by states and as to whether the mine operates under union or non-union or open-shop conditions. The union mines listed are generally considered to be as well-managed as are the non-union ones. The production per month in a few cases includes the amount of slate which is loaded and hauled out of the mine, as of course this requires nearly as much labor per ton as does the coal. These cases are noted. The number of days worked includes only the total time in which the tipple operated; not the number of days on which the mines operated. This makes the output per day appear slightly higher than it should be in

Jan 1, 1924

By Carl Belser

This paper summarizes the data on the oil-shale deposits of western Colorado, Utah and Wyoming. It is based on published reports by the U. S. Geological Survey, on the results of core drilling and sampling by the Bureau of Mines, on the drill cuttings from the Genera1 Petroleum well, on a recent unpublished report by the Geological Survey on the geology of Naval Oil-Shale Reserves No. I and No' 21 and from information supplied by geologists of private companies who have investigated the Green River formation. The paper also contains a revised estimate of the grade and tonnage of minable thicknesses of oil shale of western Colorado. Introduction The oil shales of the Green River formation of Colorado, Utah and Wyoming comprise an important natural resource for the production of synthetic liquid fuels. The oil shale in western Colorado generally is more amenable to exploitation, apparently richer, and probably more persistent than in Utah or Wyoming. Work is now being done by the Bureau of Mines near Rifle, Cola. to ascertain the best procedures for mining the oil shale, producing shale oil from the oil shale, and converting the oil into more salable products. As a part of this program, holes were drilled and cores were taken of the oil shale on Naval Oil-Shale Reserve No. I. In addi- tion, drill cuttings were obtained from a well drilled through the Green River formation by the General Petroleum Co. about 18 miles northerly of the Naval Oil-Shale Reserve. Geology During middle Eocene time a broad, shallow body of water, now called Uinta Lake, covered northwestern Colorado and east-central Utah; a similar lake, known as Gosiute Lake, was in southwestern Wyoming Each of these contemporary lakes was bounded by high hills; the drainage was to the south. The Green River formation was laid down as sediments in the bottoms of these lakes. It is 3000 ft thick and has been divided into the following four members:

Jan 1, 1949