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By E. S. Wheeler

THE conversion plant of the Climax Molybdenum Co. is at Langeloth, Washington County, Pennsylvania, approximately 30 miles west of Pittsburgh. The molybdenite concentrates converted originate in the company's mine and mill at Climax, Colorado.1 They are delivered to the Langeloth plant by rail packed in 175-lb. bags. War production of concentrates at the mill started in 1918 but it was not until about 1920 that any peacetime uses of the metal began to develop. Early conversion of Climax concentrates was mainly into ferromolybden um, produced for the company by a custom smelter. CHRONOLOGY OF PLANT DEVELOPMENT In 1924 a small hand-rabbled roaster was built at Langeloth, the roasted concentrates being used principally in the production of calcium molybdate by a conventional wet method. The size of the original plant is indicated by the fact that during 1925 about 400,000 lb. of molybdenum was converted. In 1925-1926, a multiple-hearth roaster was erected (12-ft. o.d. 8-hearth Nichols-Herreshoff); also the first experimental ferromolybdenum was produced at Langeloth. At this time calcium molybdate was produced in the furnace by a process to be described. With continued interest in and increased use of molybdenum, it was necessary to arrange for enlargement of plant facilities. Although only one 12-hearth 16-ft. o.d. roaster was erected at this time (1929), plans were prepared for a duplicate unit, which was completed in 1935, giving a potential roasting capacity of some 16,000 lb. Mo per day under the then prevailing roasting practice. Shortly after this second unit had gone into production, increased demand overtaxed the plant, and as a result two 12-hearth 18-ft. o.d. roasters were placed in operation in 1936 and 1937. This gave the plant a potential roasting capacity of 40,000 to 50,000 lb. Mo per day, and necessitated major changes in auxiliary handling equipment as well as improved facilities for producing ferromolybdenum. Following the introduction (1938) of a new product-molybdic oxide briquets and because of the constantly growing demand for molybdenum, plant facilities were again enlarged in 1940 and 1941 by the erection of two 16-hearth 18-ft. o.d. roasters. These two new units, along with a change in roasting practice, brought the potential roasting capacity to 150,000 to 190,000 lb. Mo per day, based on about 15 lb. per sq. ft. of hearth area. Other departments of the plant have necessarily grown, until today the plant is modern throughout and completely mechanized, with equipment geared to produce marketable products as follows:

Jan 1, 1944

By L. D. Jaffe, John H. Hollomon

Fox many steel parts it is desired to obtain the maximum toughness consistent with the strength required by the mechanical design. It is generally recognized that the greatest toughness at any given strength is found in steels having a tempered martensitic structure,1 and is virtually independent of the composition of the steel2 (except for carbon). The choice of the composition of a steel for the parts in question should be based, therefore, on hardenability considerations and on manufacturing facility and economy. In a recent paper3 the concept of hardenability was discussed and a somewhat new approach to the problem was suggested. The hardenability was defined in terms of the cooling conditions (speed of cooling) required to avoid the pearlite and the bainite reactions. Since all the alloying elements do not have the same effects on the two reactions, the bainitic and pearlitic hardenabilities must be considered separately. In order to design a steel for a given part, it is necessary to design a composition that has both sufficient pearlitic and sufficient bainitic hardenability. However, this requirement does not fix the combination of alloying elements to be used; an infinite number of steels would have the required hardenabilities. Other considerations limit the choice. For example, decreasing the carbon content increases the toughness at a given hardness, and for this reason low-carbon steels are often desired. Limitations or requirements of refining, casting, or forming practices often affect the level of some of the alloying elements. Price considerations enter. Frequently, however, it is very desirable to minimize the tendency toward quench-cracking while maintaining the necessary hardenability. This paper is concerned with suggesting a method for choosing compositions that will have the required hardenability together with minimum tendency toward quench-cracking. QUENCH-CRACKING Since only the case in which the entire part will transform to martensite in the particular quench employed is being considered, the analysis of the quench-cracking problem is somewhat simplified. Quench-cracking arises from the temperature gradients existing throughout the piece during cooling. Because of these temperature gradients, the contraction arising from the decreasing temperature and the expansion arising from the austenite-martensite reaction do not occur uniformly over the parts, and stresses are set up that tend to cause cracking. The temperature gradients can be reduced by decreasing the severity of quench. This, however, requires that the hardenability be correspondingly increased by increasing the carbon or alloy content. An

Jan 1, 1946

By Fred P. Dewey

Although coke is the acknowledged metallurgical fuel, and has been extensively used in this country for more than thirty years, yet the facts on record in regard to its physical properties are exceedingly meagre; and this is also true, but in a less degree, of its chemical composition. An investigation is being carried on in the National Museum which is intended to supply, so far as may be, this deficiency, and through the kindness of Professor Baird, Director of the Museum, I am permitted to present to the Institute a summary of a portion of the results already obtained. So far as I am aware, the credit for the first systematic investigation of the physical properties of coke belongs to Mr. John Fulton, Mining Engineer of Cambria Iron Co. The results of this investigation have been published in Report L, Second Geological Survey, Pennsylvania, 1875, and in a pamphlet setting forth the advantages of the Connellsville coke, the latter published also by the " Virginias"* His results are not altogether free from experimental errors, and the assumption that "the specific gravities of coke and water are very nearly alike "- is scarcely warranted. It has seemed to me, therefore, desirable to make an independent investigation of the physical properties of coke on a plan somewhat different from that adopted by Mr. Fulton. This is the investigation now being carried on at the National Museum.

Jan 1, 1884

By William E. Ford, Edward Salisbury Dana

239, Contact-Gwiorneters. - The interfacial angles of crystals are measured by means of instruments which are called goniometers. The simplest form is the contact- or hand-goniometer one form of which is represented in Fig. 377. This contact-goniometer consists of a card on which is printed a semi- circular arc graduated to half degrees at the center of which is fastened a celluloid arm which may be turned to any desired position. The method of use of the goniometer is illustrated in Fig. 377. The bottom of the card and

Jan 1, 1922

By Robert E. Tally

A recorded in the account of the Annual Meeting, on another page, the report of the tellers showed that all men nominated by the committee, which included Messrs. Wilber Judson, E. DeGolyer, W. A. Weldin, J. A. Norden, J. D. MacKenzie, Wilfred Sykes and S. Skowronski, were duly elected to the offices for which they were nominated. Robert Tally, who was elected to the presidency for 1931-2, is well known to all our members not only because he has served on the Board of Directors since 1928, but through a brief outline of his great achieve¬ments in his chosen profession pub¬lished in our issue of December last. The vice-presidents, Howard N. Eavenson and H. A. Guess, are also well known to our members. Mr. Eavenson has not only been chairman of the Coal Division since its organization, but was also a Director during 1917, 1918 and 1919., Mr. Guess was Director in 1926, was elected a vice-president by the Board last year to fill the vacancy created by the election of Mr. Bassett to the presidency, and is now elected to the usual three-year term.

Jan 1, 1931

THE. extraordinary volume of work done in this period, and the multiplicity of subject matter, make a year-by-year historical account undesirable, if the account is not to be an assembly of unrelated fragments. We shall, instead, undertake to narrate the development in this period of each of the branches of the subject separately, hoping that their interrelations will be self-evident. There is a certain arbitrariness in the selection of subject matter in the following sections. The development of important engineering alloys-for example, high-speed steel-is disregarded, for it is the primary purpose of this account to relate the advances in ideas, the growth of the science of metals; other historical accounts relate these parallel advances. Nor are advances in techniques stressed, though occasionally the most important are noted; nor is the progress described in allied fields such as welding, cutting, etc.; for though these developments have very frequently made possible the advances herein related, they are far too numerous to recount in anything short of a ponderous volume. There is a more serious arbitrariness, however; it is not an easy matter to draw the boundaries of physical metallurgy, and some contiguous subjects have been omitted that perhaps should have been included, such as, for example, corrosion, gases in metals, the magnetic behavior of metals and alloys, and certain other fields in the physics of metals. REACTIONS IN ALLOYS--DIFFUSION Many of the reactions occurring in alloys proceed by the operation of the process of diffusion in the solid state: the annealing of mixed powders to form alloys, the homogenization of castings or forgings, the freezing of alloys, the treatment of clad metals, the loss

Jan 1, 1948

By H. D. Hoskold

This instrument, shown in Fig. 1, is not generally known, though it has been used in England, and found very practical, handy and useful in work not requiring a transit or theodolite. It is not only a good miner's dial, but a circumferentor as well; that is, it can measure horizontal angles like a theodolite. The magnetic bearings are conveniently read on the inward-beveled upper divided circle; while another circle, graduated on the base-plate, is used for reading the horizontal angles with a vernier. Two leveling spirit-bubbles are sunk in the same base-plate. The vertical divided semicircle is attached to the compact-box by two short axes, which permit the semicircle, with its plain sights, to be turned down to a horizontal position, and rest upon a pin, which relieves the axes from strain. This adjustment gives a clear view of the needle and vernier, and protects the instrument from injury, when carried through low mine-workings. A groove in the semicircle receives a sliding-bridge which carries the plain sights, and a vernier for reading vertical angles. A ball-and-socket-headed tripod is used; but sometimes the instrument is mounted on parallel-plates and level-ing-screws; and sometimes a telescope is attached, instead of the plain sights. The instrument is admirable for all such Mexican surveys as Mr. E. A. H. Tays describes ;l and saves so much time and labor as to be vastly superior to the less accurate hanging-compass called by him a " bully " instrument. If the hanging-compass was ever used in England, it has long since given way to more modern and superior instruments.

Jan 1, 1905

By A. U. Seybolt

Precipitation of FeO from Fe-O solid solutions has been studied by metallographic methods. Such precipitation, which is visible, is composed largely of barely resolvable spheroidal particles. No metallographic evidence has been found for grain boundary oxide films. Oxygen diffusion into a iron does not occur chiefly by inter-granular penetration. IN an earlier communication' dealing with the solid solubility of oxygen in a iron, it was shown that under one set of conditions it was possible to show FeO precipitated from supersaturated solid solution. However, to assist in rationalizing the effect of an FeO second phase upon the mechanical properties of iron, it would be desirable to have more information on the possible modes of precipitation and on the thermal treatments required to produce precipitation.

Jan 1, 1955

By J. H. Westbrook

IT is always of interest to document the origin of real microstructures which closely approach various idealized morphologies. Such instances constitute excellent bases for experimental studies of the effect of microstructure on properties. Typical examples include the eutectoid steels (lamellae) used by many investigators and the two phase Cu-Cr alloys (spheres) recently employed by Hibbard and Hart The present note describes a structure with cylindrical particles. In a study of certain alloys in the Cr-C system, an alloy was arc melted whose composition was very close to the aCr-Cr,C, eutectic (3.2 wt pct C, according to the latest phase diagram published by Bloom and Grant2). The alloy was not analyzed but previous experience with the melting technique employed indicates good correspondence between intended and analyzed compositions with negligible tungsten contamination from the electrode. The phases present in the alloy were identified by X-ray powder patterns as a chromium and Cr,C,. Typical micrographs, presented in Fig. 1, show unmistakable evidence of the cylindrical geometry of the carbide phase. The eutectic grains are randomly oriented and, consequently, only a few show the true fibrous nature of the carbide particles, most being cut so as to show slightly elliptical cross sections. Within any particular grain, remarkable uniformity is to be observed with respect to the size, shape, spacing, and orientation of the carbide particles. Length to diameter ratios have been estimated from the micrographs to be at least 250:1, with diameters of about lp. This alloy may be of further interest from different viewpoints. On the one hand, it might be used to check the applicability of the equations derived by Fullman3 for computing true particle dimensions of cylindrical particles from opaque random sections. On the other hand, it might be possible to extract the carbide particles from this alloy and repack them in a ductile matrix to form a synthetic structure of the type discussed by Metcalfe et al.4 With the large l:d ratio and the small diameter of the carbide fibers, it is likely that the interdefect distance in each fiber is sufficiently great to permit realization of a large fraction of the presumed high strength of the carbide. References 1W. R. Hibbard, Jr. and E. W. Hart: Dispersion Hardening of Copper-Chromium Alloys. AIME Trans., 1955, vol. 203, p. 200; Joun-nal of Metals, January 1955. 2D. S. Bloom and N. J. Grant: The System Chromium-Carbon. AIME Trans.. 1950. vol. 188. p. 41; JouRnal of Metals, January 1950. aR. L. Fullman: Measurement of Approximately Cylindrical Particles in Ooaaue Samples. AIME Trans.. 1953, vol. 197, p. 1267; Journal of Metals. ~ebtember 1953 4 A. G. Metcalfe, C. H. Sump, and W. C. Troy: Fiber Metallurgy. Metal Progress, 1955, vol. 67, p. 81.

Jan 1, 1958

By Donald W. Scott, Adam Wesner

This paper describes the study of 23 nonmagnetic iron-formation samples from the Mesabi Range and shows the significance of their chemical, mineral, and physical properties in terms of their concentration. Data presented here resulted from a research project carried out from 1942 to 1952 by 10 major producers of iron ore, working in conjunction with Battelle Memorial Institute. THE inevitable depletion of Mesabi direct-shipping iron ores, hastened by recent wars, has increased the importance of developing methods to concentrate iron-formation materials. Many mining companies, independent research organizations, chemical companies, and equipment manufacturers are devoting attention to this important work. It is only natural that magnetic iron-formation materials have received major emphasis, since magnetic recovery methods apply and reserves of Mesabi magnetic taconites are large. However, the nonmagnetic* iron-formation materials are likewise believed to represent a large reserve and their study has not been neglected. tions over the years have shown that in addition to the unenriched taconite, which is dense and hard, and the direct-shipping ore, there are transition taconites grading into the friable wash, or intermediate ores. The transition taconites are less massive than the unaltered taconites and usually coarser-grained. This variation, coupled with the fact that there were no extensive drillings in the unaltered taconite, posed a most difficult problem of obtaining samples that would be representative of large tonnages of the fresh rock. The problem was increased by the tremendous extension of the nonmagnetic formation materials on the Mesabi and by the question of their accessibility to mining. A drilling program was evolved that would surmount these difficulties. Selection of samples was made by a committee representing producers in the area. The samples were procured from 1—taconite walls near bodies of stripping burden or wash ore and 2—from shafts in the process of being sunk through taconite for drainage or mining operations. Most of the samples were obtained from the cherty horizons because it became obvious early in the program that the slaty horizons represented an exceedingly difficult concentration problem, owing to the character of the gangue minerals and the fine grind required for liberation of the valuable minerals. More samples were procured from the lower cherty horizon than from the upper cherty because it was more accessible to mining. It is not known how well the samples selected represent the nonmagnetic iron-formation material. However, they were chosen by people Well acquainted with the geology of the Mesabi range and the mining problems involved. It is believed that they represent a fair cross-section of the types of materials that will be encountered. Table I gives data on the origin of the 23 samples and the horizon footages from which they were obtained. Samples 1 through 10, and 15 and 16

Jan 1, 1955

By M. Gensamer

THE PURPOSE OF THIS PAPER is to lay a foundation of elementary theory that might be useful in the discussions which it is hoped will be evoked during this Symposium. It is not my purpose to try to expound the details of the most complete theories as that would be impossible in the time at our disposal and, even if time were available, would probably be of less usefulness than a discussion of the principles underlying the advanced theoretical treatment. I shall try to discuss the fundamental bases for these advanced theories. There exists at the present time very much less need for a detailed description of complete theory than existed when this Symposium was being organized. The reason for this is that a series of papers by L. R. Underwood has been appearing in the magazine Sheet Metal Industries. It is understood that this series will he published soon in the form of a book. Dr. Underwood's articles are complete, critical and well written and it would be hopeless to try to do better in less space. The need, then, is for a brief treatment of basic theory. The objective of any theory of plastic forming- is to enable one to calculate the force and power requirements for the process, and where the deformation is not uniform, to calculate the distribution of strains- In the formed object. We need as the basis for the calculation the relationship between stress and strain in the metal, particularly for the combination of stresses imposed by the forming process. We need to know the stress-strain curve for some simple state of stress, and we need in addition some theory

Jan 1, 1948

By Walter E. Dean

Deep-sea manganese nodules are considered to be potential ores of manganese, nickel, cobalt, and copper. Considerable time, effort, and funds have been applied to the study of the distribution of nodules on the seafloor and the location of economically important areas, but less effort has been spent in understanding the origin of nodules. Most theories that have been proposed to explain the origin of manganese nodules have been based on inorganic processes. It is not by coincidence, however, that the area considered to be most economically feasible is, in the zone of high biological productivity in the eastern equatorial Pacific Ocean and underlain by siliceous biogenic sediment. The genesis of manganese nodules and the concentration of many trace elements are related indirectly, and possibly directly, to the activities of organisms.

Jan 1, 1983

By William H. Marlowe, Thomas E. Ban, Eric Johnson

Introduction In recent years, the industries of the US have been caught between ever increasing environmental concerns and an increasing uncertainty in availability of fuel. An obvious solution is to use our vast reserve of coal by direct combustion or gasification. The problem involves development of a fuel that is environmentally acceptable for these purposes. In order to resolve this problem in the shortest period of time, it would be ideal if an existing technology could be modified to produce a clean fuel from coal. Shortly after World War II, the iron ore industry was compelled to develop a high quality ore from low grade resources. This need led to the development of the taconite industry which involved milling, concentrating, and pelletizing technologies. These technologies are now fully established and applicable to conversion of coal. This presentation introduces a process for converting high sulfur coal into carbonized composite pellets, which emit low quantities of sulfur and particulate matter and may be produced by employing proven elements of technology. The new product, a clean pellet fuel (HelifuelTM) was initially developed by McDowell-Wellman Co., a subsidiary of Helix Technology Inc., at their Dwight-Lloyd Research Laboratories

Jan 1, 1982

By Bruno Nordberg

HOISTING is one of the earliest endeavors of man with machinery, for hoisting was probably used by the early Egyptians. Treadmills were used for general hoisting until early in the nineteenth century and it was a short step only to attach a Watt steam engine to the rope drum of a hoist. One of the earliest steam hoists was built for a coal mine at Frisne, near Valenciennes, France. It was a remarkable piece of engineering created by James Watt in 1811, using a wooden drum on a vertical shaft. This followed the crude hoist by Holtzhausen in 1803, which used a drum of wood on a horizontal shaft.1 In this country there were examples of crude mine hoists, which have been developed into the efficient machines in use today. African and Australian mines show examples of both extremes, and have an array of fine hoisting equipment exemplified in those built by British manufacturers. The influence of both English and American engineering in hoisting is interestingly evident in Canada. The information available to the writer does not reveal this to be true of South Africa, although American-built hoists have been furnished. Mining camps develop their own style of equipment, adapted to local conditions. For instance, the Butte mining district adheres to the straight drum with friction clutches, because of the great number of levels from which hoisting is done or to which men and material are lowered and the necessity for hoisting or lowering unbalanced. The north Michi-gan copper country uses both straight and cylindroconical drums and hoists continually in balance, so that the drums are not clutched to the main driving shaft. The Joplin mining district, Missouri, has its own peculiar small hoists. Other individual mines or localities in which a number of mines have been developed show individualisticc types of hoists, depending upon their particular problems. In each instance, however, the particular problem must be carefully analyzed, as conditions are seldom so near the same that a number of identical hoists can be used to advantage.

Jan 1, 1940

By Bruno V. E. Nordberg

HOISTING is one of the earliest endeavors of man with machinery, for hoisting was probably used by the early Egyptians. Treadmills were used for general hoisting until early in the nineteenth century and it was a short step only to attach a Watt steam engine to the rope drum of a hoist. One of the earliest steam hoists was built for a coal mine at Frisne, near Valenciennes, France. It was a remarkable piece of engineering created by James Watt in 1811, using a wooden drum on a vertical shaft. This followed the crude hoist by Holtzhausen in 1803, which used a drum of wood on a horizontal shaft.1 In this country there were examples of crude mine hoists, which have been developed into the efficient machines in use today. African and Australian mines show examples of both extremes, and have an array of fine hoisting equipment exemplified in those built by British manufacturers. The influence of both English and American engineering in hoisting is interestingly evident in Canada. The information available to the writer does not reveal this to be true of South Africa, although American-built hoists have been furnished. Mining camps develop their own style of equipment, adapted to local conditions. For instance, the Butte mining district adheres to the straight drum with friction clutches, because of the great number of levels from which hoisting is done or to which men and material are lowered and the necessity for hoisting or lowering unbalanced. The north Michigan copper country uses both straight and cylindroconical drums and hoists continually in balance, so that the drums are not clutched to the main driving shaft. The Joplin mining district, Missouri, has its own peculiar small hoists. Other individual mines or localities in which a number of mines have been developed show individualistic types of hoists, depending upon their particular problems. In each instance, however, the particular problem must be carefully analyzed, as conditions are seldom so near the same that a number of identical hoists can be used to advantage.

Jan 1, 1940

By David White

The submission of carefully prepared estimates of the oil reserves of the United States calls for no apology or explanation. In this country, petroleum is a rapidly wasting asset and an occasional appraisal of the amount remaining in the ground is a simple business procedure to safeguard the general welfare and the prosperity of the republic. The rumored danger of failure, in the near future, of the foreign supply on which we depend in constantly increasing amounts makes the immcdiatc review of our available reserves the more imperative. The Director of the U. S. Geological Survey, in March, 1921, requested the American Association of Petroleum Geologists to cooperate in the preparation of new estimates of the oil remaining in the graund. With the members of this cooperative committee, state geologists, regional geologists, oonsulting specialists, and geologists and engineers attached to many companies worked both independently and through subcommittees. The reports for districts, counties, fields, etc., after review by local or state committees, were discussed by the joint cooperative committee in conferences that, in some instances, were attended by the original compilers of estimates for the states or smaller areas. Finally the data were reviewed and the figures revised by the joint cooperative committee, so that the totals given in Table 1 represent the opinion of the committee, which was composed of F. W. DeWolf, W. E. Wrather, Roswell H. Johnsont Wallace A. Pratt, Alexander W. McCoy, Carl H. Beal, C. T. Lupton, G. C. Matson, K. C. Heald, W. T. Thom, Jr., A. E. Fath, Kirtley F. Mather, R. C. Moore, and David White, chairman. Oil geologists and engineers understand well the speculative nature and the chances of error that must attend estimates of the petroleum in the ground when they cover not merely prospective territory, but possible territory. Neither the character nor the magnitude of the factors of uncertainty is to be disguised. Further, the inevitable differences of opinion between geologists of equal rank and experience must also bc

Jan 1, 1923

By David White

The submission of carefully prepared estimates of the oil reserves of the United States calls for no apology or explanation. In this country, petroleum is a rapidly wasting asset and an occasional appraisal of the amount remaining in the ground is a simple business procedure to safeguard the general welfare and the prosperity of the republic. The rumored danger of failure, in the near future, of the foreign supply on which we depend in constantly increasing amounts makes the immcdiatc review of our available reserves the more imperative. The Director of the U. S. Geological Survey, in March, 1921, requested the American Association of Petroleum Geologists to cooperate in the preparation of new estimates of the oil remaining in the graund. With the members of this cooperative committee, state geologists, regional geologists, oonsulting specialists, and geologists and engineers attached to many companies worked both independently and through subcommittees. The reports for districts, counties, fields, etc., after review by local or state committees, were discussed by the joint cooperative committee in conferences that, in some instances, were attended by the original compilers of estimates for the states or smaller areas. Finally the data were reviewed and the figures revised by the joint cooperative committee, so that the totals given in Table 1 represent the opinion of the committee, which was composed of F. W. DeWolf, W. E. Wrather, Roswell H. Johnsont Wallace A. Pratt, Alexander W. McCoy, Carl H. Beal, C. T. Lupton, G. C. Matson, K. C. Heald, W. T. Thom, Jr., A. E. Fath, Kirtley F. Mather, R. C. Moore, and David White, chairman. Oil geologists and engineers understand well the speculative nature and the chances of error that must attend estimates of the petroleum in the ground when they cover not merely prospective territory, but possible territory. Neither the character nor the magnitude of the factors of uncertainty is to be disguised. Further, the inevitable differences of opinion between geologists of equal rank and experience must also bc

Jan 1, 1923

By William P. Blake

The occurrence and distribution of phosphorus is one of the most important questions with which the steel-maker has to do. Large sums are invested in processes for the removal of this element from ores before they come to the blast-furnace, and much greater sums in freeing the pig-iron from it. Mechanical engineers are becoming more and more critical of the amount of total phosphorus left in structural steel, the tendency being to require that it be reduced to the lowest possible figure. The old maximum of 0.1 per cent. is now considered much too high for first-class structural steel, and demands for 0.03 to 0.01 per cent. are by no means unheard of. The first to speak, in a scientific way, of the harmful effect of phosphorus on iron and steel appears to have been Meyer, who, in 1781, made mention of what we now term "cold-shortness," ascribing it to the presence of this metalloid, but not suggesting any remedy. It is, however, doubtful if a clear idea of this subject was possessed by the scientific world until after the invention of the pneumatic or Bessemer process, in 1855-56. One of the chief obstacles in the way of this renowned metallurgist,—one, indeed, the removal of which was the sine qua non of success,—was the phosphorus in the iron blown. The effect of the phosphorus does not seem to have been apprehended until many and costly experiments had been made, and then the required minimum percentage of it in the iron was secured only by the use of low-phosphorus ores. It was not until '1879-80 that practical success was reached, by the Thomas process, in the actual removal of the phosphorus from the iron. We now know something of the effect of the total amount of phosphorus on iron and steel, but very little as to the effect of the condition of the phosphorus. The state of combination in which

Jan 1, 1893

By Richard Moldenke

The paper describes the making of pig iron from the Mayari iron ores of Cuba. The outstanding feature f this pig iron is a considerable content f nickel and chromium. As a marked improvement in the quality of castings has been noted when this iron is used in the foundry mixtures, a series f melting tests f mixtures of great variety of composition was conducted with the idea f getting comparative strengths from which the effect of nickel¬chromium could be seen. These tests, on account of their number, and degree of accuracy desired, were made by the crucible melting method. The paper gives the tables of results, a series f curves showing the inter-relation of the elements involved, and a summary of the conclusions derived. THE presence of nickel-chromium in pig iron made from Cuban ores is so well known that the word "Mayan" is unconsciously associated with it. Since 1904, when exploration of the Mayari deposits of iron ore in northeastern Cuba was undertaken, there has been increasing interest in these ores. The TRANSACTIONS contain numerous references to them. This iron ore, which is shipped to the. United States in the nodulized state, has been thoroughly tested and found very valuable; the deposit covers over 25,000 acres and there is in sight over 500,000,000 tons of ore that, by systematic mining, runs practically constant in composition. With nickel and chromium present, also titanium in sufficient quantities to attract attention, as well as extremely low phosphorus and sulfur contents, the iron founder is naturally interested in the utilization of Mayari ore for pig iron for the better grades of finished iron products. The present point of consumption of Mayari ore is at Sparrow's Point, where Mayari pig iron of any desired composition is made. The com-

Jan 9, 1922

By Bruno V. E. Nordberg

Hoisting is one of the earliest endeavors of man with machinery, for hoisting was probably used by the early Egyptians. Treadmills were used for general hoisting until early in the nineteenth century and it was a short step only to attach a Watt steam engine to the rope drum of a hoist. One of the earliest steam hoists was built for a coal mine at Frisne, near Valenciennes, France. It was a remarkable piece of engineering created by James Watt in 1811, using a wooden drum on a vertical shaft. This followed the crude hoist by Holtzhausen in 1803, which used a drum of wood on a horizontal shaft.' In this country there were examples of crude mine hoists, which have been developed into the efficient machines in use today. African and Australian mines show examples of both extremes, and have an array of fine hoisting equipment exemplified in those built by British manufacturers. The influence of both English and American engineering in hoisting is interestingly evident in Canada. The information available to the writer does not reveal this to be true of South Africa, although American-built hoists have been furnished. Mining camps develop their own style of equipment, adapted to local conditions. For instance, the Butte mining district adheres to the straight drum with friction clutches, because of the great number of levels from which hoisting is done or to which men and material are lowered and the necessity for hoisting or lowering unbalanced. The north Michigan copper country uses both straight and cylindroconical drums and hoists continually in balance, so that the drums are not clutched to the main driving shaft. The Joplin mining district, Missouri, has its own peculiar small hoists. Other individual mines or localities in which a number of mines have been developed show individualistic types of hoists, depending upon their particular problems. In each instance, however, the particular problem must be carefully analyzed, as conditions are seldom so near the same that a number of identical hoists can be used to advantage.

Jan 1, 1940