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By Ralph M. Barnett, Albert K. Smith

During the last few years, a great deal of interest has been aroused in the use of more refined blasting techniques. It has been the effort of many mining companies to reduce powder cost, obtain better rock breakage, reduce drilling costs and provide safer working places. With the advent of new types of powder and such techniques as cushion blasting, line blasting, smoothwall or soundwall blasting, and presplitting or preshearing, these goals are approaching reality. Smoothwall blasting and presplitting have re- ceived much attention at the Climax Molybdenum Co., Climax, Colo., mine because of the large cost factor involved. An experimental program was begun in 1961, and during 1964 to the present has been used in many working areas. Some spectacular results have been achieved by the operating personnel in hard ground, but the most beneficial results have been in areas where the ground has been soft and highly fractured.

Jan 7, 1965

By V. Lessels, W. A. Hamilton

White Pine Copper Co. is a wholly owned subsidiary of the Copper Range Co. The property of White Pine is about 5 miles south of Lake Superior in Carp Lake Township, Ontonagon County, Mich. The new town of White Pine, adjacent to the company plant, is 18 miles south and west of the town of Ontonagon, and about 55 miles north and east of Ironwood, Mich. A diamond drilling program begun in 1937 to develop the orebody was carried on until 1950. During this period a test shaft, known as the Schacht shaft, was sunk on the orebody and approximately 8000 ft of development drift were driven. In an effort to solve the ore beneficiation problems, considerable metallurgical test work was done on ore extracted through the mine development. This work was conducted in a small pilot plant located in the mill of the Copper Range Co. at Freda, Mich.

May 1, 1956

By J. J. De Witte, J. G. Cazort

The Paranam plant in Surinam (formerly Dutch Guiana) was built during 1939-40 to supply crushed and dried bauxite for the growing U.S. aluminum industry, supplementing production from the Suriname Aluminum Co.'s Moengo works, which began operation in 1922. A subsidiary of Aluminum Company of America, Suralco's total annual production from these two plants averages 2.55 million dry metric tons of various grades of bauxite. Starting in 1941 with bauxite from mines on the west side of the Suriname River, annual production at the Paranam plant has varied from a low of approximately 450,000 tons to more than 1 million tons in 1949. High production rates during World War II and the late 1940's rapidly depleted these reserves, and in 1950 plans were made to mine the known deposits on the east bank of the river, about five miles downstream from the original Paranam plant.

Jan 11, 1960

By Robert Glass Cleland

THE OUTBREAK of World War II found Phelps Dodge, thanks to both foresight and good fortune, in a position to increase production of its mines and factories to meet the insatiable military and domestic needs of the times, far beyond all previous records. With the timely completion of the expansion program at Morenci, the company's copper output rose to approximately 447 million pounds in 1942 and to over 478 mil- lion pounds the next year, compared to some 300 million pounds in 1939. To meet the civil and military needs for fabricated cop- per products, the Phelps Dodge Copper Products Corporation carried out an expansion program comparable in size to that of the Phelps Dodge mining operations. It built new plants, enlarged and reorganized those already in operation, multiplied the number of technical experts on its staff, adopted new methods and new machines for the new prod-

Jan 1, 1952

By D. F. Hewett

[In an increasing degree in recent years, especially since the war, men in many parts of the world are turning their attention to the problems of the future, attempting to appraise the basis and extent of man's progress and interpret the problem that he faces in the near future. The war made clear to ma persons the degree to which modern industry depends upon t continuous flow of enormous quantities of raw materials, a especially of the minerals. In many circles throughout t world, the question of adequate supplies of the mine especially the fuels and metals, for near as well as more remo needs is receiving serious consideration. As a result, persons representing the state as well as industry are looking to geologists and engineers for all the data that throw light on the distribution, extent and availability of the minerals that must serve coming generations.] Obviously, in a brief research I have been able to consider only a few sources of the metals in Europe, perhaps fifty out of a total of many hundreds. In order that the conclusions may have value, however, I have chosen districts which have been important sources during some epoch of the last three hundred years or more.

Jan 1, 1932

By H. S. Munroe

To those familiar with ore-dressing practice, it is hardly necessary to dwell upon the importance of the jig. Within its proper sphere no substitute has been found that does the work as well or as cheaply. Its capacity is large, it requires but little attention, and the losses are small. In one form or another, it is the principal machine used in the concentration of low-grade ores, and for the separation of one metallic mineral from another; and it is almost the only machine used for the purification of coal. The present paper is a study of the action of the jig in the light of results obtained in the Lake Superior copper mills, ad at the St. Joseph Lead Co.'s dressing-works, in Missouri; and a description of experiments undertaken with the view of reproducing and isolating the conditions of jigging, in order to develop the laws which underlie the process. There are two recognized systems of jigging, the English and the Continental or German. The English system is a development of the hand-jigging formerly employed in Cornwall and other metalliferous districts of England, and introduced by English miners to this country. In this method the crushed ore, coarse and fine together, is first jigged oh a

Jan 1, 1889

By T. H. Dunn, P. L. Menaul

This paper discusses the results of an investigation made to develop a method of combatting corrosion of subsurface oil-well equipment caused by brines containing hydrogen sulphide. Carbon monoxide, aldehydes, and certain cyanide compounds were found by laboratory tests to effectively inhibit corrosion of steel by sulphide brines. Experiments were made for one year in eight wells in West Texas fields using formaldehyde as an inhibitor. It was found that the inhibitor treatment successfully prevented the severe corrosion previously experienced in these wells, and effected important net savings in operating costs. Introduction Corrosion of oil-field equipment has long been a problem in areas producing sour crudes. These areas include the major fields of Arkansas, Western Kansas, West Texas and New Mexico. Corrosion in these fields is caused primarily by the chemical action of hydrogen sulphide in the presence of water and by electric currents entering the wells through flow lines. Hydrogen sulphide is noncorrosive to iron or steel in the absence of water but under the usual conditions prevailing in oil wells where more or less water is present, hydrogen sulphide is very corrosive. This type of corrosion occurs over the pH range below 9, which includes all natural oil-field brines. If air is present in addition to hydrogen sulphide and water, corrosion proceeds at an extremely rapid rate. It was reported several years ago that a string of oil-well tubing was literally dissolved within 50 days where an air lift was used on a well producing considerable water and hydrogen sulphide. Air is generally absent in wells producing sour crude. After hydrogen sulphide corrosion starts, it proceeds with increasing severity and its correction becomes progressively more difficult. This characteristic of sulphide corrosion has been attributed to the formation of galvanic couples between the iron and steel equipment on one hand and the products of corrosion on the other.' Severe corrosion of subsurface oil-well equipment leads to a multitude of troubles. In addition to destruction of costly equipment, producing sands often are damaged by flooding with water leaking through corroded casing; bad mechanical conditions may develop in a well due to obstructions caused by corroded equipment lost in the hole, or partly collapsed casing; pumping operations are interfered with, and severe emulsification problems may result from the homogenizing action of corroded balls and seats.% A typical case of severe corrosion caused by hydrogen sulphide was reported in Howard County, Texas, where it was necessary to pull tubing once a week to repair leaks after the tubing had been in use for only one year. On one well in this area a string of tubing was pulled 11 times in 8 months; 11 joints of tubing being replaced because of leaks. In Ector

Jan 1, 1946

By T. H. Dunn, P. L. Menaul

This paper discusses the results of an investigation made to develop a method of combatting corrosion of subsurface oil-well equipment caused by brines containing hydrogen sulphide. Carbon monoxide, aldehydes, and certain cyanide compounds were found by laboratory tests to effectively inhibit corrosion of steel by sulphide brines. Experiments were made for one year in eight wells in West Texas fields using formaldehyde as an inhibitor. It was found that the inhibitor treatment successfully prevented the severe corrosion previously experienced in these wells, and effected important net savings in operating costs. Introduction Corrosion of oil-field equipment has long been a problem in areas producing sour crudes. These areas include the major fields of Arkansas, Western Kansas, West Texas and New Mexico. Corrosion in these fields is caused primarily by the chemical action of hydrogen sulphide in the presence of water and by electric currents entering the wells through flow lines. Hydrogen sulphide is noncorrosive to iron or steel in the absence of water but under the usual conditions prevailing in oil wells where more or less water is present, hydrogen sulphide is very corrosive. This type of corrosion occurs over the pH range below 9, which includes all natural oil-field brines. If air is present in addition to hydrogen sulphide and water, corrosion proceeds at an extremely rapid rate. It was reported several years ago that a string of oil-well tubing was literally dissolved within 50 days where an air lift was used on a well producing considerable water and hydrogen sulphide. Air is generally absent in wells producing sour crude. After hydrogen sulphide corrosion starts, it proceeds with increasing severity and its correction becomes progressively more difficult. This characteristic of sulphide corrosion has been attributed to the formation of galvanic couples between the iron and steel equipment on one hand and the products of corrosion on the other.' Severe corrosion of subsurface oil-well equipment leads to a multitude of troubles. In addition to destruction of costly equipment, producing sands often are damaged by flooding with water leaking through corroded casing; bad mechanical conditions may develop in a well due to obstructions caused by corroded equipment lost in the hole, or partly collapsed casing; pumping operations are interfered with, and severe emulsification problems may result from the homogenizing action of corroded balls and seats.% A typical case of severe corrosion caused by hydrogen sulphide was reported in Howard County, Texas, where it was necessary to pull tubing once a week to repair leaks after the tubing had been in use for only one year. On one well in this area a string of tubing was pulled 11 times in 8 months; 11 joints of tubing being replaced because of leaks. In Ector

Jan 1, 1946

By A. C. Losekamp, J. B. Conway

Thermal-expansion data for, tungsten, rhenium, tantalum, .molybdenum, niobium, W-25 pct Re, Ta-10 pct W, ant1 Mo-50 pct Re are presented covering the range from room tempature to 2500°C. In these measureMents, made in a resistively heated tungsten tube furnace operating in a helium atmosphere, data for rod and sheet specimens were found to be identical; in addition, arc-cast and sintered tungsten were found to yield essentially identical results. Optical rneasurenlents of thermal expansion .made in any atmosphere other- than vacuum are subject to a refraction error which can be quite substantial. Specimens tested in helium appear shorter than when tested in racuum and hence a special correction factor must be applied to the helium data in order to obtain accurate results. WHILE it is true that linear thermal-expansion data for many of the refractory metals have been measured to very high temperatures, it is also true that except in a few instances the data from various investigators are not in good agreement. This is particularly evident in the case of tantalum and niobium although some tungsten data have been reported which differ by as much as 40 pct from the data of other investigators. Due to the sensitivity of both tantalum and niobium with respect to impurity absorption during exposure to high temperatures, it is probable that this single factor accounts for the majority of the discrepancies in the thermal-expansion data for these metals. However, this same factor can probably not be employed to explain the existing differences in the tungsten data. In all probability, these are due to errors in the measurement technique, to material composition variations, or to changes which take place in the material during the heating process (e.g., additional densifica-tion resulting from heating a sintered specimen above the original sintering temperature). In view of the discrepancies which exist in the linear expansion data reported for many of the refractory metals, the current study was initiated in an attempt to resolve such differences. Also, no high-temperature linear thermal-expansion data were found to be available for several refractory metals. Providing such data was another objective of the current investigation. MATERIALS In this study test specimens were employed in either rod or sheet form and in several instances both arc-cast and sintered material were employed. Material compositions are presented in Table I. Helium gas was fed to the furnace at a rate of about 0.5 SCFH and no special purification procedures were employed. However, the helium contained less than 50

Jan 1, 1967

By AIME AIME

THE stage is set for the 1930 Annual Meeting. It will take place in the Engineering Societies Building. Feb. 17, 18, 19 and 20, and an unusual pro- gram of technical papers, symposia, lectures and addresses, interspersed with luncheons, dinners, excursions and worthwhile entertainment for the four days has been arranged. The curtain rises on Monday morning and the first act is by the entire company-registration. Then the meeting hits its stride, for there are ten technical sessions on Monday, and the range of subjects includes most of the Institute membership. The Committee on Coal and Coal Products, which is about to become the Coal Division, presents a symposium of a dozen or more papers on Coal Classification, concluding its afternoon session with several papers on general subjects. At its luncheon between sessions, C. E. Bockus, president of the National Coal Association, will be the honored guest. Papers of theoretical character will be discussed at the morning session of the Committee on Geophysical Prospecting; at its afternoon session there will be presented summaries of results obtained at various properties by methods described at previous meetings of this group and permanently recorded in "Geophysical Prospecting," published by the Institute early in 1929. Members of the Petroleum Division should not overlook the paper by Theodor Zuschlag, on this Committee's program. It is entitled, "Oil Structure Mapping by the Sundberg Method." Members of the Iron and Steel and Institute of Metals divisions will find it profitable to attend the session on Engineering Education on Monday afternoon. E. A. Holbrook has arranged a program of ten-minute talks on Metallurgical Education which are designed to get down to "brass tacks." and the practical man may, in discussion, contribute as well as learn. At 5 p. m. Thomas T. Read will lecture+ at Columbia University, on "Recent Progress in Economics of the Mineral Industries."

Jan 1, 1930

A. O. GATES, Salt Lake City, Utah (communication to the Secretary*).-The writer is delighted by the results shown in Mr. Bell's paper, which prove in an experimental way different from that followed by the writer' that "the work clone in crushing is proportional to the surface exposed by the operation," per Rittinger's Law. Mr. Bell's work was all clone in commercial types of crushing machines, while my work was clone in a testing machine; his work represents fully one hundred times the expenditure and time that my work represented; a great number of tests were made by his organization to determine single points, while I was obliged to depend on the general trend of a curve for results; we agree absolutely that "Kick's law," for which Mr. Stadler was sponsor, does not apply to rock crushing. While my work indicated the reliability of Rittinger's theory, Mr. Bell's work clearly establishes the reliability and makes it Rittinger's law.

Jan 5, 1917

By P. D. Proctor, M. P. Nackowski

Quantification in recording geologic phenomena and application of well-known geologic principles to engineering works continued at an increasing rate during the year. Highway departments, water resources agencies, private firms and governmental agencies involved in tunnel excavations, dam site locations and construction, consultants and government experts in subsurface liquid-waste disposal, designers of underground storage facilities and city and regional planners all confirmed greater use of applied geology in their planning and implementation of plans. Applications of quantified geologic data to highway locations, slope control of cuts, raw material sources, water sources and water run- off showed a striking increase in number. Environmental geology and geologic hazards became part of the jargon of the geologic profession, and the American public began to realize more fully the significance of where they live, and on what and near what geologic phenomena which might effect their well-being. Tunnel work for water projects of almost dream-like magnitude kept geologic engineers busily engaged in predicting and testing local geologic conditions for construction projects. Disposal of industrial and radioactive liquid wastes continued as problems, but use of stratigraphic data, fluid flow rates and direction of flow helped solve some critical waste disposal problems. Unusual applications of seismic networks, remote sensing methods and X-ray techniques in geological engineering applications added other tools to this increasingly important profession.

Jan 2, 1968

By R. I. Jaffee, F. C. Holden, H. R. Ogden

The mechanical properties of Ti-C and Ti-C-0 alloys can be altered by heat treatments to dissolve or reject carbon from solid solutions. The maximum strength is obtained by annealing just below the peritectoid temperature. Quenching from the ß-carbide field results in softening. Impact behavior is influenced by the extent of solution of interstitials CARBON is not as important in titanium alloys as it was in earlier years when graphite induction melting was more prevalent. With induction melting, carbon pickup is about 0.5 to 0.8 pct. Cold-mold arc melting with graphite electrodes, which is among the more current methods, results in carbon pickup of 0.1 to 0.2 pct. The titanium-sponge melting stock itself contains about 0.02 to 0.07 pct C, picked up from the magnesium used in the reduction process. Thus, carbon is still one of the more important contaminants in titanium and needs careful study and evaluation in order to understand titanium and titanium alloys. Moreover, it is equally proper to consider carbon as an alloying addition because, in controlled amounts in titanium alloys, it may serve a most useful function. This is particularly the case where the ultimate in toughness is not required. The addition of carbon to titanium results in a peritectoid-type system as illustrated in Fig. 1. The solubility of carbon is seen to be higher in the a phase than in the ß phase in the temperature range of interest. Below the peritectoid temperature, the solubility of carbon in a titanium decreases with decreasing temperature. This type of system permits many microstructural and heat-treatment variations which may influence the properties of the alloys. The study of how the microstructure variations affect mechanical properties is described in this paper. Experimental Procedures The experimental techniques and testing methods used in this work were the same as those described in detail in a previous paper.' No further descriptions will be given except where changes have been made. High purity iodide titanium, produced by the New Jersey Zinc Co., was used in all of the alloys. Carbon additions were made using high purity spectro-graphic carbon electrodes in order to obtain the highest purity carbon available. The alloys were prepared by double arc melting to reduce the possibility of segregation. The alloys were forged at 875°C to ¾ in. round, descaled, vacuum annealed for 5 hr at 900°C to remove the residual hydrogen, and swaged to ¼ in. round at 750°C. All heat treatments were made on material in this initial condition. Two of the early Ti-C ingots were found to have been contaminated in melting. Vacuum-fusion analyses showed that the two contaminated alloys had picked up oxygen, so the test results on these two alloys permitted an evaluation of ternary Ti-C-0 alloys. A list of the alloys and their compositions are given in Table I. Properties of Ti-C Alloys In a peritectoid-type system, such as the Ti-C system, the chief microstructural variable which influences the properties is solid-solution strengthening. For a given composition, it is possible to control the disposition of carbon, either in solid solution or as the compound Tic, by suitable heat treatments. When in solid solution, the carbon present in the alloy makes a definite contribution to the strength of the alloy. However, when present as Tic, it has very little effect on the strength. Other microstructural variables considered in this investigation were transformation structures and grain size. As discussed in subsequent sections, these variables have only a minor effect on properties as compared to the solid-solution effect. Solid-Solution Strengthening: The principal strengthening mechanism for Ti-C alloys has been found to be solid-solution strengthening. Carbon in interstitial solid solution strengthens titanium, but has very little strengthening effect if present as the compound. Since carbon has a higher solubility in

Jan 1, 1956

By F. P. Dewey

Recent discussions have furnished to the members of the Institute much information concerning aluminum and its applications. The present paper will be devoted almost entirely to the description of a process by which the metal is produced in the form of alloys. The characters which especially distinguish the Heroult process consist in electrolyzing a mass of molten alumina (Al2O3), and at the same time alloying the separated aluminum with a heavy metal, the heat necessary for the fusion of both the alumina and the alloying metal being supplied by the direct passage through the molten Al2 0, of an electric current of high amperage and low voltage. The process has been in active operation at Neuhausen in Switzerland for about two years. It is also in active operation at Froges in southern France. Both these locations were selected for this purpose on account of the presence of large and desirable water-powers. The apparatus consists of a carbon containing-vessel, which may be a single crucible for small operations, or may be built up of slabs or blocks of carbon for large and industrial operations. When built up of slabs or blocks, the whole is surrounded by an iron casing. In the earlier crucibles this iron casing was cast around the carbon, in order to secure close electrical contact. This, however, has been found unnecessary; and in the later crucibles the casings consist of plates bolted together, while pulverized carbon is packed between the carbon blocks and the iron. Electric conductors are united direct to this iron casing, and the current passes from this through the carbon lining to the interior of the crucible. By this

Jan 1, 1890

By E. L. Bruce

GOLD occurs ill many mineral deposits in the rocks of the Canadian Shield. It is present in the ores of many base metals and a considerable quantity is recovered as a by-product from the production of copper at Noranda, of nickel and copper at Sudbury and of copper and zinc at Flinflon. But the greater part of the gold production of Canada is from deposits in which gold is the only metal of value. No gold is obtained from placer deposits within the borders of the Canadian Shield. A brief review of the geological relations of some of the gold deposits of the Canadian Shield will be presented in an attempt to explain certain associations. Only those which are being worked for their gold content will be considered and descriptions will be confined to representative types of deposits, chiefly those of major importance; a few others, differing in certain features from those of the older and larger mines, will be included in order to illustrate the general conditions in which gold occurs in these ancient rocks. Brief summaries will be given of the geological relations of the Beattie and Siscoe mines of northern Quebec, of the mines of the Porcupine and Kirkland Lake areas of northeastern Ontario and of the Howey, Central Patricia and Little Long Lac mines of northwestern Ontario. Genetic relations to igneous rocks of granitic composition, outcropping in the vicinity, have been assumed for many of these deposits. Undoubtedly the ore minerals have been derived from igneous sources and, for some occurrences, there is evidence suggestive of genetic relationship between the ore bodies and neighbouring intrusive rocks. During the past few years, however, many investigators have expressed doubt of the genetic relationship of certain ore bodies to igneous masses near which they occur. As will be seen from references in the following descriptions the importance of the structural conditions in localizing deposition has been realized. This is pointed out for Canadian pre-Cambrian gold deposits by E. T. Dougherty, who also refers to the

Jan 1, 1937

By John Wulff

IN a previous paper Burwell and Wulff1 have shown by electron diffraction studies that allotropic transformations can be induced in 18-8 stainless steel by polishing to a depth of about 5 X 10-5 cm. The development of a successful etching technique, which removes accountable amounts of metal from the surface without pitting and without changing the root-mean-square profile as measured with an Abbot profilometer, led to the application of the whole technique and material to an investigation of various mechanical methods of surface preparation, such as grinding, lapping, superfinishing and cold-rolling. Ideally suited to such a study is 18-8 of low carbon and nitrogen content. The material can be heat-treated to produce a coarse-grained single-phase structure. On cold deformation there occurs not only a reduction in grain size but, at regions of maximum stress, a change of face-centered material to body-centered material, provided the metal is worked below about 200°C. When worked between 200° and 415°C., diffraction studies evidence a reduction in grain size without the appearance of any new body-centered ferrite. Ferrite, which can be referred also to strains induced by carbide precipitation, is evident when the material is worked at temperatures between 415° and 800°C. Stainless steel is advantageous because the usual surface-finishing operations do not readily oxidize it to any appreciable depth. In order to produce detectable oxide films on the surface of austenitic 18-8 in a time equivalent to that required to produce, for example, a fine ground finish on ½ sq. in., the sample must be held in a furnace or oxygen stream above 600°C. By using longer heating times, it is possible to achieve measurable oxide films on samples whose surface temperatures exceed only about 250°C. EXPERIMENTAL PROCEDURE The apparatus, material, and technique described in the previous paper1 were employed in this investigation. Samples of 18-8, 1 by 1 cm. by 4 mm., were carefully annealed in the austenitic range to produce a coarse-grained structure. They were then quenched and pickled to remove scale. On a lapping machine of the Graton2 type, both sides of each sample were polished to a flatness of 1/6 a wave length of sodium D light. Thereafter they were electrolytically etched to remove at least 1 X 10-3 cm. of the surface, a depth that is well below that of any deformations induced by surface preparation. Samples of this material, carefully mounted in steel holders, were then sent to various industrial organizations known for special finishing techniques. In the instrument shops at the Massachusetts Institute of Technology check samples were finished by the same methods, as far as they were available. Abbot profilometer3 readings were made on all the samples, which were then carefully degreased in double distilled benzine and alcohol, dried in a hot-filtered air blast, and kept in a desiccator. Suc-

Jan 1, 1941

By AIME AIME

THE paper by C. H., Lieb on the "Economics of Oil-Producing Practice" (June issue, M. & M.) contains much food for thought. The engineers should be gratified that an executive with Mr. Lieb's. responsibility should recognize their standing in the industry. Yet after giving them that recognition, he proceeds to spur them on to greater accomplishments by pointing out that their job is only partly done and in some instances poorly done. The operating policies in this paper when applied to new pools with flowing wells are sound. Neither do I take exception to their application to pumping wells. But I do wish to comment on what lie says about price when applied to the many more wells that are approaching abandonment that is, the small producing wells. Mr. Lieb states in effect that higher prices would be detrimental from the long range viewpoint. I doubt that the present prices of crude will provide an ample return from the hundreds of thousands of small wells that have possibilities of substantial recovery by means of water-flooding, repressuring with gas, and air drive. Probably expenditure for experimental work can he justified, but at this time it must usually be considered as experimental. Recently I visited a property where it was estimated that $250,000 would be spent on a 160-acre tract for flooding purposes. The rate of r e t n r n and amount of profit at today's prices are uncertain. It can be argued that if this type of recovery is not economic with crude at $1 then it can he delayed as it is now possible to secure economically an ample supply of crude from our flush fields. But these old fields still retain large quantities of crude in a dormant state, and should not he abandoned per-

Jan 1, 1936

By Richard W. Greene, Joel S. Hirschhorn

MATERIALS containing very large amounts of porosity, in the order of 50 to 90 vol pct, are extremely difficult to evaluate according to conventional mechanical behavior tests. This is usually a consequence of their low strength and brittleness, and the difficulty of preparing standard test specimens. A simple fatigue test has been developed and used successfully on porous nickel sheet materials requiring no specimen preparation; it could also be used for configurations other than sheet or plate. Samples of the sheet. 2 in. sq and about 0.025 in. thick, are placed in a vessel that is evacuated to about 50 f Hg by a mechanical pump. Distilled and deairated water is allowed to enter the vessel thereby filling the porosity (virtually all the porosity in these nickel ma-

Jan 1, 1970

By Robert W. Hunt

Delays in the completion of the alterations to the plant at the works of Messrs. Oliver Bros. and Phillips, in Pittsburgh, coupled with the increased demand for metal made from regular Bessemer pig, placing the firm many hundreds of tons behind in their deliveries, prevented Mr. Henry W. Oliver, Jr., from redeeming his promise to place his works at my disposal for further tests of high-phosphorus irons, until May 5th. Upon that date, I assumed charge of the operations in his steel-plant. Mr. Oliver had purchased Neshannock pig as a basis for a supply of phosphorus. My information is to the effect that this iron is made from low-grade Lake Superior ores and mill-cinder, the latter "ore" being utilized to about 40 per cent. of the total mixture. At all events the pig had quite as much phosphorus, and in as varying quantities, as the most exacting could desire. My experiments of last fall had well satisfied me as to the effect of from 0.35 to 0.55 per cent. of phosphorus in the Clapp Griffiths metal. Hence at this time my first trials were directed to

Jan 1, 1886

By Douglas Bunting

In the anthracite fields of Pennsylvania, mine fires occur with more or less regularity and their existence is an ever-present hazard in coal mining. In all probability 90 per cent. of the mine fires can be ascribed directly or indirectly to the ordinary miner's open lamp. Other causes may be smoking, electrical installations, gas explosions, gas feeders, and the communication of fire to the outcrops from ash dumps, culm banks, timber and brush fires. Fires in pump rooms, engine rooms, and barns have been largely eliminated as a result of the Act of Assembly, approved June 15, 1911, which provides that all inside buildings, including engine rooms, pump rooms, barns, etc., shall be constructed of incombustible materials. Smoking of pipes, cigars, and cigarettes should be prohibited in the mines and too much care cannot be exercised in preventing fires by enforcing all rules designed for that purpose. Mine fires that involve underground fighting are invariably dangerous, and all fires, irrespective of the method pursued in extinguishing them, involve property loss and expense. Each fire generally presents a more or less original problem, dependent on the particular conditions. Generally mine fires may be divided into two classes: Those occurring in inaccessible workings and those occurring in accessible workings. The methods pursued in extinguishing or controlling mine fires are as follows: (I) direct attack, (2) smothering by sealing, (3) flushing with silt or other solids, (4) flooding with water, (5) cutting off, (6) surrounding with incombustible materials, (7) digging out by stripping from the surface. Most fires arc extinguished in their incipiency by direct attack and failure to extinguish by this method is due to late discovery, lack of water, and facilities for fighting, or improper procedure in the initial attack. Should the method first pursued be unsuccessful, careful consideration should be given in determining next the method to be adopted; then the work should be carried on as rapidly as possible and under the supervision of the most competent persons. Materials and supplies should be furnished without delay and in sufficient quantities for the work to be accomplished.

Jan 1, 1922