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By Walter E. Mingramm

THE construction of rescue-apparatus on the principle of furnishing the wearer with air from a tank containing it under high pressure was given up by inventors about 20 years ago. Such an apparatus must supply continuously, for not less than two hours, nearly 50 liters of pure air at atmospheric pressure per minute, or a total of 6,000 liters (210 cu. ft.); and a cylinder containing this amount of air, under 2,000 lb. pressure, would weigh 180 lb. or more. Although apparatus has been recently constructed utilizing liquified air, no experiments have been made to determine the regularity with which the air is generated, nor has its chemical composition been determined. Moreover, the chief objection to such an apparatus is the' difficulty and cost of keeping on hand a large quantity of liquified air. The system of furnishing the wearer of a breathing-apparatus with air which has given the best results, and has found employment in all the devices now in practical use, is that in which the air contained in the human lungs at the beginning of the work is regenerated by the apparatus. By means of chemicals, such as caustic potash and caustic soda, the carbonic acid gas, CO., exhaled is absorbed, and the oxygen that has been consumed is replaced from a tank containing this gas under high pressure. The pressure of the oxygen (which is 1,875 lb. in the two cylinders at the beginning of the work) is automatically reduced to 75 lb., and is sufficient to keep the air inside of the apparatus in constant circulation, and to force it to pass through the chemicals provided for the absorption of the CO, gas. In the attempt to construct an apparatus which would (1) furnish the wearer with a sufficient supply of air; (2) replace the amount of oxygen used up by the lungs during the time of

Jan 7, 1908

By A. L. Holley

The general usage of engineers, manufacturers, and merchants, is gradually, bat surely, fixing the answer to this question. In every country rails, boiler-plates, and machinery bars, whether hard or soft, are almost universally called steel, when they are made from cast ingots. Other names for the softer steels, such as " homogeneous metal,'' "Bessemer iron," " Martin iron," and the like, have failed to obtain general recognition. The meaning of the term steel, before it was enlarged to cover newly developing varieties, has been traced, by a recent writer, down through Percy, Shakspeare, and the Bible, in a most interesting manner, from an archœological point of view. Undoubtedly, it did characterize hardness arid other qualities imparted by carbon. It is within the memory of most of us, that all steels were tool steels, and that the soft, structural varieties were introduced—varieties which harden but little, which bend cold, and which, in many physical properties, are akin rather to wrought-iron than to tool-steel. But, since both the hard and the soft steels are made by the same processes, and have their great, distinguishing structural feature in common, viz., homogeneity resulting from fluidity, it has come to pass, despite every other proposed nomenclature, that all the compounds of iron which have been cast in malleable masses, are called steel, the term wrought-iron being still confined to malleable iron made from pasty masses, and hence laminated in structure. No inconvenience has been found, so far, in distinguishing between the more or less carburized products, in general, by the terms " highsteel," "low-steel," "tool-steel," etc., and, in particular, by prefixing the percentage of carbon and other ingredients, to the terra steel. Steels which contain distinguishing ingredients other than carbon, are called "chrome-steel," "titanium-steel," and the like, just as variously compounded bronzes are called " phosphor bronze," " aluminium bronze," etc. Thus the combination of several words or symbols, and figures, may completely disclose the characters of the metal, in terms that are subject to no misunderstanding. But inasmuch as several high metallurgical authorities and clever writers have of late proposed to disturb this natural and somewhat settled nomenclature, it seems important to consider the claims of the various classifications. I shall attempt, in this paper, to show

By William H. Emmons

Jan 1, 1912

By F. von Gemmingen, E. J. Fasiska, L. Zwell

EARLIER studies of the dependence of creep on structure1 and of the dependence of creep rupture on creep behavior2 did not include detailed discussion of the phases present in the specimens under examination. It is of interest to determine the nature and amounts of such phases present since it is well known that these are dependent on composition, heat treatment and creep conditions.3 This investigation has therefore been undertaken to identify these constituents and to determine their relative amounts. This report presents the results of this investigation and describes an improved "extraction replica" technique developed in the course of the work. The composition of the Type 316 austenitic stainless steels studied in this investigation is given in Table I. The specimens were solution treated at 2000°F for 1/2 hr and water quenched. Those specimens subjected to prestrain at room temperature Methods for extracting precipitate particles from materials for electron and X-ray diffraction analysis have been described by Fisher,4 Smith and Nutting: and Booker and coworkers.6'7 Electrolytic extraction methods have been described by Andrews and Hughes.8 The first two methods have been used at this Laboratory, but have not proved satisfactory for many problems requiring X-ray diffraction analysis. It has been difficult to remove the replicas or to avoid tearing them during removal. These difficulties are overcome by backing the replica with a water-soluble plastic such as Dupont 51-05 Elvanol (polyvinyl alcohol). The backing increases the thickness of the replica so that it can be mechanically stripped from unloosened particles without folding or tearing. This procedure eliminates the stripping of wet replicas, which usually have a low tear strength. By stripping replicas after drying, it is possible to extract partially loosened particles which otherwise would remain imbedded in the metal. The modified method is as follows: after the specimen is polished, it is etched for 60 min in modified glyceregia consisting of 30 ml glycerol, 7 ml nitric acid, and 4 ml of hydrochloric acid. The sample is then washed, air dried, and coated with a 20 pct Baker and Adamson 1611 collodion (85 pct amyl acetate by volume) film. After the collodion film is dry (about 15 min), the sample is again etched in the modified glyceregia for 50 min, washed with isopropyl alcohol (to prevent dissolving the collodion) and air dried. A very thick coat of polyvinyl alcohol (about 50 pct solution "Elvanol Dupont 51-05" in water) is poured over the sample and is permitted to dry for about 24 hr. The composite film containing the precipitates is then stripped from the specimen and floated, polyvinyl alcohol side down, in water (at about 50°C) until the polyvinyl alcohol dissolves. This usually takes about 15 min. Should any of the polyvinyl alcohol remain on the replica, it does not give a crystalline diffraction pattern and therefore does not hinder identification of the precipitates. The extraction replica, floating in water, is picked up on a glass fiber and mounted in the Debye-Scherrer camera for X-ray diffraction analysis. Concentration of the etchant, and also etching time, had to be increased for several of the samples. Fig. 1 shows two extraction replicas taken from different areas of spec. M74-37; X-ray analysis showed a strong diffraction pattern of M23C6 and a medium one of u phase. A

Jan 1, 1962

By Peter J. Huck, Madan M. Singh

IIT Research Institute has investigated the potential of high pressure water jets for rapid rock excavation. During this study, an attempt was made to correlate the extent of breakage effected to the mechanical properties of rocks. Six rock types were used in these experiments and nine properties were determined for each rock variety. A regression equation using the two most significant rock properties and one jet parameter (pressure) was established. Although tests were conducted to specific pressures of 35, no minimum in the specific energy consumption was noted.

Jan 1, 1971

By W. E. Howlett, R. L. Slobod

Jan 1, 1965

By Charles H. Moore, H. Sigurdson

When lime and magnesia are used as fluxes in the smelting of titaniferous ores fluid, digestible slags low in iron oxide and high in titanium dioxide are produced. The mineral phases present in such slags are (Fe,Mg)O.ZTiOp, CaTiO3, and minor amounts of silicate glass (or its devitrification products). The flux additions are added to the ore in relative amounts to crystallize a ratio of (Fe,Mg)O.2TiO2 to CaTiO, of near the eutectic proportions of 60 pct (Fe,Mg)O.2TiO2 and 40 pct CaTiOl. FeO.TiOz (ilmenite) remains present in the slag until the FeO content is reduced to approximately 8 pct. Optimum slag composition is obtained by reducing the FeO content to between 2 and 6 pct. Continued reduction shifts the (Fe,Mg)O.2TiO2 to oxygen deficient structures classified as MgTi306 and MgTi2O.. Further reduction yields titanium oxycarbides and freezes the melts. The(Fe,Mg)0.2TiO2 structure shows a complete isomorphous replacement of iron by magnesium. It also forms a solid solution compound with as high as 12 mols of TiO2 under reducing conditions without the occurrence of rutile or reduced titanium oxides in the slag.

Jan 1, 1950

By AIME AIME

POSSIBILITY of a greatly increased manganese production from domestic source; is indicated by news that the Bureau of Mines has been successful in producing concentrates with high manganese content from the low-grade deposit, in the Las Vegas, Nev.) area. The first unit of the comprehensive group of pilot plants built by the Bureau of Mines at Boulder City, Nev., under a defense appropriation has started operations, demonstrating definitely the applicability of a process developed in the Bureau laboratories. About 12 1/2 lb. of manganese is needed for the production of every ton of steel, and substitution is difficult. The United States produces only about 3 per cent of its total needs of this ore. Only high-grade ore, such as the Russian ore, containing 18 per cent or more manganese, is generally used by American producers in making ferro¬manganese the form in which manganese is usually added in steel manu-

Jan 1, 1941

By AIME AIME

THE joint symposium on gases in metals on Tuesday: Feb. 16, between the Iron and Steel and the Institute of Metals divisions opened the technical sessions for both of these bodies. After a few words of introduction by P. D. Merica, R. S. Dean presented a paper by V. H: Gottshalk and himself on the solubility of gases in metals.

Jan 1, 1932

By John E. Gale

Seven, 15 cm diameter, cores of gneissic granite, four containing induced fractures and three containing natural fractures all oriented normal to the core axis, were tested in an uniaxial compression mode over a range of 0 to 30 MPa. At given normal stress increments, over two or three loading and unloading cycles, the flowrates and changes in fracture aperture were measured. The induced fractures gave lower initial (at low stresses) and lower final flowrates (at maximum stress) than the natural fractures. Both types of fracture exhibited permanent fracture deformation between loading cycles as well as highly nonlinear, with distinct hystersis, loading and unloading flowrate-stress curves. A significant finding of this stud is the breakdown of the cubic law for fracture flow in induced fractures subjected to normal stresses greater than 20 MPa, with the breakdown occuring at much lower stresses in natural fractures.

Jan 1, 1982

Book Review MEXICO UNDER CARRANZA. By Thomas E. Gibbon, Los Angeles, California. Doubleday Page and Co., New York, 1919, 270 pp., 711/2 X 5 in. $1.50. A vivid, accurate, convincing summing up of the Mexican problem as it confronts us today, devoid of sensationalism or bigotry. A compelling narrative of the relations of the Carranza Government and our own from Oct. 15, 1915, when it was recognized as the de facto government of Mexico, to the present time. It shows the absolute lack of promises kept or lived up to either with its own people or the United States. This is not done by invective or the indiscriminate use of adjectives but by quoting from the instruments on record on both sides of the case. The driving of the Red Cross out of Mexico, which condemned many of the native peons to starvation, and the interference with the Pershing Punitive Expedition are merely mentioned, but the crying crime against the Mexican people, who have sunk to unbelievable depths of misery obscured, but not exceeded, by the sufferings in Europe, is held up in a clarified light. Two illuminating chapters are devoted to the character and treatment of foreign investments in Mexico, Which are a complete refutation of the common statement that Mexico has been exploited remorselessly by the foreign investor. The conces-sions given by Diaz in the days of his regime most condemned are nowise as large nor the land grants as extensive nor the title so absolute as those granted to the railroad builders of our own transcontinental systems and other of our nationally subsidized works. This is not left to further argument but is settled by quoting the various official instruments and not at all in a tedious way. The author's concluding chapter is a picture of the Mexican people from Aztec times, when they had reached a civilization which gave them a better calendar than the Roman Empire ever had until modern times, to their present unhappy and pitiful condition. He concludes, basing his findings on parallel historical downfalls of a once proud people, that present conditions are the natural result of the absolute domination of an alien minority. He grants, of course, that there are many estimable Latin-Mexicans of integrity, ability and charm, but maintains that the dominant minority has continually degraded in fulfillment of the sociological law that the sure revenge of the servile class is found in the corruption of the master class. The book is replete with historical and literary allusions which, added to the pleasing style of the accomplished author, make fascinating the account of one of the world's great tragedies. Mr. Gibbon is a lawyer who has spent much time in Mexico and shows an understanding of the native people not shared by all writers on the Mexican problem. A distinct addition to all literature on the subject. P. E. B.

Jan 8, 1919

By Yap Chu-Phay

IN the previous paper, the writer showed how, on the basis of thermodynamic reasoning, it seems probable that when true equilibrium conditions obtain, carbon exists as Fe3C in the liquid state and as elementary carbon in the solid state (7 Fe), in which case the solidus would be a straight line from 0.18 to 1.70 per cent. carbon (Fig. 1). In the same paper he concluded that the solidus obtained by Honda 'and his co-workers1 probably does not represent the same conditions, insuring a complete equilibrium. Except for a downward temperature displacement, the solidus obtained by Gutowsky,2 using the Heycock and Neville method, practically coincides with Honda's solidus as shown in Fig. 1. The writer at first thought that perhaps in some way Gutowsky's thermocouple was improperly calibrated for high-temperature measurements, as his liquidus was also much lower than those obtained by Carpenter and Keeling3 and by Ruer and Goerens.4 However, the eutectic temperature obtained by Gutowsky agrees with the generally accepted value of 1130° C., so that the validity of the inference regarding improper temperature calibrations is to be strongly doubted. In Fig. 1, Gutowsky's solidus is shown both in the original and in the corrected form. In the latter, a correction of 29.2° C. is made for all temperatures above 1416° C. in accordance with-

Jan 1, 1931

By O. M. Schaus

GRATIFYING progress continues towards the elimination of the hazards confronting health and safety in and about mines. Employers and employees are diligently co-operating. One of the outstanding movements towards this end is the National Safety Competition conducted by the U. S. Bureau of Mines. William W. Adams, of the Bureau, has stated that "Through 1936 there has passed by a dozen years of this National Safety Competition, as it started in 1925 with an enrollment of 210 mines and quarries in 28 states and 68 million man-hours of employment. For 1936 it covered 328 mines and quar-

Jan 1, 1938

By Forrest W. Kinsey

The use of pellets in North American blast furnaces has made the mixes used in the associated sinter plants unique. These mixes generally contain a high percentage of fine waste oxide materials as the principal iron bearing portion of the mix, with iron ores and concentrates added in minor amounts only. Additionally, the sinter basicity is always above one and can be three or higher. This paper will discuss the large body of knowledge and experience developed by one company on this type of sinter mix. Results of laboratory tests will be used to illustrate how mix composition and feed preparation affect sinter productivity and quality.

Jan 1, 1977

By Edgar G. Hill

MUCH has been written and said recently about the methods used and materials and equipment employed in building the long tubes that criss-cross a great part of the [ ] united States, like the pattern of a spider's web. This paper will discuss the fundamentals of design of these lines from the economic as well as the engineering view-point, pointing out the effect of the volumes transported, and the load factor at which they are operated, on the unit costs of transportation, as well as the effects on costs of the character of the fluids the lines are called upon to handle. Generally speaking, crude-oil pipe lines carry oil from the producing fields to the [ ] refineries. Sometimes part of the journey is by pipe line to a coastal point and tank ships are employed for the rest of the trip. The main lines of directional flow of crude oil through pipe lines in the United States are shown on Fig. I, but this, of course, does not always show individual pipe lines. BASIC FORMULA FOR FLOW OF CRUDE OIL The laws governing the flow of crude oil through pipes are well known. The basic

Jan 1, 1942

By Edgar G. Hill

Much has been written and said recently about the methods used and materials and equipment employed in building the long tubes that criss-cross a great part of the United States, like the pattern of a spider's web. This paper will discuss the fundamentals of design of these lines from the economic as well as the engineering viewpoint, pointing out the effect of the volumes transported, and the load factor, on the unit costs of transportation, as well as the effects on costs of the character 01 the fluids the lines are called upon to handle. Generally speaking, crude-oil pipe lines carry oil from the producing fields to the refineries. Sometimes part of the journey is by pipe line to a coastal point and tank ships are employed for the rest of the trip. The main lines of directional flow of crude oil through pipe lines in the United States are shown on Fig. I, but this, of course, does not always show individual pipe lines. Basic Formula for Flow OF Crude Oil The laws governing the flow of crude oil through pipes are well known. The basic

Jan 1, 1942

By Edgar G. Hill

Much has been written and said recently about the methods used and materials and equipment employed in building the long tubes that criss-cross a great part of the United States, like the pattern of a spider's web. This paper will discuss the fundamentals of design of these lines from the economic as well as the engineering viewpoint, pointing out the effect of the volumes transported, and the load factor, on the unit costs of transportation, as well as the effects on costs of the character 01 the fluids the lines are called upon to handle. Generally speaking, crude-oil pipe lines carry oil from the producing fields to the refineries. Sometimes part of the journey is by pipe line to a coastal point and tank ships are employed for the rest of the trip. The main lines of directional flow of crude oil through pipe lines in the United States are shown on Fig. I, but this, of course, does not always show individual pipe lines. Basic Formula for Flow OF Crude Oil The laws governing the flow of crude oil through pipes are well known. The basic

Jan 1, 1942

By J. C. Branner

(New York Meeting, February, 1012.) DURING the past two or three years I have seen statements regarding the first discovery of fullers' earth in this country that seem to require correction or modification. One appears again in the Mineral Resources of the United States for 1909, part II., p. 738, where it is said that ? fullers' earth was first discovered in the United States at Quincy, Fla., in 1893." In this connection the following bit of unpublished history concerning fullers' earth in the State of Arkansas is worthy of attention. In April, 1891, when I was State Geologist of Arkansas, a Swede named John Olsen, formerly a copper-miner in Michigan, but then living south of Little Rock, brought me a sample of what he thought was fullers' earth. He reported that it was from near the town of Alexander, the locality being 1 S. 13 W., section 8, SW. quarter of the SE. quarter. My chemist, Dr. R. N. Brackett, analyzed the material, and reported: Per Cent. Silica, . . SiO2., . 63.19 Alumina, . AL2O3, . 18.76 Iron, . Fe203 7.05 Lime, . Ca0 0.78 Magnesia, . . MgO 1.68 Potash, . K2O 0.21 Soda, . . Na2O 1.50 Loss on ignition, . 7.57 100.74 Water at 110° to 115° C. = 7.84. Another sample from about the same locality, also brought by John Olsen, on analysis by Dr. Brackett gave

Jul 1, 1912

By George C. Branner

BAUXITE is produced in Arkansas from two mining districts in the central portion of the State. These are (1) the Fourche Mountain district, immediately south and southeast of Little Rock in Pulaski County, and (2) the Bauxite (town) district, about five miles east of Becton in the eastern part of Saline County. These two mining districts are about twelve miles apart, separated by territory which, so far, has produced a negligible amount of commercial ore. Mining was by open-pit methods exclusively until 1924, when underground methods came into use. From 1924 to 1930 about 40 per cent of all of the ore produced in Arkansas was mined by underground methods, mainly by retreating caving.

Jan 1, 1935

By Wllliam D. Davis

C OMMERCIAL production of oil in northeastern Oklahoma began in 1897 and in the next two decades this area became one of the greatest oil districts of the time. Its importance is now secondary, but thousands of wells in this area have produced uninterruptedly for more than thirty years. They are now classified as stripper wells. By means of what is known as water flooding their L. production can be considerably in- creased. This practice consists in injecting water under pressure into the sand surrounding an oil well, thus displacing the oil in the pores of the sand and forcing it into the oil well.

Jan 1, 1940