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By Joseph Chalmers

The Petroleum Experiment Station of the U. S. Bureau of Mines at Bartlesville, Okla., has for the past three and a half years maintained a laboratory with the necessary personnel for conducting research on methods of increasing the recovery of oil. Some of the preliminary problems encountered in starting this work, with the data obtained, were discussed in A. I. M. E. Technical Publication No. 144, "Oil Recovery Investigations of the Petroleum Experiment Station of the U. S. Bureau of Mines," which was presented at the October meeting of the Institute at Tulsa, Okla., in 1928. Scope of Paper The following discussion gives some of the results of the more recent work at the Oil Recovery Laboratory. These experiments were conducted to obtain laboratory data pertaining to the relative merits or efficiencies of various pressure media in the recovery of oil from a sand reservoir. Two general types of experiments were conducted. In one the various pressure media were passed through an artificial body of sand partly saturated with oil at a constant input pressure; in the other the pressure media were passed through the body of sand partly saturated with oil at a constant volume rate. No attempt will be made to discuss the ramifications of economic problems which enter into the choice of a pressure medium. Apparatus and Materials The two 6-in. by 6-ft. flow tubes described in Technical Publication 144 were used in these experiments. They consist of 6-ft. sections of 6-in. casing with a blind flange at each end. There are three 1-in. well openings in each tube, spaced 2 ft. 4 in. apart, the end wells being

Jan 1, 1930

By H. R. MacMichael

IN the Chihuahua district of Mexico the first smelting was that inaugurated by the early Spaniards for the production of silver bullion. The ores treated were high in silver and lead. Silver-lead bullion was first produced and the lead then cupelled to waste, with the slag produced running from 5 to 10 per cent in lead and about 25 to 40 per cent silica. The ore was mined by peon labor, often being carried out of the mine on the backs of the men, and then transported by burros. Furnaces were of primitive construction, adobe or rock being used in the earlier period and some iron later when it became available. Blast was originally supplied by bellows manually operated. Such smelting was carried on to a greater or lesser extent until the latter part of the last century, and so extensive was it that many hundred thousand tons of leady slag remained to be treated in modern furnaces. In 1908 a smelter was placed in operation at Chihuahua by the American Smelting & Refining Co. At that time the ore was practically all oxidized and by a little selection, self-fluxing mixtures could be made, but with an average lead content usually under 10 per cent and sometimes as low as 7 per cent. The bullion produced would carry from 150 to 300 oz. silver per ton. The slag made approximated 30 per cent SiO2, 42 per cent FeO, 21 per cent CaO, and perhaps 3 per cent Zn. The ores varied from hard, coarse material which was passed through a crusher, to a considerable quantity of fines which had to be smelted as it came, as crushing the coarse was the only preparation for smelting.

Jan 1, 1933

By Jesus P. Manzano

The report of which this paper is a summary was made in 1890 for the Compania Investigadora Mexicana y Americana. Since the region examined covers 900 sq. kilom., chiefly of wooded arid rocky hills, almost without roads, and for the most part uninhabited, While the examination had to be made in two months, of which period more than 15 days were continuously rainy, I need not say that this account is not complete and thorough. I. Geography and Topography. The center of this zone, 19 kilom. SW. of San Luis Potosi, is situated in lat. 21° 24' N., and long. 2° 3' W. of Mexico City. The altitude ranges from 1866 m. (that of San Luis) to . 2816 m. (that of the Realito mountain), in the Sierra de Sail Luis. The topography is hilly—partly wooded, partly bare. The principal more level areas are the Bledos valley on the south, and portions of the haciendas of Tepetates, San Fran cisco and Santiago, on the west. The water-supply is scanty. The two streams that cross the Zone, the Santiago and Bledos rivers, carry water nearly the year through, though much reduced in the dry season. Other streams are torrents of less importance. All the waters of the valley and Sierra of Sail Luis arc absorbed or sink, not passing beyond Soledad de los Ranchos. The Continental di vide is within the Zone, some waters going west to the Pacific, others east to the Gulf of Mexico. II. Geology. Concerning the geology of this district I condense the fol lowing from the memoir, Las Minas de Guanajuato, prepared for the Minister of Fomento by Senor Pedro Lopez Monroy, mining engineer, with which I am entirely in accord. He says, ill substance:

Jan 1, 1902

By L. E. Murr, P. J. Smith

A study has been made by transmission electron microscopy of thin foils of 304 stainless steel fatigued external to the electron microscope in reversed bending, and of thin foils fatigued directly within the microscope in alternating tension. The build-up of stacking faults in the thin foils during fatigue zoas correlated with the dislocatirm structures found in thin films prepared fror fatigued bulk specimens. The performance of the special devices designed for fatigue of thin foils so outlined and the importance of alternative methods of preparation of more uniform fatigue specimens bY vapor deposition are emphasized. INVESTIGATIONS on fatigued bulk aluminum1,' and stainless stee13j4 have revealed the existence of dislocation substructure on examination by transmission electron microscopy of electrolytically thinned foils representative of these bulk specimens. While this technique has proved extremely valuable, it has several shortcomings. First, the method of fatiguing bulk specimens and then thinning to foil for electron-transmission observation allows only one observation of internal structure at any one portion of the fatigue life. Second, thinning the bulk fatigued specimens to foil results in the loss of at least one original surface. Thus, what one sees in the remaining electron-transparent sections is an internal dislocation or fault structure which in many cases cannot be correlated with the original surface markings. This is an undesirable feature, since it is well-known that metal surfaces play an important part in the fatigue process.5 An obvious third undesirable feature of the thinning-from-bulk technique is the fact that static observations have difficulty (in the case of fatigue) explaining the mechanism of a dynamic process. What is required then is a method whereby a selected thin area can be continuously observed either while undergoing cyclic deformation or at various fixed stages of fatigue deformation. While Murr and wilkov6 have reported some success with an apparatus designed to fatigue thin metal foils directly within the electron microscope, the nature of the specimen-mounting procedure and the mechanical features involved in the adaptation of the fatigue device to the electron microscope make this method difficult to operate. It was not possible, for example, to make frequent observations of a selected area because of difficulty in maintaining a chosen area in a stable viewing position inside the electron microscope. Except for the build-up of a dislocation substructure and what are commonly referred to as "slip striations", little else has been reported from observations on thin-foil sections prepared from bulk fatigue specimens. segal17 has found "slip striations" in stainless-steel fatigued specimens which were electropolished from both sides, but gave no explanation as to their origin or identity in terms of lattice imperfections. The research to be reported in this paper was undertaken with the following objectives in mind. First, an attempt was made to devise a technique or techniques whereby thin metal foils could be fatigued and repeatedly observed by transmission electron microscopy. Second, it was hoped that some correlation could be made between deformation striations found in fatigued thin transmission specimens and thin foils prepared from bulk fatigued specimens. These investigations illustrate quite convincingly that a feasible method is available for the direct study of the fatigue mechanism and similar dynamic phenomena in thin transmission specimens inside the electron microscope. I) EXPERIMENTAL METHODS Three modes of specimen fatigue and observation of fatigue damage were used. These involved fatigue of thin-foil specimens in a special arrangement external to the electron microscope and observation of a selected area at various stages in the fatigue life, the fatigue of thin-foil transmission specimens inside the electron microscope, and the fatigue of bulk specimens external to the electron microscope followed by thin-foil preparation for direct observation at predetermined stages. Design of the External Fatigue Clip and Specimen Holder for the Hitachi H.U.11 Electron Micro-scope. The purpose of the fatigue clip was to provide a reversed bending fatigue stress to a thin-foil transmission specimen outside the electron microscope. In order to accomplish this, a flat-bottomed, U-shaped brass clip was made as shown

Jan 1, 1965

By Arthur S. Huey

AS the end of the collegiate year approaches, the problem of student employment again becomes acute. This subject divides itself into two phases: (1) employment prior to graduation and (2) employment following graduation. "Experience is the best teacher," according to the old adage, and the student needs all that he can get. He is afforded every opportunity to reap from his books the theories and principles of scientific and engineering practice, and occasionally he is privileged to make field trips to observe the practical side of the subject. But it is not enough for one to know the theory and to observe its application; it is also desirable for the student to get the feel of the tools during his training Such opportunities can only be afforded the student if the major companies cooperate with the universities in giving the student part-time and vacation work.

Jan 1, 1932

By Jack F. B. Silman

Proving up any large, open pit ore deposit by normal exploration drilling under the best of conditions is a noteworthy accomplishment. But, when adverse conditions preclude standard drilling methods, and the same end result is achieved by a relatively new and little known type of drilling, special comment is in order. Three major problems confronted exploration drilling at the Questa molybdenite mine of the Molybdenum Corporation of America-sampling, terrain and time. Surface and underground longhole drilling provided the needed solutions, thus making the greatest single contribution to an exploration and development program that was successful in proving a major, open pit molybdenum deposit.

Jan 5, 1965

By Paul E. Rosten

Introduction This papers describes some of the latest improvements that have been incorporated or planned by the Cleveland-Cliffs Iron Co. to reduce operating costs and improve pellet quality. The Cleveland-Cliffs Iron Co. operates and manages mining, beneficiation, and pelletizing operations in Michigan, Canada, and western Australia. This paper deals with the grate-kiln pelletizing operations at Republic, Humboldt, Tilden, Empire, and Pioneer in Michigan, and the Adams and Sherman in Ontario, Canada. Table I characterizes each operation in regard to location, ore type, pellet capacity and date that pellets were first produced. All of the operations with the exception of Pioneer and Tilden, utilize downdraft-two-pass grate cycles of drying followed by preheating. Pioneer utilizes an all-downdraft, three-pass grate cycle which consists of three drying zones followed by the preheat zone. The Pioneer and Tilden cycles have been described previously (Lindroos and Koski, 1966; Villar and Dawe, 1975; Koski, 1977). Tilden utilizes a three-pass grate cycle with a stage of updraft drying, followed by two downdraft drying stages. Recuperation systems which supply hot gases to a drying zone from second stage cooling were designed and fur¬nished for Tilden I. Tilden II will be identical. Empire IV will also be furnished with a recuperation system. The Adams grate¬kiln system was retrofitted with a recuperation system. This paper will summarize some of the efforts that are in effect or planned for grate-kiln pelletizing systems to: (1) reduce operating and maintenance costs, (2) reduce energy requirements, (3) improve product quality, and (4) meet environmental standards.

Jan 1, 1981

By H. M. Morse

This report covers the period from Jan. I, 1943 to Dec. 31, 1943. During the year, II2 wells were drilled in Mississippi, as foilows: wildcats drilled and abandoned, 54; wildcats producing oil, 4; oil wells drilled in oil fields, 26; oil wells drilled in fields, dry and abandoned, 10; sulphur-test wells drilled, 14; salt-water-disposal wells, 3; core tests, I. Prospecting Geophysical work in Mississippi during 1943 amounted to 1127 crew weeks, divided as follows: reflection seismograph, 809 weeks; gravity meter, 285; magnotometer, 30; torsion balance, 3. A considerable amount of core drilling was done over a large part of the state. The complete data on this activity are not available at the present time. Salt Domes To date, the following salt domes have been discovered in Mississippi: Midway, Edwards, Glass, Newman, Tatum, Oak-vale, Kings, Halifax, D'Lo, Hazlehurst, Byrd, Leedo, Prentiss, Carson, Moselle, Monticello, Ruth, Keno, Taylorsville. New Oil Fields Lincoln County.—On March 10, 1943, the California Company completed its Smith No. I in sec. 4, T. 7 N., R. 7 E., Lincoln County, as an oil well and produced 29 bbl. of 25" gravity oil in 24 hr. through a fi-in. choke. Two outpost wells have been drilled in this area by the California Company, and both have been abandoned as dry holes. Madison County. —Love Petroleum Co. completed its J. R. Anderson No. 2, sec. 2, T. 8 N., R. I W., Madison County, on Sept. 7, 1943. This well produced 135 bbl. of approximately 30" gravity- oil in 24 hr. through a )/4-in. choke. The production comes from a sand or porosity in the upper part of the Chalk formation of the Cretaceous age. Adams County.—The California Company drilled its National Gasoline Co. of Louisiana No. I in sec. 52, T. 7 N., R. I W., to a total depth of 10,383 ft., and at 10,280 ft, it perforated and obtained gas and a condensate. The well had several showings in the Wilcox of the Eocene age. Several of these showings were tested and the well finally was completed at 5888 ft. on Oct. 6, 1943, producing 44" gravity oil in the second sand in this formation. No other wells were completed in this field during the year. However, a number of wells are contemplated in the near future, and locations have been staked by the California Company. The Oklahoma Pipe Line Co. will market the oil through its pipe-line facilities. Wayne County.—The Gulf Refining Co. drilled Davis No. I in sec. 2, T. 9 N., R. 9 W. in Wayne County. After several stem tests 545'-in. casing was set at 6850 ft. and production was obtained in the so-called Massive Sand of the Lower Tuscaloosa. The well produced 359 bbl. of oil in 24 hr., and it Was completed on Oct. 4, 1943. Other locations have been staked ill this area and probably will be drilled in 1944 by

Jan 1, 1944

By H. M. Morse

This report covers the period from Jan. I, 1943 to Dec. 31, 1943. During the year, II2 wells were drilled in Mississippi, as foilows: wildcats drilled and abandoned, 54; wildcats producing oil, 4; oil wells drilled in oil fields, 26; oil wells drilled in fields, dry and abandoned, 10; sulphur-test wells drilled, 14; salt-water-disposal wells, 3; core tests, I. Prospecting Geophysical work in Mississippi during 1943 amounted to 1127 crew weeks, divided as follows: reflection seismograph, 809 weeks; gravity meter, 285; magnotometer, 30; torsion balance, 3. A considerable amount of core drilling was done over a large part of the state. The complete data on this activity are not available at the present time. Salt Domes To date, the following salt domes have been discovered in Mississippi: Midway, Edwards, Glass, Newman, Tatum, Oak-vale, Kings, Halifax, D'Lo, Hazlehurst, Byrd, Leedo, Prentiss, Carson, Moselle, Monticello, Ruth, Keno, Taylorsville. New Oil Fields Lincoln County.—On March 10, 1943, the California Company completed its Smith No. I in sec. 4, T. 7 N., R. 7 E., Lincoln County, as an oil well and produced 29 bbl. of 25" gravity oil in 24 hr. through a fi-in. choke. Two outpost wells have been drilled in this area by the California Company, and both have been abandoned as dry holes. Madison County. —Love Petroleum Co. completed its J. R. Anderson No. 2, sec. 2, T. 8 N., R. I W., Madison County, on Sept. 7, 1943. This well produced 135 bbl. of approximately 30" gravity- oil in 24 hr. through a )/4-in. choke. The production comes from a sand or porosity in the upper part of the Chalk formation of the Cretaceous age. Adams County.—The California Company drilled its National Gasoline Co. of Louisiana No. I in sec. 52, T. 7 N., R. I W., to a total depth of 10,383 ft., and at 10,280 ft, it perforated and obtained gas and a condensate. The well had several showings in the Wilcox of the Eocene age. Several of these showings were tested and the well finally was completed at 5888 ft. on Oct. 6, 1943, producing 44" gravity oil in the second sand in this formation. No other wells were completed in this field during the year. However, a number of wells are contemplated in the near future, and locations have been staked by the California Company. The Oklahoma Pipe Line Co. will market the oil through its pipe-line facilities. Wayne County.—The Gulf Refining Co. drilled Davis No. I in sec. 2, T. 9 N., R. 9 W. in Wayne County. After several stem tests 545'-in. casing was set at 6850 ft. and production was obtained in the so-called Massive Sand of the Lower Tuscaloosa. The well produced 359 bbl. of oil in 24 hr., and it Was completed on Oct. 4, 1943. Other locations have been staked ill this area and probably will be drilled in 1944 by

Jan 1, 1944

By R. H. Harrington

The definition of precipitation-hardening1 is well understood and its principles have been subjected to study for some time. However, the variation of properties with double aging, combined with strain-hardening, gives promise of new and useful phenomena. Properly to understand these distinctions, definitions of these terms are necessary. Precipitation-hardening1.—This reaction usually depends upon an alloy having such a composition that it consists only, or in major part, of but one phase, a solid solution, at a high temperature, so that, upon slow cooling, this solution breaks down into two phases, the solid solution and a compound. By heating the alloy to the temperature for maximum solution of the compound, quenching, and reheating to a suitable lower temperature for critical dispersion precipitation of the compound, useful properties of the alloy may be developed to a maximum. Double Aging.—Dougle aging in part is similar to the process for precipitation-hardening, consisting of heating a precipitation-hardening alloy to the solution temperature, quenching, reheating to the suitable dispersion precipitation temperature, strain-hardening, and again reheating to a suitable temperature to develop certain useful properties to a maximum. The strain-hardening may be induced by two methods: (I) a rate of cooling from the first reheat may suffice to strain the solid solution lattice of the alloy; or (2) the alloy may be cold-worked to a suitable degree between the two reheats. Pkecipitation-hardening of Copper-cobalt-beryllium Alloys1.2 The composition of principal interest is that of 2.6 per cent Co, 0.4 per cent Be, 97 per cent Cu. The alloy has been developed commercially and, with certain reasonable precautions, ordinary brass-foundry practice suffices to produce an alloy of high quality. Preliminary Precipitation-hardening Study.—Samples were cut from a I-in. round rod cast in a graphite mold. These samples were then

Jan 1, 1937

By AIME AIME

HONORARY COMMITTEE. HON. C. D. WALCOTT (Chairman.), Director U. S. Geological Surrey. HON. FREDERICK I. ALLEN, Commissioner of Patents. DR. FRANK BAKER, Superintendent National Zoological Park. MR. CHARLES A. BELL, President American Security and Trust Co. MAJOR JOHN BIDDLE, Engineer Commissioner of District of Columbia. ADMIRAL C. M. CHESTER, Superintendent U.S. Naval Observatory. GENERAL WILLIAM CROZIER, Chief of Ordnance, U. S. A. ADMIRAL GEORGE DEWEY, Admiral of the Navy. COLONEL CLARENCE R. EDWARDS, Chief Bureau. of Insular Affairs. MR. WILLIAM C. FOX, Director Bureau of American Republics. MR. CHARLES C. GLOVER, President The Riggs National Bank. GENERAL A. W. GREELY, Chief Signal Officer, U. S. A. MR. BERNARD R. GREEN, Superintendent Library Building. GEN. G. H. HARRIES, Vice-President Washington Electric Railway Co. HON. E. A. HITCHCOCK, Secretary of the Interior. COMMANDER H. M. HODGES, Chief Hydrographer, U. S. N. PROF. W. H. HOLMES, Chief Bureau of American. Ethnology. PROF. S. P. LANGLEY, Secretary Smithsonian Institution. GENERAL ALEXANDER MACKENZIE, Chief of Engineers, U. S. A. ADMIRAL N. E. MASON, Chief Bureau of Ordnance, U. S. HON. WM. M. MEREDITH, Director Bureau of Engraving and Printing. HON. V. H. METCALF, Secretary Department of Commerce and Labor. HON. WILLIS L. MOORE, Chief -U. S. Weather Bureau. HON. PAUL MORTON, Secretary of the Navy. MR. F. H. NEWELL, Chief Reclamation Service, U. S. Geological Survey. HON. S. N. D. NORTH, Director Census Office. CAPT. E. C. PENDLETON, Superintendent Naval Gun Factory. MR. GIFFORD PINCHOT, Chief Forester, Department of Agriculture. MR. HERBERT PUTNAM, Librarian of Congress. ADMIRAL CHAS. W. RAE, Chief Bureau of Steam Engineering, U. S. A: MR. RICHARD RATHBUN, Assistant Secretary Smithsonian. Institution. HON. W. T. RICHARDS, Commissioner General Land Office.

Jul 1, 1905

By C. W. Mason

TIN has long been cited as offering a classic example of polymorphism, second in repute only to the allotropy of sulphur. The notorious "tin disease," which Cohen1 has studied so exhaustively in terms of the enantiotropic transformation of tetragonal white 0 tin to cubic gray a tin, has apparently encouraged the expectation that one or more addi-tional polymorphic modifications might exist. The search for confirma-tion of this idea has, as might be anticipated, led to the accumulation of a body of miscellaneous evidence, much of which would probably never have been sought, or taken seriously even by its discoverers, but for previous assumptions. The ball apparently was started rolling in 1880 by Trechmann,' who reported a new modification of tin (y tin), which was brittle and found in "hard head," a highly arsenical, slaggy material produced in a certain stage of tin smelting. A mixture of two kinds of crystals was obtained from a Cornish tin furnace, and those thought to be y tin were studied crystallographically. The results indicated that these crystals were rhombic and of different density from the tetragonal tin prepared electrolytically by Miller.3 Their analysis was given as 98.7 per cent Sn, 1.3 per cent Fe, and traces of As, Sb, Bi and S. In 1881 von Foullon4 obtained similar crystals from a Bohemian tin furnace. Headden5 examined crystals similar to those of Trechmann and von Foullon and reported them to be monoclinic, but of analysis corresponding to stannous sulphide. Later, Stevanovic,6 by goniometric measurements, proved that these crystals of SnS were really rhombic. Groth7 pictures and describes both "rhombic tin" (Fig. 9, vol. 1) and stannous sulphide (Fig. 84, vol. 1); their faces and angles correspond within the accuracy of measurement. Spencer3 in 1921 examined the above evidence critically; he found similar crystals from Cornish tin furnaces, proved them to be SnS, and even was able to analyze some of Trechmann's original specimens, finding high sulphur content. (Apparently Trechmann's analysis had been based on a second lot of crystals, not described crystallographically.)

Jan 1, 1939

By Felix B. Shay

The Agua Fria mine is in eastern Honduras at Lat. 140" 06' N., Long. 86" 36' W. Danli, the seat of the local municipal government, is the nearest town. The property is approximately 44 miles east of Tegucigalpa, the terminus of a truck road from the Pacific coast. The mine lies at an altitude of 3300 ft. with surrounding elevations as high as 6000 feet. For 20 years the oxidized croppings of the Agua Fria vein had been worked intermittently when in 1927 an attempt was made to open the property. A shaft was sunk 300 ft. and considerable ore was blocked out, but before a mill could be installed financial difficulties arose and the mine reverted to the original owners. Erle Y. Halliburton, of Los Angeles, purchased the property in 1934. At that time a careful consideration of all factors involved showed that air transport was the only practical method of moving the equipment and machinery necessary to commence production. The other alternative was by muleback, which required sectionalizing all equipment to a maximum load of 200 lb., and during the rainy season this type of freighting was subject to serious delays. It was decided to purchase a trimotor Ford powered by three Pratt and Whitney Wasp B motors developing 400 hp. each. There were several reasons for the choice: (1) this type of plane was available at a reasonable price, owing to its replacement by faster models on most of the airlines in the United States; (2) the ship was capable of carrying a pay load of 3000 Ib. over the required distance; (3) since this airplane had been widely used there would be no difficulty in securing competent personnel or in purchasing spare parts. It was necessary to rebuild the plane for cargo servicc. The windows were removed and the fuselage was entirely covered. A hatch was cut in the top of the fuselage to receive heavy crane loads and pieces of freight that were too large or too long to go through the rear door. The seats were removed and the interior of the plane was lined with Duralumin sheets. A heavy-duty landing gear was installed and the floor was reinforced. The nearest site for an airport was two miles north of the mine. The necessary grading was done by a small track-type tractor with a wheeled grader, which was brought in overland. Six weeks was required for bring-

Jan 1, 1940

By Felix B. Shay

The Agua Fria mine is in eastern Honduras at Lat. 140" 06' N., Long. 86" 36' W. Danli, the seat of the local municipal government, is the nearest town. The property is approximately 44 miles east of Tegucigalpa, the terminus of a truck road from the Pacific coast. The mine lies at an altitude of 3300 ft. with surrounding elevations as high as 6000 feet. For 20 years the oxidized croppings of the Agua Fria vein had been worked intermittently when in 1927 an attempt was made to open the property. A shaft was sunk 300 ft. and considerable ore was blocked out, but before a mill could be installed financial difficulties arose and the mine reverted to the original owners. Erle Y. Halliburton, of Los Angeles, purchased the property in 1934. At that time a careful consideration of all factors involved showed that air transport was the only practical method of moving the equipment and machinery necessary to commence production. The other alternative was by muleback, which required sectionalizing all equipment to a maximum load of 200 lb., and during the rainy season this type of freighting was subject to serious delays. It was decided to purchase a trimotor Ford powered by three Pratt and Whitney Wasp B motors developing 400 hp. each. There were several reasons for the choice: (1) this type of plane was available at a reasonable price, owing to its replacement by faster models on most of the airlines in the United States; (2) the ship was capable of carrying a pay load of 3000 Ib. over the required distance; (3) since this airplane had been widely used there would be no difficulty in securing competent personnel or in purchasing spare parts. It was necessary to rebuild the plane for cargo servicc. The windows were removed and the fuselage was entirely covered. A hatch was cut in the top of the fuselage to receive heavy crane loads and pieces of freight that were too large or too long to go through the rear door. The seats were removed and the interior of the plane was lined with Duralumin sheets. A heavy-duty landing gear was installed and the floor was reinforced. The nearest site for an airport was two miles north of the mine. The necessary grading was done by a small track-type tractor with a wheeled grader, which was brought in overland. Six weeks was required for bring-

Jan 1, 1940

By T. E. Leontis

The specific effect of various rare-earth metals on the room- and elevated-temperature properties of magnesium has been evaluated. Alloys containing didymium exhibit the highest tensile and compressive strengths at room and elevated temperatures. All the rare-earth metals increase the creep resistance of extruded magnesium at temperatures in the range of 400° to 600°F, but the degree of enhancement depends on the temperature and on the concentration of the added metal. THE effects of rare-earth metals on the properties of sand-cast magnesium were discussed in some detail in earlier paper by the author.' The present paper deals with the effect of the same alloying elements on the properties of extruded magnesium. This investigation also had as its aim the development of a wrought alloy having a better combination of room-temperature strength and ductility and elevated-temperature strength and creep resistance than is found in magnesium-Mischmetal-manganese alloys, which have been reported earlier.2-5 The only known attempt to study wrought magnesium alloys containing pure cerium instead of Mischmetal was made by Mellor and Ridley.6 They found that in the form of rolled bars there is a definite, optimum cerium content for creep resistance at 200 °C and that the creep resistance of these alloys at 200 °C is significantly Improved by heat treatment at 550" to 580"C. In the present investigation the compositional variation in mechanical properties of the following alloy systems is presented: I—magnesium-Misch-metal. 2—magnesium-cerium-free Mischmetal. 3— magnesium-didymium. 4—magnesium-cerium. 5— magnesium-lanthanum. Alloys containing predominately praseodymium are not included in this series because of the lack of this material. Experimental Procedures The alloying ingredients used in preparing the alloys described herein are the same as those reported in the earlier paper.' Cerium-free Mischmetal is the rare-earth mixture remaining when the cerium is removed from Mischmetal, which contains all the rare-earth metals as they occur naturally in mon-azite sand, the ore from which Mischmetal is produced. Removal of both cerium and lanthanum from Mischmetal leaves what is commonly called "didym-ium," consisting predominantly of neodymium and praseodymium. Although the composition of the particular batch of each metal used may differ somewhat from the analysis presented previously, these differences are not great enough to warrant repeat- ing the specific composition of each material. The electrolytic magnesium used as the starting material in these alloys has the same typical analysis as that given in the earlier paper.' The alloys were prepared in small laboratory melts applying all the necessary precautions for alloying rare-earth metals with magnesium described by Marande.' Most melts were large enough to cast one 3 in. diam billet 10 in. long. In a few cases, particularly the didymium-containing alloys, the lack of sufficient amounts of the rare-earth metal limited the size of the billet to 6 to 8 in. All billets were scalped to a diameter of 2 15/16 in. and faced to a length of 9 ¼ in. as limited by the size of the extrusion container. The alloys were extruded into ½ in. diam rod on a 500-ton direct-extrusion press using a 3 in. container. The details of the extrusion step are: billet preheat, 925°F (2 hr); container temperature, 900°F; die temperature, 900°F; extrusion speed, 10 ft per min; reduction ratio, 36:1; and percent reduction, 97.3. The lower melting point of alloys containing didymium' necessitated reduction of the extrusion speed to 5 ft per min in order to prevent hot shorting during extrusion. Adequate lengths were cropped from both ends of each extruded rod to assure that all the material used for tests was extruded under uniform conditions. Tensile and compressive properties at room temperature are reported in the several conditions of heat treatment. The ASTM designations are used to distinguish these conditions as follows: T5—Direct age at 400°F (16 hr) T4—Heat treat at 950°F (4 hr) for alloys containing didymium T4—Heat treat at 1050°F (4 hr) for all other alloys T6—T4 + age at 400 °F (16 hr) The lower heat-treating temperature for alloys containing didymium is necessitated by the lower melting point of these alloys. All heat treatments were conducted in electrically heated, circulating-air furnaces. A protective atmosphere containing 0.5 to 1.0 pct sulphur dioxide was used for the high temperature heat treatments. Tension and creep specimens 6 Yz in. long and compression specimens 1½ in. long were cut from the extruded rod. A reduced section of ? in. diam was machined on the tension specimens, whereas on the creep specimens a reduced section of 0.450 in. diam

Jan 1, 1952

By Arthur Nomann

Recording instruments may be conveniently described under the headings of: (1) geophones, (2) amplifiers, (3) recording cameras, (4) miscellaneous parts. Geophones Geophones or seismometers are actuated by slight earth movements, and generate electrical currents, which are amplified and recorded. In all geophone desigm there is provision for differential movement between parts of the mechanism and the signal voltage is generated as a function of this differential movement. The part that conforms to the movement of the ground is called the support, and the part that remains more nearly stationary with respect to more distant unactuated parts of the earth is called the steady mass. The mechanical period of the geophone is the time required for an oscillation of the steady mass after an initial impulse is given it, and is determined by the effective stiffness of the spring joining the two parts together in relation to the weight of the suspended part. Geophones have been used with frequencies varying all the way from less than 10 cycles per sec. to several hundred cycles per second. Those with a natural frequency of less than, say, 100 cycles

Jan 1, 1940

By Arthur Nomann

Recording instruments may be conveniently described under the headings of: (1) geophones, (2) amplifiers, (3) recording cameras, (4) miscellaneous parts. Geophones Geophones or seismometers are actuated by slight earth movements, and generate electrical currents, which are amplified and recorded. In all geophone desigm there is provision for differential movement between parts of the mechanism and the signal voltage is generated as a function of this differential movement. The part that conforms to the movement of the ground is called the support, and the part that remains more nearly stationary with respect to more distant unactuated parts of the earth is called the steady mass. The mechanical period of the geophone is the time required for an oscillation of the steady mass after an initial impulse is given it, and is determined by the effective stiffness of the spring joining the two parts together in relation to the weight of the suspended part. Geophones have been used with frequencies varying all the way from less than 10 cycles per sec. to several hundred cycles per second. Those with a natural frequency of less than, say, 100 cycles

Jan 1, 1940

By R. C. Hirschfeld, H. H. Einstein, R. W. Bruhn, R. A. Nelson

The objective of the model studies described in this paper is to determine the effect of planar discontinuities on the strength and deformability of a rock mass. A model material was used because it satisfied concurrently three requirements that available natural-rock samples did not: (1) low strength, which was desirable for minimizing the loads that had to be applied in the laboratory; (2) ease of producing test specimens with geometrically regular joint patterns; and (3) uniformity of the test specimens. The model tests were performed on specimens made from a single modeling material and tested under triaxial stress conditions with [u,=u,]. Results are presented in this paper for tests on specimens that had (1) a single joint set inclined at several angles to the major principal direction, including 0º and 90°, and (2) two joint sets that were mutually perpendicular, one set perpendicular to and one set parallel to the major principal direction. Several different joint spacings were used in each series. Future tests will include a series with two sets of joints that make oblique angles with each other and with the major principal direction. The results of model tests and tests on cores of jointed rock by several investigators (e.g., Müller and Pacher,l Moore,2 Krsmanovic and Milic,3 Hayashi,4 Rosenblad,5 Jaeger,6 and Lane and Heck 7, have contributed significantly to the design of these experiments, which are believed to be the first in which a comprehensive study has been made of the combined effects under triaxial loading of joint spacing and joint orientation (Fig. 1).

Jan 1, 1970

By R. D. Pehlke, P. D. Goodell, R. W. Dunlap

The rate of dissolution of steel bars in molten pig iron has been measured experimentally in the temperature range 2300° to 2650° F. The rate of solution is shown to be a .function of bath composition, temperature, and stirring. A kinetic model based on carbon diffusion in the liquid phase has been derived to fit the experimental results. THE rate of scrap melting has long been an important variable in steelmaking operations. With the advent of the oxygen steelmaking process and the accompanying shorter heat times, the rate of scrap melting has now become one of the rate-limiting factors in steel production. As observed in commercial practice, the solution rate is influenced by the compositions of liquid and solid, the temperature, agitation, and time. However, no definitive work has been done on the Fe-C system, and there is very little information in the literature regarding the relative effects of these variables in steelmaking systems. A number of questions have been raised in regard to scrap utilization in basic oxygen steelmaking operations. Consideration has been given to the optimum size and shape of scrap, and to the use of preheated scrap as a means for decreasing the pig-iron requirement in oxygen blowing. The determination of an optimum scrap practice for a specific installation depends to a large extent upon the economics of the scrap market and also upon the behavior of scrap in the vessel. The present research was undertaken as a preliminary study in evaluating the behavior of steel in a pig-iron bath under various conditions of temperature, composition, and agitation, as might be encountered in oxygen converter operations or in any steelmaking operation where scrap behavior is an important process variable. Related studies have been carried out on non-ferrous systems. The solution rate of solid aluminum in a molten A1-Si alloy has been studied.' Furthermore, the increasing use of liquid metals has created considerable interest in studies related to dissolution of a solid in a liquid, or mass transfer taking place between a solid interface and a liquid metallic phase.2-10 In an effort to clarify the relative importance of factors influencing the dissolution of scrap in Fe-C alloys, this paper presents the results of a study of the rate of dissolution of a low-carbon steel cylinder in a molten Fe-C bath at various bath compositions, temperatures, and conditions of agitation. An attempt has been made to determine the mechanism of solution, and a model has been derived to fit the experimental results. The rate of heat transfer between the molten pig-iron bath and the solid-steel cylinder has also been studied. EXPERIMENTAL PROCEDURE A molten bath of pig iron (nominal composition 4.2 pct C, 0.5 pct Mn, 0.8 pct Si)* was held in a 200- *In view of the fact that the composition of the pig-iron bath was slowly changing with time because of steel dissolution and reaction with the surrounding atmosphere, intermittent samples of the liquid bath were taken throughout each experiment, Table 1. lb induction melting unit. The internal diameter of the furnace was 8-1/2 in. and the bath depth approximately 14 in. Cold-finished 1020 steel cylinders of 1/2-, 3/4-, 1-, 1-1/2-, and 2-in. diameters were cut into 1 -ft lengths for use as test specimens. One end of each bar was machined to fit a hand-driven, mechanical stirring device which rested on top of the furnace. This fixture permitted 7 to 8 in. of the bar to be immersed in the melt. The steel cylinders were cleaned to free the surface of grease and oxide. The rods, at ambient temperature, were immersed into the molten pig-iron bath. The melt temperatures studied in this investigation were 2300°, 2500°, and 2650°F. Different agitation conditions were achieved by operating with a) the power to the furnace, giving induction stirring; b) induction stirring plus mechanical stirring, using hand rotation with a chain and sprocket assembly at approximately 200 rpm; c) mechanical stirring alone with the power off; and d) the power off and no mechanical stirring resulting in minimum agitation, i.e., only that caused by natural convection currents in the bath. The samples were immersed in the melt for prescribed times ranging from 30 sec up to 6 min. Immersion times were measured with a stopwatch and temperature control of the melt was achieved by power adjustment following temperature measurement with an optical pyrometer. The measurements with the calibrated pyrometer were checked out to within less than 10°F with simultaneous thermocouple measurements. Following immersion, the bars were water-quenched and the diameters were measured with a micrometer at several positions on the reduced area, and by volumetric displacement. The dissolution rates calculated from the

Jan 1, 1965

By Henry F. Herley

The New Orient mine, owned and operated by the Chicago, Wilmington & Franklin Coal Co., has caused a great deal of comment and interest because of its unusual features and huge daily production. It is in Franklin County, Illinois, adjacent to the town of West Frankfort. The seam being mined is the Illinois No. 6 which in this locality is 9 to 12 ft. thick and lies approximately 500 ft. below the surface. Without fear of contradiction, it can be said that this is one of the largest coal mines in the world from a daily production standpoint. During 1928, New Orient produced 2,400,000 tons, which amounts to over 10,000 tons each day the mine operated that year. The mine is built for a capacity of 12,000 tons but has actually hoisted over 15,000 tons in one 8-hr, shift. This enormous production can perhaps be better visualized if it is realized that each day's operation depletes over two acres of coal. The general features of this mine have already been fully covered in a paper by George B. Harrington,' President of the Chicago, Wilmington & Franklin Coal Co. In a paper of the nature of Mr. Harrington's, it was unnecessary to stress any particular phase of mining conditions, consequently the ventilation problems were touched upon but lightly. In this paper an attempt has been made to describe some of the problems which have been encountered in providing adequate ventilation for the mine. Ventilating Conditions The acreage allotted to New Orient mine has a length, north and south, of approximately 6 miles, and a width, east and west, of 2 to 4 miles. A number of important considerations caused the hoist shaft, air shaft and surface plant to be located near the southeast corner of the property, instead of near the center, as is usual. During the initial phase of the mine development, the mine was ventilated through these shafts, although there was a full realization that at some future date other shafts would be required.

Jan 1, 1930