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By D. S. Tomalin, D. F. Stein

The effect of reducing oxygen to low concentrations on the fracture of high-purity iron single crystals has been examined at 78° and 20°K. It is found that iron single crystals grown by the strain-anneal method usually contain a few occluded grain boundaries which may become embittled in the presence of oxygen, thereby nucleating cleavage fractures. High purity with respect to interstitial elements was found to inhibit twinning and evidence is presented for an orientation dependence of the resolved yield stress. Deformation occurred by slip rather than twinning at both temperatures of testing with elongations of as much as 9 pct at 20°K. THE fracture properties of iron single crystals have been observedl-3 to be a function of temperature, orientation, and purity. Allen, Hopkins, and McLennan1 demonstrated that at 78°K iron single crystals became increasingly brittle as the tensile axis approached the (001) pole of the stereographic unit triangle. Iron crystals with the tension axis near a (001) pole were completely brittle and orientations near the (011)-(111) boundary were very ductile, achieving a 100 pct reduction in area prior to fracture. Later work of Biggs and pratt2 and of Edmondson3 demonstrated that by reducing the carbon content of the single crystals the transition between brittle and ductile failure at 78°K could be shifted to orientations nearer the (001) pole. Ed-mondson went further and pointed out that any mechanism which tended to increase the yield strength of the iron (i.e., carbon addition, pre-strain) also increased the tendency for brittle behavior at 78°K. Thus by a reduction of carbon content Biggs and Pratt were able to obtain ductile behavior to within 20 deg of the (001) pole, and Ed-mondson was able to obtain ductile behavior to within 26 deg of the (001) pole. Edmondson's material had a total interstitial content (carbon, oxygen, and nitrogen) of approximately 60 ppm and, although Biggs and Pratt reported no analysis, indications were that their iron contained comparable impurities. Stein, Low, and seybolt4 purified iron single crystals to a total carbon, oxygen, and nitrogen content of approximately 20 ppm. They observed a lowering of the yield stress with this increased purity, and thus one might have expected an observation of increased ductility. Although they tested specimens of orientations which the previous workers had indicated should be ductile, the crystals failed at a 78°K in a brittle manner with little elongation. Stein noted,' however, that about 90 pet of the failures could be traced in origin to occluded grains. Allen et al.1 and Edmondson3 do not report examination of their cleavage surfaces, but Biggs and pratt2 reported that microscopic examination of the cleavage surfaces of many of their specimens revealed the presence of small occluded grains. Honda and cohen6 and Keh7 have also observed the initiation of fracture at occluded grains in iron single crystals. Therefore, the additional complication of occluded grains must be considered in studying the properties of iron single crystals and the origin of fractures determined if the ductility exhibited by the crystals is to be considered meaningful. Various investigators8-12 have studied the effects of impurities on grain boundaries in high-purity polycrystalline iron. Rees and Hopkins10 showed that the addition of oxygen to low-carbon (0.002 pet) iron weakened the grain boundaries, causing a shift from transcrystalline to intercrystalline fracture and a progressive decrease on the brittle-fracture stress with increasing oxygen content. In addition, it has been shown by Low and Feustel11 that the addition of carbon to polycrystalline iron containing oxygen eliminated grain boundary brittleness. Thus, oxygen can embrittle grain boundaries in high-purity polycrystalline iron, but the addition of an appropriate amount of carbon can eliminate the oxygen-induced brittleness. The oxygen content (19 ppm) of the iron "single crystals" employed by Stein el al. was large enough to suspect impurity effects at the occluded grain boundaries. Allen et al.1 Biggs and pratt,2 and Edmondson3 may have masked any occluded grain problem in their specimens considering the relatively high carbon levels they employed. stein13 demonstrated that the addition of as little as 0.9 ppm C to previously purified (less than 5 x 10-3 ppm C) "single crystals" would increase the elongation from a few percent to more than 20 pet at 78°K and the fracture was not associated with grade boundary initiation.

Jan 1, 1965

By M. R. Lorenz

Efficient visible light emission from p-n junctions in semiconductors is currently achieved in the four materials, Sic, GaP, ]Ga1-xAs and GaAs1-x,. Recent advances in materials preparation and p-n junction formation are briefly reviewed. The radiative recombination processes in the different materials depend largely on the band structure and the impurity states of each material. The spectral distribution of the emission ranges from the blue in Sic, to green in Gap, yellow in Sic and red in Gap, Ga1-x AlxAs and GaAs1-x Px. The origin of the various processes are discussed. The conversion of the electrical power into optical power and the measurement of the conversion efficiency are reviewed. The currently maximum quantum efficiencies at 300°K are: 3 pct in GaP(red), 1 pct in SiC(yellow), 0.1 pct in GaP(green), 0.2 pct in Ga1-x AlxAs at 66001, and 0.1 pct in GaAs1-x Px at 6800. The brightness and the interplay of the quantum efficiency and the luminous efficiency are given detailed consideration. VISIBLE light generated by the application of a direct current to a semiconductor crystal was first observed by Lossev1 in 1923. Light emission came from naturally occurring junctions in Sic crystals but little was known then with regard to the mechanism of charge transport and light emission. Some nearly 30 years later and with a vastly increased understanding of semiconductors the phenomenon of electroluminescence was studied in more detail, for example in p-n junctions of germanium.2 In these early studies, the efficiency of converting the electron current into a photon current was very low and therefore aroused little interest toward practical application. More recently it became apparent that in certain materials, for instance GaAs, and under certain conditions, the conversion efficiency was not low at all.3 The subsequent discovery of the p-n junction laser4-6 provided the impetus for increased studies of electroluminescence. Light emitted from GaAs occurs in the infrared region of the electromagnetic spectrum and is not visible to the eye. At nearly the same time the use of GaAs1-xPx led to laser action at low temperatures which was visible to the eye.7 Later a red light emitting diode, made from Gap, was reportedS which emitted incoherent radiation at 300°K with an external quantum efficiency of about 1.5 pct. The fact that such efficient devices were obtainable led to a more concentrated effort in the search for highly efficient room-temperature semiconductor light sources. It is some of this later work on p-n junction luminescence with which we will be concerned here. Since our aim is centered on visible light, with hv =1.8 ev ( ?=7000?), only the wider band gap semiconductors are of interest, i.e., Eg 1 1.8 ev. Although many compounds meet this criterion, only a limited number of those are also good semiconductors, i.e. contain low resistance n and p regions. Some of the more promising candidates are listed in Table I. We will only be concerned with light generation from a p-n junction. This limitation excludes essentially the group II-VI binary compounds, although we will briefly review the case of ZnTe and the solid solution ZnTe1-xSex. As we will show they may contain a p-n junction but only of a special kind. Most of the discussion will deal with the four materials, Sic, Gap, Gal-xAlxAs, and GaAs1-xPx. These appear to be at the present time the best visible light emitting semiconductors. In the following sections we will briefly consider: 1) the electrical properties of p-n junctions; 2) some recent advances in materials preparation; 3) the formation of p-n junctions; and then in somewhat greater detail we will consider: 4) the various radiative recombination processes; 5) the measurement and observation of the external quantum efficiency; 6) the luminous efficiency; 7) the brightness of light emitting diodes (LED'S). THE P-N JUNCTION The p-n junction in a semiconductor crystal is the interface between two differently doped regions. More specifically the p region is doped predominantly with acceptor impurities and the n region contains predominantly donor impurities. The energy band structure of a degenerate p-n junction at thermal equilibrium is shown in Fig. l(a). The excess electrons on the n side of the junction are confined to this region by the barrier potential Eg. Similarly the excess holes on the p-side of the junction are confined to the p-region by a similar potential barrier. If we now apply a dc voltage V such that the p region is made positive and the n region negative, the barrier potential EB is reduced by the applied voltage, V and the junction is said to be forward biased. With the barrier potential lowered, electrons and holes can drift toward the p region and n region, respectively, see Fig. l(b). The current voltage characteristics of p-n junctions in most wide band gap materials can be described by the relation: J = Joexp(eV/BkT) [1] where the functional form of Jo is determined by the recombination mechanism. Jo is generally a complicated parameter which depends on a number of different factors including temperature, junction width, bias voltage, and carrier lifetimes. The parameter B also depends on the recombination mechanism but

Jan 1, 1970

By AIME AIME

MODERN metallurgy is an art and a science. The art is process metallurgy-extracting metals from their ores, refining them, and alloying them with one another and with certain nonmetals to produce thereby a variety of metallic materials which, owing to a wide range of useful properties, are for many purposes more valuable to man than the individual metals themselves; process metallurgy also includes shaping or otherwise treating metals and alloys to form objects useful to a complex industrial world. The science is physical metallurgy-organized knowledge of the constitution and internal structure of metals and alloys, of the relation of their composition and structure to properties, and of the laws, theories, and hypotheses that purport to explain this relation.

Jan 1, 1942

THE problem of picking the best students for an engineering college can no longer, be considered as simply one of determining the amount of general ability, but rather of finding special aptitudes for scientific work, according to Carl C. Brigham~ a Princeton University professor, who has been conducting researches on methods of selecting engineering undergraduates at Cooper Union, an evening school in New York City. When we first began this investigation seven years ago," says Dr. Brigham, "we thought the whole job would be done a soon as we had found a good method of measuring general intelligence. Today we feel that we are still about five years away from a solution, but on somewhat firmer footing than when we were looking for general ability.

Jan 1, 1928

By Samuel M. Cassidy, John A. Garcia

In some districts of the bituminous coal field the problem of constructing bulkheads to seal off water under pressure is becoming increasingly important. Recently this matter has been brought very much to the front by the loss of a large Illinois mine due to failure of a bulkhead that separated it from several old, flooded mines. As this great misfortune has provoked much inquiry about proper bulkhead design, it is felt that a description of the successful and extensive water-sealing practice at three mines that have different natural conditions will be of considerable interest to those connected with properties having a present or future water problem and to engineers that may have to design safe bulkheads of economical construction. These three mines are the Saxton and Dresser, near Terre Haute, Ind., and the Hegeler, near Danville, Ill. All three have water conditions that make it necessary to regularly seal off all worked-out sections of the mine, and there are considerably over a hundred bulkheads in each. AS far as the writers know, these three mines are the only ones in the bituminous coal fields of the United States with anything like so large a number of water seals and experience, although a number of other mines are known to have a few bulkheads. More detail will be included herein on the Saxton mine than on the others, as the writers are more familiar with it. General Mining System All three of the mines use the same general panel room-and-pillar system, which consists of rooms turned both ways off room entries and a solid block of coal left on all sides of the completed panel except on the cross-entry side, where a heavier pillar is pierced by two entries for haulage and air. On completion of the panel the two entries arc sealed and the panel is then isolated from the rest of the mine. Owing to water conditions, no pillars are pulled; recovery inside the panel barrier pillars is approximately 65 per cent.

Jan 1, 1938

By Samuel M. Cassidy, John A. Garcia

In some districts of the bituminous coal field the problem of constructing bulkheads to seal off water under pressure is becoming increasingly important. Recently this matter has been brought very much to the front by the loss of a large Illinois mine due to failure of a bulkhead that separated it from several old, flooded mines. As this great misfortune has provoked much inquiry about proper bulkhead design, it is felt that a description of the successful and extensive water-sealing practice at three mines that have different natural conditions will be of considerable interest to those connected with properties having a present or future water problem and to engineers that may have to design safe bulkheads of economical construction. These three mines are the Saxton and Dresser, near Terre Haute, Ind., and the Hegeler, near Danville, Ill. All three have water conditions that make it necessary to regularly seal off all worked-out sections of the mine, and there are considerably over a hundred bulkheads in each. AS far as the writers know, these three mines are the only ones in the bituminous coal fields of the United States with anything like so large a number of water seals and experience, although a number of other mines are known to have a few bulkheads. More detail will be included herein on the Saxton mine than on the others, as the writers are more familiar with it. General Mining System All three of the mines use the same general panel room-and-pillar system, which consists of rooms turned both ways off room entries and a solid block of coal left on all sides of the completed panel except on the cross-entry side, where a heavier pillar is pierced by two entries for haulage and air. On completion of the panel the two entries arc sealed and the panel is then isolated from the rest of the mine. Owing to water conditions, no pillars are pulled; recovery inside the panel barrier pillars is approximately 65 per cent.

Jan 1, 1938

By L. J. Howell, R. C. Sommer, H. H. Kellogg

WORK described herein was undertaken with the aim of determining some of the physical-chemical properties of electrolytes suitable for the electrodeposition of pure zirconium metal. In this paper the phase diagram, vapor pressure, and activities in the melt are considered. In a companion paper,' the electrolytic conductivity of some of these melts is reported. The melts studied were mixtures of NaCl and/or KC1 with ZrC1,. Chloride melts were chosen for study because 1) if the electrolyte is to be useful for industrial electrodeposition of zirconium, the chlorides will be preferred to the relatively costly bromides and iodides; 2) fluoride melts were being studied in another laboratory (Horizons Inc., Cleveland); and 3) melts containing oxygen, in any form, are unsuitable for preparation of pure zirconium, because of the great affinity of this metal for oxygen. Unlike electrodeposition from aqueous solution, the fundamental behavior of fused-salt electrolysis is poorly understood. In most cases, such basic electrochemical information as the phase diagram of the melt system, activities in the melt, conductivity, the nature of the current-carrying ions, the equilibrium electrode potentials, and the overvoltage behavior of the electrodes is unknown to the researcher who would develop a new electrodeposition process employing a fused salt. This research project was designed to supply information about some of these basic physical-chemical properties so that an intelligent choice of electrolyte for electrodeposition studies could be made. Experimental The experimental difficulties-encountered in this work result from the properties of zirconium metal and ZrC1,. ZrC1, is a solid which sublimes at 334°C. It is rapidly hydrolyzed by moist air to HC1, ZrOCl,, and ZrO,. Unusual precautions were exercised in this work to prevent hydrolysis of ZrC1, and rigidly to exclude oxygen, nitrogen, hydrogen, and carbon from the melts under study. These elements are known to react with and contaminate zirconium metal. All melts were studied in vacuum systems, i.e., in the presence of ZrC1, vapor only. Transfer of ZrC1, to or from the melts was accomplished entirely by vacuum sublimation. In this way, neither the melts nor the ingredients thereof were permitted to

Jan 1, 1958

By WILLIAM BOWIE

THE development of the isostatic idea during the last century would make an interesting paper in itself. But the various steps in the development have been covered in a number of papers and books which are readily available. Therefore this short paper should not give space to. the historical phases of the subject. Isostasy is really an old idea, but it is only in the last few decades that it has taken on any great prominence or importance in the study of earth phenomena. It is really remarkable how closely Dutton' sensed the isostatic principle 40 years or more ago. His general principles of isostasy as outlined by him have stood the test of time and fit in closely with the general ideas held today. It would seem, however, that some of his views with regard to the application of isostasy to geological processes must be modified or abandoned.

Jan 1, 1930

By H. M. Morse

During the year of 1940, wildcat wells were drilled in 32 counties of Mississippi; 85 wells in all. These were scattered over the state from the most northern county to the southern counties and from the Mississippi River on the west to the Alabama line on the east. Yazoo County, with 19, received the largest number. The average depth of all the wells was 5333 ft. The shallowest well completed as a dry hole was in Yalobusha County, aban-doned at 1392 ft. in the Selma. The deepest well drilled was in Scott County, abandoned at 10,365 ft. in the Lower Cretaceous Paluxy. G. C. Grasty drilled the Kentucky Lumber Company No. I well, sec. 7, T. 10 S., R. 10 E., Itawamba County, to a depth of 3530 ft. and bottomed his hole in the Ordivician. Tinsley Oil Field.—In the Tinsley oil field 104 wells were completed as producers during 1940. Five producing sands have been logged with a total average thickness of I57 ft. of oil sand. One of these sands is in the Selma, three in the Eutaw, and one in the Tuscaloosa. Vaughan-Pickens Field.—The Vaughan-

Jan 1, 1941

By H. M. Morse

During the year of 1940, wildcat wells were drilled in 32 counties of Mississippi; 85 wells in all. These were scattered over the state from the most northern county to the southern counties and from the Mississippi River on the west to the Alabama line on the east. Yazoo County, with 19, received the largest number. The average depth of all the wells was 5333 ft. The shallowest well completed as a dry hole was in Yalobusha County, aban-doned at 1392 ft. in the Selma. The deepest well drilled was in Scott County, abandoned at 10,365 ft. in the Lower Cretaceous Paluxy. G. C. Grasty drilled the Kentucky Lumber Company No. I well, sec. 7, T. 10 S., R. 10 E., Itawamba County, to a depth of 3530 ft. and bottomed his hole in the Ordivician. Tinsley Oil Field.—In the Tinsley oil field 104 wells were completed as producers during 1940. Five producing sands have been logged with a total average thickness of I57 ft. of oil sand. One of these sands is in the Selma, three in the Eutaw, and one in the Tuscaloosa. Vaughan-Pickens Field.—The Vaughan-

Jan 1, 1941

By Dilip K. Das, Douglas T. Pitman

ONE of the major uses of barium in metallic form is as a getter material in vacuum tubes. Because of the high chemical reactivity of the metal, Ba-Al alloys are extensively used. Numerous methods for the preparation of Ba-Al alloys have been published, a few of which1-4 are cited here. Most of these methods were found to be quite elaborate, involving the reduction of BaO, and not too well adapted for the close control of the final composition of small amounts of alloys prepared for laboratory use. A simple laboratory method for the preparation of Ba-A1 alloys in small batches starting from pure metals was devised, so that it was possible to control the desired compositions to within 1 pct. The pertinent features of the alloy system Ba-Al5 are 1) an intermediate compound BaAl, with the melting point of 1050°C, and 2) a eutectic between aluminum and BaAl4 at 98 pct Al. The accompanying sketch shows the experimental arrangement for the preparation of the alloys. Weighed amounts of aluminum and barium were placed in an alumina and a stainless steel crucible, respectively. According to the supplier's specification, the purity of the metals used in the alloys is as follows: a) aluminum rods—99.9 pct Al, and b) barium rods—99.5 pct Ba. The stainless steel crucible, tapered at the bottom and having a 1/16 in. diam hole, rested on top of the alumina crucible. The assembly was placed inside a graphite sleeve which rested on a refractory platform. The platform moved the assembly up and down through the field of a radio frequency coil. A glass bell jar was placed between the crucible assembly and the radio frequency coil to maintain a steady flow of helium around the melt. A small window was cut out on the wall of the alumina crucible to observe the progress of the re- action and to record the temperature with an optical pyrometer. The platform was first raised high enough to move the barium out of the radio frequency coil field in order to allow only the aluminum to melt. The assembly was then lowered so that the barium began to melt and flow out through the small orifice into the molten aluminum. In order to keep the violence of the exothermic reaction under control, the rate of flow of barium was carefully regulated by raising or lowering the crucible assembly. All the samples prepared by this technique were examined by a Norelco X-ray diffractometer using CuKa radiation, The diffraction specimens were prepared by placing the finely powdered samples in flat specimen holders. The Ba-Al alloys prepared with a high barium content were found to consist mainly of BaAl4. The structure of BaAl4 has previously been reported by Alberti and Andress.8 They found that BaAl4 was body-centered-tetragonal with an a0 = b0 = 4.530Å and c0 = 11.14Å. An alloy whose composition was found by chemical analysis to be almost 100 pct BaA1, was used to determine the relative intensities. The d-spacings were obtained from the same alloy to which a small amount of tungsten had been added as a calibrating material. Accurate values for a, and c, were calculated according to the method proposed by Taylor and Floyd.' The calculated values are: a, = b, = 4.566Å and c0 = 11.250Å. The measured d-values for BaAl4 are shown in Table I along with relative peak intensities above background and hkl indices. Acknowledgment The authors are grateful to L. J. Cronin, the head of the Techniques Dept., for suggesting the problem and for his constant interest. References 1Froges and Camargue: German Patent No. 809107, 1951. French Patent No. 935324, 1949. 2E. Bonnier: Annales de physique, 1953, vol. 8, pp. 259-312. 3M. Orman and E. Zemhela: Prac Institute of Metals; 1952, vol. 4, pp. 437-445. 4E. Fujita and H. Yokomizo: Reports Gov. Chemical Industrial Research Institute, Tokyo, 1952, vol. 47, pp. 291-297. 5E. Alberti: Ztsch. fur Metallkunde, 1934, vol. 26, p. 6. 6E Alberti and K. R. Andress: Ztsch. fur Metallkunde, 1935, vol. 27, p. 126. 7 A. Tnslor and R. W. Floyd: Acta Crystallographica, 1950, vol. 3, p. 285.

Jan 1, 1958

By David B. Reger

Wildcat drilling for new supplies of gas and the expansion of previously discovered oil and gas pools were the principal petroleum activities in West Virginia .during 1942. Much of the new gas exploration is still uncompleted and still indecisive but various wildcats made substantial extensions to existing pools. Out of 53 wildcats drilled 27 resulted in commercial gas and 6 in commercial oil. Four of the oil discoveries also had commercial gas. No strictly new pools of oil or gas can safely be described as discovered but several scattered oil and gas wells previously drilled have been confirmed as the openers of definite pools; also, various completions closed wide gaps between apparent gas pools already discovered. The proved oil territory of the state was increased about 4850 acres and the proved gas territory about 51,000 acres. The new proved oil reserves should about balance withdrawals and the new gas may represent a substantial increase. Aside from the drilling in four rather lively pools, oil activity was slight because of unfavorable operating conditions and prices. Gas drilling also declined for reasons beyond the control of the operators. The account of operations, as gathered from trade journals and other reporting services, shows that 797 new wells were drilled, providing 119 new oil wells with 2762 bbl. of daily new production; 536 new gas wells with 1,228,501,000 CU. ft. of daily open flow: and 142 dry holes. Also... 76 old wells were drilled to deeper sands, with 71 bbl. and 26,034,000 cu, ft. of added production. On the new wells the oil average was 23.21 bbl. per well per day; and the gas average was 2,270,406 CU. ft. per well per day. On new wells the ratio of dry holes to completions was 17.82 per cent. On deeper drilling the ratio of failures was 21.05 per cent. Production of oil for the year was estimated by the Oil ad Gas Journal as 3,492,000 bbl., as compared with 3,378,000 bbl. in 1941. Production of natural gas for the year is estimated by the author as 220,000,000,000 cu. ft., as compared with the U. S. Bureau of Mines final figures of 207,000,000,000 cu. ft.* in 1941. General State op Industry Leasing of wildcat acreage increased considerably. The total land of all classes under lease may now exceed 5,000,000 acres. Taking into consideration completions, abandonments and corrected figures or estimates, Table I shows cumulative and late annual statistics. New Pools and Extensions Table 2 shows the principal areas of drilling activity during 1942. Various consolidations of territory, hitherto treated as separate pools, have been made. in addition to these active pools, extensive drilling was done in numerous other areas where pool boundaries can hardly be defined. Summary or Exploration Table 3 gives a summary of important wildcat or exploratory wells drilled during

Jan 1, 1943

By David B. Reger

Wildcat drilling for new supplies of gas and the expansion of previously discovered oil and gas pools were the principal petroleum activities in West Virginia .during 1942. Much of the new gas exploration is still uncompleted and still indecisive but various wildcats made substantial extensions to existing pools. Out of 53 wildcats drilled 27 resulted in commercial gas and 6 in commercial oil. Four of the oil discoveries also had commercial gas. No strictly new pools of oil or gas can safely be described as discovered but several scattered oil and gas wells previously drilled have been confirmed as the openers of definite pools; also, various completions closed wide gaps between apparent gas pools already discovered. The proved oil territory of the state was increased about 4850 acres and the proved gas territory about 51,000 acres. The new proved oil reserves should about balance withdrawals and the new gas may represent a substantial increase. Aside from the drilling in four rather lively pools, oil activity was slight because of unfavorable operating conditions and prices. Gas drilling also declined for reasons beyond the control of the operators. The account of operations, as gathered from trade journals and other reporting services, shows that 797 new wells were drilled, providing 119 new oil wells with 2762 bbl. of daily new production; 536 new gas wells with 1,228,501,000 CU. ft. of daily open flow: and 142 dry holes. Also... 76 old wells were drilled to deeper sands, with 71 bbl. and 26,034,000 cu, ft. of added production. On the new wells the oil average was 23.21 bbl. per well per day; and the gas average was 2,270,406 CU. ft. per well per day. On new wells the ratio of dry holes to completions was 17.82 per cent. On deeper drilling the ratio of failures was 21.05 per cent. Production of oil for the year was estimated by the Oil ad Gas Journal as 3,492,000 bbl., as compared with 3,378,000 bbl. in 1941. Production of natural gas for the year is estimated by the author as 220,000,000,000 cu. ft., as compared with the U. S. Bureau of Mines final figures of 207,000,000,000 cu. ft.* in 1941. General State op Industry Leasing of wildcat acreage increased considerably. The total land of all classes under lease may now exceed 5,000,000 acres. Taking into consideration completions, abandonments and corrected figures or estimates, Table I shows cumulative and late annual statistics. New Pools and Extensions Table 2 shows the principal areas of drilling activity during 1942. Various consolidations of territory, hitherto treated as separate pools, have been made. in addition to these active pools, extensive drilling was done in numerous other areas where pool boundaries can hardly be defined. Summary or Exploration Table 3 gives a summary of important wildcat or exploratory wells drilled during

Jan 1, 1943

By G. H. LeFevre

THE Metal Sales Department, with offices in New York, is responsible for the sale of the Company's products, with the exception of gold and coal. At present the department handles the sales of lead, zinc, silver, antimonial lead, , cadmium, bismuth, arsenic trioxide, and tellurium; gold is shipped direct to the United States Mint and coal is marketed by United States Fuel Company's own sales organization. The department keeps in close touch with the metal markets and collects information on marketing conditions, which it makes available to other departments of the Company. The electrolytic lead produced at the U. S. S. Lead Refinery, Inc., is a high-uality product marketed as corroding grade under the "U. S. S.-ELECTRO" brand. It is largely sold to manufacturers of paints, pigments, lead oxides, and storage batteries.

Jan 1, 1948

By Edward H. Robie

OF the current Adirondack iron mine development, the Benson Mines operation of the Tones and Laughlin Ore Co. (Jones & Laughlin Steel Corp. wholly owned subsidiary) is the last to go into operation. Following an active construction program in 1943, the mine. concentrator and sintering plant were scheduled to enter production in the fall. This description therefore cannot include any operating data, and details of equipment and flowsheet have not as yet been released.

Jan 1, 1943

By C. W. Parmelee

THE ideal fuel for burning ceramic wares is the one that, among other characteristics, has little or no sulfur. For that reason wood was long considered the most desirable fuel but its high cost has practically eliminated its used except in regions where it is very abundant or other circumstances warrant its choice. The fuels commonly employed are natural and producer gas, oil, and coal. The last named is undoubtedly the most important, not only in this country but abroad. Occasionally anthracite is used but the larger part is bituminous. The quality of the coal used depends on the kind and the value of the products being manufactured. For some materials, such as common brick, hollow block, etc., the quality of the coal is of less importance than in the manufacture of polychrome terra cotta, pottery, porcelain, etc. It is obvious that in burning clays that contain notable amounts of pyrite, marcasite or gypsum, as is the case with many common clays, the sulfur content of the fuel is of much less importance. The permissible amount of sulfur in the coal used will depend on the kind of product being manufactured. "A good sample' of coal commonly used in pottery ovens has something like this quantity of sulfur." PER CENT. Total sulfur 1.20 Sulfur in the ash 0.11 Volatile sulfur a 1.09

Jan 9, 1919

By J. E. Howard

On Aug. 25, 1911, a rail failed on the Lehigh Valley Railroad, causing a disastrous wreck. The surface of the fracture was in a plane at right angles to the length of the rail. There was a dark-colored, oval spot on this surface, located on the gage side of the head, representing the part of the rail which was the first to fracture. The nucleus of this spot showed that the fracture had an interior origin. Other fractures of this kind, the peripheries of which had not reached the surface of the rail, presented surfaces having a (silvery luster. The darkened surface of the present fracture was caused, doubtless, by the air having had access to it. This fracture was recognized as a fatigue fracture, of a modified type, its interior origin having been due to a component in the rail which is not usually present in cases of fatigue fractures. The metal next the running surface of the head of the rail was in a state of internal compression, this being the component not commonly met with in other cases, and which caused the fracture to have its interior origin. For the purpose of giving this modified type of fatigue fracture a specific name, for identification, the term "transverse fissure" was applied. No mystery was thought to attach to its formation, or to its development. The explanation of its occurrence seemed obvious in the light of common knowledge upon the behavior of steel under repeated alternate stresses.' By reason of the state of internal compression at the running surface, the maximum tensile stresses in the head, ander bending loads, were along an interior element. Here the tensile strains were higher than in the fibers more remote from the neutral axis. Under such conditions the fracture of the rail would be expected to have an interior origin. A discussion of the subject of transverse fissures essentially becomes a discussion of fatigue fractures, since they are believed to be identical. The descriptive term employed, merely for the identification of this type of fatigue fracture, had the appearance of creating alarm. Apprehensions arose that a new phenomenon in the physical properties of steel had presented itself, the explanation of which was sought in every

Jan 1, 1918

By C. Kremer Bain

DURING the past several years of diamond drilling in Washington County, Mo., the St. Joseph Lead Co. has discovered a concentration of commercial lead-zinc ore at four different points within an area of 36 square miles. The largest and to date the most promising group of these orebodies is located in the Indian Creek area. It was considered to be of sufficient value to warrant development.

Jan 9, 1953

By David T. Day

IN 1897 I published a proposed explanation t for the variation in color and specific gravity of Pennsylvania oils. A resume of this subject was also presented at the First International Petroleum Congress, in Paris, in 1900. Since that time much experimental work bearing upon this explanation has been carried on by myself, in the United States Geological Survey, and under my direction, by Dr. J. Elliott Gilpin, Marshall P. Cram, and 0. E. Bransky, at the Johns Hopkins University. The experimental results thus accumulated seem to throw considerable additional light upon the variations in color and specific gravity of petroleum, as found in different parts of the world, and also upon the variations in chemical composition. Therefore, it seems as if a, summary of the evidence thus obtained might be of value to those members of the Institute who are interested in the examination of oil-fields. The summary is here presented for that purpose. The phenomenon has often been observed in many oil-fields that oils of different color, specific gravity, and chemical composition may be found within short distances of each other. A conspicuous example of this is the occurrence at Jennings, Welsh, and Anse la Butte, La., of petroleum chemically somewhat similar to Russian petroleum; that is, characterized by the presence of naphthenes. Another characteristic is the presence of considerable percentages of asphaltic compounds, sufficient in quantity to disguise the presence of solid paraffin wax, and perhaps also to render that paraffin wax more soluble * Published by permission of the Director of the United States Geological Survey. 1 Proceedings of the American Philosophical Society of Philadelphia, vol. xxxvi., No. 154, pp. 112 to 115 (January, 1897).

Jun 1, 1910

By A. H. Tousley

Current problems in the cement industry are discussed and suggestions for solving them by modernization are made. Cement facility modernization is discussed in considerable detail with examples illustrating before and after conditions. Itemized are the improvements realized in better working conditions, better efficiency, higher production, lower costs, and better community relations. These improvements are related to the overall profitability of the particular plant or facility.

Jan 1, 1972