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ALEXANDER, JOHN S, M,'74-6,'81-3 *ASHBURNER, C A, M, '85-7 ASMUS, GEORGE, Dl, '78-80 BACON, D H , M, '00-2 BAYLES, JAMES C , M,'80-2,'91-3 P, '84-5, V,'88-9 BIRKINBINE, JOHN, M, '83-5, V, 'S7-J, P, '91-2 BLAIR, THOMAS S , M, '74-43 BLAKE, WILLIAM P , V,'71-4,'76-7,'05-6 *BLANDY, JOHN F, V,'71-3,'78-9 BLOW, A A, C, '05-7 BOWIE, A J , JR, V,'93-4 *BRAMWELL, J H , A1, '89-91 BROOKS, THOS B , M, '72 BRUNTON, D W , V, 97-8 BUCK, STUART M , M, '83-5 *BURDEN, JAMES A, V,'80-1 BURNHAM, WILLIAM, M, '82-4. CAMPBELL, H H, M, '93-5 CHAMBERLAIN, H S , V, '96-7 CHANNING, J PARKE, V,'08 CHRISTY, S B , V. '91-2, '07-8 CHURCH, JOHN A, M, '79-8l,'94-6, V, '07-8 COGSWELL, W B, V, '74-5,'86-7

Jan 1, 1910

By Richard Birk

Rf sputtered quartz has been successfully used in multilayer interconnects for MOS devices. The target potential was 2000 v peak to peak with a frequency of 13.56 Mc per sec. The sputtering rate was approximately 60A per min with an operating pressure of argon gas at 10 to 15 p. The dielectric strength is 8.0 x 10' v per cm and the pinhole density is less than 2 x 10-2 per sq mm. Infrared absorption peaks for the Si-O vibrational bands we at 9.4, 12.4, and at 22.5 p. The etch rate of the sputtered SiO2 is 1200A per min. MOS devices have been fabricated using multilayer interconnects with no degradation of electrical characteristics. MULTILAYER interconnects require an insdating film between the metal layers which can be deposited below any potential eutectic temperature. Sputtered Si4, which can be deposited with substrate temperatures below 200°C, satisfactorily meets the multilayer insulation requirements and has been used to prepare MOS circuits with multilayer interconnects. The physical and electrical properties of rf sput-

Jan 1, 1969

By P. R. Hanes

A description of the methods used in driving two tunnels, 2 miles long each, one a 9-ft. and the other a 19-ft. diameter section, for the Owyhee Irrigation Project, Oregon. One heading of the smaller tunnel was driven 1315 ft. in 73 shifts in one month and 10,966 ft. of this section completed in ll½ months using two shifts for eight months and three shifts the rest of the time. This is a good illustration of the proper use of a mechanical shovel and the importance of careful selection of supplernentary equipment to secure best results. Large cars, speedier and heavier locomotives, 36-in. gage track of 45-lb. rail, and a good switching method increased actual shoveling time and cut down muck removal period about 45 minutes from average. The larger tunnel, after trying out standard electric revolving shovels of both the rail mounting and caterpillar tread types, was excavated with a mechanical mucker. This is the first time that a tunnel of so large a section has been handled this way. This record work was accomplished without drill carriages.

Jan 1, 1934

By William P. Blake

The occurrence of the manganiferous variety of wolframite at a new locality in Arizona was announced in the month of May last." It occurs in the granite hills of the Dragoon mountains, in Cochise county, about 6 miles north of Dragoon Summit station, on the Southern Pacific Railway of Arizona. It is found in veins of white quartz, traversing a coarsely crystalline granitic gneiss, and, so far as yet determined, is without association with other metallic minerals in the same veins, except small quantities of scheelite. It is a very pure form of the mineral, and contains but little iron, the base being manganese oxide. The color is brownish-red; it is nearly the same as the color of the mineral originally described by E. Riotte from Mammoth District, Nevada.† Thin films or plates on the broad cleavage-surfaces, and thin cleavage-flakes, seen by transmitted light, are ruby-red, or rather more like the color of red zinc oxide or the mineral known as clintonite. By long-continued weathering the surface becomes less deeply colored, and assumes a bronze-like luster, like the dull oxidized surface of

Jan 1, 1899

By August E. Vandale

Mining of the Freeport and Pittsburgh coal seams in the Pittsburgh vicinity dates back more than 100 years, and Consolidation Coal Co., or its predecessor, Pittsburgh Coal Co., has been actively mining in the area since 1900. Over the years, Consol has acquired good legal title to the coal lands purchased from individual farm owners, with broad mining rights, and in 98% or more of its title holdings, the company has a complete waiver of surface damage or the right to subside the surface land. (Titles in Pennsylvania can be in three forms: title in fee; title to the mineral; or mining rights permitting the removal and extraction of the mineral with or without waiver of surface damage.) In the early history of Consol, individual farms overlying the seams were purchased from land owners. Many of these titles severed the coal estate from the "in fee" title, and mining rights with waiver of surface damage were conveyed in the original severance deed. In this manner, Consol was able to put together its large mineable coal reserves. Consol has practiced "full recovery" mining as far as practical from its early years of hand loading to the recent era of mechanization.

Jan 9, 1967

Within the last century, and largely during the latter half of it, the increase of our knowledge of the development of man, both in his search for a livelihood and for power, and in the growth of his reason and conscience, has been greater than all we had known before. The great interest in all kinds of archaeological work and the many excavations made of buried and long forgotten places has put at our disposal historical records-not available, and in many cases not known before, and a study of these and other records of human progress from paleontological and geological sources has given us a much broader view of what we call "civilization" than was possible even a short time ago. The old idea that men were created with fully developed minds, speech and reason has yielded to the view that in the upward progress of the human race the development of the mind and reason has been a comparatively recent occurrence, as we think of the half million, and probably more, years that have passed since our earliest records of man were made. The traits that come to us without effort

Jan 1, 1939

Jan 1, 1966

By Carel Robinson

MECHANIZATION of coal mine, is radically changing the requirements for under-ground transportation. It has increased materially the need for reliability and belt conveyors are the most dependable means of moving coal away from the place where it is mined. Their record of freedom from delays is almost 100 per cent. Why then are- not belt conveyors in more general use. Part of the answer lies in the pour records made at some of the earlier installations, and in the fact that belts have so long been identified as a type of equipment suitable, in the main, only to thin seams. Another reason is lack of knowledge of the full potentialities of belt transportation.

Jan 1, 1941

By R. C. FLEMING

MINING rock asphalt for use as a paving material is an industry which has grown with the spread of the good roads movement. "Mineral Industry During 1930" reports asphaltic pavements constructed, including maintenance and repair but excluding pavement constructed with road-oil, cut-back or emulsified asphalt, as grown from 23 million square yards in 1911 to a high of 144 million in 1927. In 1930 the same source reports 106 million square yards of such paving laid and, in that year, 664,871 tons of native rock asphalt were so utilized. Many states contain rock asphalt deposits of greater or less importance but in only a few places are the de¬posits being mined commercially. In the year cited Ken¬tucky produced 305,024 tons of bituminous sandstone, Texas 270,138 tons, mostly bituminous limestone, while Alabama, Oklahoma, California and Utah produced 89,709 tons of bituminous rock for road construction. In addition Utah produced 37,906 tons of the purer asphaltic products, gilsonite, wurtzilite and ozokerite, for other uses. Speaking generally, the rock asphalt is a sandstone or limestone naturally impregnated with asphalt to an extent that makes it an ideal road surfacing material without mixing or treatment other than crushing. The asphalt content of the commercial product runs 8 to 12 per cent.

Jan 1, 1933

By William P. Blake

THE phenomena of concentric arrangement of minerals in rock-masses, generally known as "orbicular structure," have of late received much attention from investigators. Lawson, of the University of California, has described the orbicular gabbro at Dehesa, San Diego county, Cal. Kessler and Hamilton, of Stanford University, working independently upon the same subject, published their descriptions,2 giving also a list of many other localities in Europe and America where orbicular rocks are found, adding copious references to the literature of the subject. The orbicular diorite of the type locality in Corsica., familiar to mineralogists and petrologists under the name "Napoleonite," was described by Vogelslang in 1862.3 Chrustschoff, of St. Petersburg, has also given much atten¬tion to the subject, and is the author of a classification of the various known forms of orbicular structure.4 No complete and satisfactory explanation of the origin of or¬bicular aggregations in rocks has yet been offered. The patent fact is generally recognized that the constituent minerals have crystallized from a more or less molten or plastic magma, but why these minerals should be arranged in concentric spheres or crusts has not been clearly shown. Vogelslang, for example,

Jul 1, 1905

By S. K. Bradford

(Pittsburg Meeting, March, 1910.) FOR years past I have traveled in quest of promising mining-properties, over almost impassable mountain-trails to remote places in the mining-regions, usually, many miles from an assay-office. If, upon examination, the formation and the ore-deposit appeared favorable, a quick determination of the value of my samples was necessary, in order that I might take intelligent action with reference to the acquisition of the property. A journey with my samples to civilized regions often meant weeks of delay, and perhaps loss of opportunity. How many, under similar circumstances, have returned with their assay-results from such a journey, only to find that some audacious speculator had " optioned" the property ! True, a first payment could have been made and the chances taken on the results; but experience has taught that rich-looking ore is not of necessity valuable. Personally, I would not hazard a ten-dollar bill on any property without first determining by assay the value of the ore. To carry the usual complete assay-paraphernalia over such mountain-trails was impracticable by reason of the loss of time involved, the great expense of transportation (charged according to weight), and the fact that a few such trips would almost certainly wreck the outfit. For these reasons I began a process of elimination and substitution which finally enabled me to carry, in an ordinary 26-in. valise, sufficient apparatus and supplies for, say, 100 assays of adequate commercial accuracy. My final outfit was as follows: APPARATUS. Small hammer; steel mortar (2.5 in. wide, 3 in. high, with stand sawed off flat, so that it can be used as an anvil and for

Jan 1, 1911

By Benjamin Smith Lyman

THE importance of topography to geology is so commonly underrated as to deserve to be pointed out again and again. The relation of topography to the different branches of geology may be seen best by a glance at them all. Geology is well understood to consist of the observation of facts about rocks as materials of the earth (geognosy), and the explanation of those facts (geognosy). The facts to observe are : I. GEOMETRICAL, as (1) structure, including the dip and strike at different points, the size, shape, and position of basins and saddles; (2) vertical section, that is, the thickness of rock groups and of their parts ; (3) horizontal or geographical position. 11. PHYSICAL, such as texture, whether sedimentary or crystalline ; and, if crystalline, whether granitic, porphyritic, amygdaloidal, globular, or concretionary ; whether compact or granular; coarse or fine; pervious or impervious; hard or soft; firm or tender; with cleavage or without ; massive or thin ; the microscopic structure ; also whether magnetic or not ; soluble or insoluble ; fusible or infusible ; and the constituent minerals. 111. CHEMICAL that is, the composition of the rocks and of their minerals and their affinities. IV. PALAENTOLOGICAL, as what kind of fossils are in the rocks,

By Howard A. Meyerhoff

AS a source of mineral wealth, the larger islands of the West Indies have never had an enviable reputation. The Spaniards took possession of them in the sixteenth century hopeful that they would yield gold; but it was not long before they knew the rather rigid limitations of Antillean gold production and were seeking-and finding ---richer deposits of the precious metals in Mexico and on the west coast of South America. Although a great deal of wealth changed hands in the West Indian islands in subsequent years, the fact may be laid to the abundance of pirates and privateers and not to the richness of local ore bodies.

Jan 1, 1941

By J. L. SILSBEE

THE existence of large saline deposits in that flat arid basin, known as the Great Salt Lake Desert, has long been recognized, but the extent and great commercial value of these deposits has not been generally appreciated. That a very considerable interest has recently developed is indicated by the fact that about 263 prospecting permits-each covering about 2560 acres of land in this Desert-have been issued under the Potash Leasing Act (Act of 0ct. 2, 1917-40 Stat. 297), and patents granted on approximately 40,000 acres. It is reported that patents and leases have, or will be applied for on an additional 80,000 acres in the basin. , Tests have been made on probably less than 10 per cent. of the total area of the basin, but these have proved a practically unlimited supply of brine available -sufficient, probably, to. furnish the potassium and magnesium chloride requirements of this country for at least a hundred years.

Jan 1, 1925

By Arnulf Muan, Klaus Schwerdtfeger, L. S. Darken

The equilibrium ratios CO/CO, of. a gas pharse coexislitrg with selected oxide phase assemblages of the system "FeO"-MnO-SiO2 and metallic iron have been determined at 1150°C. The data obtained are combined wilh the thermodynamic data on fayalite (Fe2SiOi) and "FeO"-MnO solid solutions to derive the actiuity-coiHpQsiUon relations for the various oxide components of the olivine (Fe2SiO4-,lIn2Si04) and pyroxenoid (standard free energies of formation of ferrosilile (FeSiO,), tephroite , and rhodonite from their oxides have been evaluated. In the Appendicc~s by Darken and Schivcerdtjeger the ideal solution law for solid deri oed. THE quaternary system Fe-Mn-Si-0 is of interest in many important phases of iron- and steelmaking. For instance, reduction in the blast furnace of ores containing Fe-Mn silicates, deoxidation of liquid steel with Mn-Si alloys, formation and subsequent alterations of oxide inclusions in steels, and the oxidation of manganese- and silicon-containing steels during processing are all governed largely by the thermodynamic relations existing in the system Fe-Mn-Si-O. Although the equilibria between liquid iron and Fe-Mn silicates have been studied in detail previously,' experimental data are lacking for equilibria among the solid phases. The present paper provides such data for a selected temperature, 1150°C. I) PREVIOUS WORK The general feature of subsolidus phase relations in the system iron oxide-manganese oxide-silica under strongly reducing conditions is known.' Fig. 1 represents an isothermal section at 1150°C. The phases present, in addition to silica, are three solid-solution series, viz.. the oxide solid-solution series "Fe0"-MnO (manganowiistite), the orthosilicate solid-solution series Fe2SiO4-Mn2SiO4 (olivine), and the metasilicate solid-solution series FeSi03-MnSi03 (pyroxenoid). The "FeO"-MnO solid solution is continuous between the two end members wustite and manganositeV3 as is the orthosilicate series between the two end members Fe2SiO4 and Mn2 SiO4. 4 The metasilicate solid solution, on the other hand, extends only part way from the MnSi0.l end member toward FeSiO because the latter end member is unstable relative to the phase assemblage fayalite + silica. The letters a through m in Fig. 1 identify end members of the individual solid phases dealt with [for instance, c designates fayalite (FeZSiO4) in equilibrium with wustite, e designates fayalite in equilibrium with silica, and so forth]. In addition to the phase relations there are some thermodynamic data available for the end members of the silicate solid solutions and for the "FeO" -MnO solid solution. The free energy of formation of fayalite (Fe2Si04) from its oxide components has been studied by several investigators. Unfortunately, the data obtained show considerable discrepancies. According to recent tabulations by Kelley, the change in standard free energy Affn for the reaction

Jan 1, 1967

By Thomas T., Read

DESIRABLE as it is to summarize what has been set forth in preceding chapters, the task can only be approached with great hesitation. What follows represents the personal views of the author at the moment of writing, reserving the privilege to change them on more mature reflection or in the light of further evidence. With that reservation they may be stated somewhat as follows. Education for the mineral industries falls into two categories; general education and technical vocational, using the word vocational not in its usual sense but to signify preparation for specific activities, in which sense a law school is a vocational school. Even at the beginning, as indicated in the first chapter, mineral industry education was partly general and, partly technical and that relationship still persists, because technical education requires a firm basis of general education. Our general American system is to provide free public' general education through the twelfth grade, or completion of high-school work, though there are already many technical vocational high schools, and even in a community where nearly all the young people are preparing for entrance to college there will be some who wish to qualify for employment at the end of the high-school course, or even on completing junior high. Our educational system, therefore, has not only to provide education for those who intend to proceed beyond the twelfth grade but also for those who, for a variety of reasons, may wish or be forced to cease full-time education at any level between the first and twelfth grades. This study has been chiefly concerned with the problem of what kind and how much technical education to provide for those who have completed the twelfth grade and who wish to make their living in the mineral industries. The obvious fact that the mineral industries employ all sorts of trained persons,

Jan 1, 1941

By James Hyslop

MECHANIZATION of American coal mining continues to make rapid progress. Economic pressure will compel abandonment of manual methods wherever possible and will also provide the incentive needed for the improvement of machines and mining systems. However, rapid progress may be made along strictly technological lines and at the same time much slower progress in approaching maximum productivly and efficiency. One can well ask, just how efficient are mechanized mines, and to what extent is productivity affected by the mental attitude of management and workers?

Jan 1, 1946

By Frances Hurd, Clark

Iv 1897, Roberts-Austen(l)$ found an arrest in the thermal curves of alloys of 60 per cent. copper and 40 per cent. zinc. This break occurred from 450° to 470° C. Shepherd, (2) working in 1904, was unable to detect any change in the direction of the thermal curve. In 1911, Carpenter and Edwards(3) confirmed the work of Roberts-Austen and called this a eutectoid transformation of beta to alpha plus gamma. Hudson') in 1914, showed that the beta constituent could be produced synthetically at temperatures below the transformation point. He believed the change in the beta was polymorphic in nature rather than a eutectoid. The work of Matsuda(32) in 1922 demonstrated this break by thermal analysis, microscopic investigations, dilatation, electrical resistance measurements, and a thermoelectric study. He believed the transformation to be continuous from 300° to 480° C., and comparable to the A 2 transformation in iron. Later, in 1924, Andrew and Hay, with electrical resistance measurements, confirmed Matsuda's work. Imai(28) showed the transformation to be progressive and therefore a function of the temperature rather than the time. He stated that it was neither a eutectoid nor an allotropic change of phase. Atomistically expressed, it was a change, not of atomic configuration, but of atomic energy of some kind; and again it was compared to the A 2 transformation in iron. Imai believed that his analyses by X-rays led to the same conclusion. In order to study this change, at 470'C., in homogeneous 60:40 brass, Homerberg and Williams «0> and Homerberg and Shaw(41) quenched their material in iced brine to obtain the beta solid solution and reheated at various temperatures. At 200° C., a change in the microstructure and physical properties occurred. A fine-grained structure, which they termed alpha and which had the appearance of a sorbitic steel, appeared, with an increase in the tensile strength to 82,750 lb. per sq. in., and a Brinell ball hardness of 240 with 3000 kg. load. At 470° C., the alpha

Jan 1, 1927

By Edmund J. Korber, Donald E. Raab, Frank A. Burns

During the early 1960s, the advent of self- advancing longwall roof supports triggered serious consideration by Bethlehem management to introduce the technique of longwall mining at one of our central Pennsylvania coal mines. Although longwall mining was initially justified as a means to cope with the severe roof conditions at our Mine 32 (Watson, B., 1971), the result of the endeavor has been a consistent and reliable level of coal production, first from Mine 32 and then later from Mine 33, over a period of fifteen years. Longwall production from the Cambria Division has been the mainstay of the low volatile coal required by Bethlehem Steel for steel production. Let us review the events that led to this accomplishment, as well as where we stand today.

Jan 1, 1981

By W. J. Babyak, J. M. Sheehan, H. W. Paxton

THE- solubility of hydrogen and deuterium in solid niobium up to I-atm pressure has been established bv a number of workers.1-5 X-ray examination at room temperature of specimens reacted in hydrogen at high temperatures from 300° to 1000°C shows the presence of two phases—a bcc phase (a) based on the niobium lattice and with an u0, increasing from 3.30A for Nb to 3.32Afor NbHo.L, and an orthorhombic phase6n = 4.84A, h=4.90A, c =

Jan 1, 1960