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H. W. Turner, Portland, Ore. (communication to the Secretary*) :—Mr. Brown's paper on the complicated groups of veins exposed in the workings of the Bodie mine forme a valuable contribution to the literature of the structural features of ore-depoeits. It is much to be desired that managers should put into print the results of their observations of the mines under their charge. These observations, as well as data of production, kind of ores, etc., usually accumulate for years, and unless the mining geologists of the Geological Survey happen along before the mine is worked out, such data seldom get into print. About the year 1899 I went through the mines at Bodie with R. C. Turner, then superintendent, and made some notes on the veins and gangue-minerals, and collected some specimens. Mr. Brown refers to crystals of feldspar (albite) found on fragments of quartz on the surface. I collected a number of specimens of these crystals, mostly from Queen Bee hill, and

Jan 1, 1909

By R. H. Pemberton

The principle of airborne electromagnetic prospecting is well-known. The basic geophysical texts in most cases discuss the main elements involved in electromagnetic prospecting. However, there is certainly little information available to the public concerning the present types of airborne electromagnetic systems being flown today by both contracting companies and some of the mining companies which have their own instruments. This is unfortunate since it is difficult for those people not conducting such operations to understand thoroughly the large variation in the electromagnetic instruments available.

Jan 1, 1961

By R. W. Raymond

I desire to call the attention of members of the Institute to a new method of plotting and determining faults in mineral deposits, suggested by Prof. Hanns Hoefer, lately of the Mining School of Przi-

Jan 1, 1882

The National Research Council was organized in 1916 at the request of the President by the National Academy of Sciences, under its congressional charter, as a measure of national preparedness. The work accomplished by the council in organizing research and in securing cooperation of military and civilian agencies in the solution of military problems demonstrates its capacity for larger service. The National Academy of Sciences is therefore requested to perpetuate the National Research Council, the duties of which shall he as follows: 1. In general, to stimulate research in the mathematical, physical, and biological sciences, and in the application of these sciences to engineering, agriculture, medicine, and other useful arts, with the object of increasing knowledge, of strengthening the national defense, and of contributing in other ways to the public welfare. 2. To survey the larger possibilities of science, to formulate comprehensive projects of research, and to develop effective means of utilizing the scientific and technical resources of the country for dealing with these projects. 3. To promote cooperation in research, at horse and abroad, in order to secure concentration of effort, minimize duplication, and stimulate progress; but in all cooperative undertakings to give encouragement to individual initiative as fundamentally important to the advancement of science. 4. To serve as a means of bringing American and foreign investigators into active cooperation with the scientific and technical services of the War and Navy Departments and with those of the civil branches of the Government. 5. To direct the attention of scientific and technical investigators to the present importance of military and industrial problems in connection with the war, and to aid in the solution of these problems by organizing specific researches. 6. To gather and collate scientific and technical information, at home and abroad, in cooperation with governmental and other agencies, and to render such information available to duly accredited persons. Effective prosecution of the council's work requires the cordial collaboration of the scientific and technical branches of the Government, both military and civil. To this end representatives of the Government, upon the nomination of the National Academy of Sciences, will he designated by the President as members of the council, as heretofore, and the heads of the departments immediately concerned will continue to cooperate in every way that may be required. THE WHITE HOUSE, WOODROW WILSON. 11 May, 1918.

Jan 7, 1918

By Howard N. Eavenson

An analysis of the bituminous coal situation by an authority who traces the production, mining, safety, markets and labor trends in comparison with other fuels.

Jan 2, 1950

A. E. HALL, Palmerton, Pa.-I would like to ask the author if he has ever used, in his furnaces, any inner tube which would permit experimentation with various oxidizing gases, under varying conditions?

Jan 4, 1918

By E. Ordonez

I have read in the Bullentin a paper by H. von Hofer relating to the Origin of Petroleum, in ehich the author supports his and Englers views, express before, of the organic origin of petroleum.

Jan 1, 1915

By Thirumalai, K.

Although the term "spalling" has long been known, Norton l first referred to its usage for the fracture or disintegration of materials subjected to rapid temperature changes. Spalling of ceramic materials at high temperatures has received attention in the past. Removal of the char formed during ablation in re-entry of space vehicles has been referred to as mechanical spalling. The first experiments to evaluate the process of rock fragmentation by thermal spalling were conducted by Stoces using a series of gasoline burners on the quartz veins of the Zinnwald deep mines in Germany. After the development of rocket-jet burners, the principles of 'thermal spalling combined with high fluid momentum found wide practical application in rocks. The well-known jet piercing process for drilling blastholes in taconite and for jet channeling in the quarrying of granite are among the more notable of these application^.

Jan 1, 1970

By Cyril Stanley Smith, Earl W. Palmer

STRIP of any of the metals used for deep drawing operations occasionally yields cups that are defective because of a rim that varies in height around the cup in a wave-like manner Some such defects are traceable to tools or other press factors, but when the protuberances formed (usually four in number on brass and other copper alloys) are symmetrically disposed with respect to the rolling direction of the strip, they are invariably attributable to the metal The effect is known as "caring" and the protuberances are called "ears" Other terms frequently heard are "tips," "scallops," and "corners " It is recognized that the effect is most commonly a result of a directional crystal structure produced by rolling and annealing operations in the manufacture of the metal strip Numerous papers dealing with various aspects of the caring effect have appeared in the literature, those listed in the references' being especially interesting and valuable An investigation of the factors influencing caring of brass cups has been in progress in the laboratories of the American Brass Co for several years, and it was thought desirable to make some of the results generally available in summarized form The present paper discusses many factors that do and do not contribute to ear formation In addition, a section is devoted to methods of minimizing the caring tendency of brass sheet by proper selection of the cold-rolling and annealing schedule by which it is produced In the space available, it is impossible to quote detailed experimental procedures and numerical results However, the authors make no statement that they do not believe to be properly substantiated, either by experimental evidence obtained under laboratory conditions or by experience in the actual production of deep-drawing brass in the brass mill MECHANISM OF EAR FORMATION It must be clearly understood that the formation on cups of symmetrical ears, four or more in number, is attributable solely to the strip metal, and results from the strip having different deformation characteristics in different directions The tools used in the drawing process, or the type and completeness of lubrication of the strip, have nothing to do with the problem of ears, although they do, of course, greatly affect the "drawing quality" of the strip and the general appearance of the cup A single tip may be drawn up on the rim of a cup because of misalignment of the tools, or because the gauge of metal varies from side to side of the strip The two-ear form that sometimes appears is also traceable to gauge variations However, the four-ear and six-ear symmetrical forms that we are concerned with here are caused by factors inherent in the structure of the metal itself

Jan 1, 1942

By E. T. Wessel

UNEXPECTED brittle failures of metals in practical applications are a serious problem to many industries and to the nation as a whole. Considerable effort has been devoted to studies of the brittle behavior in metals. However, the major portion of this effort has been directed at developing techniques and apparatus for the purposes of determining the susceptibility of metals to brittle failure and of making various types of observations of the phenomena. Relatively minor effort has been made to understand the basic mechanisms involved in initiating brittle failures. A more complete understanding of the nature and mechanism of the brittle failure problem would be very helpful in efforts directed toward predicting and avoiding brittle failure and toward the development of suitable materials and designs that are not susceptible to a brittle behavior. The intent of the present investigation is to acquire this basic understanding. The pronounced transition from a ductile-to-brittle behavior is most prevalent in metals having the body-centered-cubic lattice structure, primarily be- cause metals of this structure exhibit a strong dependence of yield strength upon temperature and the rate of straining. The generally recognized qualitative concept of the ductile-to-brittle transition is that brittle (cleavage) failure occurs when the yield strength exceeds the cleavage fracture strength. This condition can apparently be achieved by decreasing temperature or increasing strain rate. Likewise, a normally ductile metal can be made to fracture in an apparently brittle manner by the introduction of triaxial stresses (notches) where the ratio of normal to shear stresses can be increased to such an extent that the normal stress exceeds the fracture strength before the critical shear stress for plastic flow is achieved. Neither of these concepts require any prior plastic deformation or explain why the observed fracture strengths are so much less than the theoretical cohesive strength. The results of several investigations of the ductile-to-brittle transition in body-centered-cubic metals illustrate rather conclusively that measurable amounts of nonelastic deformation do precede cleavage fracture, even at extremely low temperatures. These studies suggested that the early stages of plastic flow, particularly abrupt yielding, and their relationship to brittle fracture should be examined

Jan 1, 1958

By Alexander Knoll, Dwight L. Baker

THIS paper is a report on work undertaken to investigate the results and conclusions of Ravitz and Porter1,2. that galena freed of surface oxidation products and lead carbonate ("clean" galena) is water-repellent, and that the action of xanthates in flotation is the action of a cleansing agent, enabling oxidized galena particles to expose a pure lead sulphide, water-repellent surface. The apparatus, in construction and use, was essentially that of Ravitz and Porter. The only significant modification introduced by the present authors was the substitution of a three-necked flask for the flotation cell as the "reaction vessel." Our procedure was to place 50 grams of freshly ground, minus 200-mesh galena in the reaction vessel, sweep out all molecular oxygen from the system with oxygen-free nitrogen, and proceed to wash the galena surface free of its oxidation products with repeated small portions of (I) ammonium acetate (500 c.c. of water, 200 grams of ammonium acetate) or (2) ammonium chloride, hydrochloric acid (2 liters containing 200 grams of ammonium chloride and 25 c.c. of 1.18 sp. gr. hydro chloric acid). The galena was next washed with many 100-c.c. portions of oxygen-free, distilled water. The galena was finally considered free of soluble salts when wash water that had been in contact with the mineral for at least 48 hr.* gave negative tests for: (I) lead ion with sulphide; (2) chloride with silver ion; (3) acetate with cuprous chloride, sodium chloride; and (4) ammonium ion with Nessler's reagent. Next 500 c.c. of potassium ethyl xanthate solution, free of dissolved oxygen, was run onto the "clean" galena particles. For this system there were determined: I. The wetting properties of the clean galena particles by shaking the reaction flask and noting the degree of mineral collection at the liquid-air interface. This was, of course, simply a qualitative test, but it proved adequate for our purpose. 2. The removal of xanthate ion from the potassium xanthate solution on being shaken with the "cleansed" mineral. Xanthate concentrations were determined by iodine titration according to the methods of Taylor and Knoll.3 3. The pH of the xanthate solution after having been shaken with the "cleansed" galena. The pH was determined colorimetrically.4 The results of five experiments of the type mentioned above are given in Table I.

Jan 1, 1941

A knowledge of the principles of punctuation is essential to effective and intelligible writing, for the ease and pleasure of the reader, and even his understanding, may depend upon the choice and the placing of punctuation marks. To 'punctuate' is to mark with stops or points; the word comes from the medieval Latin punctuare (punctuatus), which in turn is derived from the Latin punctum, a point. The purpose of punctuation is to show the manner in which the writing is to be understood; to indicate the relations between parts of a sentence and between successive sentences. To some extent "it does for the eye what vocal stress does for the ear", but especially it marks logical relations. Some punctuation marks, such as those indicating admiration, exclamation, and interrogation, are rhetorical as well as grammatical, but most of the common ones are logical or grammatical. My discussion will be confined to grammatical punctuation in ordinary writing. "The problem of punctuation in text matter", as George Summey * says, "is to employ words, points, and paragraph breaks in such a way as to achieve at the same time clearness, proper distribution of emphasis, and the desired kind of movement." The criticism of the punctuation of a sentence or of a group of sentences is not final until the context, within the paragraph, is read. A paragraph is a sentence or a group of' sentences forming an independent unit of the composition; it represents a unit of thought. A multiplicity of paragraphs produces a choppy effect; on the other hand, paragraphs of excessive length are tiresome, because the belaboring of one unit of thought wearies the reader. The aim should be to

Jan 1, 1931

By John Birkinbine

Through the partiality of my fellow-members I have been able, during seven years' service on the Council of the American Institute of Mining Engineers, to note the development of technical societies, a subject which commends itself as an appropriate theme for me, in retiring from the office of President, at a time when we meet in convention with Canadian technical societies. Our next assembly, called at Chicago at the time fixed for an International Engineering Congress, offers additional reason for the selection of this topic. If subsequent statements appear to give to the American Institute of Mining Engineers greater prominence than to kindred organizations, they may be excused upon the ground of long association with and loyalty to its members, and to a personal knowledge of their work. Besides, data as to its growth and development are more accessible; and at a meeting of the Institute features connected with it may be considered as of greater immediate interest than those affecting other organizations. The purpose of this address is, however, to use the record of the Institute as indicating a similar development of other technical societies, rather than to claim preeminence for any organization; the work of each must speak for it. There is a general tendency to form associations at the present time. Organizations have been created and are active in every profession and in all branches of labor, trade, industry, commerce, manufactures, science and art. A record of such associations and their aggregate membership would be startling, and would show how large a percentage of the population of North America is connected with one or more of them; but the figures cannot be even approximately estimated. The class of associations representing national, state, or local trade interests, such as boards of trade, chambers of commerce, etc., may be used as an illustration. A late report shows that in the

Jan 1, 1893

By N. R. Tipman, G. E. Agar, L. Paré

The flotation chemistry of the commercial INCO matte separation process was investigated. The slow cooling of Bessemer converter matte forms discrete phases of Cu2S and Ni3S2 and a Cu-Ni alloy. After magnetically removing the alloy, the Cu2S and Ni3S2 are separated by flotation at pH 12.4 (saturated lime) using diphenyl guanidine (DPG) as both collector and frother. DPG has been used exclusively in this flotation process because of its unusual selectivity for copper minerals. The surface product resulting from chemisorption of DPG onto theCu2S was identified as the double salt CU(DPG)2SO4.CU(DPG)2(OH)2. The adsorption followed Langmuir behaviour up to a monolayer coverage. In the absence of DPG, the rapid adsorption of oxygen by Cu2S in flotation pulps was observed. The surface product was identified as the insoluble basic copper sulfate CuS04.3Cu(0H)2 with the production of sulfate ion. In the presence of DPG, the oxidation reaction appears to be suppressed. The frothing properties of DPG and commercial frothers were compared. DPG is not a powerful frother. Batch flotation tests confirmed that DPG is a highly selective collector when compared to most sulfhydryl collectors.

Jan 1, 1976

By E. S. Wheeler, M. W. Murphy

A LARGE part of the molybdenum produced in Colorado is converted and consumed in the Eastern States. As the raw materials and the power needed for the conversion of the Colorado concentrate are also accessible in the Eastern States, the conversion plant has been installed some 1500 miles east of where the ore is mined and milled. When concentrate was first produced at Climax in 1918, a custom smelter converted the product into ferromolybdenum. By 1924, the Company had decided to produce calcium molybdate and rented a building and installed equipment for that purpose at Langeloth, near Burgettstown, Pa., about thirty miles west of Pittsburgh. For the first few years the plant was a simple one of small capacity. A small hand-rabbled roaster was used, the product of which was made iota calcium molybdate by a conventional method; then an eight hearth mechanically rabbled roaster was installed to increase and speed up production. The output was considerably less than a million pounds of contained molybdenum annually until 1928, when a small part of the produc-

Jan 1, 1946

By J. C. Bayles

Jan 1, 1886

By Frederic E. Carter

THE gold, silver, copper alloys have been the subject of several fairly complete investigations by Jänecke, Sterner-Rainer1 and others, and indeed it would seem as if almost too much labor had been expended on them when one thinks of the numerous other ternary alloys calling for more light; however, the combinations of the three metals are actually so widely used in jewelry that they merit perhaps the work done on them. There are a few properties of importance and interest not treated by the authors mentioned which the writer investigated some little time ago, and therefore he has ventured to put on record the results of some of his tests made at that time. He has chosen, as being the two series of most importance to the jeweler, only the 14 and 18-kt. golds, so the subject is by no means so inclusive as that previously treated. As stated, this paper is merely a record of tests made in a practical manner on two useful series of alloys, and is not at all a critical study of their properties. 14-KARAT ALLOYS These alloys are important because they are the most generally used in 14-kt. jewelry; by changing the proportions of silver and copper there are obtained all shades of color from the green of the alloy containing gold and silver but no copper, to the red of the alloy containing gold and copper but no silver. Many 14-kt. gold alloys are made with the addition of zinc to the three metals mentioned here; the added metal does not appreciably alter the color of the alloy nor has it, in general, much effect on the working properties; it may, however, prove useful as part of the zinc added may act as a deoxidizer and render the alloy free of gas. It is not a necessary addition because with proper precautions all the 14-kt. gold alloys containing only silver and copper in addition to the gold can be made free of gas and capable of being cold rolled without cracking. The alloys in which approximately equal quantities of silver and copper

Jan 1, 1928

By W. B. Plank

THE figures on enrollment in the engineering schools of the United States and Canada indicate that the total number of students in these schools for the current year, 1949-50, is about 10% less than it was a year ago. This year, 226 - 533 undergraduates and graduate students are studying engineering in the United States and Canada as compared with. 249,913 students last year. These figures are taken from advance data in the Journal of Engineering Education for February 1950.

Jan 1, 1950

The Canadian Mining Institute has accepted the proffered arrangement as to price of the Bulletin to members and will furnish its Bulletin to members of the A. I. M. E. at $1 per year.

Jan 5, 1919

By Wallace Ralston

The East Texas district includes the northeast 38 counties of the State of Texas. It still remains one of the most important oil-and-gas-producing areas of the United States, since it includes within its boundaries the large East Texas field. Other fields of importance are: Van, Rodessa, Talco, Cayuga, Long Lake and Sulphur Bluff. Production is from the Nacatoch, Blossom, and Woodbine of the upper Cretaceous and the Paluxy and Glen Rose of the lower Cretaceous. Of these, the Woodbine is the most important, since it is the producing horizon iri the East Texas field. Fields East Texas Field.—There were 2471 oil wells, 1 gas well and 84 failures completed during the year of 1936 in the East Texas field; that is, 1565 fewer than in the year of 1935. The total number of producing wells is now 22,031, of which 50 are temporarily shut down; 18,435 wells flowing their production; 3150 pumping; 293 on gas-lift, and 82 operated by other methods. This shows an increase of 1642 wells on artificial lift over Jan. 1, 1935. The average daily salt-water production is estimated at 42,700 bbl. from 2327 wells—an increase of 1201 wells over the year of 1935. The field is now drilled to an average density of one well to 5.85 acres. Average bottom-hole pressure has dropped from 1193 Ib. to 1168 lb., approximately 1 lb. drop for each 6,600,000 bbl. of oil produced. During the month of December 1936, the estimated daily average production of illegal oil had dropped from 20,500 bbl. in December 1935 to 7500 bbl. The commercial gas production is of minor importance in the East Texas field, and figures for the amount of gas taken from the field are not available at the present time. Talco Field, Titus and Franklin Counties.—The discovery well was drilled by Housh, Thompson et al. on the C. M. Carr tract and completed in March 1936, as a pumping well making 552 bbl. per day of 24' gravity oil. This well was first completed at a total depth of 4208 ft., the top of the sand being 4190 ft. Later it was deepened to 4260 ft., which increased the production from 552 to 725 bbl. per day. This field is producing

Jan 1, 1937