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By AIME AIME

THE convention which met in Washington at the call of the Joint Conference Committee was called to order at ten o'clock on Thursday morning; June 3, by Richard L. Humphrey, temporary chairman, member of the American Society of Civil Engineers, who made a brief statement of the reason for the meeting. Lieut. Col. Charles W. Kutz, Corps of Engineers, U. S. A., and Engineer Commissioner of the District of Columbia, then welcomed .the engineers composing the convention on behalf of the District of Columbia and, the Washington engineers. Although an elaborate program had been prepared on which were many well-known speakers on interesting and important topics, , it was voted to intersperse this to fill in the usual and unavoidable hiatuses in the business program of such a convention[ Calvert Townley, president of the American Institute of Electrical Engineers, was elected permanent chairman, and J. C. Hoyt, of Washington, was elected secretary of the convention. The following committees were appointed: Consti¬tution and by-laws, Richard L. Humphrey, chairman; resolutions, Philip N. Moore, chairman; and program, F. H. Newell, chairman. Then, Gardner S. Williams, member of the, A. S. C. E. and the Grand Rapids Engineering Society of. Grand Rapids, Mich., and one-time member of the American Association of Engineers, offered the following resolutions:

Jan 1, 1920

By AIME AIME

ANOTHER meeting of the Institute has passed into history and it fully sustained the reputation of the Institute as a live organization of the men, and nowadays the women, concerned with the mineral . ? industries and those working therein. The field meetings of, the 1nstitute are cine of its pleasantest and most valuable features. As Dr. Raymond used to say, ((It is good for a mining engineer once in a while to see a mine" and these meetings bring back to the mines those who, through progress into higher executive positions, have come to visit them infrequently, at the same time that they give opportunity for the .younger men to see regions and mines aside from those in which they are then working. This, and the formal and' informal interchange of information resulting,, is of the greatest professional value to all, while the meeting of old and making of new friends causes each meeting to be notable in turn. This year's meeting at Salt Lake City was one of the largest that has been held outside of. New York City; 470 members and guests registered while many more were present at the sessions without attending to this formality. '

Jan 1, 1925

By Oliver Bowles

A NORTH CAROLINA miner dreamed that he found high-grade mica by excavating a certain corner of his mine. The next day he sank a hole on the exact spot and found mica of excellent quality. The dream came true. May not this be as good a method as any yet known for forecasting the valuable mineral content of pegmatites? The Federal Geological Survey has found in its recent detailed studies in New England that good sheet mica occurs most abundantly in zoned pegmatites, particularly in zones lying along the wall or contact of the pegmatite mass. Although this conclusion may be a valuable guide, pegmatite mining operations must still be classed as most uncertain and hazardous enterprises. Finding of the second largest diamond ever discovered in the United States-a stone of good gem quality weighing more than 34 carats-during the course of a horseshoe pitching contest at Peterstown, W. Va., is another example of unorthodox mining methods. These should not be considered, however, as characteristic mining methods developed in 1944.

Jan 1, 1945

By Steven Mitchell

BACKGROUND Homestake Mining Company began milling operations at the Bulldog Mountain Mine near Creede, Colorado in 1969. The Bulldog Mill, rated at 350 tpd, produces a bulk flotation condentrate assaying about 180 oz/T Ag and 20% Pb, from heads of about 16 oz/T Ag and 2% Pb. The circuit is straightforward with two-stage grinding to 1-5% plus 65 mesh, followed by rougher and cleaner flotation. Reagents used are Z-6, Z-11, Aerofloat 242 and Aero Promoter 404, with an Aerofroth 65-MIBC mixture for a frother. Additional information on the geology, mine and mill are available in references (1) and (2). A flow sheet for the mill and CIP plant together is attached as Figure 1. Final flotation tailings normally vary from 1.5 - 2.0 oz/T Ag. These tailings are cycloned to produce sand for underground backfill. After cycloning, the sands are repulped and given a final scavenger float. This sand scavenger recovers a small additional amount of silver which recycles back to the main flotation circuit. The tailings are recycloned and pumped to the mine or, if the mine cannot accept sand, to tailings. The majority of the silver in the flotation tailings exists in the fine fractions; cycloning upgrades the slimes and lowers the assay of the sand. The sand, after scavenging, typically assays 0.5 oz/T Ag, and the slimes assay about 3.0-3.5 oz/T Ag. From 1969 to 1976 all of the slime tailings and the sand tailings not used underground were impounded in a tailings pond located about

Jan 1, 1983

By Hermann Bach, Walther Hänig, Willi Gehrhardt, Ernst Theurich, Walter Langner

With the construction of the Magdeburg zinc works, the Georg von Giesche's Erben Mining Co. of Breslau has to a certain extent completed the program of reconstruction which it set as its goal after the boundaries of Upper Silesia were drawn by the Treaty of Versailles. During its history, covering.more than two centuries, zinc and lead mining has been its chief activity. Through the new boundaries established, it lost to Poland all its mines and smelters, including five distillation smelters. Of its extensive properties, there remained only an apparently unimportant and unexplored portion of the old Bleischarley ore field which, however, happily made possible the resumption of its old business. In 1925 the Deutsch-Bleischarley shaft-only a few kilometers from the old Bleischarley shaft—was sunk and developed, and in May 1926 production of lead and zinc ore was resumed. As facilities for smelting were lacking, the ore was at first delivered to the neighboring smelters, which had now become Polish. Realization of the plan to build its own zinc works had to be postponed at first for lack of capital. In the meantime, however, plans for the new works were worked out in all details. After extensive experimentation in a semicommercial pilot plant it was decided, at the end of 1928 and the beginning of 1929, to use the electrolytic process and, for economic reasons, to place the works at Magdeburg. With zinc at the approximate price level that had ruled since the Deutsch-Bleischarley mine had begun working, it was hoped that the plan could be completed in 1930 with the company's own resources. However, falling metal prices, already noticeable in 1929, made this impossible, and further postponement for a time became necessary. Finally, at the end of July 1933, the funds for building the works became available, in the form of a loan granted under the first employment

Jan 1, 1937

A. R. Ledoux,New York City: The so-called combination method " is generally used in assaying bar copper for silver. It has been modified from time to time. Briefly outlined

Jan 1, 1901

By C. A. WARNER

IN all the meetings of the Petroleum Division, emphasis was placed on the essential importance, in the successful furtherance of our war effort, of efficiently producing, transporting, refining, and utilizing maximum quantities of crude oil and natural gas with the minimum expenditure of critical material. With representatives present from all branches of the petroleum industry, from all parts of the United States, the sessions were opened Tuesday morning with Commander Harry P. Stolz. U.S.N.R., Chairman of the Division, and A L. Haider as associate chairmen. From that time until the symposium on petroleum economics was closed Thursday afternoon papers of exceptional interest and importance were presented and discussed in a most frank and open manner.

Jan 1, 1943

By C. E. LAWAL

WITH the object of adapting high-school vocational courses to the industrial needs of the community, a few high-school officials in West -Virginia working with the School of Mines of the State university decided to try an innovation this year. The purpose of this experiment was to teach coal mining in two high schools situated in mining communities. We thought that if a course in coal mining would be included in the list of optional courses offered in the high school, it might interest some of the boys, and if the course were properly taught it would undoubtedly be of inestimable value to those boys who later decided to take up mining work as their vocation. This coal-mining course was started last September in the Berwind and Gary high schools in West Virginia. The high-school officials in their conferences with' us decided that we should work up the outline of this course and they would assign the science teachers of the schools as instructors, with ,the understanding that we would help 'these instructors with this work. We consented to all this and submitted -an outline to the school officials which they are following this year.

Jan 1, 1929

By Eugene Guccione

"All engineering societies should encourage and motivate their members to take part in public affairs. And engineers, in turn, should learn to translate their technical knowledge in a language which politicians can understand," stated James Boyd last month as he received the Hoover Medal, which is awarded annually by four engineering societies-AIME, IEEE, ASME, and ASCE-to an engineer who has rendered important public service. James Boyd is no ordinary engineer (see box). A few weeks ago, Dr. Boyd took time out of his busy schedule to stop at MINING ENGINEERING'S editorial office for the following exclusive interview.

Jan 1, 1976

By D. F. Hewett

CONTENTS PAGE Introduction 1 Geologic features of eastern Oregon 2 Geology of the Sumpter quadrangle 2 Rocks older than the ore deposits 3 Rocks younger than the ore deposits 8 Lodes of the Sumpter quadrangle 8 Areal distribution 8 Geologic distribution 9 Major features of the veins 9 Mineralogy and texture of the veins 13 Ore deposits zonally disposed around the Bald Mountain batholith . . . . 13 Summary of mineralogy and texture 32 Zonal relations 33 Ore deposits zonally disposed around Greenhorn Mountain batholith . . . 36 Zonal relations 37 Relation of textural features to zonal arrangement of veins 37 Summary of zonal relations 38 Comparison with similar districts 39 Outlook for the district 40 INTRODUCTION IN an earlier report on the Sumpter quadrangle1 it was briefly stated that the quartz lodes of that region might be separated into several groups or belts on the basis of the kind and abundance of the minerals of which they are composed, and that these belts were disposed as areal zones around the principal intrusive mass of the region. When the opportunity to revisit the region was offered in 1929, as a result of a cooperative agreement between the State Mining Board of Oregon and the United States Geological Survey, it seemed advisable to pay particular attention to this feature of the lodes, in the hope that if the idea of zonal relations was confirmed it might serve as a guide in exploitation.

Jan 1, 1931

By T. A. Rickard

The dictionary defines 'jargon' as "barbarous or debased language". This description does not suffice. Quiller-Couch has said, it is "a kind of writing which, from a superficial likeness, commonly passes for prose in these days, and by lazy folk is commonly written for prose, yet actually is not prose at all ". The two main vices of jargon, he says, are "that it uses circumlocution rather than short straight speech", like the Babu who reported his mother's death by saying: "Regret to inform you, the hand that rocked the cradle has kicked the bucket ". Its other chief' vice is that "it habitually chooses vague woolly abstract nouns rather than concrete ones", like the newspaper statement; "He was conveyed to his place of residence in an intoxicated condition", instead of saying, "He was carried home drunk ". Jargon is "an infirmity of speech", it is not journalese, but akin to it. "Like respect- ability in Chicago, jargo4 stalks unchecked in our midst" and renders much technical writing ridiculous. It deals in periphrasis instead of going straight to the point, it loves the abstract rather than the concrete, it dabbles in words of sound rather than of meaning. Avoid it, despise it., if you purpose earnestly to write well. "III literature as in life he makes himself felt who not only calls 4 spade a spade but has the pluck to double spades and re-double." * Jargon is rampant in technical publications. Catalogues and other advertisements are conspicuous offenders, but with these the critic is not concerned, except in so far as such 'write-

Jan 1, 1931

By J. F. Myers

A bit of old philosophy: The optimist, the pessimist, The difference is droll; The optimist, the doughnut sees, The pessimist, the hole. This is a neat summation of the viewpoint of those engaged in "treating the crude mineral crust of the earth." Many of those in high places have reminded us during the year of the diminishing supply of the resources so essen-

Jan 1, 1948

By Jennings S. Cox

(Glen Summit Meeting, June, 1911.) THE following notes, prepared in 1908, as the result of a personal examination and extensive explorations under my direction in 1906, have been revised and greatly augmented after two subsequent visits and further explorations in 191.0. The hard iron-ores of the south coast of Oriente Province, in the island of Cuba, have been known for many years, in fact one mine has been in operation for more than 20 years ; but it is only within the past four years that the large mantle-deposits of brown ores of the north coast have attracted serious attention. A. C. Spencer 1 has described these ores in a paper, entitled Three Deposits of Iron Ore in Cuba, which refers to the Mayari, Moa, and Cubitas deposits. C. M. Weld,2 in a scholarly paper on The Residual Brown Iron-Ores of Cuba, has discussed the character and possible genesis of these deposits with particular reference to the Moa field, calling attention also to the Taco and Navas fields in addition to those described by Spencer. Descriptive articles with reference to the Mayari field, and a few words about the Moa deposit, have also appeared.3 It is the purpose of the present paper to give some account of the exploration of the Moa deposit and to call attention to its commercial importance. LOCATION. The Moa district is situated on the north coast of the . Province of Oriente, which is the most easterly province of the island of Cuba. It lies on the northern or seaward slope of 1 Bulletin No. 340, U. S. Geological Survey, pp. 318 to 329 (1908). 2 Trans., xl., 299 to 312 (1910). 3 Iron Age, vol. lxxx., No. 7, pp. 421 to 426 (Aug. 15, 1907), and vol. lxxxi., No. 15, pp. 1149 to 1157 (April 9, 1908).

Mar 1, 1911

By Richard Hamburger

Calculating machines permit the use of the more rapid cotangent and semigraphic solutions of plane triangulation. The results of these methods are as accurate as those of other methods. Simple adjustment of the net, and ease of calculation encourage more complete field work. Errors in field work or in computation are easily localized.

Jan 1, 1950

By H. M. Chance

STRETCHING from New York southwestwardly to Georgia is a great range of hills and mountains consisting of pre-Palaeozic schists, slates, and gneissic and granitoid rocks, known locally by many different names; in Pennsylvaniaa as the South mountains, the Berkshire or Durham and Reading hills, and in Virginia and farther south as the Blue ridge. To the northwest of this range lies the " Great Valley," underlain by Lower Silurian limestones, and known as the Lehigh valley, Cumberland valley, Shenandoah valley, valley of Eastern Tennessee and Georgia and by other local names, but all these are parts of one valley, geologically and geographically continuous from New Jersey to Georgia. Lying upon and along the northern flank of this range of mountains, and dipping northwestwardly under the limestone of the valley, is the Potsdam formation (Primal or No. 1 of the Pennsylvania Geological Survey), which consists of sandstone or conglomerate overlain by slates. The latter are sometimes arenaceous and occasionally are replaced in part by sandstone. This formation varies from a few feet to several hundred feet in thickness. At the outcrop the slates are completely decomposed, oxidized or disintegrated, forming a belt of clay several hundred feet wide occupying the interval between the outcroppings of the sandstone and limestone. This clay-belt includes a more or less continuous series of iron-ore (brown hematite) deposits, which have been, and still are, extensively worked. The belt is more or less continuously mineralized with iron throughout its length, and hundreds of large deposits of ore have been developed and worked, producing many millions of tons of ore.

Sep 1, 1908

By G. D. Van, Arsdale

IT IS particularly appropriate that a paper on this subject should be presented in Spanish, before a Spanish speaking audience, and in a South American country, first because of the facts that these countries today have not only the largest copper leaching plant in existence but also present great opportunities for future extension of hydrometallurgy; and second, because of the fact that the first copper made by any wet method was doubtless produced before existing records at the Rio Tinto deposits in present day Spain.

Jan 1, 1925

By Ralph H. Sweetser

IN the recent world-wide deflation of commodity prices the coal industry, including both anthracite and bituminous coal, had reached a level where the actual delivered market prices received by the operators were usually less than the cost of production. Many steel companies and public utilities, operating their own "captive" mines, could have bought coal during the past three years for less money than the true cost of coal produced at their own properties. Competition within the coal industry itself was cruel to the point of profitless operation, and the competition of other forms of fuel was bearing heavily on the coal producers. They were thus forced into methods of production and utilization that they had hitherto ignored; there had been almost complete absence of any appreciation (by the bituminous operators especially) of the necessity of real research work in finding better methods of preparing coal for specific uses, and in finding new and profitable uses for different kinds and grades of coal.

Jan 1, 1933

By Galen H. Clevenger

THE real and permanent advances which take place in any industry are for the most part slow evolutions which frequently develop and grow almost imperceptibly from clay to clay. A meritorious idea may and generally does require long and patient development and commercial application under a variety of conditions and in a number of localities before it emerges as standard and generally accepted practice. There must be not only technical perfection but also economic advantage. Thus a cross-section taken at any particular time of an industry may reveal little that is distinctly new and yet there may have been considerable progress. During the past year there has been little that is new in milling and yet there has been real progress; some problems have been solved and some of what we may term the newer developments have become more firmly, established.

Jan 1, 1930

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 A. J. Weinig

IN the accompanying figure consider the classified AB in closed circuit with a ball mill, wherein T = Tonnage of new feed C = Ratio of circulating load Now consider that the circulating load is made up of two portions of ore. One portion is due entirely to the characteristics of the ball mill and the tonnage of new feed impressed on the ball mill. This portion of the circulating load in no way is to be blamed on the characteristics of the classifier and is all composed of oversize. Consider, for illustration, that this portion of the circulating load is handled in the A division of the classifier, assuming that the classifier is divided longitudinally into two divisions by an imaginary line. Because the classifier does not usually make a perfect separation of the undersize, a certain portion of the total circulating load is to be directly blamed on the efficiency of the classifier. Let this portion of the circulating load be considered as being handled in the B division of the classifier. Now if the classifier is operating perfectly (100 per cent efficient), the width due to the B division becomes zero and correspondingly the efficiency of the classifier diminishes as B becomes wider in proportion to A. If E is the mechanical efficiency, then

Jan 1, 1934