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By W. Denham Verschoyle

In designing a pocket instrumeut whereby any giver1 horizontal or vertical angle may be closely approximated, the following points should be kept in view, if general utility is aimed at : 1. The instrnment should be light and compact, so that it can be carried in the pocket, or in a sling. 2. It should be capable of observing any angle whatever, horizontal or vertical. 3. Since time is often an important consideration in making a preliminary survey, it should be capable of giving the horizontal and vertical angle at one observation. I do not know of any instrunlent that will fulfill these requirements, except the one here described. Where the depression- or elevation-angle of the distant object, whose bearing is required, exceeds 50 or 60 degrees, it becomes difficult or impossible with a prismatic compass, for instance, to obtain accurate results; and since it frequently happens, particularly in mining, that much work requires to be done beyond that limit, it is obvious that an instrument which can be used to observe a high angle just as easily as a low one, if not absolutely a necessity, will at least be a great convenience. How this a pocket transit" attains to the required degree of universality will be understood from the diagram, Fig. 1, in which B is a beveled, graduated circle, attached to and freely revolving about the center of the magnet A. Light falling on B is reflected through a window in F (the compass-box), along the line AC, and is again reflected back to the eye at D by the prism C. By a simple arrangement, the tight-line BCE call be completely revolved in the vertical plane DE, which is normal to AC. It is clear, then, that no matter through what vertical

Jan 1, 1908

By F. A. J. Fitzgerald

In any kind of furnace the question of preventing the loss of heat is important, for no matter how the heat is obtained it costs something; and consequently, other things equal, that furnace is most desirable which uses the greatest percentage of the total heat generated for the particular object in view. In the furnace which uses electricity for the generation of heat the importance of preventing losses of heat is very much greater than in any other. To generate 1,000 kg-cal. requires an expenditure of 1.16 kw-hr., and consequently the cost per calorie is always expensive when electricity is used for heating. In heating any material in a furnace a general rule is that the generation of heat should be as rapid as possible. In any given furnace the heat-losses may be expressed as so many watts, and, therefore, the longer it takes to heat the furnace-charge the greater the losses will be. Suppose that a furnace contains a charge to be heated to 1,500°C. and that the average loss of heat is at the rate of 100 kw., then if the process of heating the charge takes 1 hr. the losses will amount to 100 kw-hr.; but if by using a more rapid generation of energy the charge can be heated in 30 min. the losses will amount to 50 kv-hr. An example from experiments on a certain process may be given to illustrate this point. The problem was simply to heat a furnace-charge to a certain temperature, and experiments were made to determine the effect of increasing the rate of generation of energy and comparing the kilowatt-hours required to heat a given charge. Here are typical results : Rate of Generation Energy Per Kg. of Energy. of product 88 kw. 1.7 kw-hr. 93 kw. 1.6 kw-hr.

Jan 1, 1913

By F. R. Ingalsbe

THE proposed revision of the mining law as set forth in the Arentz Bill, now before Congress, is centered about the pretty commonly acknowledged f act that the present law is outlawed both by the large mining companies and the United States Land Office. By common agreement, the law of the apex is non-opera¬tive as between adjacent properties in many instances, and this practice is becoming more common. - If this is a fact, there is no escape from the conclusion that the law is antiquated and should be revised to meet modern conditions more equitable. The thing to be considered seriously is in what direction and to what extent the laws should be changed. Before deciding this, it is logical to inquire in what particulars the present law is troublesome or useless. This was all threshed out by the committee of the Bureau of Mines that worked out the proposed bill, but their testimony was not placed before the public, so far as 1 am aware. Most mine managers and engineers connected with producing properties are a unit in agreeing that the law as applied to the underground extension of orebodies, that is, the "law of the apex," as it is called, is the source of more litigation and expense than any other phase of the law, or perhaps than all other phases combined. This being true, it seems that this part of the law should be changed. Another phase which is troublesome and will continue to be so long as there is unpatented mineral land on the Public Domain, is the discovery requirement. The present law requires that a dis¬covery be made before a claim is staked and the courts certainly agree that such must be the case before patent issues.

Jan 7, 1922

By A. Dorsey Lyon

INTRODUCTION A GREAT DEAL of attention has recently been given to the metallurgy of zinc, and much of that which has been said and written on this subject has been in the nature of a criticism. For instance, we are quite accustomed to hearing it said that the metallurgy of zinc has stood still, that it is antiquated, out of date, etc. We are, however, inclined to agree With George C. Stone1 When he says that, although there have been no such spectacular and radical changes as Were worked in the metallurgy of copper and iron by the introduction of converters, there has nevertheless been a decided and marked progress in the metallurgy of zinc, and especially during recent years. However, it must be admitted that, due to the fact that the chemistry of zinc is so different from that of the other metals, the retort process is the only process by which zinc is produced commercially; and, moreover, that losses which occur in the zinc industry-that is, in the mining, milling, and smelting of zinc ore-are very great, for it is stated' that probably less than 50 per cent. of the zinc mined, even

Jan 7, 1914

By Sooi P. Chong

Expansion of concentrator capacity at Iron Ore Company of Canada's Carol Lake plant resulted in a dramatic increase in the production of fines. With iron recovery from the fines running only 18%, Carol Lake engineers initiated an extensive test program which resulted in the installation in July 1977, of a full-scale plant utilizing Reichert cone concentrators. Results to date have indicated a 100% increase in iron recovery from the concentrator's fines product. Carol Lake is located near the western boundary of Labrador, Newfoundland, some 960 km (600 mi) northeast of Montreal. Concentrator operations began in 1962 with a design capacity of 7 million t/y (7.7 million stpy). The bulk of the concentrate was pelletized at a 6 million t/y (6.6 million stpy) pelletizing plant completed in 1963. The remaining concentrate was sold in the international market. The concentrator was first expanded in 1966 to 10 million t/y (11 million stpy) capacity. In 1967, the pellet plant was expanded to match the increase in concentrate production. Sales increases led to a further expansion in 1973. By 1977, more than 40 million tons (44 million st) of crude ore were processed to recover in excess of 17.42 million tons (19 million st) of concentrate and 10.4 million tons (11.5 million st) of pellets.

Jan 12, 1978

An "international gold conference" was held at Spokane, Wash., on Sept. 5, 1918, under the auspices of the Northwest Mining Association, which was attended by a large number of engineers, mine operators, and bankers, representing the northwestern states, as well as Alaska and British Columbia. The principal subject under consideration was the doleful condition of the gold-mining industry, gripped between the diminished purchasing value of its product, and the increased cost of its operation. Two resolutions were adopted by the meeting. The first approved the resolution adopted Aug. 12 by the American Gold Conference, a permanent organization formed at Reno, Nev., in which it is stated that relief by the United States to the gold producers of this country should he made to correspond with the increased cost of production, the extent of the relief to be fixed from time to time to Meet changing conditions. The second resolution, adopted after serious and long-continued discussion, was introduced by F. A. Ross, mining engineer, of Spokane, and a member of the Institute, and was as follows: WHEREAS, it is now clearly understood and agreed by the allied nations that national gold reserves must be augmented without delay if rapidly expanding credits are to be secured; and WHEREAS, at this time, the production of gold is daily decreasing to an alarming extent because of well known conditions that, render the mining of gold-bearing ores unprofitable; and WHEREAS there is no way by which the mining of gold-bearing ores may be made profitable except by the direct' aid and influence of the government; and WHEREAS the government has appealed to the mining industry for practical information and practicable suggestions upon this subject; therefore, be it

Jan 10, 1918

By Robert Livermore

THE Smuggler-Union mine is in the upper San Miguel mining district near Telluride, Colo., and the group of claims now forming the property were first worked in 1875. Development was slow until the completion of the railroad in 1890, when it pro- ceeded rapidly. In 1896 four hundred stamps were dropping in the district, the production was $3,000,000. A geologic section of the country rocks, where ex-posed by erosion from the valley at 8700 ft. to the sum-mit at 13,500 ft., shows the sedimentaries made up of flat-bedded sandstones and conglomerates, of the Jura-Trias, superimposed at 9700 ft. by a series of bedded rocks of igneous origin, andesites and andesite breccia. These rocks extend 3000 ft. to the rhyolite capping, largely fragmentary, which occurs at 13,000 ft. The ore horizon is, so far as known, contained in the 3000 ft. of' andesite and breccia. The Smuggler vein is a fault fissure which, with its extension to the north, the Humboldt vein, contains one of the longest continuously mined orebodies in the world. The length of the orebody so far developed is approximately 9000 ft. The width of the valuable part of the vein is, however, narrow, 3 ft. being the average, and the depth to which it has been worked up to the present is 2500 feet. There are several crossing and branch veins, all of which have been more or less productive. Of these, the so-called Flat vein, discovered in 1915, with its pro-duction of nearly 2,000,000 tons, has been the most important. This vein joins the Smuggler at an acute angle in the northern section of the property. North of the junction the two veins lie side by side and form an orebody of importance which gives promise of exten-sion with depth. The valuable metals of both the Smug-gler and Flat veins are gold, lead and silver. In the former silver is more important than lead, and the reverse relation holds in the latter.

Jan 3, 1928

ASIDE from the John Fritz Medal, in which the Institute partici¬pates through its representation on the John Fritz Medal Board, the Institute itself has four awards it may make annually, as fol¬ lows the Robert W Hunt Medal and Prize, the J E. Johnson, Jr , Award, the James Douglas Medal, and the William Lawrence Saun¬ders Medal ROBERT W HUNT MEDAL AND PRIZE The partners of Robert W Hunt established a fund which was, presented to the Institute at a fitting ceremony on May 27, 1920, to establish an annual medal and a sum of money to be awarded tinder the following rules¬ 1 The award shall consist of two prizes first of a gold medal, second of a sum of money, a certificate to accompany each prize The money prize shall not be awarded to a member' over 40 years of age, but under unusual circumstances, both prizes may be allotted to one per son provided that he is not over 40 years of age In general it will be understood that the Committee shall award the money prize to the younger men, rather than the medal 2 The awards shall be made not oftener than once a year to that person or persons contributing to the Institute the best original paper or papers on non and steel The scope of the term "iron and steel" shall be determined by the sub-committee consideing the awards In general, papers dealing with the practical side of the subject have preference over those dealing with the theoretical side in recognition of the fact that Captain Hunt's main con¬ti ibutions to the industry have been in the improvement of production and quality of material

Jan 1, 1923

By L. Dudley Stamp

On April 1, 1937, Burma, formerly a province of the Indian Empire, was formally separated from India and became an independent unit of the British Commonwealth. In future, therefore, statistics of oil production in India will exclude Burma and those for Burma will be separately published. The last few years have been marked by noteworthy, almost spectacular, developments in the oil fields of Burma and the Punjab. In Burma these developments have been the proving of unexpected extensions of the existing fields and not the discovery of entirely new fields. The new extensions are important not only to Burma in giving a new lease of life to her fields, but also in general as stressing some interesting geological aspects hitherto neglected. Production The production of crude oil in Imperial gallons has been: Burma India 1934 254,760,070 67,265,210 1935 251,338,974 . 71,323,362 1936 265,656,393 69,241,504 1937 (eat.) 270,000,000 70,000,000 The Chindwin Fields.—The small field at Indaw continues to produce steadily about 3,000,000 gal. a year, but no really deep test has yet been successfully carried out and resources are thus not yet fully known. The remote location of the field, inaccessible except by river and situated 22 miles from the Chindwin 270 miles up that river from its junction with the Irrawaddy, has not encouraged active exploitation. The field is worked exclusively by the Indo-Burma Petroleum Co., Ltd. (I.B.P.), using now an automatic gas-lift system, and the company formerly refined the oil at a small refinery at Pantha on the river near by. The chief market was for kerosene in upper Burma. The refinery has now been closed. The oil is stored on the field during the low-water season

Jan 1, 1938

By John Mathews

IT is twenty years since the writer made his first molybdenum steels and others were making them commercially five years earlier but the prevailing opinion seems to be that molybdenum steels are new; from time to time the daily press speaks of important discoveries in Europe and intimates that American steel makers have much to learn in regard to alloy steels. The earlier experiments were largely confined to the use of relatively high percentages of molybdenum in tool steels and permanent magnet steels. Recent developments deal with the types of alloy structural steels used for airplane, automobile, and other engineering requirements; in these, the molybdenum content is usually less than 1 per cent. The earlier types generally have been unsuccessful commercially, but the newer types of steels are becoming of increasing importance. The war showed our dependence on foreign sources for alloying metals; molybdenum alone is widely distributed in the United States and seemingly abundant. Many deposits are not now of commercial interest, owing to location and relatively small amount of ore available, but other deposits are being developed and a stable source of supply seems well assured. In tool and magnet steels, it was early found that 1 part of molybdenum was equivalent to from 2 to 2.5 parts of tungsten. The permanent magnet steels investigated by Madame Curie,1 in 1898, contained from 3.36 to 4.05 per cent. molybdenum; in 1902, Dr. E. L. French and the writer thoroughly tested steels containing from 2:0 to 4.0 per cent. These steels gave satisfactory tests for permanence, but were low in residual density and much more sensitive to hardening than the corresponding tungsten products. We discontinued work with them, therefore, and have no advice that such steels have been used commercially here or abroad.

Jan 2, 1921

By Richard Moldenke

AmonG the things that will always remain to the credit of the foundry-industry is the circumstance that nearly all the research-work of practical value in daily routine was done by active foundrymen, and the results were freely given by them to the world. Moreover, while consumers felt that to them was due a more systematic and exact method of work, the foundry-men again were the first to act in the establishment of specifications under which their product should be sold. To come to more recent times, the American Foundrymen's Association has not only made an elaborate series of tests on cast-iron, and adopted tentative specifications based upon them, but, in addition, it has urged the International Association for Testing Materials, through its American representatives, to make the testing and specification of cast-iron a distinct issue. The half-hearted support first granted was greatly augmented by the rapidly-growing recognition accorded to the enormous iron-casting industry; and when the president of the American Society for Testing Materials was instructed to ask for a special commission for this purpose, Europe was ready to cooperate. During the Buda-Pesth congress, at, which America was represented by Prof. Howe, Mr. Wood and myself, it was decided to add five members to the general committee on steel and iron, whose special duty should be to conserve the interests of the cast-iron branch of the industry. America took up the work at once, and enlarged its committee to 67 members, all of whom were actively concerned in the manufacture or study of cast-iron in all of its branches. At the organization-meeting in Philadelphia, April 25, 1903, Mr. Walter Wood was elected chairman, and myself secretary; and, within a week thereafter, the sub-committees were appointed and became active at once. The scope of the work was naturally limited to those branches of the iron-casting in-

Jan 1, 1905

By John Nelson

AN OUTLINE survey of the economic outlook for the United States export trade in petroleum products resolves itself broadly into two general divisions; first, a consideration of our present position in this trade, and second, a discussion of the visible factors which promise to affect appreciable changes in the immediate future in that trade. The UNITED STATES PETROLEUM EXPORTS OF MAJOR PETROLEUM PRODUCTS 1925, 1926 and 1927 Gasoline, Naphtha, and Other Light Products 1925 1926 1927* Quantity (gal.) 1,286,787,796 1,784,154,802 1,851,494,190 Value $197,491,588 $263,199,938 $214,721,652 'Illuminating Oil, Kerosene 1925 1926 1927* Quantity (gal.) 885;136,041 924,680,979 827,162,280 Value $84,699,724 $100,352,877 $80,358,082 Gas and Fuel Oil 1925 1926 I 1927 Quantity (gal.) 1,365,358,988 1,449,688,394 1,815,130,464 Value.... ? $49,040,024 $45,354,108. .. $50,343,031 Lubricating. Oil 1925... ....1926 .. 1927 Quantity .(gal.) 402,572,584 388,767,055 403,369,512 Value $90,596,671 $86,414,621 $88,926,815

Jan 1, 1928

By H. F. Yancey

Various criteria for evaluating the performance of coal washeries are discussed critically, with particular reference to ideas developed at the First International Conference on Coal Preparation held in Paris in June 1950. Criteria that relate only to the sharpness with which a cleaning unit separates coal from impurity are compared with those that reflect loss of coal or quality of products.

Jan 6, 1951

By G. S. Derrickson, R. A. Golobic

Any type of agitation within a confined vessel is primarily concerned with two parameters: a level of agitation describing the homogeneity of the constituents (whether it be suspension or mixing), and the energy efficiency with which this level of agitation is accomplished. The following is an attempt to present a solution to the problem of adequately defining and optimizing these properties. A discussion is included of the application of good design practices to the determination of a mechanically efficient shape to the blade elements of the propeller. These practices, excluding several appropriate modifications, have been known, but not well understood, in aircraft fluid mechanics for a number of years. Having optimized the direct impartation of energy to the medium being agitated, attention is turned to one of the more perplexing phenomena of multi-phase systems - definition and prediction of agitation levels. The result of recent study and testing is a method of scaling that the authors believe provides a lucid understanding of governing physical parameters within the agitator itself, allowing one to scale up and down with confidence.

Jan 1, 1985

By R. L. Braun, D. L. Leach

Laboratory experiments simulating in-situ copper recovery from primary sulfide ores in sulfuric acid systems pressurized with oxygen are reported. Copper extraction and acid consumption data are correlated with temperature in the range 50 to 150°C and quenched pH in the range 0.25 to 2. Adverse changes in the chemical composition of the leach solution and the formation of gangue-mineral alteration products and secondary sulfides can severely limit the extraction of copper above 90°C. Keeping the pH below the self-buffered value of about 2 and the temperature below about 110°C produces the maximum extraction rates. Forcing the pH too low not only results in excessively high acid consumption but may also limit the extraction of copper at temperatures above 100°C.

Jan 1, 1977

By E. P. Bucklen

Simulation is a tool useful in the evaluation of the probable effect which various changes may have on the performance of time-dependent systems. This is especially true as far as rail transportation in mining is concerned. The VPI-OCR RAILSIM program is a computer program designed specifically for solving a broad range of problems encountered in the design of haulage systems of new mines as well as in the operation of haulage systems in existing mines. This program is one of several computer applications for evaluating mining systems developed at the Virginia Polytechnic Institute and State University under contract with the Office o f Coal Research of the U.S. Dept. of the Interior. The RAILSIM program uses Monte Carlo techniques to introduce variability in the occurrence of events such as would be observed in real systems. Data are required to describe the haulage network, locomotives, stationary facilities, and other miscellaneous parameters. Output from the program lists measures of performance that are useful in assessing the capabilities and limitations of given system configurations. The output information may cover many shifts of operation to indicate the broad range of variation and interaction which can occur as the system responds to varying levels of demand for service. The RAILSIM program was tested extensively in mining operations. The results of some of these tests are used to illustrate the usefulness of this program.

Jan 1, 1972

By Kenneth Cottingham

The number of wells drilled in Ohio in 1943 was slightly in excess of the number drilled in 1942. Compared with the average annual completions for the five years preceding, the year 1943 was short 11 per cent, hut the average initial volume of gas wells was considerably improved. In 1942 the average initial open flow per gas well was 668 M cu. ft., whereas in 1943 the average was 913 M cu. ft. Although no large gas-producing areas were discovered during the year under review, some 30 small pools were found in 17 of the counties of eastern Ohio. These new pools averaged about 300 acres each, and most of them were not extensions but were separate pools adjacent to older production. The Clinton sand furnished most of these discoveries, although six were from the Berea, one was Newburg, and three were shallow sands. No discoveries were made outside former producing counties, and there was no new development the Trenton area of western Ohio. The number of oil wells decreased from 181 drilled in 1942, to 170 in the year 1943. The production of Pennsylvania-grade oil increased 7644 bbl. The total Corning production, however, decreased 91,325 bbl. The present price of Corning-grade oil, $1.31 per bbl., is too low, in the opinion of the operator, to justify exploration. Until something is done in correcting the price level of Corning grade, the production probably will continue to decline. The oil industry in Ohio is making a concentrated effort toward increased production and improved methods of recovering Pennsylvania-grade oil, and a.s this report is written a research and engineering program is being formulated for the benefit and information of the various producers of that grade in Ohio.

Jan 1, 1944

By David B. Reger

The value of carbon ratios in determining the boundaries of possible oil deposits appears to have passed the hypothetical stage. The theory that the ratio of fixed carbon in pure coals is an invariable index of incipient metamorphism in both surface and underground rocks and that it may be applied in defining the limits of petroleum, advanced by David White,' has been received with keen interest by many petroleum geologists. Detailed isocarb maps have been prepared of the Pennsylvanian area of North Texas and Eastern Oklahoma by M. L. Fuller.² A similar map of the coal-bearing area of West Virginia is given here. An isocarb3 is a line showing an equal fixed-carbon percentage, pure coal basis; the term has been proposed by David White to supersede a less expressive nomenclature. The term carbon ratio is applied to the pereentage of carbon in pure coal after water and ash have been eliminated. As a comparatively small number of analyses have been made on this basis, it is usually necessary to compute the ratio by dividing the fixed carbon of the proximate analysis by the sum of the fixed carbon and volatile matter of the same analysis. Many thousands of proximate analyses have been made by the West Virginia Geological Survey, covering nearly every county in which coal is found. Numerous others have been made by the U. S. Geological Survey and the U. S. Bureau of Mines, but as uniformity of results is best secured by adhering to one set of analyses, the tests of the West Virginia Survey have been cxclusively used.

Jan 1, 1921

By D. A. Dahlstrom

THE necessity for slime elimination from valuable mineral and coal products has become increasingly significant within the past 5 years.' , Most of the mechanized mining and present beneficiation methods have resulted in larger tonnages of extreme fines, silts, and clay, commonly called slimes, processed by the preparation plant. Economics in turn have forced the plant operator constantly to lower the bottom size of effective beneficiation, necessitating an almost complete recovery of valuable solids regardless of particle size. When these important factors are considered, the need for an efficient slime removal method for fine solids becomes self-evident. Ordinarily slimes have been classified as ranging from 75 microns, or 200 mesh, down to colloidal dimensions of less than one micron. At the same time there is general agreement that the most troublesome slimes are primarily clays, silts and extreme fines, so that the actual top size may be placed at approximately 30 to 40 microns. This immediately restricts any desliming operation to classification, as screening or other methods would be both uneconomical and grossly inefficient at such dimensions. The liquid-solid cyclone has been recognized as one of the most efficient fine size classifiers available to the mining industry. Applications of cyclones to thickening, high efficiency solid recovery, degritting,

Jan 1, 1953

By William M. Courtis

Since many accounts of Silver Islet Mine, in Lake Superior, have already been published, it is supposed that the members of the Institute are familiar with the location and character of the mine. To many, however, a more detailed account of the ore and manner of treatment will, perhaps, not be without interest. The extraordinary richness of Silver Islet ores, and the difficulty of obtaining correct assays, induced the company to erect smelting works of its own. Accordingly, ground was broken at Wyandotte; Mich., early in the spring of 1871, and the work was pressed on with indomitable energy by Captain E. B. Ward of Detroit, as president, and Mr. Thomas MacFarlane, the discoverer of Silver Islet, as superintendent of the works, so that by July 1st the works were so far completed that smelting could be commenced. The intention was to work Western ores with those from Lake Superior, since the latter contain but a small amount of lead. Hence the capacity of the works is much larger than is needed for the present yield of the mine. The planned process for treatment was smelt-