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The Library of the above-named Societies is open from 9 A.M. to 10 P.M., except on holidays. It contains about 70,000 volumes and 90,000 pamphlets, including sets of technical periodicals and the publications of scientific and technical societies. Members of the Institute, with few exceptions, are forced to spend a portion of their time in localities isolated from sources of information. To these the Library, through its Library Service Bureau, can render valuable service through correspondence; letters requesting information will receive especial attention. The Library is prepared to furnish references and photographic copies of articles on mining and metallurgical subjects; to determine the existence of mining maps, and to furnish general information on the geology and mineral resources of all countries. All communications should be made as definite as possible so that the, information received may be what is desired and not include collateral matter which may, not be of interest. The time spent in searching for such collateral matter will be saved, and the information will be sent more promptly and in more usable shape.

Jan 4, 1917

The Library of the above-named Societies is open from 9 A.M. to 10 P.M., except on holidays. It contains about 70,000 volumes and 90,000 pamphlets, including sets of technical periodicals and the publications of scientific and technical societies. Members of the Institute, with few exceptions, are forced to spend a portion of their time in localities isolated from sources of information. To these the Library, through its Library Service Bureau, can render valuable service through correspondence; letters requesting information will receive especial attention. The Library is prepared to furnish references and photographic copies of articles on milling and metallurgical subjects; to determine the existence of mining maps, arid to furnish general information on the geology and mineral resources of all countries. All communications should be made as definite as possible so that the information received may be what is desired and not include collateral matter which may not be of interest. The time spent in searching for such collateral matter will be saved, and the information will be sent more promptly and in more usable shape.

Jan 10, 1916

By J. Weng

The equations of heat conduction are numerically solved for two kinds of artificial freezing- mechanical freezing and liquid nitrogen freezing. A two dimensional finite difference model simulating the freezing field is developed. The procedure introduces a way to simulate the effect of latent heat released when water transforms from liquid to solid. The procedure also produces a way to calculate the harmonic mean of heat conductivity used when dealing with heterogeneous material. The theoretically derived temperature distributions in frozen soil are given and compared with measured data. An analysis made on the thermal design in shaft freezing. The average temperature of frozen soil is calculated by using numerical integration. The regularity of development of frozen soil radius is revealed and given in an appropriate mathematical model.

Jan 1, 1984

The Library of the above-named Societies is open from 9 A.M. to 10 P.M., except on holidays. It contains about 70,000 volumes and 90,000 pamphlets, including sets of technical periodicals and publications of scientific and technical societies. Members of the Institute, with few exceptions, are forced to spend a portion of their time in localities isolated from sources of information. To these the Library, through its Library Service Bureau, can render valuable service through correspondence; letters requesting information will receive especial attention. The Library is prepared to furnish references and photographic copies of articles on mining and metallurgical subjects; to determine the existence of mining maps, and to furnish general information on the geology and mineral resources of all countries. All communications should be made as definite as possible so that the information received may be what is desired and not include collateral matter which may not be of interest. The time spent in searching for such collateral matter will be saved, and the information will be sent more promptly and in more usable shape.

Jan 11, 1917

The library of the above-named Societies is open from 9 A.M. to 10, P.M. except on holidays. It contains about 70,000 volumes and 90,000 pamphlets, including sets of technical periodicals and publications of scientific and technical societies. Members of the Institute, with few exceptions, are forced to spend a portion of their time in localities isolated from sources of information. To these the Library, through its Library Service Bureau, can render valuable service through correspondence; letters requesting information will receive especial attention: The Library is prepared to furnish references and photographic copies of articles on mining and metallurgical subjects; to determine the existence of mining maps, and to furnish general information on the geology and mineral resources of all countries. All communications should be made as definite as possible so that the information received may be what is desired and not include collateral matter which may not be of interest. The time spent in searching for such collateral matter will be saved, and the information will be sent more promptly and in more usable shape.

Jan 9, 1918

By D. E. Moore

The strength of a natural serpentinite gouge was measured at 400°C and an effective pressure of 100 MPa. The strength of the gouge decreased with increasing pore pressure to 50 MPa and then was nearly constant between 50 and 125 MPa. The samples at 50-125 MPa pore pressure slid stably, whereas those at 3-25 MPa pore pressure showed stick-slip behavior. Lengthening the pre-heating time to 72,000 s of samples at 100 MPa pore pressure led to increases in both the strength and the likelihood of sliding unstably. With still longer pre-heating times, the strengths decreased again and sliding once more became stable. The strength of the gouge at 3 MPa pore pressure was unaffected by changes in pre-heating time. A possible explanation for the results is that excess pore pressures are being generated in the gouge, causing the true effective pressure to be lower than the apparent value.

Jan 1, 1984

By F. Lynwood Garrison

As the specific gravity of low-carbon steel seems to be attracting considerable attention as a means of détermining the quality and value of the metal, I give here a few of the results of a long series of experiments recently made by me. The object of the experiments not requiring more than approximate correctness in the third place of decimals, the extreme precautions to obtain accuracy which are sometimes used in determining specific gravity were not observed. But each piece of metal was carefully cleaned to remove scale, rust, dirt, etc., thoroughly dried, and then weighed in air, all weighings being carefully repeated. The balance used was one of Troemner's finest, and sensitive to one-tenth of a milligram. Before weighing in distilled water, care was taken to remove, as far as possible, the air enclosed in the pores of the metal. The pieces of metal were suspended by means of fine silk thread, a correction of course being made for the weight of the silk. Care was taken that the water in which they were weighed should he always at the same level, and, as far as possible, at the same temperature.

Jan 1, 1887

Harrison W. Craver, Director The Library of the above-named Societies is open from 9 A.M. to 10 P.M., except on holidays. It contains about 70,000 volumes and 90,000 pamphlets, including sets of technical periodicals and the publications of scientific and technical societies. Members of the Institute, with few exceptions, are forced to spend a portion of their time in localities isolated from sources of information. To these the Library, through its Library Service Bureau, can render valuable service through correspondence; letters requesting information will receive especial attention. The Library is prepared to furnish references and photographic copies of articles on mining and metallurgical subjects; to determine the existence of mining maps, and to furnish general information on the geology and mineral resources of all countries. All communications should be made as definite as possible so that the information received may be what is desired and not include collateral matter which may not be of interest. The time spent in searching for such collateral matter will be saved, and the information will be sent more promptly and in more usable shape.

Jan 5, 1917

By Howard S. Strouth

SINCE the days of the Conquistadores, people have told exaggerated tales of the wealth and possibilities of Mexico and Central and South America, and the mining fraternity has never been known to exaggerate any less than any other professional group known to man or beast. However, during a short stay in Mexico one can probably hear more whoppers than at any other time, when dozens of mining propositions are thrust across the desk, and it is not necessary to remind anyone that a listing of the do's and don't's for Mexico requires special mention of the fact that most mining propositions offered south of the border eventually turn out to be a beautiful fairy tale. The following is not suposed to be either an exact description of Standard Mining Corp.'s operations in Mexico by its mining associate, the Corporacion Minera y Beneficiadora Anahuac, S.A., or the last word as to the most economical way to start such an operation. But rather it is the sum total of the recent experiences of the writer while commencing such an operation in 1951-52 with the help of many qualified gentlemen.

Jan 6, 1953

By J. Wayne Erickson

One of the major problems facing today's mining industry is how to manage people and control costs in the underground mine. It is a problem with a solution. Because of the concerted effort to find and mine minerals near the surface, open-pit mine opportunities for certain minerals are becoming more limited; the mining industry will eventually be forced to produce more and more from underground mines in order to obtain those resources necessary to sustain our civilization. Although much technical progress has been made towards solving problems associated with the underground mine, such as - mine design, ventilation, rock support, equipment, and blasting techniques, little has been written on managing mining personnel. Much of what is being taught and practiced today about human relations, motivation, incentives, etc., applies to the underground miner, but the uniqueness of his group dictates a different treatment from that associated with the typical construction worker or factory employee. The difference lies with the kind of man attracted to underground mining and his working environment. Anyone who has had the responsibility of managing an underground mine would agree it is a unique problem.

Jan 9, 1976

By L. Massé, Th. Koulomzine

NOTE ON HAALCK'S FORMULA QUANTITATIVE interpretation of magnetic anomalies is admittedly a difficult process. Few authors have attempted a general approach to this problem. A [ ] number of publications can be found widely scattered through scientific periodicals, which present particular solutions obtained by the introduction of simplifying assumptions, such as the reduction to an equivalent magnet or pole, or the hypothesis of a very thin vein. The practical applications of these solutions are necessarily very restricted though they have given satisfactory results in isolated cases. Probably the most widely known equation of this type was given by Haalck.l His classic work contains curves calculated for typical conditions, and has now become a standard reference. However, a close scrutiny of Haalck's derivation reveals that, aside from the hypothesis of a thin vein, it rests on the

Jan 1, 1947

By Charles E. Wait

IN order to secure cupels uniform in size, density, etc., I have arranged a machine which has proved quite satisfactory, and is so simple and inexpensive as to be within the reach of nearly everyone. It has been in operation here about four years, and with it all cupels used in the assay department of the School of Mines have been made. As shown in the accompanying figure, it consists of a common letter-press, the movable platen of which has been removed. In place of the plate, there is attached to the screw a plunger, which turns with the screw, moving up and down, and making the depression in the cupel. The ring holding the bone-ash is held in place directly underneath the plunger by a wooden guide fastened to the base of the press. There is also fastened to the top of the guide for the ring, at a distance above the base of the press equal to the height of the cupel-ring, a piece of mood about § inch thick, under which the ring will just slide into place, and through which there is cut a circular hole exactly fitting the plunger, guiding it in its downward movement always in the same vertical line; this last guide not only directs the plunger, but also prevents the lifting of the ring by the plunger, upon the raising of the latter.

Jan 1, 1886

By Francis Cameron

Mining is both exciting and rewarding-although at times somewhat frustrating-and we all can have real pride in our industry, in its people, and in its accomplishments. It is, however, with concern that I have noted a deterioration in this Country in what might be called mining's stature and in the growth of a belief in many quarters that our mineral reserves are rapidly approaching exhaustion. In other words, there is a popular image that we are fast becoming a "have not" nation in many respects and that the domestic mining industry can no longer be considered, in the vernacular of Wall Street, to offer much in the way of "growth potential." I do not subscribe to this hypothesis, nor do I believe that the record of the mining industry bears this out. However, let me add that we can, in time, talk ourselves into this frame of mind and we can hasten the day when this very well might come about by unnecessary and unwise legislation or regulation. My remarks today are basically designed to give my reasons for refuting this negative philosophy and to review our record. With your help, I know we can improve our image, and the public's recognition of our industry's peculiar problems.

Jan 4, 1968

Magnetic Measurements on Auriferous Veins in Brazil. BY MARK C MA¬LAMPHY (Contribution 72-Preprint; also Trans, vol 110 4900 words) One of the lesser known gold-bearing regions of Brazil is in the vicinity of Lavras, in the State of Rio Grande do Sul Recently the Companhia Estrada de Ferro e Minas Sao Jeronymo has been making a detailed survey of the area, and the author of this paper was requested to study the possibility of applying geophysical methods. The present paper gives a few details of the work and the results obtained The problem was difficult and the results not particularly brilliant, according to the author, but the data are believed to represent another advance in the application of the magnetic method of prospecting The instrument used was a Schmidt-Lloyd vertical magnetic field balance made by Askania Werke It did not prove of value for the discovery of auriferous veins of the type there found It is believed, however, that fair results may be expected when studying the continuation of veins that disappear under alluvial covering The data thus obtained should be of exceptional value in directing the excavational work of prospecting A short appendix to the paper gives the results of magnetic observations in the Sao Jeronymo coal mine

Jan 1, 1935

By Lane D. Schultz, John D. McLennan, Jean-Claude Roegiers

During construction of the intake tunnels for a nuclear power facility in Ohio, evidence of a potential geological discontinuity was discovered. Assuming that the discontinuity might still prevail underneath the site, it was decided to measure the stress profile across the discontinuity. This information would be used to assess future stability on the basis of predicted shear stresses acting along the fracture. Seven intervals were hydraulically fractured to determine the magnitude and orientation of the stress tensor, in order to infer the shear stresses acting along the discontinuity. The formation consists of tightly interbedded shales. This, in combination with the shallow depths, would be expected to lead to horizontal hydraulic fractures -- a situation which generally provides limited information. Careful testing procedures, and meticulous interpretation, allowed the determination of the horizontal stress components as well as the vertical component, via the initiation and/or propagation of multiple fractures. The measured stresses fall within the range of stress magnitudes and orientation determined in other areas of the northeastern and north-central United States and in southern parts of Canada. In addition, a small stress gradient anomaly was recorded at depth. On a different scale, the measured stress regime is also evaluated in light of the regional geological setting.

Jan 1, 1982

By W. P. Yant

THIS paper presents evidence of the general occurrence of methane in a large number of the coal fields of the United States and substantiates the apparent unnecessary differences in the ventilation requirements and codes in the various states, as was brought to the attention of the Committee on Mine Ventilation of the American Institute of Mining and Metallurgical Engineers at its Pittsburgh meeting in October, 1925, by J. A. Garcia.1 The data in his report have been compiled from the files of the Gas Laboratory of the Pittsburgh Experiment Station of the Bureau of Mines and represent samples collected throughout the various states and submitted for analysis by its engineers, also by mine operators and State mining departments, since 1911. Several thousand analyses were available but most of them were rejected because they represented abnormal conditions, undefined place of sampling, special investigations, or duplications in the same mine. Only those samples were included which, without reasonable doubt, were ascertained to fall within three major classes, namely, main return, air splits, and face and rooms of live workings. In the case of air splits, and face and room samples, only the one which contained the highest percentage of methane found in a given mine was taken.

Jan 1, 1927

By Harry V. Warren

There are two topics which may be considered as opening gambits in any conversation in any part of the world, weather and health. Nothing much can be done about the former, and it would appear that no great changes can be anticipated in the immediate future. With respect to health, a great deal has been achieved in the past 150 years, curiously enough not all of it by medical men. It would appear that the time is now appropriate for geologists to come to the assistance of medical men. During the past few decades, medical science has mastered many of the diseases commonly associated with childhood. As a man tends to live longer, those diseases usually associated with middle and old age become more prominent. Thus we must realize when we say that today more people are dying of cancer and coronary disease, absolutely and relatively to other diseases, this should not suggest that these diseases did not exist a hundred years ago; it does suggest that more people are living to an age where death from these diseases is apt to become more common.

Jan 7, 1962

By R. A. Wyman

KYANITE schists in the Sudbury area have been generally described by Haw,' who has also given particuLar information on preliminary treatment of three large samples from Dryden township, Ontario.' Kyanite, garnet, biotite, quartz, and feldspar comprise the main ingredients of this ore. Kyanite is the valuable mineral. About 5½ tons of —35 +200 mesh product, made by dry rod milling, screening, and separation on the Exolon magnetic separator, were available for treatment by flotation. Magnetic separation had effectively reduced garnet and biotite so that flotation feed consisted essentially of kyanite, quartz, and feldspar, the kyanite content averaging 32 pct and representing about 86 pct of the kyanite in the original ore. Earlier work on kyanite at the Mines Branch, Ottawa, s-c employed an acid circuit, but to avoid production difficulties in the use of acids and at the same time take advantage of the fact that industrial minerals respond somewhat to soap flotation, it was decided first to investigate the higher pH levels. Exploratory tests using —65 +200 mesh feed ended with production of 96.6 pct kyanite concentrate rep-

Jan 1, 1959

By E. B. Swanson

Crude oil production in Iraq during 1932 was maintained at slightly higher levels than in 1931, but the output continued to be restricted to the requirements of local consumers. The Iraq Petroleum Co., representing British, American and French interests, which has been operating within its concession east of the Tigris River since 1926, began drilling operations on Apr. 5, 1927, and completed its first well at Baba Gurgur on Oct. 14, 1927, to which area the company has since confined its drilling activities. Relatively small quantities of oil have been produced annually, but the products have been utilized in company operations and have not been offered on the Iraq market. The Khanaqin Oil Co., which has its field of operation at Naft Khana in the so-called Transferred Territories, has been supplying the Iraq market with petroleum products from Iraq wells since March 12, 1927. The output of the Khanaqin Oil Co. refinery, at Alwand, during the past three fiscal years ending March 31, has been as follows: (In Barrels of 42 Gallons Each) 1930 1931 11931 Gasoline................................. 102,940 104,571 118,012 Kerosene................................ 104,010 108,112 111,624 Fuel oil...........................1 286,9001 332,142 354,244 503,850 544,825 583,880 The Iraq Petroleum Co. has a small topping plant, with a capacity of about 150 bbl. a day, used in the manufacture of petroleum products for the company's own needs. During the 1932 fiscal year, the production was 3918 bbl. of gasoline and 2235 bbl. of kerosene, as compared with 8157 bbl. of gasoline and 6308 bbl. of kerosene during the preceding fiscal year.

Jan 1, 1933

By C. O. Babcock

In this Bureau of Mines report, the authors present the results of laboratory tests on the burst proneness of coal. Many researchers have studied the violent breaking of large coal masses in underground mines, called bursts, but the causes remain uncertain. They have often assigned to geology and gas pressure the causative roles. The objective of this work is to show that stress can produce bursts in many coals if constraint is necessary for pillar survival and is suddenly lost. We tested coal samples from 15 mines, in 11 coal seams, in six states in the laboratory, and 13 were made to burst. These bursts were produced in several ways, but segmented steel platens were used in the tests reported. Two parameters analogous to the momentum and kinetic energy were used to rank the burst proneness of the coals tested. Tangential strains over the lower surface of the model coal pillar were measured to reveal a periodic slipping prior to the burst. High-speed motion pictures (350 frames per second) reveal the burst behavior in slow motion. We propose a modified Mohr-Coulomb stress-failure criterion to describe the burst behavior. When the horizontal constraint is suddenly lost with little change in the vertical stress, the Mohr stress circle increases in size dynamically, exceeding the static failure condition. When the inertia of the coal mass is overcome, a burst occurs. We conclude that most coals can be made to burst and that such bursts can be expected in mining at increasing depths.

Jan 1, 1984