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By T. M. Barry

HOW often have those who make mining a career said that, "mining is different"? This kind of feeling often expresses itself in talking shop with men of other industries. And there is no doubt about it; mining is different. There are different marketing problems, different production problems, and we certainly have different personnel problems, to cite but a few. Mining people have recently been discovering though, that many of their problems are not unique to mining. They are beginning, in fact, to find that many of them are dead ringers for problems that other industries have had to face and solve years ahead of mining.

Jan 6, 1954

By Dr. Hermann Wedding

Albert Ludwig Serlo was born February 14, 1824, at Crossen-on-the-Oder. After completing his school-studies and his training as a mining official, he received in 1851 an appointment as Royal Manager of salt-works (Salinenfactor) and member of the Administratioll of Salines at Konigsborn, near Unna, Westphalia. The issue of new regulations for the training of higher State officials in the Department of Mining, Metallurgy and Salines, led him to pass in 1856 a special examination for the rank of Assessor, in consequence of which he was called to Berlin, to serve for a few months as an assistant in the Ministry of Commerce, which had charge of mining, etc. In the same year he became Bergmeister and member of the mining administration at Bochum, Westphalia, and in 1858 Oberbergrath and member of the provincial administration, called the Oberbergamt, having its headquarters located at Dortmund. In 1861 he was appointed Director and head of the newly-reorganized mining

Jan 1, 1900

New Products Equipment

Jan 10, 1951

Jan 1, 1939

Jan 1, 1946

Jan 1, 1946

Jan 1, 1957

By S. H. Williston

IT is not often that bore hole surveys can be checked by actual civil engineering methods. A recent Arizona survey was checked by normal surveying methods and the comparison of the results should be of value to both oil and mining men. During the summer of 1948 the Phelps-Dodge Corporation, at its Copper Queen property near Bisbee, Ariz., drilled a 1245 ft, 8 in. diam, churn drill- hole in a mineralized area and cased part of it, intending to use it to transfer mill tailings for stope fill. The hole, as frequently occurs, was not straight, and, in endeavoring to locate the bottom in- the underground workings, they found no evidence of the hole at the underground coordinates directly below the surface location. The noise of the drilling tools was reasonably clear, but the direction of sound was uncertain. Preliminary tests with available equipment were not successful in locating the bottom of the hole. Be- cause of the mineralized character of the area and the fact there was some casing in the hole, any magnetic method of well surveying would give results ' of doubtful value.

Jan 1, 1950

By Kenyon E. Richard, James H. Courtright

Thomas W. Mitcham (Strategic Minerals, Inc., Grand Junction, Colo.)—The authors have presented a significant contribution to the field of mining geology. The article is graphic, remarkably concise, and crisply original. The presentation is made on only three pages with two maps, but their Silver Bell story is entirely adequate in background, development, and conclusion. Most of their colleagues would agree that this paper reflects the high quality of the work which these unusually capable men have done in the Silver Bell area over the past few years. The Silver Bell area is one of complex tectonic structure, and time and spatial relationships are by no means apparent. Actually, most of the observations and interpretations in this paper are new to published geologic literature on the Silver Bell area. I am in agreement with these interpretations with two possible exceptions, which are discussed below. One might well define the three roughly parallel west-northwest faults, shown on the insert of Fig. 2, as the major structural elements of the area. North to south, I propose that these be named the Ragged Mountain fault, the Silver Bell fault zone, and the Waterman thrust, after the mountain ranges which are the results of these major structures. While I would agree with the authors that the northern two of these major structures are high-angle faults of the Laramide revolution, my impression is that the southern structure is a low-angle thrust of approximately Miocene age. In support of this opinion, I submit the following observations: 1) irregularity of the fault in strike; 2) scarcity of Laramide intrusives and alteration of sediments along the fault; 3) present high re- lief of the Waterman Range which indicates youth or certainly rejuvenation; and 4) existence of a series of parallel structures farther to the south which results in an outcrop pattern suggesting imbricate thrusting. The authors have stated that Laramide igneous activity began with the intrusion of alaskite. Some dacite flows appear to be conformable with Cretaceous beds, and thus my impression was that alaskite followed the intrusion and extrusion of dacite. I would be interested to learn of evidence in support of the reverse relationship suggested by the authors. Kenyon Richard and J. H. Courtright (authors' reply)—The authors appreciate Mr. Mitcham's attention to this paper. The names he proposed for the major faults seem appropriate. His suggestion that the Waterman fault is a thrust may be correct because he did more work in that particular area than the authors. However, it is believed that no direct evidence of a low-angle thrust relationship has been recognized, and the authors consider that indirect evidence favors a high-angle fault interpretation. The pre-dacite flow age of the alaskite is definitely established, the authors believe, by the fact that the flows rest on an erosion surface which was carved in the dacite porphyry, an intrusive clearly younger than the alaskite, as evidenced by inclusions of alaskite occurring in dacite porphyry. No direct evidence of Cretaceous sediment-flow rock relationships was found at Silver Bell, but in the nearby Tucson mountains dacite agglomerates, megascopically similar to those at Silver Bell, overlie a basal conglomerate which in turn rests on the truncated edges of steep-dipping Cretaceous arkosic beds.

Jan 1, 1956

The German Kaiser is employing the keenest engineering talent of his own and allied empires in his attempt to defeat the world. American employers are paying engineers such attractive salaries that voluntary enlistments of high class technical men in the United-States Army, are below requirements. This deficiency is also probably due in part to the lack of proper information concerning the engineering branch of the service. Few civilians know that it is possible for them to perform in the Engineering Corps almost exactly the same kind of work as that in which they are now engaged. The best results in any organization are obtained only when the energy of every man in it is concentrated along the line for which he is best suited by natural ability, education, and training. It. is more important to have the right man in the right place in our Army, where lives of men are at stake, than it is in any business enterprise. The First Replace meat Regiment of Engineers was organized at Washington Barracks, D. C., on Dec. 14, 1917, with the express idea of accomplishing this. end. Its specific, purpose is to keep all engineering units of the Army at full enlistment strength during the period of this war. This regiment has not only the responsibility of finding men to fill depleted ranks, but it must also fit them to step into the work of trained, efficient and disciplined soldiers. The preliminary work of the recruit is first a thorough training in military drill, for the engineer soldier must be prepared to lay down his shovel and take up his rifle at any time. Infantry drills gradually give way to engineer work and more specific technical training. The. engineer soldiers must know how to tie knots and lashings, to build spar and truss bridges, to construct revetments, dig trenches, place wire entanglements, construct machine-gun emplacements, build pontoon bridges, and to construct roads: They must, also know the methods of demolition, sapping, and mining. Specialized training in lithography, zincography, surveying, mapping, photography, carpentry, blacksmithing, electricity, and machinery, are also given to those qualified for further training in any of these branches. Engineers are called upon to perform such a wide range of work that practically every man with any technical training or mechanical ability can find a place in this organization. Every male citizen in the United States who is physically fit, and between the ages of 18 and 21, and 31 and 40, is eligible to join the regiment by voluntary enlistment.

Jan 5, 1918

By Robert Greenwood

The advent of the space age and its promise of interplanetary flight has prompted new ideas for propulsion systems that will allow maximum energy with minimum fuel weight. The use of cesium as the source of energy for such rocket flights has been found desirable. Theoretical efficiency of a rocket fuel is measured in terms of specific impulse, defined as the number of pounds of thrust per pound of propellant consumed per second. Specific impulse is usually expressed in seconds (the number of seconds for which one pound of fuel would produce one pound of thrust) although it is really a measure of total energy, not of power. The most sophisticated chemical fuels have a specific impulse of 300 to 400 sec; liquid hydrogen heated by nuclear reactor has a specific impulse of 1000 to 1200 sec. Specific impulses as high as 20,000 sec, however, are theoretically attainable with the ion rocket, in which free cesium ions are accelerated across a voltage drop and ejected at high velocity.' Characteristics of the system have been sketched by Boden. The desirable properties of an ion propellant are: 1) low ionization potential, 2) low boiling point, and 3) high atomic weight. Alkali metals best fulfill these requirements, and Table I indicates the superiority of cesium. The use of heavy complex ions such as UCl; is ruled out by their instability and other disadvantages.

Jan 5, 1960

By O. M. Schaus

REDUCED activity of mining, because of the business recession, had the effect of lowering working time, hence of reducing exposure to accidents, so it is probable that 1938 will be found to have had a lesser number (both fatal and nonfatal) though the accident rate may remain about the same as in 1936 and 1937. During periods of re-employment, such as occurred during 1936, 1937, and 1938, the new men entering the industry are less experienced and not as well trained in accident prevention as are the older, more experienced men and are frequently subject to more accidents. This situation should tend to correct itself as the new employees be- come better trained.

Jan 1, 1939

By Bashir Ahmed, Fred D. Wright

Numerous investigators have studied the various factors that influence the ultimate strength of model mine pillars, such as ratio of height-to-least width; restraint or friction on the top and bottom; 1,2 the effect of stress distribution in pillars on their strength;3 and the scaling factors involved in applying the results of model pillars to full-scale pillars. However, the load-bearing capacity of pillars after initial failure does not appear to have been investigated. Yet many mines employ methods in which small pillars or pillar remnants are left systematically; these pillars crush as mining progresses and, of necessity, affect the behavior of surrounding rock even after initial failure. The effect of such crushed or crushing pillars depends largely on their load-deformation characteristics. This chapter presents the results of a preliminary investigation to determine the load-deformation characteristics of a few model mine pillars to and beyond initial failure. Various investigators have also studied the elastic and viscoelastic behavior of mine structures. In such studies, computers are frequently employed to obtain numerical results by the finite difference or finite element methods. It would be entirely feasible to write a program that would approximate the load-deformation characteristics of pillars to and beyond the crushing stage if these characteristics were known. More accurate information on the induced stresses and deformations in overlying strata and on surface subsidence could be obtained, information which should result in better strata control by enabling the engineer to calculate more accurately the effects of changes in pillar spacing, size, and shape.

Jan 1, 1972

Jan 1, 1938

Jan 1, 1938

By AIME AIME

Air transport supplants the old methods. The 3-piece canoe fits in the plane and likewise makes possible not a bad division of labor over a 5-mile portage

Jan 1, 1933

By M. W. Lightner

IN 1947 the steel industry rebounded from its wartime effort and produced a record-breaking peacetime tonnage of steel ingots. During the first six months of the year the industry produced 42,000,000 tons of ingots and expected to produce 85,000,000 tons for the year. With a rated capacity of some 91,000,000 tons, production was at a rate of about 93 per cent of capacity. Credit must be extended to the steel producers who have maintained this steady state of operations while faced with many problems, not the least of which was a continued shortage of satisfactory scrap. Furthermore, the steel industry started a record-breaking peacetime expansion program at a total cost of more than $1,000,000,000. This program will increase the ingot-making capacity of the country by 2,500,000 tons and should be completed in 1948.

Jan 1, 1948

Jan 1, 1916

IF you do not make the disc at the same time as the core and as part of it, it is necessary to make it by itself. This is done by spreading on a board or other flat surface a layer of clay as thick and wide as [88] the disc that you made at the feeding head of the first pattern of the gun. When it is dry, mark it exactly with compasses and then, cutting with a chisel or rasp, make it fit exactly into the empty space at the head. Likewise, make a hole just as wide as the thickness of the core exactly in the middle of this clay disc. When you have put the disc in its place in the mould and then pass the core through this hole, it passes exactly through the center of the mould in such a way that it meets the iron ring that you put at the foot of the mould for this purpose. As I said above, if' you do not make it as part of the core, it is necessary to proceed in the aforesaid way. But if' you wish to make it attached to the core (which I like better because it can be done more accurately) make a

Jan 1, 1942

By C. Legrand

THE CHAIRMAN (B. B. GOTTSBERGER, Miami, Ariz.).-I think this experience of the Burro Mountain Copper Co. with oil engines as described by Mr. Legrand comes at a very opportune time. The fuel almost universally used in the mine power plants of the Southwest is oil. Additional economy in its use for power production is much to be desired. In the case of the Miami Copper Co., we have lately found it necessary to enlarge our power plant and, based on the experience of the Burro Mountain Copper Co., we have decided to install oil engines similar to those in their plant. I think it would be very interesting to have some discussion on this subject. Mr. Langton, did you tell me you had prepared some remarks?

Jan 12, 1916