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By Leon Dominian

The lack of Aryan roots for the names of metals commonly known among the Aryan settlers of Asia Minor, as well as the later colonizers of Europe, indicates that these races were generally ignorant of the use of metals until they came into contact with Semitic peoples. Practically all mining-terms in current use among the earliest Greeks resemble very strongly their distinctly Semitic equivalents, which can be traced all the way in a broad belt beginning in Lower Mesopotamia, and extending westwardly to the Syrian shores of the Mediterranean. The Greek word 'metallon," for instance, used indiscriminately to designate mine or ore, probably came from the earlier Semitic equivalent, " matal." Again, the Greek words " chry-sos " (gold) and " chalkos " (copper) seem to be descended from the Semitic forms " chrouts " and " chalak." It is a natural inference that primitive mining-methods were evolved by the dwellers in the mineralized areas of Asia Minor, from whom later Greek, Roman, and even North European miners obtained their first not.ions of the reduction of metallic ores, by

Jan 1, 1912

Apart from the general cooperation received in many quarters, the Unitization Committee desires to make specific acknowledgment to the following individuals for assistance rendered in the study to this time. California.—Committee members: Joseph Jensen, chairman, L. L. Brundred, E. M. Butterworth, H. Norton Johnson, D. B. Myers, W. R. Wardner; others who contributed: C. R. McCollom, F. C. Merritt, E. B. Noble, Ralph Arnold, J. R. Pemberton, Roy R. Morse, T. F. Stipp, John R. Roberts, R. D. Bush, Alexander Anderson, J. A. Taff, F. 0. Martin, J. E. Van Gundy, E. K. Parks, A. C. Rubel, Lew Suverkrop, W. L. McLaine, Gerard Henny, Walter Stalder, Lester C. Uren, Hoyt S. Gale, W. L. Walker. Rocky Mountain.—Fred E. Wood, chairman, J. G. Bartram, C. E. Dobbin, Wilson B. Emery, Charles E. Erdman, R. D. Hawley, E. W. Krampert, Foster Morrell, W. T. Nightingale, K. B. Nowels, C. M. Rath, Earl Shoenfelt, J. W. Steele, E. T. Wilson, J. J. Zorichak. Kansas-Oklahoma.—Committee members: C. E. Beecher, chairman, A. W. Ambrose, R. C. Hauber, Clyde Alexander, R. F. MacArthur, C. R. Swarts, M. M. Valerius, E. H. Griswold, G. 6. Rollin, L. Murray Newman, David L. Trax, Richard K. Huey, Marvin Lee, Harry Johnson; others who contributed: E. A. Carr, Paul S. Ache, K. C. Slater, R. S. McFarland, J. R. McWilliams, Joseph Chalmers, Henry A. Ley, Dorsey IIager, H. C. George, W. K. Whiteford, L. G. E. Bignell, L. E. Smith, George E. Burton. Texas, Louisiana, Arkansas, New Mexico.—Frederic H. Lahee, chairman, Donald C. Barton, C:. E. Beecher, Olin G. Bell, G. E. Campbell, Paul Wagner, John West, Robin Willis, J. M. Forgotson, E. J. Gorman, P. S. Haury, Marvin Lee, C. F. Lytle, L. H. McBee, T. F. Petty, C. C. Pope, F. S. Prout, J. C. Stewart, J. R. Suman, L. P. Teas, W. C. Thompson, A. F. Truex, R. B. Campbell, M. G. Cheney, P. C. Dean, F. W. DeWolf, Dugald Gordon, B. A. Hardey, F. E. Heath, J. F. Lucey, George C. Matson, W. H. Perot, T. W. Pew, W. A. Price, W. A. -Reiter, R. C. Stewart. Eastern United States and Foreign Fields.—H. H. Hill and E. L. Estabrook, chairmen; Dr. Richard Ambronn, Gottingen, Germany; Arthur R. Andrew,

Jan 1, 1930

FRIENDS of the late Charles F. Rand presented in 1930 a sum of money from which the income is available to support various phases of the work of the Institute in which Mr. Rand was so deeply interested. At present the fund amounts to $10,900. The specific terms of the deed of gift are as follows: "The fund collected to establish a memorial to the late Charles F. Rand shall be placed in the custody of the Board of Directors of the American Institute of Mining and Metallurgical Engineers, to be set up as a trust to be known as the `Charles F. Rand Foundation,' the income of which shall each year be applied to a distinct purpose to be decided upon in that year by vote of the Board of Directors. This purpose shall be such as to promote the general welfare of the Institute and to constitute a permanent memorial of the usefulness of Mr. Rand, who for many years gave unstintingly of his time and talents in its service. "It shall be within the discretion of the Board of Directors to establish a medal to be known as the Charles F. Rand Memorial Medal to be awarded at such a time and under such rules as may be determined by the Board of Directors, for Distinguished Achievement in Mining Administration." The establishment of this medal was announced at the annual meeting in February, 1932, the term "mining" being defined in its broad sense to include metallurgy and petroleum. Robert Linton is chairman of the Charles F. Rand Foundation Award Committee.

Jan 1, 1942

By John Birkinbine

Since the presentation of the paper upon " The Concentration of Iron-Ore," which the writer, associated with Mr. Thomas A. Edison, read before the Institute in February, 1889 (Transactions, vol. xvii., 728-744), much time and money have been devoted to applications of various forms of concentrating apparatus, particularly in treating magnetic iron-ores. An indication of the interest which has been developed is shown in the four payers presented at and printed in advance for this meeting." The question, does magnetic concentration pay? is now being discussed by many owners of magnetite deposits, and affirmative answers can be readily obtained from patentees or agents of special machinery, while ultra-conservatism may give a prompt negative reply, based mainly upon the apparent impracticability of handling, crushing, sizing and separating large quantities of ore, and upon the generally

Jan 1, 1891

By Dever Ashmead

ENGINEERS, operators, miners, and others di-rectly interested in mining will readily agree that more of well-directed illumination in mines will result in a reduction of accidents and general im-provement in the working conditions, comfort, and effi-ciency of those employed underground. Progress has been made in the amount of illumination from individual lamps carried by miners. The candle, which a great many of us can remember as the general method of lighting, was replaced by the oil lamp or torch, later by a specially prepared oil known as "Sunshine," and eventually by the carbide cap lamp. The metal mines still present a field for progress from the standpoint of general illumination, particular-ly those mines having high stopes. Attention is being more and more focussed upon the advantages of im-proved lighting in mines, in order that the underground employee may benefit as the factory workers have al-ready done. The management is vitally interested in the morale of its employees, the reduction of costly accidents and increased production, all of which, judging by results in other industries, will be sub-stantially benefitted through the means of improved general illumination. From data available to the writer, 40 to 50 per cent of the accidents in the metal mines occur at the face; they may be due to roof falls, movement of loose ore, loading of cans, handling of tools, etc. Very probably a large proportion of these accidents may be attributed to lack of light. If sufficient illumination had been present the employee could have seen what was happen-ing and taken the proper precautions. The introduc-tion of better illumination means better visibility, de-crease in accidents, and increase in efficiency.

Jan 6, 1928

By Roy Thomas

SOON after the Waelz plant for the fire concentration of low-grade zinc ores was put into operation in the early part of 1929 at Katowice, it was found that the conveyor equipment for transporting the hot residue from the furnace dust chambers was inadequate. Hand tram-ming with water cooling was used for a time, but that method was injurious to the workmen as well as costly. The problem was to find some practical mechanical means of conveying flue dust at temperatures of from 450° to 600° C. as it was drawn from the dust chambers. After considerable preliminary investigation it was decided to install pneu-matic equipment for conveying the hot materials to a central mixing plant, where it would be mixed with slime and from which it would be returned to the furnace feed hoppers. The first pneumatic equipment was installed in 1930, and has been in successful operation since that time. The pneumatic method of transportation has shown a considerable saving in operating costs over the former methods of dust handling and a decided improvement in working and hygienic conditions at the plant, through the elimination of the dust hazard. Additional pneumatic equipment was installed in 1933 for conveying the furnace fume from the baghouses to the roaster plant. At the same time pick-up lines were provided for collecting the cleanings from the vertical and horizontal cooling pipes that are between the furnace dust chambers and the baghouses. The latter installation has practically eliminated a dusty and costly hand-tramming operation.

Jan 1, 1939

By S. P. Barber, G. W. Cutting, V. Alesse, M. Ciriachi

Just what is happening in the preparation and mineral separation stages are questions frequently asked about most processing plants. It is unusual to find the answers readily available in the operating metallurgical data. Knowledge is nominally available from metallurgical balances about the head ore grade, grade and recovery of the concentrates, and the plant tailings. However, the mechanisms which control grade recovery and losses are seldom monitored in such a way as to permit specific analysis: Thus, when questions about the effectiveness of the process are asked, the answers are based frequently upon intuitive professional judgments and local expertise. Detailed investigations of process functions are extensive in terms of manpower, time, and interference with production. An investigation method in which process operating conditions could be provided in a cost effective manner would assist in local process assessment and control. Such a collection of process operating data is defined as a process audit and the development of the necessary techniques forms the subject of this paper. A typical application to a lead-zinc concentrator highlights both the manner of implementing a process and the plant data made available for local use.

Jan 1, 1980

By E. C. Pechin

The attention of the members of the Institute of Mining Engineers is asked to a description of the minerals of Southwestern Pennsylvania, as representing the minerals of an enormous area, stretching continuotisly, with local variations, along the western slopes, and at the base of the Alleghany Mountains, through Western Pennsylvania, West Virginia, and Kentucky, and destined to play no mean part in the future of the iron trade of the country. The particular locality is at and near Donbar, in Fayette County, where the most careful examinations and extensive developments have been made. The deep gorges cut by the Youghiogheny and Monongahela Rivers, in their passage through the mountains and lower lands, give admirable facilities for observing the measures lying between the sandstones of No. 11 and the upper coal measures. Apart from its varied mineral and agricultural resources this section of country has great historic interest attaching to it. It was down the Monongahela that Braddock led his ill-fated army to its defeat under the wails of Port Duquesne, and it was up the Youghiogheny River and Dunbar Creek that the shattered remnants hastily fled to gain the camp of Colonel Dunbar, the second in command, who was entrenched upon a high knob, at the head of the creek which bears his name, and which is still known and visited as Dunbar's Camp. Numerous streams, runs, and localities preserve the names of the guides and pioneers who accompanied, in early colonial times, young George Washington, who was pushing his surveys into the trackless and hostile wilderness, and many of them taking up large tracts of

By Daryl R. Tweeton, William H. Engelmann, Orin M. Peterson, Jon K. Ahlness, Gregory R. Anderson

The Bureau of Mines measured the geochemical changes as H2SO4 was used for in situ uranium leaching by Rocky Mountain Energy Company near Casper, Wyoming. Cores and ground water were analyzed before leaching. Water samples were taken from observation wells located between injection and production wells as the leach solution was brought up to full strength in several steps. Measurements were made of pH, Eh, temperature, conductivity, total dissolved solids, dissolved oxygen,HC03, U. V, Na, K, Ca, Mg,S04, CI, Mo, Mn, Fe, AI, Si, F, P, As, and Se. The data were gathered to assist in geochemical modeling of leaching and to study the potential environmental effects of acid leaching. Environmental considerations appear favorable. For example, the concentration of Se, a toxic element often found in uranium deposits, stayed below the EPA standard for drinking water.

Jan 1, 1979

By Walter C. Smith, O. J. Seeds

METALLIC bismuth was known in the Middle Ages and the name is supposed to come from the German Wismut. The origin of the German name is uncertain. References to bismuth are found in the writings of Valentine, Paracelsus, and Agricola between 1450 and 1550. Early specimens of bismuth were very impure and often were confused with antimony, tin, and zinc. About the middle of the eighteenth century, J. H. Pott, C. J. Geoffroy, and Torbern Bergman succeeded in producing fairly pure bismuth and showed it to be an elementary metal similar in many respects to lead. H. S. Washington has estimated that bismuth occurs in the earth's crust about as abundantly as tungsten and silver; i.e., to the extent of 10-6 or 10-7 pct. It is found as native metal, both alone and associated with tin, copper, and other metals, and in a large variety of ores. The important ores are the sulfide (bismuthinite), the oxide (bismite), and the carbonates (bismutite and bismutosphaerite) . Other occurrences of bismuth are in the vanadate (pucherite), the selenide (guanajuatite), the telluride (tetradymite), and in many complex sulfides, arsenides, and antimonides. Bismuth minerals have been found in many parts of the world but very few of the bismuth deposits have been of economic value, the oxide ores from parts of China being the exception. The major portion of the bismuth production of today is the so-called by- product bismuth. Bismuth often occurs in ores mined and treated primarily for other metals, and during the treatment of these ores

Jan 1, 1953

NEW MEMBERS The following list comprises the names of those persons who became members during the period of June 10, 1917, to July 10, 1917. BANKS, LEON MAXWELL Agent 3. Supt., Grant Leasing Co. Metcalf Ariz. BEAUCHAMP, HENRY CLAY : Mine Operator, Sisson, Siskiyou Co., Cal. BOCKING, CHARLES, Asst. Mgr., Butte & Superior ,Mining Co., Rialto Bldg., Butte, Mont. BEYER, HERMAN E., Chief Engr., Condenser Dept., Ingersoll-Rand Co., 11 Broadway, New York, N. Y. BLACK, HERBERT F 1512 Oliver Bldg., Pittsburgh, Pa. BRENNAN, PATRICK J., Gen'l. Supt., Elkhorn Division, Consolidation Coal Co., Jenkins, Ky. BUTNER, DANIEL W., Chem. & Supt., Underground Min., Spanish American Iron Co., Daiquiri, Santiago de Cuba, Cuba. CARLTON, DAVE P Nevada-Douglas Cons. Copper Co., Ludwig, Nev. DE AROZENA, JOE Min. Engr., 321 Preusser St., San Angelo, Texas. DICKIE, CHARLES HERBERT, Pres., Georgia River Min. Co., Duncan, Vancouver Island, B. C., Canada. DOBBINS, WALTER Mill Foreman, Chino Copper Co., Hurley, New Mexico. DRURY, CHARLES W., Asst. Professor of Met., Queen's University, Kingston Out. Canada.

Jan 8, 1917

Discussion of the paper of IRVING A. PALMER, presented at the Salt Lake meeting, August, 1914, and printed in Bulletin No. 91, July, 1914, pp. 1447 to 1460. L. S. AUSTIN, Salt Lake City, Utah.-With the union of the Guggenheim interests and the American Smelting& Refining Co. in 1900, competition among the lead-smelting companies appeared to have been largely eliminated. This condition prevailed for but a short time, owing to the erection of smelteries by competing companies. Naturally, as competitors, the older companies endeavored to keep improved methods to themselves, not realizing, it would appear, that such knowledge could never be bottled up, but would drift into the common field of practice. Of late it has begun to be felt that more is gained than lost by adopting a franker and more open policy. The line, however, is drawn in. giving details of costs, which, fully known, it is felt, would be taken advantage of by a rival. As Mr. Palmer says, steady and substantial progress has been made, and latterly, I may add, the improvements have been radical. Sintering by the Huntington-Heberlein method or with Dwight-Lloyd machines has effected an important saving over reverberatory roasting, the cost being, say, 50 to 75c., as compared With $2 per ton by the older method. Moreover, the .large use of a sintered product has resulted in doubling blast-furnace tonnage. However, the change has not been an unmixed blessing, as in the machine roasting little time can be given to the breaking up of the blende, and it has been impossible to decompose largely the zinc sulphide, so detrimental in later blast-furnace treatment. The satisfactory roasting of the blende is still an unsolved problem. Nor is this all. For the best reduction it has been found that a part of-the change should be crude (unsintered) ore, indicating that the already fused material is only too ready to change to slag, thus lessening the opportunity for better reduction.

Jan 11, 1914

By C. A. Heberlein

INTRODUCTION THE present war in Europe seems to have stimulated the demand for quicksilver. In July last, the price ranged around $35 per flask of 75 lb., while to-day it seems to fluctuate between $47.50 and $50. The use of quicksilver in the form of fulminate, containing 70 per cent., and as corrosive sublimate, containing 73.8 per cent., must be extensive and a further market advance may be expected. With such an advance, some revival in quicksilver mining maybe looked for, particularly in California, where many abandoned properties exist. What can be done with low-grade quicksilver ores under favorable conditions, particularly with low mining cost, may be seen from the following description of the Oceanic mine, near. San Luis Obispo, Cal. Its operations date back to 1876, when rich sand ores were discovered. In three years 7,400 flasks of quick-silver were produced, but since then the deposit has been only sporadically worked. Until two years ago various attempts had been made by the Oceanic Quicksilver Co. to mine the more refractory "mud rock," which was encountered lying beyond the "sand rock." Mud and sand rock in varying quantities were treated together with poor results, but operations were successful with sand rock of fair percentage. About two years ago,, when all the sand rock had been exhausted, Murray Innes purchased the Oceanic mine. He found large quantities of low-grade mud rock, varying from 6 to 8 lb. of quicksilver per ton, which at the prevailing low price of quick-silver demanded very cheap mining costs, in conjunction with high but cheap metallurgical extraction. At that time the extraction of quicksilver from mud rock ranged between 40 and 50 per cent., as far as I am able to, learn.

Jan 2, 1915

By Charles Catlett

Some years ago the writer was struck by what might be called the remarkable vitality of the Virginia furnaces during the panic of 1893; and attention was called to the fact in the American Manufacturer of February 8,1895. From the second half of 1892, which was a period of maximum output, to the second half of 1893, when the full effects of the depression had been reached, the output of pig-iron had fallen off in Illinois 85; in New York, 66; in Ohio, 51; in Tennessee, 44; in Pennsylvania, 28; and in Virginia only 15 per cent. It seemed a reasonable inference that the State which had thus shown its marked ability to meet hard times could make and market its product with a larger margin of profit than any of the other States. This was true at that time, and to a certain extent the reasoning still holds good; but my mistake was in not fully realizing the marked effect of the Mesabi development, combined with reduced economies in transportation, and the consequent advantage to those furnaces which were so situated as to utilize these new commercial factors. The effect of these factors is seen in comparing the second half of 1894 with the second half of 1892. New York had dropped off 44, Alabama 23, Tennessee 21, Illinois 19, and Virginia 16 per cent., while Pennsylvania had increased 5 and Ohio 10 per cent. While there is no question of the great economy which has been made possible for certain interests which are peculiarly situated with reference to the ores of the Northwest, it is yet too early to say what furnaces not so fortunate will have to pay for their raw material. Already an increase of twenty cents per ton of ore has been announced, based upon increased cost of production.

Jan 1, 1900

By Alvin H. Lense

In the spring of 1967, after a careful study of existing geology along the Pacific Coast including Alaska, the USBM, in conjunction with the USGS, decided that the offshore area around Nome, Alaska, presented an unparalleled land-to-sea comparison site for the evaluation of marine core drilling techniques and sampling equipment. Considering the geological evidence available and the production history of the Nome Beaches (5-6 million oz. of gold recovered), it appeared likely that gold in commercial quantities could occur in the offshore area. A 180 sq mi area of Norton Sound, extending roughly 14 miles to the east and west of Nome and averaging 6 miles to the south, was tested by approximately 530 line-miles of sub-bottom profiling. A total of 4043 ft (56 holes) were drilled in unconsolidated sediments, yielding mixtures of gravel, sand, silt and clay. Of the total holes drilled, 16 went to bedrock and six were terminated short of their intended depths due to boulders which halted penetration, or rough seas which caused the ship to move as the anchors slipped over hard sea-floor surface. The rest of the holes were terminated when the penetrative capabilities of the drills were reached, or when the required amount of geological data were attained.

Jan 8, 1968

By E. C. Pechin

THE attention of the members of the Institute of Mining Engineers is asked to a description of the minerals of Southwestern Pennsylvania, as representing the minerals of an enormous area, stretching continuously, with local variations, along the western slopes, and at the base of the Alleghany Mountains, through Western Pennsylvania, West Virginia, and Kentucky, and destined to play no mean part in the future of the iron trade of the country. The particular locality is at and near Dunbar, in Fayette County, where the most careful examinations and extensive developments have been made. The deep gorges cut by the Youghiogheny and Monongahela Rivers, in their passage through the mountains and lower lands, give admirable facilities for observing the measures lying between the sandstones of No. 11 and the upper coal measures. Apart from its varied mineral and agricultural resources this section of country has great historic interest attaching to it. It was down the Monongahela that Braddock led his ill-fated army to its defeat under the walls of Fort Duquesne, and it was up the Youghiogheny River and Dunbar Creek that the shattered remnants hastily fled to gain the camp of Colonel Dunbar, the second in command, who was entrenched upon a high knob, at the head of the creek which bears his name, and which is still known and visited as Dunbar's Camp. Numerous streams, runs, and localities preserve the names of the guides and pioneers who accompanied, in early colonial times, young George Washington, who was pushing his surveys into the trackless and hostile wilderness, and many of them taking up large tracts of

Jan 1, 1875

By James Hall

A geological map of a State involves very much, and its pre sentation to the public incurs grave responsibilities. It has been for a long time my earnest desire to bring out and place before the pub lic a geological map of New York which might be creditable to the State and worthy of a place among her scientific publications. We have done much for the advancement of geological science in this State—very much, and in many directions—but unfortunately, this feature, which should have been made the basis of all our work, has been too long neglected and delayed. For twenty-five years I have been laboring and looking forward to this consummation. I have recorded the field-work, systematic and desultory, upon such maps as were available for this use; and notwithstanding their imperfec tion, I have been able to transfer this recorded information to a more perfect base, which it is hoped will be completed during the early months of the next year. In 1883 I had combined, upon a small map of the State, the in formation which we possessed at that time, and communicated the same with my annual report to the Legislature. The report mas published in the regular course, but the special appropriation made for the map was vetoed by the Governor. Not discouraged by this untoward and unexpected circumstance, I continued my work, and made every effort to render the map more complete, preparatory to its communication with the next annual report. I brought together all the information within my reach, whether published or unpublished, reviewing and revising, as far as practicable, the work done by myself and assistants in southern and southeastern New York.

Jan 1, 1893

By D. Harrington

EFFICIENT ventilation of metal mines consists in having such complete control of air currents that. there is always supplied at places where men work sufficient moving air to allow working at maximum capacity without injury to health; and in case of underground fire or of surface fire in the vicinity of mine openings, underground air currents may be quickly reversed if desired, or air may be sent into or excluded from any region and fire fumes confined to only part of the mine workings, instead of penetrating practically the entire mine. Health and safety of workers in mines as well as proper safeguarding and operating efficiency of mining properties are so intimately associated with proper ventilation of mines (both coal and metal) that they are inseparable, yet mine ventilation is only too frequently neglected, especially in metal mines. The metalliferous operator, generally not confronted with inflammable gas or explosive dust which so frequently force ventilation of coal mines, usually disregards air supply altogether except such as may be obtained from compressed air; and generally, even when attention is given to metal-mine ventilation, the air currents rarely are found where they are needed, namely, the working places, especially the working faces. After several years' study of miners' consumption, the writer is. convinced that long continued breathing of air impregnated with large quantities of any kind of finely divided dust, such as is found in a large number of the working places of our mines, will ultimately produce some respiratory disease, whether it be asthma, bronchitis, or phthisis; and the progress of these diseases is hastened. if there are also present high temperatures, high humidities, or harmful gases or if there is present (and allowed to remain to be breathed) large quantities of the finely divided dust when air temperatures are low, hence favorable to maximum performance of work with accompanied maximum breathing into the respiratory passages of the harmful material. It is generally accepted

Jan 2, 1922

By G. R. Green, R. C. McDonald

The International Nickel Co., Ontario Div. mines, faced with rising production requirements, short labor supply, and ever increasing labor costs turned to mechanized mining for a solution to its problems. The degree of mechanization of ore removal has increased from 1966 with the purchase of the first diesel-powered load-haul-dump (LHD) machine to the present, with over 53% of all underground production handled by these units. Keeping pace with mechanized ore removal, there has been a parallel development of drilling equipment to complement the mucking units. This paper deals with the applications and economic advantages of mechanized drilling at the underground mines of Inco, Ontario Div. It covers the use of various types of mechanized drills in such mining methods as cut-and-fill, induced block caving, and sublevel caving. The economics of raise boring are also discussed.

Jan 1, 1974

By R. H. Merrill, D. W. Wisecarver

The paper "Design of Surface and Near-Surface Construction in Rock" by Deere, Hendron, Jr., Patton, and Cording discloses a principal difference between civil and mining engineering as applied to openings in rock. Generally, the civil engineer considers an opening as an asset, where a mining engineer finds that most of his openings are a liability. The openings, or rock surfaces, treated in the paper by Deere and coauthors are designed for lasting stability and the foundations for dams, the diversion tunnels, abutments, and surface excavations are expected to be stable for long periods or provide continuous access and other useful purposes. Except for those openings used for the transportation of men, materials, ore, and for ventilation, the mining engineer finds that his underground openings serve no useful purpose once the mineralized rock has been removed. Usually, these openings create problems such as reduced ventilation efficiency, added requirements for scaling, sealing, and other tasks necessary to maintain or isolate the openings. The surface openings and mine plants present another liability to the mining engineer. After the product has been removed from the earth, the abandoned pits or strips, tailing ponds, dumps, and buildings sometimes become hazardous, unsightly, or occupy surface areas that could be used for other purposes. As a general rule, the various disciplines involved in rock mechanics have different objectives and uses for openings; however, the basic concepts regarding the design or control of openings in rock are similar for each discipline. The review by Deere and his coauthors contains examples of the duplications in this technology, and, in particular, the common approaches used by civil and mining engineers. Therefore, both the review paper and this report consider the problems that are common to most of

Jan 1, 1967