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By R. L. Stegman, M. R. Achter

R. L. Stegman and M. R. Achter (U.S. Naval Research Laboratory)—In a study of the surface structures developed in the fatigue of nickel at low strains as a function of temperature, we have obtained similar results.3 As our apparatus permits fatigue tests to be conducted in vacuo, there was no masking of the surface at high temperatures by oxidation so that the structures there could be observed directly. The relatively few broad slip bands observed at room temperature gave way at 300°C to a large number of uniformly distributed and narrower slip bands. At 550°C deformation began to concentrate around the grain boundaries and progressively increased up to 800°C. In addition fatigue strength was observed initially to increase with increasing temperature up to about 600°C due to the effectively increased ductility caused by the dispersal of fatigue damage. The fatigue strength then decreased at higher temperatures as grain boundary cracking dominates. Maria Ronay, W. H. Reimann, and W. A. Wood (authors' reply)— The authors are pleased to note that R. L. Stegman and M. R. Achter reach similar conclusions from their study of surface slip on nickel. However, they would emphasize that their own conclusions are based on what is shown by study of specimens that have been sectioned and that this study also shows that surface slip is not necessarily representative of what happens below the surface.

Jan 1, 1965

By LeRoy Scharon

EACH year it becomes apparent that geophysical activities in the fields of mining and engineering are increasing in the number and variety of applications. Many mining companies are including, as part of their exploration programs, geophysical surveys. The value of geophysics in highway and structural foundation investigations has been realized and is now an important part of subsurface investigations in conjunction with soil and rock borings. United States of America One of the major orebody discoveries of the year is that of the Grace mine near Morgantown in Berks County, Pa. This orebody, now under development by the Bethlehem Steel Co., was discovered by an airborne magnetometer survey carried out by the Aero Service Corp. of Philadelphia. The orebody, the geological occurrence of which is similar to those existing at Cornwall, Pa., was found at a depth of 1500 ft under a cover of Triassic sediments and is reported to have a reserve of well over 100 million tons. Shaft sinking and other construction work has started at the site. Resistivity work was carried out at proposed dam sites in New York and in connection with the search for fluorspar veins in Kentucky. Spontaneous polarization investigations were pursued in the Appalachian region at various localities from North Caro¬lina up into Virginia. This work was done in connection with the search for sulphide-bearing structures. Several indications were proven by subsequent drilling to correspond to unknown sulphide deposits, a few of these occurring in the vicinity of properties long under exploitation. Refraction seismic methods applied to bedrock depth determinations as related to water problems on the Marquette Range and the extension of the. regional gravity survey on the Menominee Range to learn the major structural features of the area have been reported by, Lloyal O. Bacon. A gravity survey has been completed in the vicinity of Tioga, Bradford County, Pa. with a gravity profile being observed from Tioga east to the Delaware basin. The Indiana Geological Survey is concerned with a state-wide gravity survey. Judson Mead, University of Indiana, reports that the bulk of the State Survey's geophysical work, however, has been "seismic refraction work in connection with drift thickness problems. The survey has made almost 1000 determinations in areas of moderately thick drift. The results of this work are of interest to both the coal mining industry and to the stone industry." In the southeastern Missouri lead belt, magnetic electrical resistivity, and electromagnetic applications for the discovery of new lead deposits have been used with success. A gravity survey of the residual-barite deposits in Washington County, Mo., was made during the summer season with preliminary computations of tonnages checking with tonnages mined. Robert M. Dryer, of the University of Kansas has had considerable success in mapping structural features in southwestern Kansas with the gravity meter and is now engaged in tracing shoestring sands in eastern Kansas by resistivity surveys. Several, foundation sites were investigated in greater St. Louis using electrical resistivity and seismic refraction methods with success. A minimum amount of drilling data was available for checking and interpreting the geophysical results (Fig. 1). It is to be noted that geophysical methods are finding a place in subsurface investigations for highway and foundation problems. Interest has been so keen in this field that the American Society for Testing Materials, at its annual meeting in June of this year, devoted one session of its symposium on surface and subsurface reconnaissance to geophysical papers involving the application of the electrical resistivity and seismic refraction methods to subsurface studies. At least three major mining companies in the United States have entered the field recently in geochemistry. The program of research and development of geochemical techniques by the U. S. Geological Survey continues. Experimental field projects were conducted over lead-silver, cobalt, copper and zinc deposits in Idaho, Oregon, California, Wisconsin and Montana. Similar experiments were carried on by M. P. Nackowski in the Illinois-Kentucky fluorspar district and in the Tri-State Zinc district by R. Maurice Tripp with favorable results. Geophysical activities of the U. S. Geological Survey for 1951 were extensive and varied. About 21,000 miles of airborne magnetic and 10,000 miles of airborne radioactivity traverse were flown in 1951 by the U. S. Geological Survey. A total of 35,000 miles of aeromagnetic traverse were compiled, 57 aeromagnetic maps were published and 14 preliminary maps were placed on open file. Airborne surveys were made in Aroostook County, in the Katahdin and Dead River areas in Maine; in northwest Washington; over the Mother Lode district in California; in northeastern and northwestern Minnesota; and in the New York-New Jersey highlands. Of special interest were the surveys in Washington, where highly magnetic Eocene lavas gave information on structures in the overlying Miocene sedimentary rocks and in northeastern Minnesota over the Duluth gabbro. The latter survey was made following the discovery of nickel-copper mineralization in the gabbro near its contact with the Virginia slate. The principal ground geophysical surveys for metalliferous deposits and related purposes were made in the Colorado Plateau region, where electrical surveys assisted in prospecting; in Aroostook County, Maine, where ground magnetic surveys, following aeromagnetic surveys, have permitted tracing

Jan 1, 1952

THE committee in charge of arrangements for the meeting of the Institute in September has com-pleted its program. The headquarters of the meeting will be at the Palace Hotel, San Francisco, and the registration committee will be at the hotel all day on Sunday, Sept. 24, and from 8 a.m. until noon on Monday. On Sunday afternoon, automobiles will be available for sightseeing trips around the city. Monday will be devoted to technical sessions. In the morning, there will be sessions on Mining and on Iron and Steel; in the afternoon, sessions on Mining and Milling. At these sessions, in addition to the papers mentioned in the tentative list printed in August, there will be presented three papers on the geology, mining and milling of the Comstock lode; one on the Aztec mine, Baldy, N. M.; one on the Colombian oil fields; and one on charcoal precipitation of cyanide solutions. The luncheon on that day will be Dutch Treat, for men only, at the Engineers Club. On Monday evening, there will be an informal buffet supper at the home of F. W. Bradley. On Tuesday morning, a party of 50 men will leave for Hetch Hetchy. During the four days of the trip, the party will see the Priest tunnel and earth dam under construction by steam-shovel and hydraulic-fill methods, the Big Creek shaft and tunnel, early intake power plant and tunnels and the Hetch Hetchy dam under construction. For those who remain in San Francisco, Tuesday will be "San Francisco Day." There will be motor trips to the Presidio, Cliff House, Golden Gate Park, and other points of interest, and shopping trips to Chinatown. On Wednesday, "University of California Day," the party will be guided through the university by members of the Mining Association, the affiliated stu-dent society, and will see the Greak Theatre and not-able buildings. Thursday will be "Leland Standford, Jr. University Day." Automobiles will leave the Palace Hotel at 10 a.m., and will return from the university at 4.30 p.m. Friday has been reserved for trips to the Selby Smelter, to Mt. Tamalpais, or to other points of interest. Arrangements will be made to visit the mines or gold dredges in California, if members desire to do so, but such trips must of necessity be considered special trips and arrangements will have to be made to suit the convenience of the individual or party. The Golf Committee will make arrangements for those who wish to play golf.

Jan 9, 1922

The movement for Federal endowment of engineering and industrial research was revived early in the present Congress by the introduction of two bills into the Senate. The first bill, introduced by Senator Smith of Georgia, provides for the establishment of an engineering experiment station in each state under the direction of and in connection with some university, engineering school, or land-grant college. The state legislature of each state is authorized to designate the institution best equipped to conduct the work but wherever the land-grant college has facilities approximately equal to those of the other institutions of the state, it shall be designated. All designations of institutions are made subject to the approval of the Secretary of Commerce. The Secretary of Commerce is authorized to secure practical uniformity of methods, and efficiency and economical expenditure of funds by indicating such lines of work as shall seem to him important from a military; naval, industrial or national standpoint, but the responsibility for the initiation and conduct of research shall rest with the individual engineering experiment stations. Uniform standards of research are further provided for by making each experiment station a depository of the Department of Commerce and the Bureau of Standards, and the work of each station shall conform to the standards established by the U. S. Government through said bureau, which may whenever practicable utilize the facilities of the station for the prosecution of research.

Jan 8, 1919

The sum of $100 was appropriated to the War Minerals Committee for expenses of letter paper, postage, etc. The report of the Treasurer was accepted and ordered filed. Upon the recommendation of the Committee on Membership, sixty-eight Members, two Associate Members, and ten Junior Members were elected. The Secretary presented a letter from the office of the Chief of Ordnance, U. S. A., offering him a commission in the Ordnance Officers' Reserve Corps, and asking him to submit to the governing body of the Institute a request for release from his contract with the Institute, in order that he may accept the commission in question. The following minute was then passed. "The Executive Committee is of the opinion that the Secretary of the American Institute of Mining Engineers can be of more use to the Nation in his present situation, in view of the fact that there is no possible substitute for him in this position, than he could be if he left to accept a commission as an officer in the Ordnance Department, and this Executive Committee requests that an executive officer of the Institute go to Washington and confer with the Chief of Ordnance, requesting a withdrawal of the offer to the Secretary of the Institute and presenting the names of substitutes therefor." The payment of 'a special clerk for the Committee on Increase of Membership at the rate of $100 a month was ordered continued for a further period of six months.

Jan 10, 1917

Meeting of Dec. 19, 1913.-The President reported the appointment of the Committee on Junior Members and Affiliated Student Societies, and the Committee on Coal and Coke, which .appointments were approved. The President was authorized to appoint the members of a Committee on Safety and Sanitation. The President appointed the Finance Committee of the Institute as a Committee to audit the accounts of the Treasurer (By-Law V). On the recommendation of the Executive Committee, Charles F. Rand was appointed a representative of this Institute on the Board of Trustees of the United Engineering Society for a term of three years (By-Law XIV of the Institute, By-Law XI of the U.E.S.). The Executive Committee reported that it had passed the following resolutions: That the next summer meeting of the Institute be held at Salt. Lake City during Aug. 10 to 14, 1914, inclusive; That an exchange of .the Bulletin and Transactions be made with the Canadian Bureau of Mines; That a sum of $50 be contributed for the year 1914 to the Commission publishing the Annual Tables of Physical and Chemical Constants; That the Secretary be given power to reduce at his discretion the number of exchanges between the Bulletin and other publications which are not retained as a permanent part of the Library; That the contract for binding Volume XLV of the Transactions be awarded to the Butler, Ward Co., in accordance with their bid of Nov. 21, 1913;

Jan 1, 1914

By W. T. Isbell

Although the pressure to meet the heavy demand for lead still took precedence over new metallurgical developments in the field of roasting, smelting, and refining of lead in 1948 there nevertheless has been considerable activity in the experimental development of new processes and improvements as well as plans for the modernization of many plants both here and abroad. Increasing labor and material costs have stimulated the trend to greater mechanization, revamping of flow sheets, and construction of larger units wherever possible. Although there have been many serious labor stoppages in the United States, Mexico, and Europe, labor supply has improved in most plants even if it has fallen off in efficiency.

Jan 1, 1949

Last October a committee was appointed by The War Service Association of Manufacturers of Solder and Bearing Metals, Inc. to consider the report of the U. S. Bureau of Standards to the Conservation Division of the War Industries Board, a letter of the War Industries Board, and the discussions of this letter as reported at the meetings of association and to summarize the information thus obtained. The report of this committee has just been printed. The committee agrees with the Bureau of Standards that 99 per cent. tin can be used. It also finds that a very small amount of lead might increase the tendency of the bearing to crack and that lead has a hardening effect on babbitts up to a possible limit of 10 per cent. of lead. Still in the so-called genuine babbitts, in the presence of lead a certain proportion of low melting point eutectic is introduced which admits of the bearing being poured into thinner sections and is decidedly advantageous in the die-casting process in producing a much smoother casting. But the committee recommends that the Bureau of Standards thoroughly investigate this point. Lead-base babbitts, to give satisfactory service, must be carefully made of the proper raw materials. The bronze hearing that has been thoroughly tinned and containing the thinnest possible babbitt lining is now becoming recognized as the ideal bearing. The compositions, recommended by the committee are as follows:

Jan 2, 1919

By AIME

PROBABLY no greater world traveler has ever been Chairman of one of the Institute's Divisions than Henry Frederick Hebley. To begin with, he was born almost as far away as possible-in Christchurch, New Zealand, Dec. 15, 1893. There he grew up, studying mechanical engineering at the local Seddon Memorial Technical College. Then he went over to Sydney, Australia, for a bit of work before sailing for the U.S.A. in 1915. After a few months as draftsman in a San Francisco office he moved over to Clarkdale, Ariz., in the engineering department of the United Verde copper smelter, which had just gone into operation. But the war was on, and Henry thought he belonged in France with the Canadian Engineers, the United States still remaining aloof from the conflict, and that was the last the copper industry saw of him. After almost two years in France he was wounded, convalesced in England and Canada, and then went back to his native New Zealand to design concrete factory buildings. But soon the United States called again, and this time he landed in Salt Lake City with the Oregon Short Line R.R. Co. Then to Chicago in 1920. where he really got into the coal industry for good, working for the Allen K Garcia Co. on the design and operation of coal mines, beneficiation plants, and combustion equipment; and joining the Institute.

Jan 1, 1946

The week of Sept. 22, will be a week of convocation of societies in Chicago with the exposition of Chemical industries. The American. Institute of Mining and Metallurgical Engineers will occupy the stage for most of the week, American Ceramic Society meets on Wednesday, the American Electrochemical Society on Thursday, Friday, and Saturday, and the Technical Association of Pulp and Paper Industry from Wednesday to Saturday. There will also be a symposium upon Safety in the Plant and Mine under the chairmanship of M. L. Leopold, Safety Engineer of the U. S. Bureau of Mines, and in the evening after this sleeting-which will occupy an entire afternoon-there will be shown a series of motion pictures of safety work in plant, field-and mine. The motion picture program will consist almost entirely of films now being made. Even in motion pictures, the Exposition is outstanding as the place of introduction to the public of the newest and most recent developments. Each improvement of the projectoscope in motion-picture projection has been reserved for first public demonstration at the Exposition. Mention cannot be made of the new exhibits that are engaged for the Exposition, other than to say that the electric furnace will be in operation. These will give, probably for the first time, men of science an opportunity to see and compare the various designs and judge them for the various work to which they are applicable.

Jan 8, 1919

Raphael PUmpelly, who became a member of the Institute in 1871, the year of its organization, and retained his membership for a long period, died at his home in Newport, R. I., Aug. 10, 1923. He is survived by a son, Raphael, Jr., and by two daughters, one of whom is the wife of Prof. Henry L. Smyth, of Harvard. Doctor Pumpelly was born in Oswego, N. Y., in 1835. He studied sciences and mining engineering in Paris and at Freiberg, later taking his Doctor's degree at Princeton. He was Professor of Mining at Harvard from 1866 to 1873. Doctor Pumpelly made geological explorations in many lands. In 1861-63, he conducted a scientific exploration for the Japanese government, and for two years thereafter carried on researches in central, western, and northern China and Mongolia. In 1864-65, he undertook a voyage of exploration across the Gobi desert, returning to Europe through Siberia. He was State Geologist of Michigan from 1869 to 1871; Director of the Missouri Geological Survey from 1871 to 1873; and Chief of Division, U. S. Geological Survey, directing the mineral industries division of the tenth census. He organized and directed the Northern Transcontinental Survey, 1881-84; directed the explorations inaugurating the iron ore industry of most of the ranges of Michigan and Western Ontario, 1897-1901; initiated and directed a physical-geographical and archeo-logical exploration of Central Asia under the auspices of the Carnegie Institution of Washington, 19034.2.

Jan 1, 1924

W. Morton Webb, Germiston, Transvaal, South Africa (communication to the Secretary*):—The experience of Mr. Boeh-mer in the Leadville district and his reputation as an engineer assure the interest of anything he may write on the ore-bodies of that district; and all engineers who have operated in Leadville will agree that the theory of the origin of the Leadville deposits, as given by Mr. Emmons in his famous monograph, does not adequately explain the genesis of all the deposits. The solutiou of the problem does not, however, appear to be quite so simple as Mr. Boehmer would make it; and the advance pamphlet issued by the U. S. Geological Survey, pending the completion of the main report, shows that there is still much ground for controversy. No doubt the later eruptive0 had a greater influence on the deposition of the ore-bodies than was thought at the time of the first investigation by the Survey; but it has always appeared to me that the influence exerted by these dikes mas more in the nature of a physical than a chemical one. The weight of evidence in recent years is mostly in the direction of ascension rather than lateral secretion; and one of the strongest evidences is the fact that most of the ore-bodies lie under one of the comparatively impervious layers which help to make up the structure of these hills.

Jan 1, 1911

By George W. Riter

OUR mineral-land laws need revising so as to provide definite title at the outset to the mineral deposits within any definite piece of land. The laws as they now stand, especially those applicable to lodes, breed uncertainty as to rights of possession prior to patent; and to my mind this is the worst feature of all, worse even than the apex bugbear. It is now almost impossible for anybody to tell-with certainty what mineral rights exist within any area that is not covered by patent, or whether any valid rights exist at all. Our system is unique in permitting individuals to appropriate and exploit mineral lands of the public domain without notice of any kind to the Federal government, and to relinquish them without any ceremony at all. The result is a clouded record that cannot be cleared up until each claimant is put to some sort of final proof. In order to accomplish this, new Federal legislation will be required. The requirements for a mineral survey and the proceedings for patent have always been cumbersome and expensive; and perhaps out of regard for the poor claim owner, who can ill afford the outlay for that sort of thing, the law does not require him to go. through it unless he chooses to do so. Consequently, every active mining district has become encumbered with tangled groups of doubtful or conflicting locations, whose rights and boundaries, when any valuable ore is found, must usually be determined by lawsuits that are as expensive and as distressing as the stakes are high. So deeply has litigation entered into our mining system that a claim whose rights have never been disputed would probably be set down offhand, by $miner of the old school, as of no value. Think of the litigation over rights of possession on the Com-stock lode—12 leading companies involved 'in an aggregate of 245 suits within a period of less than eight years! Ambiguous local records; the chance of erroneously placed or obliterated monuments; doubt as to the sufficient performance of the statutory annual labor; uncertainty as to prior conflicting or overlapping locations; anxiety as to the changing attitude of the Department of the Interior and the Forest Service—such considerations as these make an unpatented mining claim an unclean thing in the eyes of possible investors. Is it any wonder that they keep themselvesand their money at a safe distance,

Jan 1, 1915

By AIME AIME

MONDAY, Feb. 21, evokes memories of the Silver Corridor at the Waldorf to be recalled and reflected upon for time to come when thoughts drift to the Annual Meeting of 1944. Crowded though it was, on occasion there lurked in the mind's eye a vision of what might have been had the 2886 persons who put in an appearance at one time or another milled around in the lobby of 29 West 39th Street. Some confusion resulted from difficulty in locating meeting rooms, but for the most part everyone found what he wanted. The usual bulletin board of members registered was missing this year and rumor has it that tile Waldorf didn't approve. Registration broke all previous records with many a busy engineer realizing that the program had something to offer that would be of use in his particular job. It might be noted here that "Arpad" co-operated nicely, previewing spring days on Monday, Wednesday, and Thursday; Tuesday was a bit damp.

Jan 1, 1944

By H. W. Hindry

This paper presents the ingredients com-~osing a type of oil-base mud that has been successfully used in drilling oil horizons in California, the effect of ingredient concentrations on physical properties, methods of handling at the well and possible advantages of a waterless drilling fluid with excellent plastering properties. Introduction An oil-base mud is a rotary drilling fluid in which oil has been substituted for water as the principal liquid ingredient. In recent years such a mud has been developed and used successfully for drilling the oil horizons of wells in various Calilornia fields. There are several types of oil-base mud, but only the type that is currently used to any appreciable extent will be considered at this time. The oil-base drilling-mud compositions used by Shell Oil Company, Incorporated have been covered by several patent applications on which patents are expected to issue at an early date. The purpose of this paper is to present data on the fundamental design of the mud; the ingredients used and their specifications; the effect of ingredient concentration on physical properties; the selection of the proper mud; the facilities needed for handling the mud; and a general discussion on drilling with oil-base mud. In view of the early stage of development of oil-base mud, the great number of vari- ables, and the almost unlimited possible combinations of these. variables, which in turn require extensive laboratory study, there are certain irregularities and omis. sions in the data presented here. However, it is believed that sufficient data are at hand to permit a fairly complete analysis of the characteristics of oil-base muds. In view of the excellent plastering properties of oil-base mud when properly proportioned, its use should: (I) minimize the possibility of impairing the natural flow potentialities of the producing horizon such as that resulting from infiltration of water from water-base muds; (2) permit smaller clearances for setting liners, since the mud sheath has no appreciable thickness; (3) eliminate the possibility of clogging the perforations of the liner with thick mud sheath; (4) facilitate the removal of the mud sheath from the walls of the hole, for its mud sheath has no appreciable strength; (5) assist in drilling through formations, such as "heaving shale," where water wetting appears to be a source of difficulty. (6) permit cores to be obtained without contamination from drilling water. Fundamental Design of an Oil-base Mud In the design of any rotary drilling mud it is necessary to select materials that will fulfill the following requirements: (I) act as the liquid medium and regulate the viscosity; (2) impart initial and final plastering properties; (3) give gel strength and structure in order to prevent settling; (4) serve as a weighting material. The

Jan 1, 1941

By H. W. Hindry

This paper presents the ingredients com-~osing a type of oil-base mud that has been successfully used in drilling oil horizons in California, the effect of ingredient concentrations on physical properties, methods of handling at the well and possible advantages of a waterless drilling fluid with excellent plastering properties. Introduction An oil-base mud is a rotary drilling fluid in which oil has been substituted for water as the principal liquid ingredient. In recent years such a mud has been developed and used successfully for drilling the oil horizons of wells in various Calilornia fields. There are several types of oil-base mud, but only the type that is currently used to any appreciable extent will be considered at this time. The oil-base drilling-mud compositions used by Shell Oil Company, Incorporated have been covered by several patent applications on which patents are expected to issue at an early date. The purpose of this paper is to present data on the fundamental design of the mud; the ingredients used and their specifications; the effect of ingredient concentration on physical properties; the selection of the proper mud; the facilities needed for handling the mud; and a general discussion on drilling with oil-base mud. In view of the early stage of development of oil-base mud, the great number of vari- ables, and the almost unlimited possible combinations of these. variables, which in turn require extensive laboratory study, there are certain irregularities and omis. sions in the data presented here. However, it is believed that sufficient data are at hand to permit a fairly complete analysis of the characteristics of oil-base muds. In view of the excellent plastering properties of oil-base mud when properly proportioned, its use should: (I) minimize the possibility of impairing the natural flow potentialities of the producing horizon such as that resulting from infiltration of water from water-base muds; (2) permit smaller clearances for setting liners, since the mud sheath has no appreciable thickness; (3) eliminate the possibility of clogging the perforations of the liner with thick mud sheath; (4) facilitate the removal of the mud sheath from the walls of the hole, for its mud sheath has no appreciable strength; (5) assist in drilling through formations, such as "heaving shale," where water wetting appears to be a source of difficulty. (6) permit cores to be obtained without contamination from drilling water. Fundamental Design of an Oil-base Mud In the design of any rotary drilling mud it is necessary to select materials that will fulfill the following requirements: (I) act as the liquid medium and regulate the viscosity; (2) impart initial and final plastering properties; (3) give gel strength and structure in order to prevent settling; (4) serve as a weighting material. The

Jan 1, 1941

By John S. Brown

AT opposite ends of a mineralized belt of northeast-southwest trend, and ten miles apart, are the Edwards and Balmat zinc minas, in St. Lawrence County, New York, west of the Adirondacks. The principal town is Gouverneur, fifteen miles west of Edwards, eight miles northwest of Balmat, and the area is often referred to as the Gouverneur district. (See Fig. 1.) At various times the district has been noted for its hematite mines, pyrite mines, and marble quarries, all now abandoned. At present, in addition to zinc, it is the country's largest source of industrial talc. A short distance to the east important magnetite mines are operating. Geologically the district lies at the southern margin of the Canadian shield, where this great expanse of Pre-Cambrian igneous and metamorphic rocks merges into the foothills of the Adirondacks. The rock formations in approximate order of areal extent and importance are as follows:

Jan 1, 1947

By John R. Lotz

DEVELOPMENTS in Iran currently arousing interest in a considerable portion of the world, particularly on the part. of that country's immediate neighbor on the North and in our own country, an inseparably related to and largely dependent upon the government's attempts to strengthen its economy and improve the standard of living of its people. These efforts are encompassed by provisions of the Seven-Year Development Plan recently enacted and not, in the process of implementation. It is a fine example of what one financially sound but extremely backward and poorly equipped country has undertaken to do on its own account and with its own resources. This Seven-Year Plnil was formally authoriztld by an act of the Iranian Parliament in February 1948. Its stated objects are to carry out such plans for the development of the country and its economy as ail1 raise the standard of livinc: and standard of education of the people, and re- duce the cost of living. A seven-yrar program for carrying out the work within the limits of appropriations was assigned under the law. The total amount to be expended during the seven- year period was fixed at the equivalent of $670 millioil at current rates of exchange.

Jan 1, 1950

By WALTER S.

(New York Meeting, February, 1912,) THE earliest example of attempting to form finely-divided materials into larger masses for better adaptation to commercial use was probably the briquetting of peat and lignite-waste at Paris by the use of a clay binder. It was from this attempt that our word briquette has arisen (Fr. la brique), the formed masses being shaped similar to ordinary bricks. This term does not, however, lend itself to the many shapes of such formed material as are now being produced, as few of them aside from some of the European brown-coal products bear any resemblance to the shape of that well-known article. The term "agglomeration " has therefore been chosen as more accurately descriptive of the products now being manufactured, this term including the molding as well as the sintering. With the increasing prices of fuel and ores and the greater demand for economy in the operation of industrial plants, more ,attention has been paid in recent years to the utilization of waste products and low-grade ores and fuels. Much of the waste has been occasioned by the inability to utilize finely ,divided ores and fuels in the furnaces because they could not be kept there, or else because they clogged up the furnace-shaft so that gases could not be forced through under ordinary conditions of operation. As a result, all such fines were thrown on the dump. Again, with the exhaustion of the richer deposits of ores, concentration of lower-grade ores becomes a necessity, and most concentrates are produced in a finely-divided condition. Aside from these considerations, there is also the economy in the cost of operating the plant; a furnace running on agglomerated material will have a much greater output than one working on fines. In one instance the charge of an iron blast-furnace was changed from fine concentrates to briquettes and the output was increased four-fold; better results could have been obtained had facilities been at hand for taking care of the increased output.

May 1, 1912

By Edmund M. Warner

Any city dweller who has walked alone along a remote mine passageway has to be impressed by the eerie silence-the total absence of noise except for one's own breathing and scuffing of boots on the bottom. An underpound mine can have tremendous contrasts, from complete silence to the ear piercing clatter of percussion drills working in the mine roof. Noise in underground mining machines is both useful and detrimental. Without characteristic noises that are recognizable to miners, operators would have a more difficult job operating their machines. Noise serves as a warning of approaching machinery, and changes in noise give indication that breakdowns may occur. But excessive noise is a health hazard. In recognition of this fact, our congress included noise exposure as a part of the "Coal Mine Health and Safety Act of 1969." As [Fig. 1] indicates, allowable noise exposure is established by specifying a time duration permitted at different noise levels. This is the well known "Walsh-Healey" criteria which govern noise exposure in many industries. In most industries noise exposure is not a constant value. Noise emitted from coal mining machinery varies widely, and therefore interpretation of compliance is not a simple matter. Time, environment, instrumentation and machine productivity, as well as the designed machine characteristics affect the results. It is the purpose of this paper to present the underground coal face machinery noise problem from a manufacturer's point of view. Manufacturers are very much aware of their responsibility to alleviate the noise problem. Not infrequently, orders are received from coal operators that a given new machine must comply with "The Coal Mine Health & Safety Act" noise regulations. Such a request is indicative of the misunderstanding which exists with machine users, while indicating their desire to comply with the law. Obviously, if all machinery could be designed and used at some arbitrary low noise level, it would be possible to simplify the regulations. However, there still remains the pervasive problem of existing machines. Extensive investigation to create practical retrofit kits for existing machines, to substantially reduce noise have been only marginally successful. Certain machine mechanisms are inherent noise makers. The only really good solution is to substitute a quieter mechanism. Such overall new designs have been undertaken, and several examples are mentioned later in this paper. Before describing machine noise problems, it is necessary to define noise values. Noise levels are measured in decibels. The designation "DBA" is decibels measured on the "A" scale, or one in which the frequency sensitivity of the instrumentation is about the same as the human ear. The numbers are often misinterpreted because it is a logarithmic, rather than an arithmetic scale. In comprehending the numbers, it should be remembered that any increase of 3 dB doubles the sound power. In practical terms this means that two noises of equal power at the same distance away increases a dB reading by three. Consider [Fig. 2] showing a simplified case of a worker on a machine subject to

Jan 1, 1980