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By A. G. Kim

Coal formation begins in peat swamps or bogs, in which microorganisms alter plant material and initiate the formation of carbonaceous sediments. Methane, which constitutes about 98 percent of the hydrocarbon gas in coalbeds, is known to be a product of anaerobic microbial metabolism. To determine if other hydrocarbon gases could be produced in an environment similar to that of a swamp, samples of wood cellulose and lignin were inoculated with soil micro-organisms and incubated anaerobically. The resultant gases included methane, ethylene, propane, propylene, butanes, pentanes, and carbon dioxide. Hydrogen was also produced from the wood samples during the first month of incubation. Over 90 percent of the produced gas was methane; C02 was the other predominant component. Concentrations of all other hydrocarbon gases ranged from l to 20 parts per million, approximately 0.1 percent of the total hydrocarbons, which was less than the concentration in coalbeds. Therefore, although higher hydrocarbons could be produced in a swamp environment, subsequent mechanisms, either concentration by adsorption or formation during geochemical reactions, must affect the final concentration of higher hydrocarbons in coalbeds.

Jan 1, 1972

By Victor E. Kral

"INTRODUCTION The Phelps Stokes iron deposit, also known as the Iron Mountain claim, was examined by G. L. Thompson, an engineer of the Bureau of Mines, in January 1943. As a result, the Division of Geophysical Exploration 3/ made a magnetorater survey of the deposit in June 1944, and the Mining Branch included it in a,project to explore Nevada iron deposits.The Bureau explored the deposit from September to November 1944 by means of 643 feet of diamond drilling and 445 feet of trenching holes were drilled, all of which penetrated more than: 100 feet of good-grade magnetite, although nearly all the ore except that found in the first hole contained an excessive amount of sulfur. Trenching was done largely over the first two holes, PS-1 and PS-2, and exposed the full width of the ore.The deposit is in Nye County, Nevada, 7.7 miles east of Gabbs. The property was discovered in 1902 was patented in 1907. There has been no production from the property and except for the Bureau's investigation,,has not been, explored since it was patented.Magnetite is the principal ore mineral; it occurs as fine-grained particles associated with sulfides and cemented with talc and calcite."

Feb 1, 1947

By Kevin A. Rider, Bernard J. Martin

Reaching movements are planned and subsequently executed [1] using visual and somatosensory feedbacks [2], where absence of visual feedback is known to increase endpoint variability [3]. Visual occlusion decreases the ability to make rapid online compensatory movements, which results in initial radial deviations that are highly correlated with radial dispersion at the target. Perturbations of rapid, visually-guided reaches are compensated on-line and result in endpoint dispersions poorly correlated with initial deviations, emphasizing the strong effect of visual feedback in temporally-constrained reaching tasks. In control conditions (no vibration), these uncompensated, rapid reaches serve as estimates of the individual’s intended trajectory. When ride motion is present, trajectories of rapid, visually-occluded reaches provide a measure of the natural biodynamic response of the cantilevered spine-arm-hand linkage. These intended movement trajectories and the biodynamic response (vibration feedthrough) are used to predict the effect of ride motion on the performance of rapid reaching tasks. Goals of this study are to investigate the influences of vehicle motion on human reaching and pointing, and to reveal movement strategies used in visually-occluded reaching tasks. Methods A six degree of freedom human-rated Ride Motion Simulator (RMS) was used to generate a dynamic vehicle environment. Participants performed discrete, rapid pointing tasks to targets presented on three touchpanel displays under stationary and random whole-body vibration. Reach instructions included successfully reaching identical circular targets (Ø = 0.25”) with the right index fingertip as fast as possible. Targets were presented on resistive-touch displays mounted approximately 60 cm from the participant’s nasion. The touchpanel displays were located in the forward and lateral directions at eye level, and forward at 45° of elevation. These displays measured the spatial error of the reach destination. A ten-camera VICON motion capture system recorded the upper body kinematics of the participant. Reflective markers were placed on the participant’s torso, head, and arms. Initial kinematics of the fingertip (i.e. time and magnitude peak tangential velocity) and tangential velocity at target were used to estimate the planned endpoint of the reach. Results and Discussion Ride motion resulted in increased endpoint variability compared to reaches performed in the stationary condition. Reaches to the elevated touchpanel consistently resulted in the largest variability across all motion conditions, suggesting that a vehicle occupant would not be capable of accurately activating a control in that location. Principal axes of endpoint ellipses were along and perpendicular to the direction of fingertip movements. Example graphs of endpoint variability with ellipses containing 95% of the data points are shown in Figure 1. These ellipses

Jan 6, 2006

By H. A. Doerner

Tellurium is a silver white solid with metallic luster, the e17atal.line torm being ver., brittle aud e.g,s!ly powdered. It has a specific gravity of 6,27, melta at 45a0c. and boils at red het, giving off a. golden 1ellow vapor when air 11 excludei. When heated in air, telluri'UiD burns with a bl\te name tinged with green, and evolves wh1 te vapors ot tellurium dioxide. An amorphous form of tel­lurium, obtained by red.uction and precipi ta.tion from so).ution, haa II specific gr1.vity ot 6,015, and when heated ia cho.nged to the cry:.,talline variety. Telluri,a 11 insoluble in water, c&rbon diaiJ.phido, or h;rd.rochl oric acids, but it 11 41a-1olved bJ nitric or concen t1·ated. sulphi.U·ic acid. It 1..oea not tamiah in moiet ah•• 11 ree11tant to alkaline solutions, e,;:ctpt concentrated KOB, but it 11 cliaaolvecl by tuaed. &lkl 1••. I ts 11.to!!lic weight h..'l.a been the "J.Ubject ot mch controverq, bu\ t.he value 137 .5 :.a bl!ten generally accepted, Tho chflmietr:, of tellurium ia eim1lar to that ot IUlphur. It tonne throo xid.ee TeO, To02, and Te0 , al10 tellur14ea, t•llurite,, and. tellur1.t11, A number of halide compoWld.1, a 3iulph1de, and. a .ulpbat.e are known.

Aug 1, 1922

By W. E. Young

Iron ore occurs in abundance in Iron and Washington Counties in southwestern Utah. Outcrops are encountered over a wide area extending from Paragonah on the northeast to Bull Valley on the southwest. Outcrops also occur on the Wah Wah Range and on Blue Mountain on the north edge of Iron County. The greater concentration of known deposits occurs in and around the margins of three mountainous uplifts - Iron Mountain, Granite Mountain, and Three Peaks - comprising a belt about 3 miles wide and 23 miles long (fig. 1). This area was partly explored by the Bureau of Mines in cooperation with the Geophysical Division of the Bureau of Mines and the Geological Survey under the strategic minerals program during 1942 to 1945. The exploratory work comprised geological and topographic mapping, geophysical prospecting with a magnetometer, diamond drilling, trenching and test pitting, sampling ore exposures and old workings, and constructing and repairing roads. The Pinto-Iron Springs district is the most important known source of iron ore for the steel plants of the West. The future economic status of the Intermountain and Pacific coast regions will depend largely upon the successful development and exploitation of substantial iron-ore bodies in this district.

May 1, 1947

By Thomas V. Falkie, R. Venkataramani

The method of analysis was to test a large model containing potentially significant variables and on the basis of the results obtained, to reduce the model to one containing only the essential significant variables. This stepwise procedure of "scanning" a large proposed model and subsequently condensing the model consisted of two cycles of the same series of computational procedures. Data Preparation A majority of the variables measured were continuous over a specific range of values; for example, the variable "Width Ratio" varied in practice from 0.25 to 1.00. However, "dummy" values were assigned to certain operational variables in order that these varia¬bles would have numerical expression. The following variables were described in this manner. Variable "Dummy" Value x3: Development/Pillaring 0, if pillar extraction was being done 1, if development mining was being done x4: Boxcut/Open Cut 0, if a box cut was being made 1, if an open cut was being made The variables under consideration are represented symbolically as follows: Y: Loading rate (tons per minuts): TONS/MIN x1: Ratio, width of cut/width of cutter: WDRATIO x2: Ratio, height of cut/diameter of cutter: HTRATIO x3: Development or pillaring: D/P

Jan 1, 1972

By D. B. Dow

In collecting and dissctinating inforr:.at'ion on ir.:,provec.. practices us0i in the pr eduction cf petroleur:1 and in the r;:;.:.1.nuf __ cture of gasoline, the Bureau of Mines ha.s aidei in creatin5 an interest i-n efficient 11:ethods in all phasas of tr.e oil ani gi:i.s iniustry. In the refinin£ ir...mstry ther.:: is a growing tend.ency for incre.:l.sea. effi. ,:;iency, ana inforr;.Eition rela:tin!s to ic:;p·roved practices should be of value not only to the larger and. core efficient plants, but particularly to srr.a.11 refineries unable to carry out a lar6e experLnental pro!§.rarn. The refi?eries of the United States required 4.3,915,029 barrels cf crude oil J.uring the year 1920*, inclu.::.in1:, 611136,210 barrels of Mexican cru::...e. This yielded. 4,8821546,599 gallons of E>asoline, a.n avara.t;,e ciaily pro;.iuct1on of 13,340,291 e,allons·, Besides the easoline obtainel fro;., cruie· oil by-fr:;.cticna.1 distillation and. from heavy oils by crackini:,, this a,-r;ount incluC1.es 3,152,924 bar­rels of natural-ga.$· gasoline blended. With asoline fro,., th otha two sourcs.

Apr 1, 1922

The coal deposits in Alaska occur in several major coal fields or basins. The deposits underlie about a quarter of the state, an area larger than Montana. Approximately 60 percent of the coal is bituminous and 40 percent is subbituminous. Less than one percent is lignite or anthracite. Although known coal reserves are estimated at only 6.1 billion tons (about 1.25 percent of U.S. reserves), estimates place the hypothetical reserves at 5.5 trillion tons and the identified reserves at 170 billion tons. The differences are due to limited exploration programs within the state. Conditions affecting mining and reclamation are unique to Alaska because of its extreme northern latitude. For example, permafrost occurs in about 75 percent of the state; tundra vegetation occupies vast treeless regions; and the climate is characterized by extremely cold winter weather and a short summer season. In addition, hydrologic conditions are considerably different from those in other states; major streams fed by silt-laden glacial melt water contain greater concentrations of natural sediment than the effluent discharge limits permitted by federal regulations. Also, some coal field locations are subject to potentially high seismic risk. These factors make coal mining and reclamation in Alaska more difficult than in other states. Alaska's program to regulate surface coal mining was approved May 2,1983. The Abandoned Mine Lands program was approved December 23,1983.

Jan 1, 1992

By W. J. Pena, C. W. Owings

"Generally, the hazard of cool-dust explosions in tipples and cleaning plants is not given the consideration that is given it underground. This lack of consideration is probably due to failure to appreciate the potential hazard. An explosion in a tipple or cleaning plant is basically little or no different from an explosion underground. If bituminous-coal dust is raised into a cloud in the air and comes in contact with arcs from motor brushes, switches, or open flame, the dust is very likely to ignite, and flame will very probably propagate or extend through it if the quantity of dust per unit of air space is sufficient. The open space in a tipple or cleaning plant may reduce the violence of the explosion, but it is not likely to prevent ignition or propagation of flame.The movement of coal through a tipple or cleaning plant naturally puts into suspension a large amount of dust, which finally settles on exposed surfaces. Any disturbance that will put this dust into suspension in a sense enough cloud can result in the dust being ignited by an arc or open flame if one should be present. An explosion of bituminous-coal dust in a tipple or cleaning plant generally can be prevented either by keeping it thoroughly clean or by removing all sources of ignition, or both.The tests at the U.S. Bureau of Mines Experimental mine have shown that the explosibility of coal dust is proportional (other things being equal) to the ratio of the volatile matter to the volatile matter plus the fixed carbon, indicated thus:The volatile ratio for the Pittsburgh coal bed is calculated as follows:Therefore, as the volatile matter decreases the liklihood of ignition decreases; however, coal-dust explosibility depends on other factors also, such as fineness, dryness, and cloud density; and under some conditions other factors also intervene.Proof of the explosibility of coal dust in the absence of explosive gas has been shown in numerous cases in mines and mine plants and also by a series of tests. In these tests a dense cloud of dust is blown onto an open flame or an electric arc, almost invariably with resultant exploding of the dust. The Safety Division of the United States Bureau of Mines has made a number of demonstrations of the explosibility of Pittsburgh coal-bed dust, using a small gallery or box in which a cloud of coal dust is blown onto a lighted match; larger-scale tests have been made with an electric arc as the igniting agent. Bituminous-coal dust is readily ignited with a medium arc, but with low-volatile coals a larger arc is required. For test purposes, a 100-ampere arc has been used. Ignition has occurred readily under these conditions with Pocahontas No. 5 coal dust with ratios of volatile to total combustible of 0.232 to 0.253, and with Pocahontas No. 3 coal dust with a combustible ratio of 0.242. Lower Kittanning coal dust, with a ratio of 0.187, did not give definite ignitions, and Pocahontas No. 4 dust did not explode, although part of the coal-dust cloud ignited. It is probable that even the low-volatile coal dust will be found to be explosive with a higher-amperage electric arc as the initiating agent."

Jul 1, 1936

By R. R. Sayers

Carbon monoxide poisoning is one of the most widely distributed and most frequent causes of industrial accidents . Carbon monoxide gas is a product of incomplete combustion , and since it is without color , odor , or taste , its presence is frequently unsuspected in many places where it exists . It is an ever present danger about blast and coke furnaces , smelters , and foundries . It may be found in buildings having a leaky furnace or chimney , and in buildings where a gas stove is used without a proper flue connection , such as is often found in tenements , tailor shops , and boarding houses . Hospitals receive annually a great number of victims of poisoning , either by accident or in an attempt at suicide , from artificial illuminating gas . People may be affected by leaks wherever water gas is formed or used . The exhaust gases from gasoline motors under average running conditions usually contain 5 to 7 per cent carbon monoxide , and sometimes as much as 13 per cent ; deaths from running an automobile engine in a closed garage are not infrequent . A similar danger may arise in operating gasoline engines in launches without sufficient ventilation . The gas is formed also in stoker rooms , in gun turrets on battleships , in petroleum refineries , and by the Lablanc soda process in cement and brick plants . In underground mines carbon monoxide may appear as the result of shot firing , mine explosions , or mine fires , and in tunnels where automobiles , coal or oil - burning locomotives are operated . In spite of the common occurrence of carbon monoxide poisoning there appears to be no uniformly recognized treatment for a person overcome by carbon monoxide . In the rescue work of the United States Bureau of Mines , however , a method has been developed which has been supported by laboratory investigation , and has proved successful in practical experience , over a period of years . As outlined in this article , the method is useful in the hands of first -aid men as well as physicians .

Dec 1, 1921

By D. J. Parker

State governments are increasing their efforts each year toward promoting the safety of miners .. Accidents underground are being avoided and mines made safer by means of revising and adding to their mining laws , by enforcing them through mine inspection departments , and by hearty co - operation with other agencies working miners ' safety . The U. S. Bureau of Mines is glad to testify to the co -operation that it receives from State mining departments in its safety work ; reports of the field mining engineers of the Bureau bear witness almost daily to the efforts of the States toward safety in mining . * This Through the courtesy of Mr. William Ogilvie , District State Wine Inspector of District No. 2 , with headquarters at "cAlester , Oklahoma, the Bureau has been furnished with a copy of a letter sent to various mining companies of Mr. Ogilvie's district in Oklahoma, relative to safety in Oklahoma mines . letter shows both the vigorous efforts which the State of Oklahoma is making toward increased safety in mines , and the recognized value of the types of electric cap lamps approved by the U. S. Bureau of Mines as " permissible " for use in gaseous mines ; it is accordingly reproduced in part : "hen during my first inspections of several coal mines in the district I found gas , or fire- darp being given off more or less constantly from the freshly cut coal at numerous points throughout the mines , I became uneasy relative to safety conditions , and am still considering your safety from many angles , but I am more concerned about the gas given off and the coal dust produced daily, than any other factor at the present time .

Jun 1, 1922

By A. R. Elliott

In the early part of the your 1919 the Bureau of Mines undertook a study of methods of handling oil after it had buon produced, with the view of pointing out the losses due to evaporation and other causes. Observations on present methods show that the oil is subject to largo losses in both quantity and quality from the time it loaves tho well until it is recoivod by the pipe-lina company. During this time it is splashed into four or more tanks of various sizes and with little or no protection over the tops. From the settling tank, where the flow of oil is tamporarily stopped in order to permit sparation of ter and sediments, through the gago tanks and leaso gathering tanks to the largo tank storage where it is hold for many days, rich gasoline vapors roadily escape, especially from tho ghor gravity oil. As no effort is made to measure the oil before it reached the storage tanks, where it is delivered to the pipe-line company, the lossos of the light products of the oil can only be approximated, and, as final results will show, are no doubt usually very much underestimated. In conducting this investigation, the Bureau has endeavored to make tests that would show quantities and values lost, in order to impress better upon those concerned what might be saved through a little more diligence. Eperiments were conducted on both California and Mid-Continent oils. The field operimental work done in California, on which a report is to be published in the near future, is cutlined briefly below: The field work consisted in collecting from operating companies data on storage of oils in large tankage and in performing experiments in the field on storing and piping oil to small lease tanks under practical conditions. Acourate Easurements were takon on the volume, gravity and gasoline content of the oil as it passed through the various stages in its removal from the lease. The work extended over the four seasons of the year in order to obtain better the effect of varying winds and high and low atmospheric temperatures during those periods. Thanks are due to the many oil operators who have taken a personal interest in the work and gave valuable information and assistance. One company furnished the oil and tanks and much of the apparatus and labor. This company also per- mitted the work to be done on its properties in the Coalinga field. This was of material aid, as the results were to be comparative and therefore it was necessary that the same gravity oil be used throughout the experiments.

Oct 1, 1920

By G. Nuñez, M. A. Pathak, C. F. Stanley

"Holographic interferometry is a non-destructive technique to detect small deformations1 of an object. It is a whole-field technique· with an accuracy of a few microns. An adaptation of holographic interferometry is time-averaged holographic interferometry which is particularly useful in detecting small vibration amplitudes of an object under investigation. Its application to biological tissue is especially difficult due to the combination of (a) the high sensitivity of the technique, and (b) the tendency of these objects to deform excessively, or move during the testing period. (This is also compounded by the changing moisture content of the tissue surface.)Ideally, a pulsed laser and fast-acting thermoplastic film camera could be chosen to overcome these difficulties, but the total equipment cost could exceed $75,000. In this paper we describe our relatively economical method to apply time· averaged holographic interferometry to an excised animal lung, utilizing holographic plates and a mechanically-shuttered continuous-wave Argon laser.EXPERIMENTAL METHODThe schematic of the experimental setup is shown in Fig. 1. The holographic equipment, including the laser, is fixed on a 3 ft x 6 ft x 4 in. honeycomb holographic table. This table is functionally similar to one described by Mark and Horsch2 which can be constructed for about one thousand dollars. The holographic table itself rests on six inner tubes to absorb floor vibrations. All unnecessary vibrations must be reduced to preserve the quality of the holograms. A laser beam from a 0.5-watt continuous-wave Argon laser is split by a circular variable beamsplitter (Newport Corporation Model 50GOOAV.1) into two beams, i.e., an object beam and a reference beam. The object beam is again split into two beams of equal intensity by a 50150 beamsplitter (Newport ·Corporation Model BS.1). These beams are optically filtered and expanded by spatial filters (Newport Corporation Model 910) to cover as much area of the object as possible. Soft biological tissues exhibit low reflectives, resulting in a relatively high reference to object beam ratio of roughly 5 : 1 at the holographic plate."

Jan 1, 1989

By E. D. Gardner

An explosion occurred in a high-pressure compressed-air line in October, 1930, at an Arizona copper mine. The explosion was unusual, and nothing had teor. noted by the plant operators to indicate the possibility of such an occurrence. It is necessar The air is The mining company uses compressed-air locomotives to haul about 4,500 tons of ore per day from the stopos to the pockets at two hoisting shafts. The ore cars hold five tons each, and are pulled in trains of 30 cars. to charge the locomotive with compressed air at both ends of the trip. conveyed from the compressors at the surface to the distributing points unier roun in special high-pressure four inch steel pipe that was tested to withstand 2500 pounds per square inch before being installed. The air is delivered to the loco- motives at a pressure of 1000 pounds per square inch. There are no receivers in the system. The air for running the locomotives is compressed by one three-stage and two four-stage compressors which have capacities of 600 and 300 cubic feet per minute, respectively. These machines are operated by electric power, and are in an end of the main compressor building in which air is compressed to supply the air drills in the mine. Whenever the demand decreases, as at the noon hour, one or more of the Compressors are shut down. On this particular occasion, at the end of the noon hour, one of the operators was approaching the high-pressure compressors to start the two smaller machines that were not running, when the explosion took place under the floor a few fost ahead of him. The man was mocked down and received some superficial cuts and bruises, but was not seriously injured. The floor was torn , the side of the building blown out, and holes imo cited in the roof some twenty feet above. The explosion was immediately followed by a fire which was quickly put out by the plant operators with hand fire extinguishers. At the time of the explosion the 600 cubic foot compressor was running alone, and the pressure in the system at the machine registered 1040 pounds por square inch. On examination it was found that two 6-fout sections of pipe, about tan feet apart, were completely ruptured into twisted fragments; the rest of the pipe line, apparently, was not injured. The destroyed sections were in that part of the pipe near the large compressor and above the connection from the two smaller machines. It is not definitely mom what caused the explosion. Explosions in other compressed-air systems have taken place, and, although of rare occurrence, have caused loss of life. Such explosions are not confined to high-pressure installations and several have occurred at plants compressing air te one hundred pounds per square inch, or less. plosions of this nature are not to be confused with the rupturing of compressor cylinders from excessive air pressure caused by the discharge valve being closed.

Feb 1, 1921

By E. P. Youngman

Although, an effort has been made to standardize and codify the mining law to apply to the entire German Nation, nothing has yet been accomplished. abstract, which applies only to Prussia, the largest and most important of the German States, is based upon the Prussian Mining Law (Preussisches Berggesetz) of June 24, 1865, which grants to certain provinces, communities, and districts special exceptions, of no particular significance, except locally.

May 1, 1930

By K. Rubow, Z. Zhlqun, V. Marple

A theoretical technique has been developed and verified experimentally for determining the aerodynamic diameter of irregular shaped particles. The aerodynamic diameter of a particle is a very important property in determining where that particle deposits in the respiratory tract. Many instruments, such as impactors and cyclones, will determine the aerodynamic size distributions of aerosol particles but few analyze the particles individually. The theoretical approach of our technique is to solve, by use of high speed computers, the three dimensional Navier-Stokes equations to obtain the flow field around an irregular shaped particle of any contour. The computer program will then determine the drag on the particle, and thus the aerodynamic diameter of the particle can be calculated. The experimental approach has been to pass the particles through a centrifuge and collect the particles upon a collection foil. The position of a particle on the foil is an indication of its aerodynamic diameter. These particles were then shadowed in two orthogonal directions and inspected under an SEM. The top view of the particle in the SEM plus the views of the two orthogonal shadows allows one to determine the three dimensional shape of the particle. Studies have been performed on silica, coal and talc particles with aerodynamic diameters in the 1 to 4 um size range. The three dimensional shape, as is determined from SEM analysis was used in the theoretical computer program and the results compared. It was found that in most 'cases the agreement between the experimentally and theoretically determined aerodynamic diameters was within 5%.

Jan 1, 1988

The optimum situation in sealing the soil with latex would be to locate the sealant at the depth where natural permeability is lowest, and to narrow distribution of the latex to a film. To ascertain how closely we were achieving these objectives it was necessary to devise a method to measure the concentration of latex in soil. A number of methods were explored and two were used in actual field tests. SBR latex tagged with c14 was prepared and used to determine the distribution of polymer in the soil. The latex was made by copolymerizing a mixture of radioactive and normal styrene with butadiene in bottles by conventional methods. Average particle size was 600 Å. Diluted aliquots had 1.40 microcuries radioactivity per gram of latex. Tagged latex was mixed with soil in a range of proportions from 0.01 to 0.25% by weight to develop a calibration curve. Analyses of soil in the laboratory and from the field were determined by comparison with this master curve. Styrene-containing polymers have a characteristic peak at 700 cm-1 but crosslinked SBR is not soluble in solvents normally used in infra-red spectroscopy, e.g., carbon disulfide. We developed a method for solubilizing the crosslinked polymer by stirring overnight at room temperature a soil sample in chloroform with t-butyl hydroperoxide and osmium tetroxide. The filtered chloroform residue was dried to constant weight, thoroughly mixed and pressed into a KBr pellet, and concentration was determined by measuring the absorption at 700 cm-1. Details are given in an Appendix.

Jan 1, 1972

By D. Harrington

Examination of numberous disasters , such as fires or explosions , and the evidence at coroner's inquests following such disasters in several States , have shown the writer how frequently men in charge of the operation and safety of mines have forgotten, or have failed to learn , details of safe mining practices , After securing a position of trust as superintendent , or a certificate of competency to act as shot -firer , fire boss , or mine foreman, some men seem to have felt it unnecessary to keep safety principles in mind , or to keep abreast of current progress in safety ; they have concentrated on getting out maximum tonnage at minimum cost . • In coroner's inquests , the testimony after disasters has shown that firebosses , foreman , and coal -mine superintendents are noticeably lacking in knowledge of the provisions of the State mining law relating to fans or doors , frequency of crosscuts , nature of stoppings necessary , electrical equipment , records of daily mine examinations , quantity of air required , or splitting and overcasting .

Jul 1, 1922

By David Hoadley, Kenneth R. Maser, Ashok B. Boghani, James E. Billar, D. Randolph Berry, Mackenzie Burnett, Robert H. Trent

B 3 Principle Program Nomenclature The principal variable names used in the computer program are defined below. The following dimensions are applicable, unless otherwise indicated. Distance - Ft Velocity - Ft. /Minute Time - Minute

Jan 1, 1976

By James D. Sisler

Location and Age The main bituminous coal field of Pennsylvania lies in approximately twenty counties west of the mountain area which extends in a northeast southwest direction through the central part of the Commonwealth. The coal fields lie in a dissected peneplain, still in the youthful stage of erosion There are numerous V shaped valleys in the bituminous fields and the tributaries of the larger streams have rather steep gradients The main streams flow in rather narrow valleys with comparatively small flood plains. The coal beds of Pennsylvania are of Carboniferous age, and are confined to two systems, the Permain and the Pennsylvanian The latter system is divided into an upper or Pittsburgh series and a lower of Pottsville series The Peimain system is divided into an upper and lower series The Pottsville series of the Pennsylvanian is represented in western Pennsylvania by the Upper Pottsville only The upper or Pittsburgh series of the Pennsylvanian is represented by the Monongahela, Couemaugh, and Allegheny groups Geologic Structure. The rocks of the bituminous coal fields are folded into many anti clines and synclines extending in a general northeast direction across the western part of Pennsylvania The intensity of this folding in creases toward the mountain region West of Chestnut Ridge, which is in Fayette, Westmoreland, and Indiana counties, the folding is minor, and the coal beds have low dips East of Chestnut Ridge, v here folding is stronger, the basins are wider and the coal beds rise steeply on the flanks of the anticlines Geology. The bituminous coals of Pennsylvania are associated with shale, sandstone, clay, and limestone Each group has different proportions of these deposits, and the proportions vary at different localities within the same group.

Jan 1, 1928