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By Eric H. Brown

One of the best methods by which the results of accident-prevention work can be measured for any particular period is to keep an accurate record of the accident experience, which may then also be compared with the experience of others. The purpose of this report is to compare records of the salt-mining companies operating in Louisiana, and their assistance in making available their accident records is gratefully acknowledged. PRODUCTION Four companies produce salt in Louisiana -Avery Salt Co., Avery Island; Jefferson Island Salt Mining Co., Jefferson Island; Myles Salt Co., Weeks; and Carey Salt Co., Winnfield. Three of these companies operate within 30 miles of each other in the southern part of the State, and the other operates in the central part.

Jan 1, 1938

By A. U. Miller

Definite progress has been made in accident prevention in Illinois during the past few years; the State Department of Mines and Minerals is receiving excellent cooperation from coal companies and employees, the companies are making greater effort to maintain their mines in good condi- tion, and the employees are eliminating more unsafe practices. As a result, some coal companies have made commendable safety records that prove that coal can be mined with a comparatively low accident rate. However, there is need for further improvement, as the accident rate of the State as a whole is much higher than it should be. During the 55-year period 1882-1936, in- clusive, reports of the State Department of Mines and Minerals show a total of 7,005 (an average of 127.36 per year) men killed in and around the coal mines. Of this number, 6,425 (91.7 percent) were killed underground, 346 (4.9 percent) in the shaft, and 234 (3.3 percent) on the surface. Of the fatalities underground, 3,300 (51.3 percent) were killed by falls of roof, sides, or face coal, 1,167 (18.1 percent) by haulage, 639 (9.9 percent) by handling explosives, 579 (9 percent) by explosions, 151 (2.3 percent) by electricity, and 589 (9.1 percent) by other means. Of the fatalities in the shaft, 171 men (46.5 percent) were killed by falling down the shaft, 14 (41.6 percent) by the cage, and 31 (8.9 percent) otherwise. On the surface, 113 (48.2 percent) of the fatalities were due to railroad cars, 51 (21.7 percent) to machinery, and 70 (29.9 percent) to other causes. The fact that 7,005 lives (an average of 127.36 per year) were lost during 1882-1936 is sufficient evidence that in the past too little interest has been taken in safety by either the management or workers. A realization of this deplorable loss of life should act as an incentive to the industry to make greater effort to prevent accidents in the future. After an accident occurs, the facts pertaining to it become history, and anything that may be done afterward cannot change in any way the damage that has already been done, such as loss of life, personal injury, and destruction of property. The main benefit that can be derived from an acci- dent is that suitable procedure may be adopted and some lesson may be learned to aid in preventing a similar accident in the future. All accidents, par- ticularly serious ones, therefore should be investigated and an effort made

Apr 1, 1938

By L. C. IlsLey

A list of permissible mine equipment, tested and approved prior to Jan 1, 1937, was published in Bureau of Mines Information Circular 6942 • .ll The present list inc ludes additional equipment approved during the calendar yea r 1937. The ma terial has been listed und er the same. headings as th ose used. in Information Circular 6942. The number that appears at the beginning of each it em represents the number o f this type of ma.chine appr.oved including the machine in questi on; for instance, the miing ma.chine numbered 70 was the seventiet h co al cutting ma chine design for which approval has been isnued. All of the equipment listed represents new designs except that covered by the first item, that is, 57 under the • heading nLoading Machines and Conveyors. 11 This item covers the approval of the 500-volt design of a machine the 250-v olt design of which was approved on January 17, 1935. The system under wich these devices were tested permits the manu-. facturer., after his equipment has passed certain tests prescribed by the 'Ui"eau of Mines, to mark his equipment with a seal showing that it has been approved by the Bureau. These tests are designed to insure t hat equipments hav,e the minimum requirements for safety in use. The only object of the :Bureau in making such tests and publishing lists of permissible equipment is to help decrease the hazards of mining.

Apr 1, 1938

By Oliver Bowles

Marble is one of tile most beautiful and enduring materials employed in the construction industries. Because of its diverse colors, decorative patterns, and varying textures, it has furnished material for artistic architectural design for many centuries. The marble industry is described in some detail in Bureau of Mines Bulletin 106, The Technology of Marble Quarrying, which, unfortunately, is now out of print but may be consul ted at most large libraries. Onyx marble and travertine are discussed in Bureau of Mines Information Circular 6751. The purpose of this paper is to describe the main features of a distinctive group of ornamental marbles known as the serpentine marbles or verde antiques.

Jan 1, 1938

By Ellis S. Hertzog, James R. Cudworth

Tremendous interest has been evidenced in the subject of dewatering and drying ooal for the past 10 years, and yet little effort has been made to summarize the literature, at least so far as this country is concerned. Only a few published articles have dealt solely with dewatering and drying coal. In most cases the subject has been discussed briefly, either in general terms or as to specific installations. It is desirable that a compendium be prepared collecting in one place information on the dewatering and drying of coal, the needs for this process in various fields, the available equipment, and the current American practice in regard to it. This work was underta..lten by the :Bureau of Mines in cooperation with the University of Alabama. New coal-washing plants in which various types of dewatering and drying equipment were in operation were visited in-Pennsylvania; Ohio, India...~a~ and Illinois. The dewatering·and drying of coel has .been studied in this coimtry by the Surface Preparation ·Committee of the ·coal Operato~s• Committee of the .American Mining ·Oongress. In GermaIJY .it has received the special attention of the Reichskohlenr·at, and in Great Britain of the Utilization of Fuel Commi-t-tee of the Insti ti.ite of Min"ing Engineers.

Apr 1, 1938

By J. J. Forbes

The activities of the Bureau of Mines include the development and testing of self-contained oxygen breathing apparatus and other devices for respiratory protection, the development and tasting of devices for detecting dangerous or noxious mine atmospheres, and the training of men in the mineral industries in the use and care of this equipment to enable them to render effective service in mine rescue and recovery operations following mine fires and explosions, or under other conditions where irrespirable gases may be found in mines or mining plants. The first use of self-contained oxygen breathing apparatus for com- bating mine fires and explosions in the United States dates back about 30 years. Previous to that time, exploration for any distance ahead of fresh air was virtually impossible without great risk to life; moreover, the men called upon to render service at mine disasters were not well-versed in the properties and physiological effects of gases likely to be encountered. It was also impossible to work ahead of fresh air to restore ventilation, and if many stoppings were blown out by an explosion, air had to be introduced into whole areas or sections at once without knowledge of the conditions ahead; moving an explosive mixture of methane and air over live fire had to

Jan 1, 1938

By L. C. IlsLey

Many accidents rightly classifiable as electrically caused are not so classified for the reason that in numerous accidents the part that electricity played in causing the fatality is only suspected. For instance, a workman might receive a shock that would cause him to lose his balance and fall beneath a trip of cars; if no one saw the first part of the accident, the cause undoubtedly would be charged to "haulage." This paper covers a brief study of fatal and nonfatal electrical accidents. The first usually result from direct contact with the electrical circuit or electrical apparatus; the second more often are the result of arcing or flashing due to handling defective apparatus or making repairs on "live" equipment or circuits. It is hoped that helpful suggestions may be offered for minimizing accidents of these two classes.

Jan 1, 1938

By Walter B. Lenhart

This paper is one of a series on milling methods and costs being. published by the Bureau of Mines. The milling practices and special problems relating to grinding, tailings disposal, and choice of a treatment process at the Cardinal mill are discussed. The property of the Cardinal Gold Mining Co. is about 18 miles southwest of the town of Bishop, Inyo County, Calif., at an altitude of approximately 8,500 feet. The camp has been designated Bishop Creek by the postal authorities. The property comprises 33 mining claims, including fractions and millsite in sections 19, 20, 29, and 30, T. 8 S., R. 31 E. These claims are located in a general way along the strike of a band of quartzite.

Jan 1, 1938

By E. D. Gardner

This is one of a series of paper's being published by the Bureau of Mines on placer mining; it is written as a supplement to Information Circular 6788, "Placer Mining in the Western United States, Part III", by E. D. Gardner and C. H. Johnson which was published in February 1935. Since Information Circular 6788 was written (1933), considerable advance has been made in the technique of mining placer gravels with power shovels and draglines. Although new washing plants continue to be built in accordance with untried designs the trend of new installations is toward proved equipment. A substantial number of plants are now being operated successfully (1937).

Jan 1, 1938

By Albert L. Toenges

The purpose of this paper is to describe some of the methods and practices of mining coal mechanically where more than one shift is worked, with the view of determining the advantages and disadvantages of various types of equipment and mining systems now in use. This paper is in the nature of a progress report, and, as the number of mines discussed in it is limited, the conclusions drawn in the comparison of various systems are not final but may be revised after subsequent investigations. Physical conditions vary in different and in the same mining districts and determine, more

Jan 1, 1938

By S. H. Lorain

This paper is a preliminary report on recent lode gold mining activity, operating conditions, and mining and milling methods at properties in production in September 1936 in the gold belt of northeastern Oregon. A few inactive properties are described also. Districts, inactive in 1936, that have been important producers at some time in the past are mentioned briefly. This is one of a series of similar papers describing western mining districts. The past production record of the gold mines of northeastern Oregon entitles the region to be ranked as one of the important gold-mining regions of the United States. Although comparatively inactive for many years, lode mining in the region has recently undergone a marked revival.

Jan 1, 1938

WHY IS IT that smoke-abatement efforts do not bring more satisfactory results? The main reason is an incorrect estimate of the kind and size of the job. When an industrial community realizes that keeping the air clean is a project of similar magnitude to keeping streets clean, providing clean water, removing city waste, or guarding the moral atmosphere, then there maybe a real hope of success. We usually think of the project in too small terms. It is thought of as is the dog catcher or the boiler inspector--a matter of a man or two, a job or two, a small appropriation of variable and uncertain amount, to be abolished in a fit of economy and reestablished under pressure of a vigorous minority. Even so, it is surprising how much is obtained for the effort; but the community is rarely satisfied, for the job is bigger than it was conceived to be. Continuous, never-ceasing effort is required to clean up a smoky city. A few months of relaxation and the situation slips back some years of effort.

Jan 1, 1938

By L. B. Berger

The Haldane gas-analysis apparatus used by the Bureau of Mines is patterned after the device developed by Haldane 4/ and differs from it only in structural modifications that have been added to facilitate operation and simplify construction. The apparatus was developed to permit determination of carbon dioxide, combustible gases, and oxygen with a degree of accuracy not attainable with apparatus of the types ordinarily used for the analysis of fuel gases, flue gases, and similar mixtures. The Haldane apparatus is used by the Bureau of Mines chiefly in the analysis of air samples collected in coal and metal mines and other underground workings and is applied also in the analysis of many other types of gas mixtures when accurate determination of certain constituents is desired.

Jan 1, 1938

In the interest of safety in underground coal mining, the Bureau of Mines recommends: 1. That doors used to control ventilation (a) Shall be installed in pairs to form air locks, (b) Shall be self-closing, (c) Shall not have latches or other devices for holding them open, (d) Shall be constructed and maintained to prevent excessive air leakage through or around them, (e) Shall be fire resistant. 2. That wherever practicable the use of doors shall be limited to development openings. The Mine Safety Board is of the opinion that the best practice in coal-mine ventilation makes use of a split system employing overcasts or undercasts with doors limited as far as feasible to development openings. The distance between air-lock doors on haulageways should be sufficient to accommodate a trip or train of maximum length. Where auxiliary doors are installed to control ventilation during emergencies, they should be so placed that they can be utilized readily in case of damage to the air-lock doors.

Jan 1, 1938

By L. C. IlsLey

The increasing use of Diesel engines for operating equipment on trunk-line railroads and for power-plant units has stimulated interest in the use of Diesel engines for other lines of work, among which is the possibility of substituting Diesel locomotives for trolley locomotives for mines. The possibility of developing Diesel locomotives for duty in American mines is not as remote as it might seem, particularly in view of the fact that locomotives of this type are already used in considerable numbers in European mines. A study of Diesel locomotives in Europe is contained in Report of Investigations 3320, Diesel Mine Locomotives - Development and Use in European Coal Mines, by George S. Rice and F. E. Harris.

Jan 1, 1938

By D. Harrington

In this period of generally increasing taxes of various kinds, one hears less complaint by mining companies about the high cost of workmen's accident compensation than was the case a few years ago, the reason perhaps being that other and more pressing phases of the tax problem now over shadow the heavy expenditures for compensation premiums which a few years ago were considered a severe burden on the mining industry. Nevertheless, the financial expenditures of the mining industry in higher compensation benefits and hospitalization or in higher premium rates, or both, instead of being less have actually increased in many States in the past year. In the spring of 1937, proposals for increased benefits to injured employees in compensation, hospitalization, or medical aid were actively before legislatures in California, Connecticut, Georgia, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Massachusetts, Michigan, Minnesota, New Mexico, Oregon, Pennsylvania, South Carolina, Texas, Utah, Washington, Wyoming, and possibly other States. In some cases, the proposed increases in benefits were so much greater than expenditures for similar items in the past that premium rates per $100 of payroll would almost certainly rise sharply. At this same time, occupational-disease-compensation coverage also was under consideration by legislatures in Arkansas, California, Delaware, Idaho, Indiana, Kansas, Massachusetts, Michigan, Minnesota, Montana, Nebraska, New Jersey, Ohio, Pennsylvania, Tennessee, Utah, and Washington. Sooner or later (and probably within the next few years) occupational-disease compensation will be accorded practically as wide recognition as accident compensation receives at present, and, unquestionably, mining in all of its branches will be affected more or less drastically. Hence, the present outlook is that the mining industry, in company with practically all other industrial activities, will be confronted by materially higher compensation costs than those of the past or the present, to which rather violent exception has been taken, at least in some States and at some times.

Jan 1, 1938

By William O. Vanderburg

This report3/ gives the results of a reconnaissance of mining districts in Eureka County, Nevada, made from September 25 to October 20 and from October 27 to November 5, 1577. During this time, virtually all the districts were visited and many data obtained on active and inactive properties. This report covers the locations of the various districts, geological background, ownership and brief descriptions of mines and prospects, information on past and current operations, and, other data likely to be useful to those interested in the development of our mineral resources. From the viewpoint of past production in the county, the silver-lead-gold deposits at Eureka have been tie most important, followed by the silver deposits at Cortez and Mineral Hill. The period of greatest activity in the foregoing districts was from 1870 to 1990, when Eureka was one of the principal mining areas in Nevada; the production of lead was sufficient to affect its price in all the commercial centers of the world. Eureka also merits the distinction of being the birthplace of the silver-lead smelting industry in the United States.

Jan 1, 1938

By S. H. Lorain

This paper briefly describes the principal known commercial and near commercial deposits of gold-bearing gravel end the principal placer mining operations of Idaho County, Idaho. It is one of a series of similar papers on western mining districts. The data used in writing this paper were gathered during the summer of 1937. Information concerning gold-bearing gravels was obtained from prospectors and operators, while operators supplied most of the data on mining operations. No attempt was made actually to test the gravels. The principal object of the examination was to indicate placer areas worthy of further investigation by prospective operators.

Jan 1, 1938

By G. E. McElroy

As one phase of a general program of enthracite mine-fire research initiated by the Bureau of Mines in September 1935, a study of the records of past fires was considered a necessary approach to a proper understanding of present and future fires because only limited information could be obtained directly from existing active fires on account of their inaccessibility. Through the courtesy of interested operators, all available records of fires that had occurred in a large group of steep-pitch anthracite mines in the Western Middle and Southern fields of the Pennsylvania anthracite district were examined and analyzed for data on the causes, costs, behavior, and control of fires, and this report is primarily a discussion of these factors based on a close study of these particular records. Mining Conditions The records pertain to a group of mines that have contributed about 12 percent of the total Pennsylvania anthracite production and constitute a large proportion of, and well represent, steep-pitch operations in this district. Throughout the area represented, the coal occurs as a series of up to 20 parallel seams in folded slate and sandstone strata and almost entirely on pitches of 400 to 80°, with vein thicknesses of 5 to 60 feet. Practically all are old mines with histories dating back to 1850, or thereabouts, and present operations are either under or adjacent to mined-out areas extending to surface or to the saddles of anticlines. All operations are at relatively shallow depths, that is, within 1,000 feet, vertically, of the surface. Mining methods are largely a heritage of the past and embrace typical breast and pillar operations with practically no mechanized mining and with the coal shot ?off the solid.? Most of the mines are rated as gassy and are operated now on a closed-light basis. Permissible explosives are now used entirely for breaking coal, and dynamites for rock work and chute-starting blasting.

Jan 1, 1938

By Carlton E. Brown

Inquiries and instructional work on the determination of the number concentration of dust in atmospheres known or suspected to contain pneumoconiosis (silicosis and asbestosis) - producing particulate matter indicate a need for a description of the impinger method used by the Bureau of Mines. The impinger method consists of the collection of dust in a liquid medium and the counting under the microscope of the particles in a known portion of this liquid. The dust-collecting device is called an impinger. The dust in the air drawn through this collector at a known rate impinges at high velocity upon a smooth surface under a bubbling column of liquid. The dust is either picked up from this surface by the liquid or removed from the air as it passes through the liquid.

Jan 1, 1938