Search Documents

By H Haas

H. HAAS, San Francisco, Cal. (communication to the Secretary?). -Fig. 1 plainly shows that the comparison of the steam-turbine and Diesel-engine plants was made on a basis of 6,000 kw. continuous operating load. The tabulation of costs for an 8,000-kw. load is merely done to show the relation of increased output on' the unit power costs. Both plants would sacrifice their reserve capacity, which is to insure continuous operation, if operated to generate 8,000 kw. continuously; unless Mr. Hawkins advocates the operation of one of the turbines at 33.33 per cent. overload, retaining the other as a standby, which, besides overtaxing the turbine, results in a great loss of efficiency. It would he well for Mr. Hawkins to qualify certain of his statements. Thus, under the caption "Diesel Engines, Selection of Units," he says that "two of the largest Diesel-engine builders take the position that, in the present state of the art, they would not attempt to put out units over 1,000 kw.;" he should qualify it by saving that "two of the largest American Diesel-engine builders take the position that, in the present state of the art in the United States, they would not attempt to put out units over 1,000 kw." The reason that American manufacturers restrict themselves at present to units of that size is to be found not so much in a lack of experience in building large units as in a lack of a sufficient, demand for them in the United States to justify the heavy capital outlay connected with the development of such engines. There are relatively few localities in the United States where fuel prices are as high as they are in the Southwest, and regions of high fuel prices are sparsely settled and have a very limited demand for power. Where low fuel prices obtain, steam turbines are active competitors of Diesel engines for large power plants, particularly when the station load factor is low. As most of the American manufacturers of Diesel engines work under license agreements with European manufacturers, which limit their market to the United States and its possessions and Canada, a further limitation is imposed upon them, leaving to European firms practically the entire world as a market.

Jan 5, 1917

By D I. Cliff

The loss of 11 miners in the 7 August 1994 Moura No.2 Underground Mine Disaster was the catalyst for major change in the way safety was managed in the Australian Mining Industry. The impact was felt across all sectors not just underground coal. It was the catalyst for the overhaul of the regulatory frameworks, moving away from prescription to management systems and risk management. This had a substantial impact on the way not only the industry operated but also on how the regulator functioned. It heralded the introduction of competency-based training across all levels of the mining workforce. Since that time major improvements in safety performance have occurred. However, hiding within the statistics are some disturbing trends. This paper aims to analyse the progress made in the past 30 years and identify the current and emerging issues. Automation is bringing major production and safety benefits, but at the same time other factors such as the reduction in workforce numbers and ever-increasing production pressures are leading to high turnover rates. This in turn causes to a loss of experience and expertise. In addition, and of particular importance, is the recognition of psychosocial wellness on workforce safety. Many of these factors are not unique to the mining industry however they may be exacerbated by the scale of mining, the remoteness of the mines and family unfriendly mining rosters.

Apr 16, 2024

By Robert Lee, Jeff Corace, Rob Cyr

Blasting in the heart of the historic Byward Market District of Canada’s capital, Ottawa, presents a unique set of challenges. The obvious difficulties arising on projects requiring blasting within 3 m (10 ft) of 125 year old buildings in various states of disrepair have been encountered and successfully dealt with countless times before. The complexities increase exponentially when tenuous property boundaries, unknown structural details, litigious histories and the need for encroachment agreements lead to individuals with competing interests all able to impact the same operation. Blasting on three projects in the Market was started in early 2005 after months of negotiation. Ultimately, the potential for the projects to proceed hinged on the ability to successfully disseminate blast data to the various stakeholders. As part of the agreements drawn up, property owners demanded immediate notification of the measured vibration levels with contract provisions including clauses such that any exceedance of the USBM criteria immediately triggered project shut down and complete blasting program redesign, and approval by all parties. With stakeholders located in various cities and, in some instances, on various continents, a conventional attended monitoring strategy would not satisfy the requirements. In response to the critical reporting need, Explotech Engineering Ltd. installed unattended monitoring stations around the sites, all incorporating wireless telemetry. After each blast, data was automatically transferred from the monitoring stations to a web-linked server via the wireless network, where it was immediately available to project stakeholders through a password protected website. The solution required a unique blend of data acquisition, telemetry, database, and security technologies, all married to produce a reliable system that was easy to maintain and use. While these types of systems were originally developed for use as permanent monitoring networks in operating mines and quarries, monitoring professionals are increasingly benefiting from the technology on temporary building projects that have typically been the realm of attended monitoring strategies. Globally, this has emerged as a solution to provide more timely access to data for stakeholders, and to minimize the legal exposure from multiple violations of vibration limits. As this trend is likely to continue, the regulated vibration control industry is likely to see a continued shift in technology development to leverage wireless networks and the Internet to continue to improve data transfer, archiving and distribution.

Jan 1, 2006

By FREDERICW K. BRADLE

I HAVE been puzzled by two lines of thought'; one emanating from Washington, D. C., to the effect that we must all cheer up, that in a very short time, measured in terms of months, prices would begin to recover, business would become normal, and prosperity would continue on its way just as before the interruption of a year ago; and a second, coming from certain industrialists and economists, expressing fears that all commodity prices were in for a long downward trend, which would cause much unemployment, eventually drag down wages and so restrict purchasing power as to further aggravate the situation. One basis for the fear of a downward trend in commodity prices' is that ifter great wars a depression could last for something like 40 years-the downward trend to such a depression after our recent World War having been postponed for some reason or other; and the basis for another fear was that the production of gold was becoming less. I had 'also been trying for some time past to refresh my recollection as to how my ow11 particular lead interest climbed out of the depression of 1893; and as all the metals have had, and still have. relative values and prices, I can best express what I have in mind by talking principally about lead.

Jan 1, 1930

By J. Mikhael Erekson, Connie Campbell Brashear, Brent Meins

Christmas morning 2020, an IED in an RV was detonated along an evacuated section of downtown Nashville, Tennessee. The blast damaged over 40 buildings, including AT&T’s Main Central Office and caused internet and cell outages across 1,200 zip codes for three days including the airport and EMS services. Published investigations by the ATF and FBI were inconclusive in determining the explosive composition and size. Video captured a large fireball that may indicate a fuel-air-mixture explosion which would create lower peak pressures than high explosives, but longer pressure duration and significant impulsive loading. Blast pressures were amplified by reflections in the urban environment bordered by the 8-story AT&T building and a row of multi-story historic buildings. Some structures had little damage as they were shielded from the blast pressure by closer buildings, and seemingly far-field structures contained damage from the pressure wave after multiple reflections and propagation through porous parking garages. Damage to the reinforced concrete frame AT&T building included snapped masonry ties, cracking and spall to the closest column, and vertical displacement of the elevator, even with the brakes applied. The historic structures directly across the street from the blast partially collapsed. Initial damage included complete failures of unreinforced masonry façades, broken timber beams, and uplifted roofs. Secondary, progressive collapse took place over months as the brick walls and weakened historic mortar could not resist typical wind and environment loads. One of the close historic structures was renovated in the 1990’s and structural retrofits to comply with building codes were required. The addition of steel columns and façade tie-ins improved survivability and it remained standing with a high percentage of the front brick intact. Generally, the observed blast damage was related to a structural component’s mass and flexibility. Internal timber framing was unscathed, but many steel studs required replacement. Glazing damage was observed several blocks away and many roof membranes were punctured by falling debris. Secondary damage from broken sprinkler lines and loss of environmental control often led to more costly repairs than the initial blast pressure damage. The proliferation of bomb-making knowledge leads to hundreds of bombings each year in the US. Building risk considerations should include explosive threats along with other hazards. ASCE structural standards and design manuals have been published to address these risks and may be useful guides for building construction.

Feb 6, 2023

By C. Travis Anderson

"Nickel is an essential metal in stainless steel, armor plate, and nickel steels and also in nonferrous alleys, such as monel metal and cupre-nickel, which are used in marine service. Nickel is one of the metals that must be greatly restricted in civilian use to provide the amounts needed for our War program. Consequently, it is desirable to investigate every possible substitute.The 5-cent coin no z in use contains 2.3 percent nickel. At the end of 1941, about 450 tons of nickel was being consumed annually to produce these coins. If the nickel used for that purpose in 9141 had been diverted to military use, 15,000 tons of armor plate could have been produced. As nickel is vitally needed for military as well as essential civilian products, it would seem desirable to substitute some other alloy for the 25 percent nickel alloy now being used. The Bureau of Mines has been asked to suggest possible substitutes.The substitute should have physical properties similar to the alloy now being used. It should have a metallic appearance and ring and a reasonably white color, so to be distinguishable from the present 1-cent coin. It should also be reasonably resistant to corrosion."

Aug 1, 1942

By Michael L. Wayman

Archaeological and ethnographic work during the last century has shown clearly that metals have played a small but important role in prehistoric Arctic cultures. For at least the past several millenia both iron and copper have been used in the North, primarily for blades, projectile points, knives, awls, engraving tools, fishhooks, scrapers and axes. In addition they were used for joining purposes as staples and rivets. It is of great interest to enquire into the origins of these metals. In this connection one begins with the observation that to date there has been no clear evidence for the smelting or melting of metals in the Arctic prior to the arrival of Europeans. This can be explained partly by the absence of traditional pyrotechnologies such as the high-temperature firing of ceramics and the heat treatment of bone and wood. Another factor which surely inhibited the development of smelting/ melting operations is the relative absence of wood in the region. The production of charcoal for smelting requires large quantities of wood, to the extent that the desertification of a number of areas in the Old World is believed by some to have been at least partly caused by charcoal production. In the North this was obviously not possible. Thus the Arctic peoples were restricted to using native (naturally occurring) metals and metals obtained by various direct and indirect forms of contact with areas of the world where smelting was practiced. Both of these sources were important in the case of iron; we know that meteoritic iron, telluric (native) iron and smelted wrought iron were all used in the Arctic. These three types of iron will be considered in tum.

Jan 1, 1999

By R. G. Zaripova, N. D. Ryan, H. J. McQueen

The austenitic and ferritic stainless steels do not undergo any phase transformation that induces very fine grains in the product through thermomechanical processing as practiced in most other steels. Considerable grain refinement can be achieved by intense multistage deformation descending through warm to cold working; notably multi-axial forging of bulk material can attain high strains with diminished risk of cracking. Hot working to improve ductility yields finer grain sizes as the T is reduced and strain rate E raised; increased strain has limited effect due to the steady state regime. Ferritic steels develop subgrains with size diminishing as E rises and T falls with the advantage of retained strain hardening; recrystallization delivers grains several times the cell size. In austenitic steels, dynamic recrystallization (DRX) provides finer grains at higher E and lower T with a lower limit due to intergranular cracking. The DRX grains contain a strengthening substructure that can easily be retained by quenching; if static recrystallization is allowed to occur the grain size rises markedly. Multistage rolling with diminishing T is able to provide grain refinement to the same degree as straining at the finishing T yet provides better ductility. grains on recrystallization. As a result of the strain induced transformation to martensite, small subzero deformations of austenitic or duplex steels produce very high dislocation densities that yield marked grain refinement when they revert upon reheating.

Jan 1, 2004

By J. F. Burr, D. P. Snyder, G. W. Luxbacher

"The Mine Improvement and New Emergency Response Act (MINER Act) of 2006 (PL 109-236, 2006) established the Office of Mine Safety and Health, functioning as the Office of Mine Safety and Health Research (OMSHR) within the National Institute for Occupational Safety and Health (NIOSH) and provided authority for awarding contracts related to the development and implementation of new mine technology and equipment. The OMSHR external contracts program was formed in accordance with the MINER Act and has since issued more than 150 contracts focused on worker health and safety. Initial funding for this program was provided by the United States Congress through two emergency supplemental appropriations and was focused on emergency oxygen supply, communications and tracking, and refuge chambers (also referred to as refuge alternatives). Since the MINER Act, Congress has continued to fund the program through the annual NIOSH mining appropriation. The program was supplemented starting in 2009 with an academic capacity building program directed toward developing university tenure-track faculty and facilities and supporting graduate students in the area of mine ventilation. Ground control was added as an additional focus area in 2011. A short synopsis of each contract is published on the NIOSH Mining website (www.cdc.gov/niosh/ mining/researchprogram/contracts/index.html) and final reports are available in digital form on request. A summary of the progress OMSHR has made over the 10-year period since the Act was published previously (Snyder et al., 2016).External contracts are broadly classified by the following areas:• Communications and tracking.• Emergency response.o Self-escape and breathing air supply.o Refuge alternatives.o Escape and rescue.• Equipment safety.• Fires and explosions.• Ground control.• Mine environmental systems (mine ventilation and atmospheric monitoring).• Worker/workplace health and safety.Contracts are issued under a request for proposal (RFP), through a broad agency announcement (BAA) or under an interagency agreement (IAA). An RFP solicitation includes a specific problem description and a well-defined scope of work to guide the offeror in preparing a bid to conduct the research. Under the BAA several problem areas are described and the offeror develops the scope of work and deliverables for the proposed research. An IAA is very similar to an RFP except it is a contract between two federal government agencies."

Jan 10, 2018

By M S. Powell

In this paper it is argued that we are entering a new mining era, based on considerably more challenging orebodies as we rapidly expand minerals production by exploiting previously uneconomic deposits. Rapidly increasing production costs cannot be sustained by continually increasing commodity prices, as illustrated by the recent downturn in the industry.Driven by reduction in grade, requiring the processing of 50 to 100 per cent more ore to recover the same amount of metal, often accompanied by finer grain structure - necessitating a finer product size and more challenging recovery - the productivity of the mining industry is dropping in real terms. The author suggests that tweaking current technologies and relying on economies of scale will not turn the industry around, but rather a switch to considerably more efficient processing is required.It is imperative to utilise the properties of the orebody, especially in terms of variability, in revolutionising our processing techniques. Our new mantra may be æselective mass mining with flexible processingÆ. This paper explores how this may be implemented using current technology and equipment in order to change the cost profile of the new mining industry. Orebody knowledge, based on the underlying process drivers, rather than proxies, is required. These properties and their variability will need to be propagated into the orebody through utilising the geological data rather than smoothing block averages, which destroys information on variability.Novel flexible circuit designs are presented that can respond to a wide variability in ore properties and throughput requirements in order to slash processing costs and energy utilisation, while enhancing overall recovery. The success of these circuits will be based on an ability to predict at both design stage and in everyday processing the variable ore properties, which is dependent upon reliable orebody knowledge that caries variability and underlying processing properties.CITATION:Powell, M S, 2013. Utilising orebody knowledge to improve comminution circuit design and energy utilisation, in Proceedings The Second AusIMM International Geometallurgy Conference (GeoMet) 2013 , pp 27-36 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 29, 2013

By AIME AIME

COMMITTEES. CANAL ZONE.-Col. George W. Goethals, U. S. A., Chairman; Lt.-Col. H. F. Hodges, U. S. A. ; Lt.: Col. D. D. Gaillard, U. S. A. ; Lt.-Col. William L. Sibert, IT. S. A. ; H. H. Rousseau, U. S. N.; Col. W. C. Gorgas, U. S. A.; Maurice H. Thatcher ; Joseph Bucklin Bishop ; Lt.-Col. Charles F. Mason, U. S. A.; S. B. Williamson ; Major Eugene T. Wilson, U. S. A. ; Edward Schildhauer ; Henry Goldmark ; Edward C. Sherman ; W. G. Comber ; W. B. Corse ; J. A. Walker; Joseph A. Le Prince; J. A. Smith ; Lt. Frederick Mears, U. S. A. HAVANA.-V. T. Polledo, Chairman; Diego Lombillo Clark, Jose Primelles, J. R. Villalon, Jose Artola, J. Ducassi, Luis Morales, Enrique Montonlieu. ENTERTAINMENT ON SHIPBOARD.-William L. Saunders, Chairman; Mr. and Mrs. S. D. Warriner, Mr. and Mrs. Thomas Robins, Mr. and Mrs. George.D. Barron, Mr. and Mrs. R. B. Watson, W. E. Greene. GENERAL MANAGEMENT. .Joseph Struthers, Chairman; Albert E. Vaughan. There were ten sessions of the Institute held for the presentation and discussion of, technical or professional papers. Eight of these sessions were held on the steamer while en route, and two in the ball-room of the Hotel Tivoli, at Ancon, C. Z. Mr. David W- Brunton, President of the Council, presided at all the sessions, except the sixth, at which Mr. Charles Kirchhoff, past President, occupied the chair. The following list includes the papers presented in oral abstract by the authors: First Session., October 24. The Summit Hill Mine-Fire, by W. A. Lathrop, Philadelphia, Pa. Mine-Fire at the Calumet and Hecla Mine, No. 8 Shaft., by S. D. Warriner, Wilkes-Barre, Pa. Fire in the Big Lick Stope, Lykens Valley and Williamstown Colliery, by R. V. Norris, Wilkes-Barre, Pa. Mine-Fire in the Hecksherville Valley, Schuylkill Field, Pa., by W. J. Richards, Pottsville, Pa.. Fire in the Monarch Mine, near Rock Springs, Wyo., by S. A. Taylor, Pittsburg, Pa.

Dec 1, 1910

By A. A. Sadegh

A laboratory investigation was carried out on the characterization and beneficiation of sillimanite ore. Petrographic analysis indicated that the ore consisted of massive elongated sillimanite grains in a matrix of hematite, garnet, feldspar and silica. A procedure for estimating the percentage of sillimanite was developed using float-sink and magnetic-separation techniques. A liberation study was carried out to determine the level of size reduction required to achieve sufficient liberation while ensuring that gravity concentration techniques would be applicable. Laboratory testing was performed on the liberated ore to investigate the applicability of using wide-angle dense-medium cycloning to upgrade this ore. Initially, medium-only tests were carried out using various size distributions of magnetite and ferrosilicon as the dense-medium solids to evaluate the effects of operating conditions on medium segregation. Depending on the medium solids and operating conditions, either positive of negative differentials (difference between the relative densities of the underflow and overflow streams) were obtained. Based on these results, separation tests were performed to process nominal -1.2-mm sillimanite ore. The results indicated that sillimanite concentration could be obtained using a medium relative density that was much lower than would typically be used in a dense-medium cyclone separation.

Jan 1, 2007

The National Economic Viewpoint? Any substantial project undertaken by private enterprise would normally be subjected to a Discounted Cash Flow analysis of its commercial viability, and would proceed only if the rate of return was judged satisfactory. A 'national viewpoint' analysis attempts to do the same but from the viewpoint of the community as a whole. The objective is to ensure that those projects are undertaken which yield the best return, economic and social, to the nation as a whole.

Jan 1, 1984

1. Domestic Production and Use: In 1983, 12 companies operated 27 primary aluminum reduction plants, with 4 firms accounting for 65% of production. Washington, Oregon, and Montana accounted for 35% of the production; Indiana, Kentucky, Maryland, New York, Ohio, and West Virginia 35%; Tennessee, Alabama, South Carolina, and North Carolina 14%; other central States 16%. Based on published producer prices, output of primary metal in 1983 was valued at over $5.7 billion. Aluminum consumption by 25,000 firms was centered in the East Central United States. Packaging accounted for an estimated 37% of domestic consumption in 1983, transportation 19%, building 17%, electrical 9%, consumer durables 8%, and other uses 10%.

Jan 1, 1984

By John G. Parker

The rare-earth elements, sometimes known as the lanthanides, comprise the series of 15 chemically similar elements with atomic numbers 57 through 71. Yttrium, with atomic number 39, is often included in the group, because its properties are similar and it more often than not occurs in association with the lanthanides. Thorium is included in this survey due to its close association with the lanthanides, particularly in the mineral monazite. The lanthanides were first recognized as elements around 1750 and were the subject of much study by chemists during the 19th century. The purely chemical methods then available failed to resolve the strange intimate relationships between these elements, and it was not until about 1920 that the full series was explained.

Jan 1, 1971

By Richard Paul Seelig

The following review covers published information on pressing of metal powders at room temperature. Only those operations are considered which occur between the time the powder is filled into the cavity and the compact is ejected from the die. Thus, this review does not concern hot pressing, coining or sizing feed or flow problems, commercial presses nor designs. It was also necessary to disregard to a large extent the effect of pressing on subsequent operations and on properties after sintering. 'The pressing operation is considered independently in its function to compact loose metal powder into useful shapes which can subsequently be handled. There are some comments by the writer in connection with a few of the findings quoted in the literature in order to stimulate thought and discussion. The selection of references quoted in the text is in some cases arbitrary although an attempt was made to favor papers containing novel ideas, techniques or results which mag stimulate future research. In order to enable the reader to check further into the subjects mentioned, the original, rather extensive, bibliography is appended even though not all the references are touched on in the printed version of this review. The equipment used by various workers, for example a die design created by Bridgman,22 is very interesting. 'The die insert has a conical external surface. The vertical pressure exerted on the punch transmits itself to the die which in turn is pushed harder into its tapered retainer. Thus, the higher the pressure exerted on the punch, the higher also the pressure exerted inwards on the die inserts. Inasmuch as this pressure counteracts the internal pressure from the compact the two stresses balance each other so that it is possible to obtain tremendous pressures without breaking the die. The die collar was made from an oil hardening tool steel, heat treated to a tensile strength of some 300,000 psi. The die was closed at the bottom by a plug made from special tool steels. Bridgman found that there is no steel which will withstand a com-pressive stress of 700,000 psi without continuous slow flow or immediate fracture. Therefore, the only material suitable for use in the pressing punch was sintered carbide. In view of the ingenious design it was possible to use special tool steel as die material. Jones22 raises the question whether this method of pressing has practical application in powder metallurgy. Although these tremendous pressures cannot readily be utilized without many special precautions, the tapered die and retainer idea is believed to be useful even for lower pressures. Bridgman, himself," alls attention to the fact that the properties

Jan 1, 1947

By Richard Paul Seelig

The following review covers published information on pressing of metal powders at room temperature. Only those operations are considered which occur between the time the powder is filled into the cavity and the compact is ejected from the die. Thus, this review does not concern hot pressing, coining or sizing feed or flow problems, commercial presses nor designs. It was also necessary to disregard to a large extent the effect of pressing on subsequent operations and on properties after sintering. 'The pressing operation is considered independently in its function to compact loose metal powder into useful shapes which can subsequently be handled. There are some comments by the writer in connection with a few of the findings quoted in the literature in order to stimulate thought and discussion. The selection of references quoted in the text is in some cases arbitrary although an attempt was made to favor papers containing novel ideas, techniques or results which mag stimulate future research. In order to enable the reader to check further into the subjects mentioned, the original, rather extensive, bibliography is appended even though not all the references are touched on in the printed version of this review. The equipment used by various workers, for example a die design created by Bridgman,22 is very interesting. 'The die insert has a conical external surface. The vertical pressure exerted on the punch transmits itself to the die which in turn is pushed harder into its tapered retainer. Thus, the higher the pressure exerted on the punch, the higher also the pressure exerted inwards on the die inserts. Inasmuch as this pressure counteracts the internal pressure from the compact the two stresses balance each other so that it is possible to obtain tremendous pressures without breaking the die. The die collar was made from an oil hardening tool steel, heat treated to a tensile strength of some 300,000 psi. The die was closed at the bottom by a plug made from special tool steels. Bridgman found that there is no steel which will withstand a com-pressive stress of 700,000 psi without continuous slow flow or immediate fracture. Therefore, the only material suitable for use in the pressing punch was sintered carbide. In view of the ingenious design it was possible to use special tool steel as die material. Jones22 raises the question whether this method of pressing has practical application in powder metallurgy. Although these tremendous pressures cannot readily be utilized without many special precautions, the tapered die and retainer idea is believed to be useful even for lower pressures. Bridgman, himself," alls attention to the fact that the properties

Jan 1, 1947

The Bureau of Mines human factors research program is directed toward reducing accidents and improving the overall efficiency of the person-machine environment interface found in surface and underground mines. The focus of the hum factors program therefore, is to insure that sound knowledge is available concerning human capabilities and limitations, and that this knowledge is applied to the design, of mining equipment, work tasks, and management procedures. The papers presented in these proceedings summarize some of the recent Bureau research in hum factors. The papers focus on two broad areas, human resource issues and human engineering of equipment, tools, and work procedures found in mines.

Jan 1, 1987

The ready solubility of gold in dilute aqueous solutions of the cyanides of the alkalies or alkaline earths provides a convenient method for the separation of the precious metal -from the large surplus of associated materia1. The finely ground ore is pulped with a weak solution of cyanide, agitated to dissolve the gold, filtered and washed. The lowgrade filtrate is then clarified and the gold precipitated by some electronegative agent, the most usual being finely divided zinc or zinc dust. The slight precipitate is collectedon some form of filter coated with a filter aid, the filter cake being then known as "gold slime".A typical analysis of this slime is given in Table 1.

Jan 1, 1956

By R. R. Sayers

The hazards connected with work under abnormal air conditions are becoming of increasing importance from a financial as well as a physiological stand- point, due to the extension of compensation laws to include diseases caused by dusts, toxic gases, and abnormal temperatures and humidities. The United States, with the excention of California, North Dakota, Wiscon- sin, Massachusetts, and Connecticut, is the only English-speaking country to-day where silicosis is not compensated.3 Cases of permenent total disability or death due to silicosis mar aprear in common-law courts, particularly in the States that have not recognized silicosis as an occupational disease for which compensation should be provided. Such cases have recently been tried in one State, according to a magazine editorial, not providing scheduled commensation for employees affected by silicosis, with results favorable to the claimant. Clearly established cases definitely linked with occupation as the cause may be expected to be recognized as deserving by juries and courts, and awards will be made. In one Atlantic Coast State, according to this editorial, 108 claims for silicosis, including 21 deaths therefrom, are said to have been filed against two small plants engaged in finely pulverizing quartz sand.

Sep 1, 1932