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By J. D. Davis

"Introduction.Sixty years ago, M. Berthelot found that ethylene could be selectively absorbed from gaseous mixtures by concentrated sulphuric acid, and that the compound formed by the chemical union of the gas and acid was readily decomposed by heating with water, yielding ethyl alcohol. Only within the last few years has there been any attempt to make use of this discovery technically.Bury*, working in England at the Skinningrove Iron Works and on a commercial scale, developed a technical method for converting, the ethylene of coke-oven as into alcohol. With a gas containing less than 3 per cent of ethylene, he obtained a yield of 1.6 gallons of alcohol per ton of coal carbonized.De Loisy** perfected a technical method for treatment of coke-oven as for alcohol. Evidently this work was carried out on a semi-commercial scale. His method is based on the use of catalytic agents for hastening the absorption of ethylene by sulphuric acid. He uses part of the spent acid for drying the gases and pact for the manufacture of ammonium sulphate. Excess acid is reconcentrated by waste heat. Others have worked on the problem, but so far there has been no large recovery of ethylene from coke-oven gases. The chief difficulty seems to lie in the low efficiency (about 50% of methods and tae relatively low concentrations of ethylene in the gases treated. Gas from Trent amalgam*** contains much larger percantages of ethylene than does coke-oven gas, as Will presently be shown, and if it should ever prove practIcal to treat industrial ;as for alcohol, this gas would offer attractive possibilities,* Bury, Ernest, Ethylene as Alcohol from Coke-Oven Gas: Gas Journal' Vol. 148, D. 30, 1919, pp. 718.** DC Loisy, M.E., Sur un procede' industrial de fabrication syntlotique de l'alcool et de l'ether a partir des gaz de distillation de la houil Comp Rend, vol. 170, Jan. 1920, p. 50-3.*** A paste consisting of approximately part oil such as that obtained as for cleaning coal. See Perrott. in cleaning coal, Chem 3 parts finely pulvarized coal and 1 final product in the Trent, process StJ, and Kinney, S.P. The use of oil Vol. 35 August 3, 1921, p, 183.. & Met."

Nov 1, 1922

By R. Agarwal

The in-situ stress field was determined, using the overcoring technique, at two underground sites at the Pea Ridge Mine, Sullivan, Missouri. At one of the sites in magnetite, the three dimensional stress field showed the largest principal stress to be compressive (-4564 psi), nearly horizontal and closely parallel to the strike of the orebody. The smallest principal stress was also compressive (-2047 psi) and nearly vertical. Considerable difficulty was experienced in drilling porphyry rock at the second test site in the host rock. Only one hole was drilled at this site. The secondary principal stresses obtained in the porphyry are -9464 and -4945 psi, respectively. The-test site in magnetite is located at a depth of 2505 feet whereas the site in porphyry rock is at 2475 feet. The vertical stresses: due to overburden loading at these sites are -3590 and -2782 psi, respectively. Field determined values of the vertical stress are -2207 and -5098 psi, respectively. The variance; between the two sets of values is most likely attributable to the orebody formation and the differences in the modulii of the host rock and the orebody.

Jan 1, 1977

By W. W. Adams

"The third annual safety contest for plants producing sand and gravel, which was conducted in 1911 by the United States Bureau of Mines in cooperation with the National Sand and Gravel Association, registered further progress in safety as compared with the two previous annual contests. Both the accident-frequency rate and the accident-severity rate were reduced.The period covered was the calendar year 1931; sixty plants participated, and 17 States were represented by the participating companies.The contest covered accidents and man-hours worked by all men at the participating plant who were employed by the same company; and it included work up to the point of delivery of the material directly to the consumer or to an independent agency of transportation--in other words, to the point of relinquishment of control of the material by the producer.The purpose of the yearly contests for producers of sand and gravel is to aid in the promotion of safety among the employees and in the reduction of accident costs to the companies. The contests develop friendly rivalry among the various plants and among the employees of individual plant in a concerted effort to prevent accidents.Two safety trophies are awarded annually, both of which are provided by Rock Products magazine. One of the trophies is for the host safety record among plants that were in operation the contest year 100,000 or more man-hours; the other trophy is for the best among plants that were in operation lees than 100,000 man-hours. Awards and the relative standing of the various plants are based upon statistical compilation by the Bureau of Mines of accident reports and employment reports furnished by the enrolled companies. are summarized at the close of each year, and the summaries are submitted to each company concerned for certification as to the accuracy of the summary and the completeness of the company's reports from which the summary was prepared. When the summery is returned signed by an official of the company, the records are considered to be a trustworthy basis for determining the relative standing of the various plants. The position of each plant is determined by its accident-severity rate; that is, the number of days of disability resulting from accidents for each 1,000 men-hours of work done by all employees at the plant."

Aug 1, 1932

By Lloyd A. Morley, Robert Stefanko

1. Anonymous (Berggewerkshaftliche Versuchsstrecke), "75 Jahre Berggewerkshaftliche Versuchsstrecke, 1894-1969," 1969. 2. Anonymous, British Symposium on Flameproofing and Intrinsic Safety, IEEE Conf. Report Series No. 3, 1962. 3. Anonymous (Ministry of Fuel and Power), "A Review of Electrical Research and Testing with Regard to Flame-Proof Enclosure and Intrinsic Safety of Electrical Apparatus and Circuits," 1943. 4. Australian Standard Specification, ASC-98, "Electrical Equipment for Explosive Atmospheres," 1970. 5. Belgium Standard Specification, Norme NBM 286, "concernant la protection par enveloppe antideflagrante," 1965. 6. Bossert, J.A., "Approval for Electrical Equipment for Hazard Locations," paper PCI 66-33, IEEE 16th Annual Petrol. and Chem. Ind. Conf., L. A., California, Sept. 15-17, 1969. 7. Bossert, J.A., "Intrinsic Safety in Canada," Electrical Safety Practices, ISA Monogram, vn. 112, 1969. ,8. British Standards, BS229, "Flameproof Enclosure of Electrical Apparatus," 1957. 9. British Standards, BS4683 Part 1, "Classification of Maximum Surface Temperatures," 1971. 10. British Standards, BS4683 Part 2, "The Construction and Testing of Flameproof Enclosures of Electrical Apparatus," 1971. 11. Brown, G.R., and Silver, S., "An Explosion Hazard Due to Inflam¬mation of Aluminum Particles in Flat Flanges of Flameproof Enclosures," CEAL No. 197, Canadian Explosive Atmospheres Labor¬atory, 1969. 12. Campbell, J.D., and Chudleigh, J.P., "Problems Encountered in Designing Electrical Systems for Hazardous Areas," paper PCI-69¬31, IEEE 16th Annual Petrol. and Chem. Ind. Conf., L. A., California, Sept. 15-17, 1969. 13. Canadian Standards Association, C22.2 No. 30, "Explosion-Proof Enclosures for Use in Class I Hazardous Locations." 14. Dainty, E.D., and Brown, G.R., "Explosion Gas Temperatures at the Entrance to Flanges of Enclosures Containing 8.5% Methane-Air Mixtures," CEAL No. 196, 1969.

Jan 1, 1974

By Charles Vaught, Warren G. Lacefield, Ronald D. Wasielewski, Philip K. Berger, Henry P. Cole, John V. Haley, Shannon L. Price

A comprehensive review of published research was carried out to identify methods for teaching and assessing critical but nonroutine skills needed for coping with emergency situations. Computerized searches of the relevant data bases were carried out, along with identification of relevant articles and materials by personal contact with experts in many fields. The citations listed in this bibliography resulted from this systematic literature search and review. The computer searches and an analysis of this literature are described in technical report 1. Specific methods for assessing critical skills proficiency in aviation, medicine, organization management, the military, and other industrial/ technical workplaces were described. The potential application of these methods for teaching and assessing (1) critical first aid and (2) self-rescue and escape skills to underground coal miners in annual refresher training was explored. Research and development activities that may improve mine health and safety training were suggested. Most of the entries in this bibliography were assembled in 1984 through 1985. Study of these materials contributed to the completion of the project research that followed. This later work is reported in the project technical report 2 and the final report. This bibliography is most useful when combined with examination of technical reports 1 and 2 and the final project report.

Jan 7, 1988

By R. V. Ramani, A. S. C. Owili-eger

List of Numbers

Jan 1, 1974

By By Staff

"These proceedings consist of papers presented at a Bureau of Mines Technology Transfer Seminar on postdisaster survival and rescue research. Several seminars are held each year to bring the latest results of Bureau research to the attention of the mining industry as quickly as possible.INTRODUCTIONThe postdisaster research program is directed toward research and development of technology and equipment that increases the chances of a miner surviving or being rescued after an underground mine disaster. A disaster is an accident of major proportions, and it may result in the entrapment of miners whose normal egress from the mine is cut off. This often necessitates a rescue operation and a means of keeping the trapped miners alive while they await rescue. The Bureau is currently pursuing research to develop the technology that will enhance the ability of miners to survive such an occurrence. The research is divided into two basic problem areas, survival and rescue. Both areas are concerned with the inability of miners and rescue teams to cope with the postaisaster environment, such as toxic gases, unstable roof conditions, water flooding, and lack of oxygen. In addition, research is also conducted to find ways of locating and quickly reaching trapped miners. Most of the research conducted by the Bureau has been directed toward the postdisaster problems associated with coal mines. However, most of the research results are also applicable to noncoal mines as well.The papers presented in these proceedings address some of the recent research conducted by the Bureau of Mines that has been directed toward the postdisaster problems outlined above. The topics covered range from an overview of the technology developed for oxygen selfrescuers to training programs for mine rescue. Any questions or comments pertaining to this research are encouraged and appreciated. Open file report (OFR) references in the proceedings listed as available from NTIS may be obtained from the National Technical Information Service, Springfield, Va. 22161, and are also available for reference at Bureau of Mines facilities in Denver, Colo., Twin Cities, Minn., l3ruceton and Pittsburgh, Pa., and Spokane, Wash.; the Department of Energy facility in Morgantown, W. Va.; the National Mine Health and Safety Academy, Beckley, W. Va., and the National Library of Natural Resources, U.S. Department of the Interior, Washington, D.C."

Jan 1, 1982

By Wesley A. Grosh

The Vest nickel prospect, in Floyd County, Va., was discovered about 25 years ago. Limited exploration of the deposit had indicated some appreciable nickel mineralization in the sulfide ore. The property was examined on March 9, 1943, by an engineer of the Bureau of Mines in company with C. W. Vest, owner of the property. A limited exploration program was recommended. Two holes totaling 320 feet were diamond-drilled in January 1944. Drilling indicated the sulfides are sparsely disseminated. The only nickel values of interest were at the old prospect shaft.

Jan 1, 1949

By Lloyd A. Morley, Robert Stefanko

This report has presented a literature review of explosion proof¬ing of coal mine electrical equipment. The international "state-of¬the-art" is an extremely difficult definition to quantify but, from the preceding paragraphs, it is evident the international community be¬lieves that it is represented by the International Electrotechnical Commission's Publications. Five questions were set forth during the beginning of this report. Each will be evaluated in light of the preceding discussion. 1. Can Schedule 2G specifications on explosion-proof containers be substantiated? Literature was found in the three main problem areas, surface temperature, mechanical strength, and explosion transmission, to determine this. Surface temperature requirements are adequate except for equipment that can normally overload, and the required intern¬al pressure does afford some margin of safety. However, in terms of safety, gap dimensions are about ten times smaller than that needed. 2. Is it possible to replace the Schedule's design requirements with performance specifications? Two primary areas were determined as mechanical strength and explosion transmission. As was mentioned, for present flange and gap standards, the 150 psig requirement is adequate. Furthermore, it is the authors' opinion that the level cannot be re¬duced if the present gap requirements are retained. The Schedule now requires that 16 tests be run, but the literature suggests that only from three to six examinations are necessary. Then by using the abso¬lute maximum pressure from these measurements or 150 psig, whichever is

Jan 1, 1974

By Philip G. Freeman

The growth-promoting properties of coal-derived humus were tested by a variety of bioassay methods. Humate materials used included leonardite, a form of naturally oxidized lignite, and humic acids extracted from leonardite. It was found that the greatest effects were evident when water-soluble humic acid was applied to excised root tips. No significant short-term effect was noted when water-soluble humic acid was applied to stem or coleoptile sections. Root initiation was promoted in bean stems when high concentrations of coal-derived humate were applied. Gross weight of tomato plants was increased by up to 40 percent when coal-derived humates were added in concentrations of 101 to 104 ppm to the nutrient in a hydroponic growth test of 6 weeks' duration. It is concluded that coal-derived humate promotes the uptake of minerals, specifically iron, by serving as a metal chelate.

Jan 1, 1968

By Jr. Watts, B. K. Cantrell, D. H. Carlson, K. L. Rubow

"Abstract — The use of diesel equipment in underground coal mines is controversial because the National Institute for Occupational Safety and Health (NIOSH ) regards ""wholediesel exhaust"" as ""a potential occupational carcinogen."" Threshold limit values (TLVs ) are recommended for the gaseous pollutants CO, CO2, NO, NO2, SO2 and some hydrocarbons emitted in diesel exhaust. There is, however, no TLV recommended for diesel exhaust aerosols (DEA) nor is there a standard method for sample these aerosols.The University of Minnesota and the USBM have collaborated to develop a personal diesel exhaust aerosol sampler (PDEAS) that utilizes size selective, partial impaction and gravimetric analysis. During the field tests of this sampler, numerous air quality measurements were conducted in underground coal mines that used diesel equipment. The objective of this report is to present these data and to assess the impact of diesel face haulage equipment on mine a quality.Air quality data were collected in four underground coal mines. The mines used continuous miners and diesel haulage equipment. Daily samples were collected at the section intake, haulage way and on haulage vehicles. Both full- and partial-shift samples were collected using a variety of aerosol instruments. These included the PDEAS and the micro-orifice uniform deposit impactor (MOUDI) that sample the mine aerosol diesel exhaust fraction. Two of the mines were also monitored for the major gaseous constituents found in diesel exhaust CO,CO2, NO, NC, and SO2. These measurements were made by either collecting bag samples for subsequent gas analysis or by Palmes dosimeters.Concentrations of CO, CO2, NO, NO2 and SO2 were well below regulated levels. The mine average DEA concentration determined by the PDEAS in the haulageway for the three mines surveyed was 0.79 mg/m4, with a standard deviation of 0.19 mg/m3 DEA contributed 65% of the respirable aerosol, at this location. These results were the same as the mean DEA concentrations calculated from size distribution measurements obtained using the MOUDI. This was 0.78 mg/m3, with a standard deviation of 022 mg/m3."

Mar 1, 1992

By John R. Benham

In 1979 and 1980, the U.S. Bureau of Mines and U.S. Geological Survey conducted a mineral survey of the 20,500 acre Black Butte RARE II area (No. 5102) in the Los Padres National Forest (fig. 1). The work by the Bureau of Mines indicates that the potential tor mineral resources in the area is low. Samples of outcrops and stream channels contained no economic minerals. A mercury deposit near a granodiorite-sedimentary rock contact occurs 2 mi northeast of the study area, but similar deposits have not been discovered within the area. Geothermal potential exists near Tassajara Hot Springs, but no thermal springs occur in the area; nor have oil, gas, or coal resources been found.

Jan 1, 1982

By Ludwig Schmidt

Investigations conducted by the Bureau of Dines pertaining to the reduction of evaporation losses of petroleum have shown that such losses may be reduced 70 to 80 per cent by the use of vapor-tight tanks equipped with vacuum and pressure relief valves, and vapor-tight thief hitches. Additional studies have shown that it is often economical to supplement this type of construction with other measures that will reduce evaporation losses still further. Water-cooling systems, insulation, and light colored paints are the measures most often used in connection with vapor-tight tanks. Painting with light colored paints probably is employed in the greater number of cases. On account of the cost of insulation, or of installing water cooling systems, the use of these methods are restricted to tanks containing gasoline or crude petroleum with a very large content of low-boiling fractions. The effect of cooling systems has been discussed in a previous report.2 In choosing paints for tanks many factors must be considered. Probably the three most important are cost, protective value, and color. Many companies have adopted a standard color for all of their tanks in this way they reduce the initial cost of paint by buying in large quantities. The tank farms of such companies usually have a neat appearance, resulting from the uniform painting of all tanks. This procedure also has advertising value. Unfortunately, most of the paints used to protect steel are of the darker colors, usually red or black. These colors accelerate the rate of evaporation. Several companies have solved this difficulty by using a dark colored metal-protective paint as a primer coat, and a paint of any desired color for the final coat. Special metal-protective primers to be used under light-colored cover coats have been placed on the market by several paint manufacturing companies.

Jan 1, 1925

By G. E. McElroy

This paper3/ is one of a limited series being prepared by the Bureau of Mines to supplement a more extensive series on mining and preparation methods in the various mining districts of the United States. It describes ventilation methods and practices at the anthracite collieries in the Northern field of the anthracite measures of Pennsylvania as obtained by personal inspections in twenty of the larger collieries during 1933 and 1934 and from supplementary information furnished then and later by operating officials. This field is one of the four major divisions - Northern, Eastern Middle, Western Middle, and Southern - into which the anthracite deposits of Pennsylvania are naturally divided, and constitutes, in plan, a slightly bowed lens, about 60 miles long, and that extends from Forest City on the north through Scranton, Pittston, Wilkes-Barre, and Nanticoke to Shickshinny on the south with a. maximum width of 6 miles. It is the oldest and largest producing field of the four, and has produced continuously from 1S09. The total anthracite production for the State reached a peak of about 100,000,000 tons a year in 1917, but in recent years production has averaged about 50,000,000 tons, of which somewhat over half comes from this Northern field. The operations of three of the largest producing organizations in the State are almost wholly included in this field, as well as about half of the operations of two others of the six largest producers, It comprises the first 14 of the 25 numerically designated anthracite State inspection districts.

Jan 1, 1937

By G. R. Hopkins

[Apparent progress in economy at petroleum refineries, as measured by the average amount of hest units required to refine a barrel or crude oil, received a set-back in 1938, when the average rose to 567,000 B. t. u., compared with 562,000 B. t. u. in 1937 (see fig. 1). The primary factor in the rise in average heat requirement's per barrel of crude oil refined in 1938 was the decline in total runs to Invariably the average requirement increases when crude inn to stills decline, and vice versa. In other words, annual gains in fuel efficiency at refineries are masked by the degree to which the capacity is utilized. Additional crude runs give lower average heat requirements in two grays first, because they are mane with the expenditure of cc-comparatively small amounts s of auxiliary heat, and, second, because additional runs generally represent simple topping operations. In 1938 crude runs to stills declined 1.6 percent (from 1,183,440,000 barrels in 1937 to 1,165,015,000 barrels in 1938), but the total heat consumption declined only 0.4 percent, or from. 663,866 billion B. t. u. in 1777 to 660, 56 billion in 1938.]

Jan 1, 1939

By S. R. B. Cooke, J. Bruce Clemmer, Will H. Cognill, F. D. DeVaney

"INTRODUCTION The domestic production of potash has made rapid strides in the past 4 years. In 1929 the United States produced 109,820 tons of potash-bearing material, equivalent to 61,590 tons of pure potash (K20). In 1933 to this had increased to 331,110 tons, containing 143,378 tons of potash, due chiefly to the development of the potash deposits near Carlsbad, N. Mex. The potash ores of that district occur at a depth of about 1,000 feet and as mined consist of a mixture known as sylvinite containing about 40 parts of sylvite (KC1) and 60 parts of halite (NaCl). By careful mining the extraneous material does not amount to more than 2 or 3 per cent. Such ore was used in the experimental work here reported.The usual chemical method for the recovery of potash from sylvinite, while efficient in the production of pure potassium chloride, requires,expensive equipment and is costly to operate. It occurred to the Bureau of Mines that ore-dressing methods, which have been applied to other nonmetallic minerals, might be adapted for the production of a grade of potash suitable for the fertilizer industry. After preliminary study by the Bureau of Mines showed that ore-dressing treatment was possible the investigation was extended under a cooperative agreement between the U.S. Bureau of Mines, the Potash Company of America, and the Missouri School of Mines and Metallurgy, Rolla, Mo.ACKNOWLEDGMENTSAcknowledgment is here given for valuable assistance in the laboratory of R. G. O'Meara, assistant metallurgist. U.S. Bureau of Mines, Tuscaloosa, Ala. who was on detail at the Rolla station during the early work; by E. W. Gieseke and Albert Ollar, temporarily employed by the Potash Company of America; and to N. H. Lenz, an engineer temporarily assigned to the station."

Feb 1, 1935

By C. V. Davis

In the lnvestlg::ìt1on of mAthods for aSS8.7ing platin",. conducted by the Bureau ot MinAs, reoent experiments have d~velopad tha~ with ce..tain orei, especially when thr, quantity Of platinum 1s eonlidarablfl, nit'!le acid w111 not etfßct a iepard-Han of platinum and pa11adium. 'lhe following m;lthod has been found to be accurate and to reiu1 t in a complete S''lun''ation of' th~3:l metals. It is therefo 1" '!eeommei:ed that 1 t ba followed rath::r- than the method of separation with nitrio acid, givèn in Technical Pape'! 270.* At line 22, pagi 14, of that paper, bAglnnlng with ~tarm th,~ metals '.'ith dilute¡ nitrio acid," strikE out the rest of the paragraph, and substttutt~ the pro_t cedure g1 ven below. ?lunder and Thuringer.. have developed mnt¡iods for th"i sflparation of palladium from all the platinum metals exoept platinum bj m ,ans of dlmethy- 19lyoxlme. They state that the~ is no action for several hours if an excess of dimeth¡lglyoxime is added to an aqueous solution of ohloroplatinic acid in the cold, alio that only on boiling is the platinum pTecipi ated ¡~d than only PST't of the platinum i srenoved from the sUut1on. They found that palladium 1s p~ecipi tated quati tat! vely in the oold as (CaH 4N40 Pd) which is insoluble tn water, dilute hydroohlorio acid, dilute acetIc aofd or in 50~ ethyl alcbhol. All of their pT'90ipi tations we~p Carl". ied out ~hile the solutions were being heated. This caused a pal"tia~recipltation of the platinum along wi th the

May 1, 1922

By G. E. Walden

The Bureau of Mines is currently engaged in a continuing investigation of the thermodynamic properties of certain inorganic compounds. As a part of this investigation, the heat contents of bismuth and cerous chlorides were measured throughout the temperature ranges of 370° to 630° K. and 370° to 1,200° K., respectively. Equations representing heat contents as a function of temperature were derived from the data by the method of least squares. These equations were used to calculate heat contents at selected temperature intervals ranging from the ice point to 650° K. for bismuth chloride and to 1,200° K. for cerous chloride; also, the heats of fusion of both compounds were calculated at their respective melting points. EXPERIMENTAL Materials The cerous chloride used in this investigation was supplied by the National Carbon Company of Cleveland, Ohio. A chemical analysis indicated Ce 56.57 percent and Cl 43.39 percent. No attempt was made to purify the compound or identify impurities since the analysis showed only about 0.04 percent total impurities. Reagent grade bismuth chloride was used without additional purification.

Jan 1, 1961

By Walter O. Snelling, C. G. Storm

Although descriptions of the methods of analysis of explosives are to be found in many books on explosives, and in works on engineer- ing chemistry or chemical analysis, most of these descriptions are incomplete and lacking in details. The methods of analysis employed in the laboratories of most explosives factories are frequently treated as trade secrets, and very little information is published from such laboratories. This bulletin outlines the methods of analysis that are used by the Bureau of Mines in the examination of certain classes of explo- sives. The present form of most of these methods has been worked out in the bureau's explosives laboratory. The methods employed by Prof. C. E. Munroe were taken as a basis, and were elaborated to meet the demands incident to the treatment of complicated mix- tures and to the development of the explosives art. A subsequent bulletin will discuss the methods of analysis of "permissible" explosives, many of the latter being of decidedly complicated char- acter and requiring special treatment. This bulletin presents the methods of analysis of "ordinary" dynamite, and the ammonia, gelatin, low-freezing, and granular dynamites, and the common grades of black gunpowder and black blasting powder. The bulletin is published by the bureau for the information of all persons inter- ested in explosives and their safe and efficient use in mining work. As the term "ordinary" dynamite, though much used, has no conventional meaning, and may be used to cover a wide variety of compositions of matter, it may be noted that the standard dynamite used at the Pittsburgh testing station is a good example of the "ordinary" dynamite known in this country. This testing station dynamite has the following composition:

Jan 1, 1913

By G. St. J. Perrott

Through the development of manufacturing processes whereby ethylene glycol can be made on a large scale; ethylene glycol dinitrate is now being used in high explosives (dynamites and permissible explosives) by some manufacturers as a low-freezing ingredient of the "explosive oil" instead of such compounds as nitropolyglycerin and nitrosubstitution compounds. The amount of ethylene glycol dinitrate being used constitutes 25 to 50 per cent of the oil. The purpose of this report is to give the results of toots, to determine the effect on the safety and physical properties of permissible explosives of subsituating 25 peg cent of ethylene glycol dinitrate for an equal amount of nitroglycerin or a mixture of nitroglycerin and nitropolglycerin.

Jan 1, 1929