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Show 4 INTER-MOUNTAI- Fire-Dam- p and Coal Dust Explosions. BY PROFESSOR II. IIIRSCIIING. The recent explosions in the St. Louis Gilson-it- e mines near Fort Duchesne, killing two men and slightly wounding three freighters, who stood 300 yards away, has called my attention p to the phenomenon called explosions and the prevention of such disasters in coal and asphaltum mines, I consider of great importance to life and property. A few years ago I received some samples of asphaltum from Fort Duchesne district for analytical examination and I found a high percentage of light carburetted hydrogen compounds, free hydrogen and free oxygen, and this result impressed me with the great danger of handling the mineral in the mine as well as outside of the mine. In my report at that time I called attention to this fact and that the proper name for it is glance pitch, and that it can be used for varnish and insolation. The asphaltic limestone found in other sections of the Wasatch chain contains 'also a percentage of explosive gases and if mined underground the same danger exists as with the glance pitch. The former mining inspector of Utah consulted me about the subject and I gave him the necessary advise. Speaking about mining inspectors I cannot refrain from expressing my disapproval of having appointed to such responsible politicians offices, or men who have never seen or worked in any mine, but I am more surprised that incapable men have the audacity to accept such positions. I am of the opinion that as far as tentrical knowledge is concerned the best and the most capable authority of a state should be selected. The miners life and the property should be protected by the most approved modern methods, and therefore no politician, but an engineer of high standing and long practical experience should occupy such a responsible position. The next legislation should consider this question and should pass a law whereby the office will be freed from political llre-dam- influence. A great many able articles have been pub- - j lished and many investigations about the causes of explosions in coal mines have been made. All agree that the 'cause of explosions are the and coal dust, be it by spontaneous or artificial ignition. Safety appliances or many varieties are sugges- fire-dam- ps ; 1 f i ; ted, ventilation and spraying with water, are considered as to the ultimate best preventations. In tunnels or galleries, the first mentioned method is preferred, in rooms the second is resorted to and yet in many collieries frequently explosions occur and lives are lost and properties are destroyed. At the time I was engaged in the practical study of mining, I worked also in a coal mine, and I carefully the nature and character of the deposits. In regard to the coal dust pro-- ; duction, no doubt can exist about it3 source, it is due to the breaking off the coal from the main bank, be it by blasting or picking, the re sult is the same. If we examine such produced coaldust under a microscope, we notice cavities, druses and pores everywhere and subjecting them to a careful chemical analysis we find these cavities filled, with gases, which ignite readily if opportunity, is. given. We have at our academy a simple apparatus, where the gas from coal dust can be recovered and examined and will be pleased to show it to anyone. ob-serv- t . j 1;. ed N MINING REVIEW. Therefore I arrive at the conclusion that coal dust itself is of no explosive character, but the gases which are confined in the coal skeleton are the explosive elements. The more divided the coal particles are and the smaller the coal dust is, the more gas is liberated and ready for ignition and explosion, the glance pitch mining is more dangerous for the reason that more gas is stored up in its dust cells than in coal, and a greater quantity of free hydrogen and oxygen is produced than by any other mining operation. Further we have observed that sometime great cavaties and druses exist in coal and in asphaltum banks and the gases confined in there are all of an explosive character ; if by blasting or picking such caverns are opened great danger of explosion exists. It is of little consequence if small caverns are suddenly opened, as by proper ventilation the percentage of explosive gases will be so diluted that no explosion can occur, but if large caverns are opened the ventilation will not have the desired effect and frequently an explosion is the consequence. If there is a great quantity of coal dust in the mine, it can certainly be ignited spontaneously or artificially for the above stated reasons and a terrific explosion is the consequence. By constant spraying with water the danger is apparently reduced but by no means absolute safety is guaranteed, for it is proven that water by spraying upon coal dust and gases, might decompose and more hydrogen and oxygen is produced thus increasp exing the danger. Studying the plosions from this standpoint in view we come to the conclusion that the prevention of explosions in collieries must be in another direction than in the ordinary safety devices and applications as described. We must look for another method, by this I do not suggest to do away with the already known methods entirely, but in addition to them I wish to introduce a method or a new idea based upon the foregoing principles in order to lessen the danger of explosions and at the same time I have in view to utilize the stored up energy in the form of explosive gases in the coal banks. I have pointed out that the existing gases in coal and glance pitch mines consist chiefly of light carburetted hydrogen compounds, hydrogen and oxygen, and we also know that these gases are decomposed or combined as the case might be by an electric spark into innocuous gases or liquids. Supposing we have made in the breast of a gallery a great many drill holes, say from 4 to C feet deep and leave the iron bars in the holes, connect them with an electric source, the gases in the holes, and if a cavern is struck, will be ignited and the produced energy will loosen the coal, thus saving blasting powder and labor; if no explosion occurs by this application a blast can safely be set, as no firedamp is present. If at certain distances in the mine, and especially at such places where jets are noticed to be active, electric sparks are constantly produced, no large and destructive explosion can ever occur, as the accumulated gases will continuosly be converted into or innocuous compounds. This method of purifying the air in the coal and glance pitch mines looks from the chemical, physical and technical standpoint in view, very and I if believe, practical, properly introduced will make coal mining absolutely safe; of course experiments only can tell the feasibility, and if any one desires to try this method I will assist in carrying out the details; and I further be lieve that the great problem of an(j coal dust explosions in collieries can be solved in this manner and the life of miners and the properties will be not endangered in &uch a way any more in the future, as it has been in the past. Professor Hirschings strictures on the ap. pointment of a politician to the important office of coal mine inspector do not apply to the present incumbent of the office, who is an coal miner, and is in every respect thoroughly capable of filling the duties of the office. Ed. firo-dam- p exper-ience- d Gasoline and Oil Engines. The purpose of trade journals is not only to gather the latest and most reliable information on all subjects which are considered of interest to its patrons, but it is of equal importance to so disseminate the news as to keep its readers posted concerning the latest and best improvements and devices pertaining to their business. The Review has frequently called attention to the use of gasoline engines for mining purposes, especially for hoisting, running pumps, air compressors and mills. This type of engine was first successfully built by the Union Gas Engine Co. of San Francisco, and it has gone through all the stages of development customary with patented machinery, until the modern Union engine has reached a point of simplicity, durability and economy not dreamed of a few years ago, and an examination of that companys recent product discloses a very high class of engineering ability. About 2,000 have been built under the patents of the ellic-ienc- y, Jen-gin- es fire-dam- non-de-structa- ble Union Gas Engine Co. ranging in size from 1 to 150 H. P. in actual use, for all kinds of serv- ice. Amongst the advantages possessed by this type of power is the fact that there is no toiler, fire, heat or ashes to contend with, and the plant is started up only when required for work. It is started and stopped in a moment, and when doing no work there is no expense, and while at work the expense is only in proportion to the power exerted, as the Union gas engine is fitted with a very sensitive governor which accurately regulates the supply of oil in proportion to the power required. Of the many mining companies using Union engines, we have noted that the Sterling Mill & Mining Co. has iwo 25 II. P. and two CO U. P. engines. The Pacific Coast Borax Co. also has four of these engines and hoists, some of which have been in use for five years. The Pioneer Gravel Mining Co. has four engines, one of which, for the past three years, has been at work in a tunnel 1,400 feet from its mouth at the head of the incline. The Santa Rosalia Mining Co. of Sonora, Mexico, the Croesus Gold Mining Co., Nevada City, Cal., Eureka Gold Mining Co., De Lamar, Idaho, the Marguerite mine near Auburn, the Keystone mine, Boundary Line mine and many others. the The illustration above represents one comlatest type of combined hoists built by tni pany. It is strong and compact, and intruded especially for mining use in districts where wood and water are scarce. It is pretty hard to beat one of these outfits for prospecting and developing mining properties. The accompanying illustration is taken from a 10 H. P. thoist which has a drum capacity for COO feet of ope, and will easily raise one ton 125 feet per minute. . is Co. The address of the Union Gas Engine 319 Howard street, San Francisco. : |