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By Geo. A. Murphy

MR. ARTHUR E. GIBSON (General Manager, Consumers Mutual Coal Company of Utah) : I suppose the reason I was called upon to read this paper was because I was at the mine for several years, but I have not been there for the past four years and the installation has been put in since I left. This article has been written by my successor-it follows: At the very urgent solicitation of your Secretary I have consented to prepare this paper descriptive of the spiralizing plant which is a part of the new steel tipple recently erected by the Spring Canyon Coal Company to serve its mines at Spring Canyon, Utah. I have been reluctant in giving this consent for two reasons: one of which is an excellent one, and the other isn't any good at all. First,, I find that it takes a long time to become familiar with the eccentricities of spirals-to get wise to their whims and peculiarities, and while this plant has been in operation for a number of months, something new seems to crop up nearly every time I see it, and -it would be impossible to describe all of these things even if I remembered them. The second reason is, purely personal. Among the many things I have learned by attending the sessions of the Rocky Mountain Coal Mining Institute is that if a man is not pretty sure of the ground he attempts to cover, he had better keep his mouth shut, because if he isn't right, he is dead sure to be called down by someone. However, as I will not attend the session, this feature will not hurt much, but it will make it necessary for someone else to read the paper and this will make it much better for those who are obliged to listen to it because I don't read English very well. To begin with I will say that what is said in this paper applies only to the plant under discussion as I have had no experience with any other plant. While spirals have been in use for quite a number of years, and there are some large plants in the East, their use has not been general, and I believe the plant at Spring Canyon is the only one in the United States west of the Mississippi River. The details of the plant were worked out by Mr. Thos. R. Stockett, General Manager of the Spring Can= yon Coal Company; it was manufactured by the Anthracite Separation Company of Hazelton, Penn., incorporated in the design and erected by the Link-Belt Company of Chicago, in connection with the balance of the tipple. It consists of five units. Each unit consists of a vertical wood column about 6 inches in diameter, and 9 feet 6 inches in height, around which the spiral is built. It is something like a triple screw conveyor, set vertically, with flights down which the coal and refuse travel by gravity in the process of separation. There are three of these flights, forming a sort of nest but about 7 inches apart, and they make 21 turns around the column in its length. These flights dip toward the column about 27 degrees; they have a uniform pitch downward of 31 degrees; they are 19 inches wide at the top (measured from the column) and taper gradually until they are about 9 inches at the bottom. They are not made with one continuous plate from top to bottom, but are made up of a number of plates. Some of these plates are slightly waved, others have small corrugations in them and still others are perforated with small holes, all of which are intended to accelerate or. retard the movement of the coal and refuse as they pass down, At intervals there are adjustable plates in the flights for the purpose of decreasing the maximum outside;

Jan 1, 1926

Jan 1, 1985

Jan 1, 1926

H. DEAN JACOT RMCMI PRESIDENT 1987-1988 on behalf of The RMCMI Board of Directors and Officers The Rocky Mountain Coal Mining Institute cordially invites you and your family to attend the 84th Regular Meeting and Convention to be held June 26, 27 and 28, 1988 at Beaver Run Resort Breckenridge, Colorado

Jan 1, 1987

Jan 1, 1985

MR. MARGOLF: Our final speaker this afternoon before we have an opportunity for some questions for the members of the panel, is a gentleman who has spent more than 40 years in the newspaper industry. He started out as an office boy while he was still in high school. He worked his way through college working for a newspaper in Lexington, Kentucky where he graduated from the University. He has a long association with the Albuquerque Tribune but what brings him here today is in his position as editor of The Rocky Mountain News which is certainly one of our largest circulations. I think it is the largest circulation newspaper in the Rocky Mountain states. Ralph Looney, in that

Jan 1, 1982

By J. L. Floyd

The Trapper Mine is a large surface coal operation located in northwestern Colorado US. The coal seams at the mine dip an average of 8 degrees so, historically, their dragline pits have been orien-tated parallel to the dip of the coal seam to balance stripping ratios. However, the mine plan in the future G and Z pits is designed to take advantage of pit orientations that are parallel to the strike of the coal. During the initial presplit and cast blasts in G pit, significant slope damage occurred. This damage included the opening of joints and tension cracking. There was also block movement directly above the L coal seam, which is the main plane of weakness in the slope. A detailed site evaluation was conducted to develop specific blast design modifications to protect the slopes during future blasting. The modified de-signs successfully controlled vibration levels during the blasting of the Z pit box cut. This paper includes a review of the blast vibration related factors that influence slope stability along with a detailed discussion of the field tests and design modifications developed.

Jan 1, 2004

PRESIDENT LITTLEJOHN: Before we open the discussion on the Utah mining laws, I want to bring out what I consider a slight misunderstanding on some of the things that I said this forenoon relative to our comparison of accidents. I did not mean to infer that we, as mine officials, are satisfied we have done the best we can to eliminate the accidents, when I was talking about a four-to- one comparison. I do not want any- one to get the idea in their heads that I do not think we are doing all we can. There is not any of us who can state that, even if we better these figures. It is the general understanding that these figures are based upon ratios per thousand man shifts and not upon the tonnage basis that we use. If it were based upon a tonnage basis, I think the figures would be pretty nearly reversed, for we are producing from two to four tons more per man than they do in Great Britain. The discussion will now be continued as I said this morning. There is a gentleman in the audience here that is as guilty of making these laws as I was, and I am quite sure when speaking he will confine himself to the subject of Utah Mining Laws and the prospective results. Before Mr. Monay starts with his paper, I want it understood that this discussion must be finished by 2:30 for the reason that we have still quite a lot of business before us this afternoon.

Jan 1, 1925

By C. B. Huntress

"We have ourselves to blame in the steel industry for our condition." These words were addressed twelve days ago by James A. Farrell, President of the United States Steel Corporation, to his "comrades" at a meeting of the American Iron and Steel Institute. They carry a note of challenge to all industry, and particularly to the coal industry, where they point the way to the pressing need for operators everywhere to get their feet under one table. It is that note which I would stress to all producers. You have yourselves to blame for your condition. True, there are inter-district competition and competition of substitute fuels, but they'll always be with us, more or less, and the only sensible, sane course is to remove the evils within our respective districts, which can be done only by constructive effort along cooperative lines. It's the same story in Alabama, the same in Illinois and elsewhere. The larger number of the men gathered here are at the front, as it were, in the business of mining coal. They are the men who are doing a remarkable operating job. And naturally, the sessions of this annual meeting treat of news from the front, of technical problems. But, as in actual warfare, those at the front are often uninformed of developments in the rear. They keep on fighting without fully sensing the significance of a disaster at headquarters. You've played your eighteen holes today and evidenced the efficiency of your technique in the, production of coal. It is not amiss to take advantage of this moment, the nineteenth hole, to ponder over what it's all about. After all, what do improvements in the art of mining mean if business policies engulf you in red ink? To the extent that mechanization is a factor in increased overhead, which in turn increases the pressure to produce regardless of market demand, it only aggravates our troubles unless there is the controlling influence of coordinated effort.

Jan 1, 1931

PRESIDENT LITTLEJOHN: Is there any member that has any question to ask Mr. McCleary on the subject? MR. TESCHER: What do you figure it costs to do this? MR. McCLEARY: Between one and a half and one and three-quarters cents per kilowatt hour. MR. TESCHER: That includes all charges? MR. McCLEARY: All charges, fuel and labor. PRESIDENT LITTLEJOHN: Mr. McCleary, you were talking about a ten-inch top on the cars. Don't you find there is considerable spillage when raising or lowering the cars? MR. McCLEARY : Not after the men get accustomed to loading cars properly; at first, they just loaded it on in any old way, but wall it onto the cars solidly after a few days at the mine. I do not think we have that condition now. PRESIDENT LITTLEJOHN: Did I understand from the paper there that the rock dust you are using contains 90 per cent silica? MR. McCLEARY: Twenty; less than twenty. PRESIDENT LITTLEJOHN: I got that figure wrong. Are there any other questions to ask? MR. SCHLOSS: I would like to know what kind of machinery Mr. McCleary is using for rock dusting and are they rock dusting the rooms, or not? MR. McCLEARY: We have only recently started rock dusting, and the machine that we are using is Mr. Tescher's machine. We start in at the face of the main entry and move against the air current rock dusting every room and the entry every 50 feet. Every 50 feet, we stop the machine fifteen or twenty minutes at that point and rock dust up in the room and around the entry at that point. PRESIDENT LITTLEJOHN: Do you do any water sprinkling at the faces-at the working face? MR. McCLEARY: Yes, sir, every working face is sprinkled every day, and at least every two days at all points in the mine. PRESIDENT LITTLEJOHN: Does it affect the rock dust in any way? MR. McCLEARY: That was true before we started rock dusting. The faces only are sprinkled now. PRESIDENT LITTLEJOHN: Where you stop to sprinkle with water, you do not figure on rock dusting? MR. McCLEARY: I will just change that around. Where we do rock dusting, we do not expect to sprinkle. Where the faces of the coal are fresh, from day to day, that is where the sprinkling will be clone. PRESIDENT LITTLEJOHN: That is the fresh faces? MR. McCLEARY: Yes. I might add right here, I believe Mr. Tescher made the statement that cross-cuts up an 8 per cent pitch were the steepest that

Jan 1, 1925

By R. S. Morton

MR. CHAIRMAN AND GENTLEMEN: To be invited to address the members of The Rocky Mountain Coal Mining Institute on a particular subject is an honor I sincerely appreciate. The subject of this paper is, ?The Advantages of Having Such Men as the Fireboss Under State, Rather Than Corporation Jurisdiction." On the fireboss, primarily, depends the safety of the mine. When all the rest of the mine workers are still comfortably sleeping in the wee small hours of the morning the fireboss steals noiselessly away, from his bed to take up his daily task, a tour of inspection. He enters the mine, he inspects alone they workings that will be filled with men whose safety is in his keeping. Loyal to his fellow men and responsibilities of his position; he seeks for danger in every place, on every road and travelingway; going over caves, through dangerous places where none of the others are expected or allowed to go alone. How many of us give a thought to these dangers and the faithful work that this guardian performs for our safety. After the fireboss has made this round of inspection, he reports all the dangerous places to the foreman and enters them in the book; he is supposed to have performed his duties; he has no authority to enforce his recommendations. He has found a number of rooms that have not been timebered as they should be for the safety of the digger; he has told the diggers to they timber, up better for their own safety; he has kicked to the foreman about these same places. These conditions. continue until there is an accident. The fireboss reports, broken crossbars or bad roof on a roadway or some other danger to the foreman, but the foreman does not have it fixed, making, excuses, as he cannot put any one on that work today; or that it will stand until some idle day, and that is the way things go until the fireboss gets so he wonders what good he really is, is it any wonder it is hard to get good men to take this position of fireboss? The remainder of the shift the fireboss is used as a general roust-about, having to do such, work as building stoppings, help the timberman or track layers, pull rails out of danger in pillars, a trapper is off and he is told to trap that day, when the mine is idle he is laid off to cut expenses. That is the way the fireboss is treated. The fireboss is not merely a merely a necessity to be lightly regarded but a factor whose authority should be unquestioned. The fireboss has made his district and knows just what conditions the workings are in, and sees lots of dangers that the foreman does not. In the morn-

Jan 1, 1921

By E. R. Gibson

It is quite generally conceded that the coal mining industry is among the most progressive in the adoption of modern and efficient equipment and mining methods, but most woefully antiquated in many respects in the matter of systematic accounting. The cause of this condition is problematical, but is usually thought to be due to false economy. We realize that those who do not understand accounts, or like accounting, are inclined to be disdainful of accounts and statistics, and to under-estimate the benefits derived from the expense and labor involved in proper accounting. The business that is run without a proper accounting system is subject to haphazard financing and courts disaster. Furthermore, the operator who disposes of his product without due regard to the requirements of the industry as a whole, as reflected in the cost of doing business, is an unfair competitor. No one will deny that the possible production of coal in the United States is much in excess of the demand. While it is true there is an occasional shortage in certain localities, it is due to temporary abnormal conditions which are overcome in a short period of time, when the mines are again obliged to take idle time, and herein lies the danger, not alone to the operator who neglects to keep informed as to operating costs; but to his competitor as well. While physical conditions and operating methods differ materially, accounting methods must likewise differ in some respects, but irrespective of how the result may be obtained, a true statement of cost is absolutely essential. Daily cost statements may be preferred by some, but have proven unsatisfactory, generally speaking, because of variation in production as well as in both labor and material expense from day to day; therefore, we will confine our attention to a monthly cost statement. To be most effective, operating cost statements should be prepared and submitted to the officers as soon after the close of the month's busi¬ness as possible, to enable them to remedy any defects in the operations that might be discovered by an analysis thereof. Opinions differ materially with respect to the most efficient method of compiling and the distribution of labor and material. The writer believes that a time book which provides space in which to enter the number of hours worked each day of the month by each employe, together with distribution thereof, is the most accurate, simple and complete. This record will show the service performed by an employe each day of the month and the account to which same is properly chargeable. This, of course, refers only to the employe working by the-day or month. While there can be but little said concerning the compiling and distribution of miners' wages, as the weighman's bulletin used almost

Jan 1, 1921

By Geo. B. Pryde

Dear Sir: Yours of July 23rd, relative to my appointment on the Safety Committee in connection with the Rocky Mountain Coal Mining Institute. As you say in your letter, "The duty of this committee is to draft suggestions as to safer mining practices with the idea of preventing disasters in coal mines." Much has been written and many suggestions made on this same subject, and it is very hard to put up further recommendations than have already been made. The disasters you mention in your letter unquestionably have direct reference to coal mine explosions, which from time to time still occur in this and other countries. As far as our Western mines are concerned, you know that sprinkling and shot firing by electricity have been very extensively carried out. Notwithstanding these precautions; we have had a few rather serious disasters in the past in these mines. I do not care to place any blame or responsibility on the companies having these disasters, but it is a fact that in each and all of them, after careful investigation has been made, that the human element has had more or less bearing on the accidents happening. From most reports that we gain, either directly or indirectly, it is very evident that investigation shows after an explosion that the rules governing one or both of the above safety measures have been somewhat carelessly or negligently carried out. Much has been written and read about rock dust sprinkling, but it is questionable if this method is doing a great deal toward the eliminating of disasters. While it is true it may have the effect of preventing propagation, still I do not believe anyone claims for it a sure preventative against initial explosions. I had occasion not long ago to visit a mine, after an explosion, in which dust barriers were supposed to be hung, and from indications it was quite evident that the dust barriers had been in operation, but they did not prevent the explosion from reaching. all open parts of the mine. It is also true that profuse scattering of rock dust throughout a mine would have a beneficial effect, but there is a question arises here as to whether the sprinkling by rock dust or the spraying by water, if available, is the most effective. I am satisfied that if all coal mines are kept well sprinkled and all open workings maintained in a thorough moist condition, that the biggest factor in a coal mine explosion is in this way eliminated. There is no doubt but what the use of permissible powder, particularly if shot by electricity, has had a very marked effect on the number of dis¬asters in mines, and if this method of shooting was energetically carried out there would be a difference in the number of explosions, both minor and Major, all over the country. Some of the recent explosions have taken place where no shooting was being done, but there is no denying the fact that the other ingredient, namely, coal dust, entered in the elements very extensively. We have read and heard of hydraulic cartridges and other patents (substitutes for powder) that were being worked out for the purpose of

Jan 1, 1923

By John Bevan

In a discussion of the personal dangers that may arise from mine gases, it is necessary to take into consideration the gases which may result from an underground fire, or a fire in or about the downcast shaft, and the methods of avoiding or minimizing the danger arising therefrom. In all cases of the combustion of carbonaceous material such as coals and timber, carbon dioxide and water vapor are formed. In cases where the air supply is limited, some carbon monoxide is produced, the quantity varying with the readiness with which the oxygen from the air can get into intimate contact with the consuming carbon; in addition to these products there may be produced large volumes of irritating fumes consisting of unconsumed vapors' distilled from the burning material. Apart from the physical distress that may be caused by the irritant action of the fumes, the chief danger to life underground arising from a fire in or about the downcast shaft or intake airways is due to the carbon monoxide which the smoke is almost certain to contain. The physiological effects of this gas have already been discussed in mining papers and ref¬erence should be made to this. The prevention of fires at the surface near to the mouth of the downcast shaft, or in the shaft itself, or at the bottom of the shaft, usually lies outside the duties of the fireboss. An outbreak of fire at such places would, however, immediately foul the air current passing into the mine, and, assuming the men were in the mine, create a situation demanding urgent attention of the fireboss. As a rule, each case of fire creates its own problems, but in all cases the guiding principle should be to restrict the poison-laden 'air to the smallest part of the mine that is practicable, by opening separation doors, or breaking down selected stoppings at the most accessible points near the seat of the fire, so that the gases and smoke may pass directly into the return and so to surface. In the case of a shaft fire it will have the effect of fouling both shafts and in the case of a fire in an intake airway, both roadways leading to the shafts. It requires the use of some judgment. Therefore, in circumstances as to whether men inside the mine should attempt to escape to the shafts or should remain in the mine, and attempt to protect themselves from the poisonous air by suitably short circuiting the air-current and retiring from the main air-ways. In order to make such restraint easier, it is very desirable that all mines should be equipped with telephone communication from all sections of the mine to the surface so that men in the mine may be informed of what is being done at the surface to secure their safety, or instructed as to what they themselves should do. In cases of fire in or about the shafts, the question of the reversal of the air-current will probably arise. Should this be decided on by the management at the surface, the fireboss in the mine may have to give some attention to the effects which this action will have on the circulation of the

Jan 1, 1922

By R. A. Marshall

Much has been written by men connected with the coal mining industry, and mining laws have been enacted for the safety of the men employed in the mines, and for the protection of property connected therewith. It seems almost impossible for anyone to select a subject that has not already been read, discussed and put into effect, especially in the coal mines of Western America. There is, however, a subject of much interest to the mining public, and to which I have given a great deal of study and consideration, and which I believe will be received by this convention, and will be given due consideration in the future in applying it to the safety of the mine,- "Efficiency in Shot Firing." Beginning with 1865, and for a period of 28 years in the state of Colorado, the annual reports of the chief inspectors show that 1159 coal miners were killed in the following manner: Five hundred eighty-two by falls of rock and coal ; 517 by gas and dust explosions; 6o by careless handling of explosives and the shooting of coal by the, individual, miner. It is my firm belief that 75 per cent of these fatal accidents might have been avoided, if a safe and proper shot firing system had been installed, at each and every mine. This may sound unreasonable, but I believe that the blasting of coal by the individual miner, and the use of black powder, squibs and fuse has, in reality, caused the death of many miners, from shock after blasting, the shooting out 'of timbers, and working in powder smoke, which fatal accidents were attributed to falls of rock or coal. These conditions led the people of Colorado, through their representatives of the General Assembly of Colorado, to enact a new coal mining law, and in 1913 this law became effective, containing twelve sections devoted to the subject of Efficiency in the System of Shot Firing. During the period 1913 to 1920, the employment of a shot firer, the use of permissible. powder, and the electric hand battery has resulted in safer mines, safer miners and safer shot firers, and I believe every coal mine in the state should employ first-class, certified shot firers, use permissible powder and fire the shots with an electric hand battery. I believe where gas generates in dangerous quantities, which is generally determined by inspection of the mine, and the daily report, the shooting in. such a mine should be done by electric battery located outside of the mine. Where permissible powder is used, I have seen the shot firer start down the mine with a belt around his waist containing one hundred caps, a safety lamp to test for gas, and an open light to ignite the fuse. Would it not be much safer for the shot firer if he used the electric hand battery? In non-gaseous mines where black powder is used, I have. seen the miners carry fuse into the mine, and shot firers have been known to partly tamp the holes, which was

Jan 1, 1921

By Eugene McAuliffe

The subject of my few remarks addressed to the Rocky Mountain Coal Mining Institute, "Guessing or Knowing! Which," may perhaps suggest but little to you here today. However, I am sure you will all agree with me when I say that in the conduct of a coal mining operation there should be no choice between guessing and knowing. The value of, and the results to be obtained from this Institute, its meetings and printed transactions, as well as those of other similar educational organizations, depend very largely on the mental attitude of those who constitute, through their pronouncements, the more active portion of the membership. Perhaps the most apt criticism that is now being made of the coal industry is that, to an extent possibly exceeding any other industry of similar magnitude and importance, it depends for its conduct altogether too much on "rule of thumb" and "tradition," rather than on proven practice and actual fact. The records of our coal mining association meetings bear expression of many conflicting opinions, the majority of which are sincerely put forth by those expressing same as representing the facts; the extremes expressed, however, frequently fix the question raised as one yet located in "no man's land." There are yet too many chances taken we are still "weighing pounds on railroad track scales" and measuring yards with the proverbial "bit of string." The actual expense of conducting any one of the several operations incident to the production of coal is rarely determined, and in many instances the general cost figures, prepared some weeks after the work is complete, are of that sweeping character that very little can be abstracted therefrom. Many coal companies are now making a daily cost sheet, showing the cost of labor and material in detail, as used in the several related operations,, and such is decidedly helpful, particularly to the mine superintendent and his foreman, who, without such, sail an uncharted sea; the auditor's belated monthly summary rarely ever seen by these men who are held responsible for the labor and material used. I have made reference to this situation as an accentuation of the fact that the coal industry contains more "serious minded, conscientious guessers" than does any other similar industry, although the annual cost of our product runs up well beyond the billion dollar mark, and what is more important, our industry is one that still continues to exact a heavy toll of human life. Now this brings me to the question of safety, the one question that should be, and which is, I know, uppermost in your minds. The coal mining world, engineering and operating, is now well sold on at least two things the theory of using permissible explosives and the elimination of the open light. Furthermore, the industry, particularly that portion which is located in Great Britain and the United States and Canada, are now planning vast extensions of the use of "rock" or "shale dust," both in the form of "dust barriers" and in "direct application" to entries and cross-cuts. This is well; however,, my study of past mine explosions has convinced me that the great majority of such had their very beginning in gas accumulations; frequently originating in restricted areas at the working face, in abandoned worked-out areas, or in some other certain place where ventilation is not, maintained as it should be; and that again leads me to the point where it can again be well said, that there is too much "rule of thumb," too much guessing now being done in regard to the volume of air required, and continuously furnished, in a given entry,, panel, room or area. Just to emphasize this situation, is it not a fact that the majority of mine inspectors express the ventilation conditions as measured by them, in terms of cubic feet per man employed, in each certain split, and does not the mining laws of many states yet demand a minimum of "100 or 150 cubic feet

Jan 1, 1924

MR. HARRINGTON: I would like to ask Mr. Bottomley if they fire their shots while the men are in the mine? MR. BOTTOMLEY: No sir; the shot-firing law in our State requires the shots to be fired after the men are out of the mine. We fire more shots than we did under the hand method of loading. Where formerly four holes were drilled, now we drill eight, using the same amount of powder as we did formerly, perhaps a little more, but we use a slower grade of powder. CHAIRMAN LITTLEJOHN: Any further discussion, gentlemen? MR. GIBSON: Mr. Chairman, I would like to ask Mr. Bottomley, if, in his shot-firing system, as I understand it, he has a very high coal and is working something like eleven feet? MR. BOTTOMLEY: Something like that. MR. GIBSON: I read the article that you referred to. Did you use both the first and the second delay explo¬ders in shooting the coal? MR. BOTTOMLEY: We use the ordinary fuse. MR. GIBSON: That is what I wanted to find out; whether you use the delay exploders and the detonators. In Utah, we are getting away from the fuse altogether, because we do not think it is accomplishing anything to use the electric light on the cap, and' at the same time shooting with fuse. We are defeating the object we might gain in using the electric safety lamp. That is a point that might be discussed a little further. MR. E. H. JOHNSON, The Coloder Company: I would like-since it is a general opinion that mechanical loading breaks up the coal, to ask Mr. Bottomley, if he finds a larger percentage of small coal, or how much, through the use of the mechanical loaders? MR. BOTTOMLEY: We do not find any great difference. In fact, we have succeeded in improving our lump coal percentage, and that is important, because it is largely domestic. At first, when the machines were installed, the boys shot the coal too hard, and we fell down a little, about two or three per cent, the first month, in our lump percentage, and we tightened up a little and changed our methods in shooting and got on to the stunt of drilling more holes and getting a slower grade of powder. We could not load as much coal in one day as we could before, but we did succeed in in. creasing our lump coal percentage four and a half per cent over the hand method, and that is quite a factor-quite an important factor and since our domestic trade is over with, we loosened up on the shooting and we are running about the same as we did with the hand loading, maybe a half per cent more, or one per cent, but pretty much the same. MR. SHUBART: Your coal is very high? MR. BOTTOMLEY: Yes. MR. SHUBART: Have you tried sunbbing the coal before shooting? MR. BOTTOMLEY: No, we have not tried that. It is very hard coal to shoot; we have no defined cleavage in our coal. It is the worst coal I ever saw to shoot. We do not try to snub it. Formerly, as I said, the miners drilled four holes, pretty well up near the top, and then four holes down, within about three feet of the bottom. It is the same thing as a snub shot, and that we find is the best method for shooting the coal. We have not tried any mechanical device for snubbing as yet. SECRETARY SHUBART: At one mine I saw snubbing tried with a Jeffrey undercutter with a seven-foot Jeffrey bar. This mine, by the way, is very similar to Mr. Bottomley's condition. They have very high coal, so the snub cut is a small percentage. They cut a seven foot undercut and raise the machine on an eight inch tie and undercut five feet to give the effect of a snub cut, 14 inches at the front of the cut, and then six inches at the back of the cut. They made a very marked increase in lump. (The bug dust would be a small percentage of the total coal), and they increased the percentage of the slack at the same time. They found a decrease by reason of the easier shooting of about 15 per cent in their slack. In other words their nut and lump coal ran considerably higher and their slack decreased 5 per cent with the snubbing cut. Mr. Bottomley, I believe, understands those conditions.

Jan 1, 1926

D. HARRINGTON: Owing to lack of funds, the United States Bureau of Mines have made no experiments in the Bruceton mines in the use of mudite. MR. McAULIFFE: I doubt that mudite cam be delivered at fifty cents a ton and that a mile of heading can be treated with mudite for ten dollars. You could not dig a ton of sand out of a sand hank for that money. L. C. CLARE: The tram road leading to Wattis mine crosses a shale bed and it is easy to screen the shale through a %-inch sieve and load it into a mine car. W. J. REID: A slow trip passing through a mudited entry will dislodge practically no dust, a rapid trip will make air disturbance enough to coat the cars with fine dust. MR. PRYDE: We have used mudite on stoppings around a fire in Reliance and for two months thought they were getting good results, but the fire was found to be drawing air and to be spreading. This mudite was smeared over the stoppings with a trowel. After this apparently failed we used dry adobe.

Jan 1, 1925

[WILLIAM LITTLEJOHN President Castle Gate, Utah BENEDICT SHUBART Secretary-Treasurer 521 Boston Bldg., Denver, Colo. .JAMES DALRYMPLE Vice-President for Colorado State Office Bldg., Denver, Colo. HORACE MOSES Vice-President for New Mexico Gamerco, New Mexico .J. B. FORRESTER Vice-President for Utah Hiawatha, Utah P. H. BURNELL Vice-President for Wyoming First National Bank Bldg., Ogden, Utah EXECUTIVE BOARD COLORADO: J. B. DICK Walsenburg R. A. McALLISTER Trinidad NEW MEXICO: W. W. RISDON Albuquerque J. B. MORROW Dawson UTAH: CHAS. LEGER Rolapp R. R. KIRKPATRICK Sunnyside -WYOMING: F. L. McCARTY Rock Springs J. C. RAE Gebo]

Jan 1, 1924

By Parley Potter

GENTLEMEN OF THE COAL MINTING INSTITUTE: I was requested to write an article on mining a short time ago; however, the time has been so short that I have not had time to prepare an article as I would like to have presented it to this body. In writing this article it has not been my intention in making comparison of various mines, to favor one or discredit the other. I hope it will be considered in that light. The coal mining industry as I have seen it in the past, at present and in the future. In years gone by large tracts of coal land could be obtained at a very small cost, and as yet coal land may be purchased at a reasonable price in this country, but I believe the time is near at hand when the methods of mining will have to be changed greatly in this country. Many changes have taken place-in the last few years, some of them have been forced by law, others by the coal operators themselves, after being convinced that the changes made were for their own benefit. During my 20 years in the mines I have seen thousands and thousands of tons of coal lost that could have been saved if proper methods of mining had been used. The Room and Pillar system of mining coal is none. too good at its best ; a certain per cent of the coal is always lost, yet it is about the only system that can be used under certain conditions, but where the Longwall system can be used I believe it is the best system yet introduced. If the Longwall system is used' there is no coal lost. You get it all as you advance with the workings. Some coal operators object to the Longwall system for several reasons, and most of the reasons they advance are not founded on facts. For instance some of them claim it is too expensive. I will admit that the cost per ton is a little higher in Longwall than it is in Room and Pillar as a rule for the amount of coal' mined, but after the Room and Pillar mine is finished as a rule there are thousands of tons of good coal lost, for the simple reason that it cannot be mined at a profit. In many cases if the same mine had been operated on the Longwall system every ton of saleable coal could have been mined at a fair profit, and in the long run would have netted the owner much more money than it did under the Room and Pillar system. The Longwall system has been in operation many years in Europe and especially Great Britain, and is the most approved of systems in many countries at the present time. Millions of tons of coal have been saved by its use in those countries. It is claimed that the Armour Packing Company loses nothing but the squeal of the hog when it is killed, and doesn't allow it to squeal much. Why lose coal if the Longwall system of mining will save it? The Longwall mine is far more easy to ventilate than the Room and Pillar mine; the air has a much less distance to travel for the same amount of working face in Longwall than it has in the Room and Pillar.

Jan 1, 1921