1898 - Coalmininghistorypa.org

No. 11. BUREAU OF MINES. xiiiresponsibility for mine accidents lias beeu made. The tables audmatter relating to accidents apply to all mine accidents in the State.It has been found impossible to take up the subjects referred to in theAnthracite mines, other than that which will be found in the reportsof the several Inspectors, relating to machinery.The system of mining in the Bituminous mines is principallydouble entry; room and pillar. In some mines the single entry systemis still practiced. An effort is made to draw the pillars in allbut 54 mines. It is very evident, however, judging from the thicknessof the seams and the number of tons secured from an acre, thatthere is not so much of the coal secured as there should be.This isbelieved to be due largely to the fact that in certain localities the coalis easy of access and in almost unlimited quantities, thus creatingno apparent necessity for any effort to depart from old and crudemethods which result in a large portion of the coal being wasted. Onthe other hand, Avhere the coal is not so easy of access, and requireslarge inyestment for development, much more effort is manifested inan endeavor to secure all the coal. Old methods are lost sight ofand new systems are devised suitable to the conditions that exist,having in view the securing of all or the greatest possible quantityof the coal. In a visit to the Oliver Mines, in looking over the mapsvnd in conversation with the superintendent, Fred. C. Keighley, itwas found that old methods had been ignored and new ones adopted,which resulted in a very material increase in the number of tonssecured per acre. Realizing the great necessity for improvement,and having in view the many reasons there are for securing all thecoal, and indirectly to stimulate and encourage the timid, Mr.Keighley was asked to write a description of the difference betweenthe old and new methods, and to make some drawings illustratingthe same, which are herewith produced.Mr Robert Brownlee, Chief of Bureau of Mines, Pa.:Dear Sir:In compliance with your request for me to furnish youw'th a description of our mining methods, I herewith enclose to youplans of part of the workings of Oliver No. 1 and No. 2 mines,Oliver, Fayette county. Pa.By inspection of plan you will observe that the object we havebeen working for, for nearly seven years, was to reach our boundariesas quickly as the circumstances would permit, and in the meantimekeep up the output of coal required for 0.30 coke ovens—nearly700.000 tons of coal per year, which was no ordinary undertaking.You will further note that the boundaries have already been reachedill one large section and th(^ retreat successfully begun. Of coursethis added to the cost of producing coal, very materially, during thepast seven years, and the work of development was more than usually