Show tha evolution of mining I 1 n 1 in the stone age ace mi mining tillia took no capital and a minimum amount of f experience the tools tran man employed probably consisted of a stone hammer a horn of somo some sort for a pick a board for a shovel and a crude basket for hauling away the pieces of chert for arrow and spear tips which they grubbed out of shale and soft limestone beds X 2 V ev kh re 1 I AE when steel became popular the type of mining changed to wha a hols holes were drilled by hammering on a piece of sharpened steel these holes were then loaded with black powder and blasted the overhead cost for each heading was still very small 3 with the advent of the pneumatic drilling machine costs took a sub stant lal rise the outlay for each heading exclusive of labor rose to around many timea the previous amount r jj ol 01 4 As d development and prospecting have had to bo be done at increasingly farther distances from the main haulage ways speed has become essential sent ial lal necessitating better methods accordingly power driven mucking machines and two or armore m ore machine Jum jumbos boll or drill carriages have replaced hand mucking and single machines until now the total outlay for each heading in it a mechanized chani zed mine Is about |