When loading his boxcars a miner had to ensure that a minimum amount of rock was mixed with the coal; too much rock could result in reduced earnings. At the bankhead the coal was passed over a conveyor belt so that rock and shale could be removed. This work was frequently assigned to boys on entering the industry. Steady work, its difficulty varied depending upon the area of the mine from which coal was being extracted; coal from newly developed areas would generally arrive for sorting with more impurities. The wages were lower than those paid underground workers, and many older miners spent their final years before retirement at this somewhat less arduous task. The proximity of boys and older miners at the sorting table provided an opportunity for the transference of mining lore to a new generation of miners. The sorting of coal by hand was eventually replaced by special screens which permitted automatic sorting.
