Before the present day coal industry developed, there were two methods used for mining coal.  The first was the painstaking use of picks and shovels to manually dislodge the coal from the mine walls.  The second was the use of explosives to either blast holes in walls or drop the roof to the floor so that the coal could be picked up and put on carts.  Both of these methods were dangerous and physically taxing.
    The present day method of mining coal is the use of machines called "Continuous Miners."  These machines have hinged front portions containing rotating teeth that move back and forth, chewing the coal out of the walls, and at the same time, carrying it to the back of the miner to be loaded onto a transport shuttle.  Below are pictures of these machines: