Mules were originally used to haul the coal out of the mines.

Once locomotives were adapted to coal mines, mules were replaced.

Mules were replaced with locomotives, like the one pictured here, that ran on rails laid throughout the mines.

Men rode into mines on a machine called a man trip.  The one pictured here ran on rails.  Prior to man trips, miners would have to walk into and out of the mines.

Inside a mine.

Mine roofs were supported with beams.  The coal seam is straight ahead.

Another coal seam.

The only light in mines came from the small lamps the men wore on their heads.

The height of a coal mine was determined by how thick the coal seam was.

This coal seam was much thinner than that of the previous photo.  Notice neither of these miners are standing upright.

Locomotives were eventually replaced with continuous belt systems that carried the coal to the surface.

Miners began "rock dusting."  This procedure reduced the amount of dust in the air, which reduced the chance of an explosion.  The machine here blows the dust onto the mine walls.