When the Pit Ponies Lost Their Way

In the coal mines of South Wales in 1904, pit ponies hauled carts through tunnels so narrow that miners guided them with a steady stream of profanity. The animals learned to respond to curses the way a family dog responds to "sit" or "stay." Then something broke open. A twenty-six-year-old former coal miner named Evan Roberts began holding prayer meetings in Loughor, a small village where the River Loughor meets the sea.…