HUNTSVILLE -- Although it was built in the 20th century, the most infamous exhibit in the Texas Prison Museum could be a relic from the Dark Ages: a tall, high-backed, austere, solid oak chair, fitted with leather shackles, like some kind of dungeon throne. Washed in a spotlight's eerie glow, it appears almost medieval. The high-voltage killing machine was the end of the line for dead men walking. From 1924 to 1964, the Texas chair snuffed 361 lives. The electric chair is fading into obsolescence, a dying form of dying in America. It's an optional form of execution in four...