BARNEY D. EMMART served in the Army Air Forres as a meteorologist during the war, was graduated from Harvard in 1947, and took his doctorate at the University of London. He is now living in Baltimore.

Last of the water witches? At 33 years young, Scott Hemmer walks Nebraska farmland, waiting on the soft twitch of brass rods held in his hands. “Right here,” he says, pointing to the ground. “About a ...