Donald Wolfe said he would walk there from his apartment on West 50th Street in Manhattan — 38 steps to the elevator, 54 steps through the lobby, 75 steps down the block to the corner and 37 steps across Eighth Avenue. First he put the jug with the water on his wheelchair. His oxygen tank was already in place, on the back. Off he went, pushing the wheelchair, a transport device for the garden supplies if not, at the moment, the gardener. He was not shuffling. Not shambling. But not speedwalking, either. “We’re so dry right now,” said Mr. Wolfe,...