Flying over a desert area in an airplane, two scientists looked down with trained eyes at trees and bushes. After an hour's flight one of the scientists wrote in his book, 'Look here for probable metal'. Scientists in another airplane, flying over a mountain region, sent a message to other scientists on the ground, 'Gold possible.' Walking across hilly ground, four scientists reported, 'This ground should be searched for metals.' From an airplane over a hilly wasteland a scientist sent back by radio one word, 'Uranium'.