Tree. Flying the mail between Salt Lake City and Pasco, Wash., for Varney Air Lines, Pilot Jack O'Brien passes over a tiny settlement in the treeless desert near the Idaho-Utah boundary. Always a group of children and their teacher run out from the schoolhouse to wave at their "friend"; always Pilot O'Brien waggles his wings in salute. Last week, to the joy and amazement of the youngsters, Pilot O'Brien circled the schoolhouse at low altitude, dropped a tree, flew on. Looking back, he could see the children seize it, drag it toward the...

