Giant Among Globes -- This 11-foot-diameter world globe, a magnificent achievement in cartographic and engineering skills, dominates Explorers Hall, the National Geographic Society's new museum of discovery and exploration on the ground floor of its new headquarters building. The globe can be maneuvered in any direction and to any position from the portable console in left foreground. Standing at the console are Dr. Melville Bell Grosvenor (right), president and editor of National Geographic; Dr. Melvin M. Payne (center), executive vice president and secretary of the Society; and Ralph E. McAleer (left), the Society's chief cartographer, who directed design and construction of the unique globe. The thousand-pound sphere, built by Atkins & Merrill, Incorporated of Sudbury, Massachusetts, is set in a black granite fountain and pool. Explorers Hall will be open to the public beginning January 20, 1964.