The U. S. Naval Observatory is preparing to send its 7-in. transit circle to El Leoncito, Argentina, the site of the Southern Observatory operated in collaboration with the University of Cuyo. This expedition has two purposes: (1) to observe the southern reference stars and (2) to improve the positions of the fundamental stars. The latter work will be carried out in conjunction with the U. S. Naval Observatory's 6-in. transit circle operating in the northern hemisphere.