408 P . M O O N A N D D . E . S P E N C E R

Centennial Celebration of A.A.A.S. Centennial celebrations commemorating the founding of the American Association for the

Advancement of Science will be held in Washington, September 13-17, 1948. Events of the celebration, centered around the theme "One World of Science," will consist of: (1) morning symposia and panel discussions in various scientific fields of general interest; (2) afternoon excursions and visits to scientific and cultural institutions; (3) evening lectures and social affairs.

The Optical Society of America will not hold concurrent meetings with the Association at this time, but its members are invited to participate in the various events.