National Geographic Society bookmark commemorating the flight of the balloon 'Explorer II'

Printed on the bookmark is a photograph of a balloon in flight and the text 'This fabric bookmark is a part of the balloon 'Explorer II' which in the service of science attained a world's altitude record of 72,395 feet above sea level on November 11, 1935'. Details of the 'flight of the National Geographic Society - U.S. Army Corps stratosphere balloon' are printed on the reverse, including flight personnel.