National Geographic : 1957 Sep
© National Geographic Society 350 + Rear Adm. George J. Dufek (Left), Commander of Task Force 43, Briefs the Press Newsmen dubbed their headquarters "Bullheim." Correspondents and cameramen for the United Press, Associated Press, Time, Life, The New York Times, the NATIONAL GEOGRAPHIC MAGAZINE, and other publications played a vital role in relaying news of IGY activities to millions of readers around the world. New York Times correspondent Walter Sullivan (center) wrote a best seller on Antarctica, Quest for a Continent, earlier this year. + IGY scientists from the University of Wisconsin set up these instruments at McMurdo Sound to make gravity observations in Antarctica. Measurements of the earth's pull at far-flung spots help determine the globe's exact shape, a key factor in establishing precise distances between continents. Padded case at left contains two delicate quartz pendulums whose rate of swing varies from place to place with differences in gravity. Pulses of light reflected from the pendulums' mirrored faces are converted by a photo multiplier (center) into electronic signals and recorded by the time-interval counter at right. Here Robert M. Iverson and bearded Dr. John C. Rose take a reading. Infrared lamps, used to bring room heat up to 60° F., shed a red glow. Pendulums will not operate accurately when room temperature is too low.