The Air Almanac

In 1932, Weems devised an almanac that greatly reduced the time needed for computing position based on celestial sightings. The U.S. Naval Observatory showed little interest in it at first, but the Royal Observatory in Greenwich began publishing it in time for World War II, when it proved invaluable.

Caption:
It reduced computations for celestial sightings through the use of the Greenwich Hour Angle.
Type: Artifact
Image Date: 2013
Credit: National Air and Space Museum, Smithsonian Institution.
Origin: National Air and Space Museum, Smithsonian Institution.
Creator: Eric Long
NASM2013-00812
Navigators & Inventors
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It reduced computations for celestial sightings through the use of the Greenwich Hour Angle.