Longines Lindbergh Hour Angle Watch

In the mid-1930s, the Longines-Wittnauer watch company marketed a line of watches designed in collaboration with Charles Lindbergh and P. V. H. Weems. The Hour Angle Watch sped computations for determining celestial lines of position. Its bezel and dial allowed navigators to read off the hour angle of a celestial object at Greenwich, eliminating a simple but troublesome calculation.