With Longines Watch Co. Francillon Ltd. Extract from the Archives confirming the sale of the present watch to Mr. Zenetos - Longines agent in Greece at the time - on 11 June 1931.
The precise measurement of time has been vital to the progress of navigation throughout history. With the late 1920s started a period of revolutionary changes in navigation and foremost among those responsible for some of the improvements was Captain Philip Van Horn Weems, U.S. Navy, who also trained the famous aviator Charles A. Lindbergh.
One of Weems' inventions was the Second Setting Watch, designed to help aviators plot their courses more accurately. At sea, celestial sights had to be taken with the help of a hack watch, which was set to the ship's chronometer. It was difficult, however, to set the watch exactly, meaning that it differed slightly from the chronometer, which in turn differed from Greenwich Mean Time.
Weems deducted that the difficulty in setting the watch came from the fact that, at the time, it was almost impossible to set the second hand exactly. However, as the second hand could not be set to match the dial perfectly, the solution was to make the dial movable, so that the dial and the second hand could be synchronized at the right time. This ingenious system was subsequently patented by Longines in 1935. Another characteristic of the "Weems" watch is its large ball-sized winding crown, allowing a pilot to rewind the movement while wearing gloves.
The model is illustrated in Longines Watches by John Goldberger, pp. 78 & 79, and an example from the same year as the present wtch, 1931, is on permanent exhibition in the Longines Museum.