The Longines Lindbergh Hour Angle Watch - World's 1st Transatlantic Flight

The Longines Lindbergh Hour Angle Watch was designed by Charles A. Lindbergh, the first person in the world to fly non-stop across the North Atlantic.

The design is based on an improved navigation system developed by U.S. naval officer Philip Van Horn Weems in 1927. Weems developed a series of navigation devices that could work in conjunction with a special clock.

Weems and Longines developed a watch with a rotating disc that allowed the wearer to synchronize the second hand with a GMT signal—more precisely, a radio signal.

It worked, although the technology with radio beacons was still in its infancy

There are no radio beacons during an ocean crossing. Nevertheless, Lindbergh managed to cross the Atlantic in a modified Ryan M-2, called the Ryan NYP (New York – Paris). Thanks to sponsorship, the aircraft was named the Spirit of St. Louis.

He took off from Roosevelt Airfield on Long Island on May 20, 1927, and arrived at Le Bourget Airport in Paris exactly 33 hours, 30 minutes, and 29.8 seconds later. It was almost a miracle that he succeeded in the crossing, as six previous attempts had ended in death, his aircraft was completely wrecked, and he relied largely on luck.

Upon his return, Lindbergh began work on his air navigation system, based on Weems's development. The exact mechanism is quite complex, but essentially it involves the combination of time, hour angle indicator, sextant, nautical almanac, and calculations of longitude and altitude to determine geographic position.

This is a new navigation instrument that Lindbergh and Longines bring to life in a wristwatch: the Longines Lindbergh Hour Angle Watch, also known as the Longines-Wittnauer Lindbergh Hour Angle Watch.

How does the Longines Lindbergh Hour Angle watch work?

The hour angle hand shows the equivalent of longitude, not in degrees, but in an angular distance that represents the time difference between Greenwich (GMT) and any other point on Earth.

So, if you can use a sextant to measure your position relative to a particular celestial element, see where that element is in Greenwich at a particular time, and know your own time, you can calculate longitude and latitude. More or less

The history of the Longines Lindbergh Hour Angle Watch begins in 1931. The first Longines Lindbergh Hour Angle Watch dates back to 1931 and has a diameter of 47.5 millimeters.

This is the perfect size for a navigation or pilot's watch. It features the Longines 18.69 NSC caliber, a hand-wound mechanical movement housed in a sterling silver case.

This caliber was originally a pocket watch movement, like most navigation watches of the period. The dial is white with champagne. Approximately 2,000 examples were produced by Longines and distributed in the USA by Longines-Wittnauer. In 1938, Longines produced a second series of the Lindbergh.

It has the same case, but with the Longines caliber 37.9 N, also a hand-wound mechanical movement. We're not sure, but it seems the dial, also white with champagne, has changed slightly.

For example, on some models, the Roman numeral IV was changed to IIII. We also found a few models with a diameter of 32.5 millimeters. Perhaps these were versions for women, as Lindbergh's wife often accompanied him on his flights after 1927. This could explain why Longines reissued 33-millimeter versions in the 1980s and 1990s.