Available Now: Introducing The UNDONE Aero Scientific 1940 for The Rake & Revolution

A Little History On The Rotating Bezel

It is widely assumed that the rotating bezel we see on so many timepieces has been invented for diving watches. After all, the rotating bezel part of a dive watch is a vital component for divers as it allows them to see how many minutes have elapsed during a particular dive, and to estimate how much oxygen is left in a diver’s tank to ascend back to the surface.

Well, it turns out that the rotating bezel we’ve all come to love was actually created as a navigation tool for aviation in the 1930’s by U.S. Navy officer Lieutenant Commander Philip Van Horn Weems (1889-1979). P.V.H. Weems stands out in history for his work on what was then called “avigation” which highly influenced modern air navigation, earning him the distinction of “Greatest Living Navigator of his Time.”

U.S. Navy officer Lieutenant Commander Philip Van Horn Weems (Image TBWS)

Lieutenant Commander Weems wrote many books on the principles of aerial and celestial navigation and also invented the tools to stay alive while putting them into practice. The Weems System of Navigation was later taught to many military aviation navigators, and marine navigators. He determined that it was essential to simplify aviation navigation computations, and to develop fast, reliable methods of navigation that were simpler than maritime techniques, even if slightly less accurate.

One of his inventions was the Second-Setting Watch which added a rotating 60-seconds bezel which could be locked in place. This was a game-changer as being able to track activity by the second was a vital requirement for military pilots at the time where accuracy was vital to pinpoint flight paths and avoid navigation miscalculations of hundreds of miles over the course of a flight. With a simple radio call, troops could align the bezel’s vertical zero position with their watches’ seconds hands and coordinate military actions. Ever wondered where the phrase “synchronise your watches” in movies comes from? That’s where; it’s when military men are turning their Weems bezel.

A vintage ad for the Longines Lindbergh Hour Angle Watch and Weems Second-Setting Watch (Image TBWS)

P.V.H. Weems had already worked with Longines on creating the Longines Lindbergh Hour Angle Watch, due to Weems association with Lindbergh after his successful solo flight across the Atlantic, so it was natural that Longines would create the Weems Second-Setting Watch as well. The first versions of the watch featured a bottom clamp to lock the bezel in place, but this was later replaced with a second crown at 2 o’clock to serve that purpose.

US Patent 2008734 for the rotating bezel (Image TBWS)

Vintage Longines Weems Second-Setting US Naval Academy bottom lock watch featuring the US Patent number on the dial (Image courtesy MWR Forum user: rojda)

If you would like to learn more about the complete history of the Weems Second-Setting watch, I highly recommend reading these two in-depth stories which give plenty of information:

The Rotating Bezel Invented by Weems- the Rotary Verge Ring

The History of the Rotating Bezel

Introducing The UNDONE Aero Scientific 1940 - An Homage To The Weems Second-Setting Watch

The UNDONE Aero Scientific 1940

For the aviator and vintage design enthusiast, UNDONE has created the Aero Scientific 1940 with an exclusive aged dial specifically for The Rake & Revolution in a limited edition of 200 pieces. In our eternal pursuit of the best value for our readers, the watch comes with both a leather strap and a stainless steel bracelet.

The UNDONE Aero Scientific 1940 does not only encapsulate the spirit of P.V.H. Weems, it also pays homage to the original timepiece from the 1930’s and the important place it holds in the history of horology; it is a watch that is true to its origins.

The watch features the additional crown at 2 o'clock which functions as a bezel lock, it is designed to clamp down with just a twist of the crown. The wider bezel allows for larger fonts and printing; increasing legibility, while also giving pilots a more accessible instrument to operate while wearing thick, leather flight gloves. True to its vintage inspiration, the Aero Scientific 1940 features an exclusive aged dial for The Rake & Revolution which mimics the feel of patina appearing after many years of wear on the wrist.

Three hands are aligned to three separate tracks for ease of legibility and accuracy of setting. The blued syringe hour and minute hands are luminescent, where the minute hand lume perfectly aligns with the 5-minute markers, allowing for readability and clarity throughout flight at night. At 40mm in diameter, the watch is a comfortable size and the use of 316L stainless steel will insure durability without foregoing the vintage feel of the timepiece. The nostalgic aviation watch is powered by the tried and trusted SII NH35A; a self-wind, hackable, workhorse movement displaying time in a three-hand format, and the Aero Scientific 1940 is fitted with a screw-down crown.