One major part of the Tank Cintrée’s allure is a sort of horological optical illusion dreamed up by Louis Cartier. Says Cartier collector and watch expert Eric Ku, “The watch was just so radical. Think about going to a dinner party in the 1920s and seeing a Tank Cintrée on someone’s wrist. It would have just blown your mind. The amazing optical illusion of the Tank Cintrée is that it has this aggressively curved shape, and when you see it on the wrist, you ask, ‘How is it possible that they fit a movement in it?’ The genius of the design is the caseback is flat but is recessed into the case, so that it is totally hidden when you wear it. People talk about amazing achievements in architecture in the early 20th century such as the Empire State Building. To me this is equally significant. It is a complete rethinking of how a case is constructed to serve the purpose of beauty. This is why I love Cartier.”
In order to make the watch function, Cartier had to source a very special movement. For this, he tapped the brilliance of his friend Edmond Jaeger, who was himself a dynamic watchmaking entrepreneur. Jaeger designed an incredibly thin movement to make the design possible. In Cartier-speak, it is the caliber 123. It is round in shape and features 18 jewels, a Swiss lever escapement and a Breguet overcoil hairspring. But if you look at how it sits just behind the curved dial of the Tank Cintrée, you can see that there is barely a fraction of a millimeter to spare as it nestles inside the aggressively curved case. Later, Cartier and Jaeger would create the European Watch and Clock Company as the movement maker for Cartier’s watches and so many of the calibers in the Tank Cintrée are signed with the acronym EWC.
