The Tank Basculante was introduced by Cartier in 1932 as a rectangular wristwatch whose case pivots inside a fixed frame, so the dial can be turned face-down to protect the crystal during sport or travel. Its name comes from the French “bascule”, a seesaw. Early examples were small, hand-wound rectangular watches in gold: a Paris-signed example sold by Monaco Legend Auctions measures 23 by 37 mm in 18k yellow gold, with a 22-jewel manual movement, Roman numerals, a chemin de fer minute track and blued steel hands. The model matters as the Paris house’s own solution to the problem of protecting a watch glass, arriving one year after the Jaeger-LeCoultre Reverso.

The Basculante was made for active wearers playing polo or tennis. Unlike the Reverso, whose case slides along a single track, the Basculante swings in a frame and can rotate fully, even standing upright as a small table clock. The link with the Reverso is close: dealers and auction houses credit the mechanism to Spécialités Horlogères SA, the LeCoultre affiliate behind the Reverso, which made the Basculante for Cartier. Like many interwar designs of the house, it never entered regular production at first. The model was revived in the 1990s, including the reference 2391 limited to 365 pieces in an 18k gold case of 25 by 38.5 mm, and later appeared in the Collection Privée and as the Tank Basculante Mécanique with the hand-wound calibre 610.

Collectors treat early Basculantes as rare Art Deco objects, and Paris-signed gold examples command strong prices: the Monaco Legend example, dated to the 1960s, sold for CHF 90,000 against an estimate of CHF 50,000 to 100,000. Enthusiasts often compare it with the Reverso, valuing the Basculante for its rarity and its more playful swinging frame, while the Reverso remains the better-known and more widely produced flip watch. The original model is no longer produced, and dealers report that the later Tank Basculante Mécanique was also discontinued within the last decade, so today the Basculante is found on the vintage and pre-owned market rather than in current Cartier boutiques.