A similar watch is published in Cartier; The Tank Watch by Franco CocoGNt,1998 Edition, pp. 99-99 and 214-216. Cartier Cabriolet wristwatch At the beginning of the 20th century, wristwatches started to become fashionable namely because they were so much more practical. A watch worn on the wrist, however, was exposed to shocks and accidents of all kinds. Hence, the protection of the watch glass was a major concern for watchmakers, until the invention of new, stronger types of glass, made of strengthened mineral and synthetic sapphir e. Sliding shutters or grills covering the watch glass were effective but the advantage of wristwatches was that they could be pivoted or tipped so that the glass would be placed against the wrist and be even more protected. From 1910 onwards several examples were patented and on July 6, 1926, Cartier was granted a patent for a "wristwatch in which the glass is turned towards the wrist. A point or one ofthe sides o/the case is mounted on the strap in such a way as to allow the watch to pivot around this side...". In the same spirit, a few years later, LeCoultre together with Cesar de Trey and Jaeger, Paris, created the celebrated Reverso (invention of Rene-Alfred Chauvot, patented March 4, 1931). [See also the note entitled " Montres bracelets a couvercle" in Antiquorum's catalogue, Geneva Auction, April 12- 13, 1997, lots 404 and 603.] hi 1932, Cartier launched a watch, initially known as Cabriolet Reversible, later referred to as Tank Reversible. It was reserved for Cartier and patented by Specialites Horlogives S.A., (the distribution company for watches manufactured by LeCoultre, based in Lausanne, founded by Cesar de Trey). The Cartier- Jaeger invention was definitely an ingenious system, permitting a complete 360 degree rotation of the watch case around the horizontal axis and its insertion inside a second case, so as to reveal or conceal the dial. R led to Cartier's Tank Basculante ( meaning "tipping" or "swinging"), in 1936, made on the principle of a number of successive planes inserted one within the other, in which the lateral bars of the case, integrating the strap, were considerably slimmed down. From 1932 to about 1942, a small number of versions with slight variations were produced by Cartier, called Cabriolet, Reversible or Basculante, as well as the very elongated 1942 model. Very few pieces of this type of watches were made by Cartier during the 1950's and 1960's, see The Magical Art of Cartiertheme auction, Antiquorum, Geneva, November 19, 1996, lots 340 to 345. In 1972, Cartier launched the Reversible cabriolet and Reversible gentleman and lady models (see The Magical Art of Cartier theme auction, Antiquorum, Geneva, November 19, 1996, lots 589-590 and 591-593. Finally, in the 1990's, Cartier produced special editions inspired by its watchmaking tradition, namely: 1992 Tank Basculante, limited edition in yellow gold of 400 pieces, made in 1991, retailed in 1992. ( with sapphire cabochon). 1996 A unique Tank Basculante, in yellow gold, dial in gold with roman numerals at 3-6-9-12 and "baton" indexes. ( with sapphire cabochon). This watch was sold by Antiquorum in The Magical Art of Cartier theme auction, Antiquorum, Geneva, November 19, 1996, lots 234. A unique Tank Basculante, in yellow gold, dial in gold with the letters C.A.R.T..I.E.R.P.A.R.LS. ( with sapphire cabochon). This watch was sold by Antiquorum in The Magical Art of Cartier theme auction, Antiquorum, Geneva, November 19, 1996, lots 233. 1997 Collections Arivees de Cartier, a range of exceptional timepieces celebrating the jeweler's 150th anniversary. - Tank Basculante, limited edition in yellow gold of 15 pieces, dial with the motif of "150 years of Cartier". (with ruby cabochon). - The same in jewelry version. - The same with transparent back. - The same with transparent back and Arabic numerals on the dial. - The same with skeleton mechanical. 1999 Tank Basculante, in stainless steel. - large size with mechanical winding. - medium and small size with quartz movement. (with sapphire cabochon). From the time they were first produced, there was a specific market demand for this type of watches, even if only of a select clientele, which arose more from social and aesthetic reasons, rather than from strictly functional ones, since such watches could be worn With the dial side up or concealing the dial and showing, engraved on the case, a motto, coat of arms or initials. Literature Cartier, The Tank Watch, by Franco GOLOGNI, Flammarion, Paris- New York, 1998, pp. 97-100,214-216.