The holidays are ending. The season of dieting and calorie counting has begun. But one bulging shape is timeless. It's the Tonneau watch case. In French, tonneau means a "cask" of varying liquid capacities often associated with the aging of wine. As a watch case design, head-on it resembles a barrel -- rectangular with rounded sides. These sides are sometimes squat; sometime curvaceous. The shape allows for a variety of dial openings including round, elongated, and of course one that follows the same contours of the outer case. Cartier introduced the design in 1906 and it is its second oldest model after the Santos Dumont in 1904. Six years later, the first Vacheron Constantin Tonneau appeared.