In 1912, Louis Cartier collaborated with clock maker Maurice Couet to fashion the first Mystery clock, one of Cartier’s most coveted objets d’art. The futuristic design creates the illusion that the clock’s hands are floating in space, unattached to any movement. This year the company unveiled its Cartier Santos Mystérieuse wristwatch (www.cartier.com), part of the Collection Privée Cartier Paris. Production of the $144,000 watch is limited to 120 pieces. Like its ancestors, the Santos Mystérieuse employs transparent sapphire disks and a cog system that is concealed under the case’s periphery. Cartier constructed the case out of palladium, a rigid and unyielding bright white metal in the platinum family that watchmakers are utilizing with increasing frequency in high-end timepieces. . . .