6 - CARTIER PRISME, MIRRORED QUARTZ DESK CLOCK An unusual Cartier quartz desk clock employing an optical prism and mirror system to display a concealed Roman numeral dial.

CARTIER PRISME, MIRRORED QUARTZ DESK CLOCK An unusual Cartier quartz desk clock employing an optical prism and mirror system to display a concealed Roman numeral dial. Year: Circa 1980s Dial: White dial with black Roman numerals and black hands, concealed within the base and reflected through a system of mirrors and prisms, signed Cartier. Calibre: Quartz movement. Case: Rectangular architectural case with gilt metal frame, vertically ribbed silver sides and mirrored prism interior, base signed Cartier and numbered 582011. Dimensions: Approx. 28 x 41 mm Gross Weight: Approx. 118.5 g Signature: Dial and case. The Prism Clock, patented by Cartier in 1937, is a small feat of theatre. Inspired by the workings of an underwater periscope, an ingenious arrangement of prisms conceals the mechanism, revealing the dial from the front while leaving the reverse apparently empty. It was the invention of Gaston Cusin, a colleague of Maurice Coüet, the celebrated creator of Cartier's Mystery Clocks. While the latter employed transparent discs to create the illusion of floating hands, Cusin achieved a similar effect through the reflection of a concealed dial.