IWC Calibre 79091
A total of 659 mechanical parts, 71 of them jewels, twelve patents and 21 functions and displays, including a perpetual calendar for the next 500 years, together with a perpetual moon phase display made of polished goldstone representing a star-studded night sky. Working inside the case are a chronograph and a highly complex minute repeater with an all-or-nothing piece slide. This wonderful invention chimes the time out the time in crystal-clear tones which are activated by the slide on the left-hand side on the case. Two tiny, precision-made hammers are released and chime the time in hours, quarters and minutes on two gongs. Developing the striking mechanism was a technical tour de force. Initially, the chimes were inaudible outside the solid platinum case, so the glass was freely suspended on a platinum membrane to enable it to amplify the vibrations produced by the gongs via the sound transmission pin. The case, too, finished in solid platinum with a fineness of 95 percent is first class. Despite the complex design of the case, the Grande Complication is unaffected by superficial water splashes.
