The Greenwich meridian or prime meridian is equal to zero. The great circle line passes through the Greenwich observatory in England. Greenwich clock on support takes the shape of an armillary sphere which was invented by the Greeks already in III century B.C. and used as an observation tool for the sky. In the Greenwich observatory there is an armillary sculpture exposed, representing the peak of wisdom and knowledge. Incantesimo Design creates the base in high density and purity transparent methacrylate, the motion work is made of chromium-plated brass. The cut and engraving are carried out with high-tech, computerized devices.