Conventional watchmaking relies on circular motion to indicate time. This category takes a different path. Within Jacob & Co, the Caligula platform introduces a vertical time display where hours and minutes are revealed through a rolling system positioned along the side of the dial. Instead of hands sweeping across a surface, time advances through controlled linear movement, creating a reading experience that is immediate and unconventional.

This mechanism is driven by a set of rotating cylinders that shift precisely to display the current time. Each transition must align perfectly within a confined space, requiring exact mechanical coordination to ensure consistency and readability. The design places emphasis on structure and visibility, allowing the movement of the display itself to define the character of the watch rather than traditional dial elements.