Hautlence HL Sphere – a spherical jumping hour with retrograde minutes
Retrograde displays are typically semi-circular indications featuring a hand or pointer that follows the curve of an arc to highlight a horological function.
Examples include either the hours, minutes, the date or the day of the week. At the end of its travel across the arc, the hand will automatically “jump” or spring back to its point of origin and thereafter, repeat its journey.
The retrograde display is an apt term to use for such horological indications. “Retrograde” originated from the Latin word “retrogradus” that was used in the late 14h century in the study of the apparent motion of planets. The observations of planetary motions, Earth’s orbit around the Sun in particular, has allowed us to define time.
“Retro” means “backward” while “gradi” refers to “step” or “move”. It was in the 1530s that “retrograde” was taken to mean “to revert”.
Pocket watches with retrograde displays were produced in the late 17th century. One example with retrograde hours indicated time for 12 hours before returning to its point of origin and restarting yet another 12-hour journey.
Even bi-retrograde displays have been created. For example, one notable pocket watch had the 12-hour retrograde hour display on its left and the 60-minute retrograde indication to its right.
In the late 1700s, Abraham-Louis Breguet used the retrograde mechanism to indicate the date and even the equation of time.
Retro designs or fashion styles inspired from the past have become trendy in recent times. Though it dropped out of the horological spotlight at one stage, the retrograde display function made a comeback in the late 20th century. What must be noted is that the retrograde display is a classic design that has never really gone out of style.
The retrograde date display is a popular indication. Like the standard circular date display disc commonly used, months with less than 31 days will have to be manually corrected.
For perpetual calendar watches such as Patek Philippe Perpetual Calendar with retrograde date display Ref. 5159G, manual setting of the date for months with less than 31 days isn’t necessary thanks to its complex system of cams and levers that can automatically correct the date.
One innovative use of the retrograde display can be found on the Rolex Oyster Perpetual Yacht-Master II as it features a retrograde countdown timer that is designed to be used in sailing regattas.