Blogged about Alex’s Jaguar Jump hour yesterday and of course the questions being asked today is – What is a jump-hour watch?
Basically, a jumping hour watch indicates the hour via a rotating disc, with the current hour displayed through a window in the dial on in the case of this Jaguar watch a black line at 6 o’clock.
At exactly 60 minutes the dial jumps forward 30 degrees or in the case of this Jaguar slowly rotates until the next hour comes around. The overall effect is that of a visual simplification to the watch.
Always found jump-hour watches a bit unique and we even picked up a NOS Damas jump hour in December last year. This is your typical jump hour watch and whilst most jump hour look simple in design they actually have more complicated movements. This is because the movement needs a complication that will rotate the hour disc 30 degrees in a snap.
This requires additional force as well precise timing. The trouble is that historically, these movements have been inaccurate due to the additional power requirements needed to jump the hour, additional stress is put on the movement creating inaccuracy and in some cases failure.