That finky electric clock posted below got me digiing through the books and pics.
Thought you might be interested to see some early "digital" watches. In these watches, the hour and minutes are displayed numercally, and use rotating plates, similar to those used in the date function of a modern watch. A spring driven finger causes the disk to "jump" to the next position, hence the name.
Quite possibly the earliest jump hour was this one by Blondeau, a one of a kind piece from 1830. It was made for Louis-Philippe d'Orléans, the French king at the time.




Later on, in the 1880's, The production jump hour watch was designed by Joseph Pallweber for manufacture by Cortébert and International Watch Co. (IWC) in the 1880s.
Cortrebert:

IWC:

Finally, a promotional watch by Modernista in the early 1900's, this one with a retrograde minutes complication.



Cheers
Harold