I visited my parents recently. My Dad presented me with my grandfather's wrist #watch. I had totally forgotten about it but it's really quite cool. It's a late 60s model #Bulova #Accutron. These were early progenitors of the quartz watch but rather than a quartz crystal keeping the time the Accutron had a tuning fork. The beauty is that it still works! It has the original purchase slip with it (Jan 1970). My Dad looked up how to power these old watches and now it's humming a nice steady F#.