[Jan]’s prototype can be seen in action after the break. Also take a look at this master clock that signals slave clocks and runs for a year on a single AA battery.

The breadboard clock may not be the prettiest thing, or a textbook example of how to prototype circuits, but that was fixed with [Easton]’s friend’s PCB layout of a 12-hour clock.

The clock is a 500-foot-tall, 12-foot-diameter cylindrical shaft with a spiral staircase running along its inner ... The first prototype of the 10,000-Year Clock was completed in time to strike ...