As a rule, Donald Saff doesn’t collect clocks he can’t see inside of. It’s the harmonic entanglement of gears—and the skill needed to craft them—that first lured him to horology, the study of ...

Here’s how to build a pendulum-controlled clock which can be made really accurate. Retro? – yes, but an interesting project all the same. You’ll need a spare quartz clock which must be adapted by ...