Q-I am interested in old wall clocks that advertise products. Where can I find some? Also, do any modern advertising clocks have value? A-Modern clocks that advertise beer or pop, for instance, are… ...

Commuting calm This was no ordinary second hand: Mr Hilfiker designed it to complete its revolution in 58.5 seconds then stand still for 1.5 seconds more to, as he put it, "bring calm in the last ...

The clock could one day be used to redefine the second itself. The new timekeeper, called an optical lattice clock, uses lasers and the oscillations of strontium atoms to parcel out time.