Hi. I have been a longtime subscriber and I am interested in asking a question to your Technically Speaking staff. I have a 1967 Corvette and the clock will only work when I tap the face of the clock.

Richard Preiss sat Tuesday in the workroom at Eternal Timepieces, his Mesa clock repair shop, gently holding in one rock-steady hand a small pair of tweezers that grasped an even smaller brass gear.

Mohammad Ayaz Khan, a clock repairer, prefers to be called a craftsman. His workshop in Churiwalan in the walled city is a charming little museum of antique clocks -- mantel, wall, table-top and, ...