With antique usually used to describe clocks over 100 years old, most are.

What are the dials on a grandfather clock?

Grandfather clock moon dials consist of a round disk displaying two pictures of the moon. A one-half rotation of the disk occurs every 29.5 days which is one lunar cycle.

What does RA mean on a clock pendulum?

The R A on the pendulum stands for: retard/advance. It is a common pendulum bob, used by many manufacturers, worldwide. As a rule of thumb, the thread on rating nut is designed so that one full turn changes the clock about 2 minutes per week.

How did they know what time it was the first clock?

sundial One of the earliest of all devices to tell time was the sundial. The sundial is looked on as being a form of sun-powered clock. Ancient civilizations such as the Sumerians did have this knowledge, but when the culture died, knowledge was lost along with many other aspects of the civilization unfortunately.