It was operated by an escapement mechanism and the earliest known chain drive.

He needed the actual performances only in the same way that a clock needs its tiny little escapement mechanism; it kept him ticking nicely.

Su's clock tower employed the escapement mechanism two centuries before it was applied in clocks of Europe.

The clock tower was driven by a rotating waterwheel and escapement mechanism.

The claim that he drew a simple escapement mechanism, the first known in the West, is now questioned.

Like the Chinese, Arab engineers at the time also developed an escapement mechanism which they employed in some of their water clocks.

The escapement mechanism was in the form of a constant-head system, while heavy floats were used as weights.

In the 11th century, Chinese inventors and engineers invented the first mechanical clocks driven by an escapement mechanism.

He improved the German action by adding an escapement mechanism.

The situation without a check varies depending on whether or not the action in question has an escapement mechanism.