Page "Anchor escapement" Paragraph 21

The above two problems were remedied by a modification to the pallets, resulting in a much better variation of the anchor escapement: the Graham or deadbeat escapement.

This is often erroneously credited to English clockmaker George Graham who introduced it around 1715 in his precision regulator clocks.

However it was actually invented around 1675 by astronomer Richard Towneley, and first used by Graham's mentor Thomas Tompion in a clock built for Sir Jonas Moore, and in the two precision regulators he made for the new Greenwich Observatory in 1676, mentioned in correspondence between Astronomer Royal John Flamsteed and Towneley