The inscription ?Patent? and ?Detach?d? on the balance cock, refers to the invention of the detached form of lever escapement patented by Edward Massey in 1815. Good example of a watch fitted with this escapement which paved the way for the development of the single-roller lever escapement in the early 1820?s.Massey Edward (1772-1852), son of Edward Massey, was a Coventry maker. He invented, patented and manufactured various mechanical logs and sounding machines, which were used by mariners throughout the world during most of the 19th century. A comparable achievement was his invention and production of a series of detached lever escapements for watches and a means of winding a watch by depressing the pendant. His detached lever, patented in 1815, was the first, simple detached lever since the more cmplicated work of Mudge, Emery, Leroux and Grant. Its simplicity and good rate encouraged other English makers to take an interest in the lever escapement.