A type of top for bracket clocks and long case clocks which appeared about 1765 and is characteristic of the style of George Hepplewhite. The arch is incomplete, having a small ledge or step where it joins the sides of the case. Break-arch clocks usually had circular dials with brass bezels, but a number are known with silvered all-over, enamelled or painted dials. Dials with a semi-circular top are also known as break arch.