Lot Essay
William Shepherd is recorded at 13 Bath Street, Liverpool 1848-1852. John Hartnup, the designer of this handsome balance, was superintendant of the Liverpool Observatory and being acutely aware of the problems caused by middle temperature error designed his balance, circa 1847 which was constructed with the assistance of William Shepherd. Hartnup apparently refused to patent the balance and in fact publicised it in the June 1849 issue of Monthly Notices of the Royal Astronomical Society. Other chronometer makers such as Charles Frodsham (1810-1871) and Thadeus Winnerl (1799-1886) experimented with the design but being an expensive and complicated balance to make it was only used in very small numbers.