Lot Essay
Joseph Knibb, 1640-1711, was one of the most celebrated clockmakers of the period. Although not certain, it is thought he served his apprenticeship under his cousin Samuel Knibb (1625-70) before moving to Oxford to work for his elder brother John. By 1670 71 he had established himself in London and became a Free Brother of the Clockmakers' Company.
Joseph Knibb was one of the most innovative clockmakers of his time and quite apart from his standard domestic clocks his work included turret clocks, night clocks and lantern clocks (see lot 152). He specialised in movements of long duration (one or three months) and occasionally employed a 1¼ second beating pendulum, a variation that was little used owing to technical problems but theoretically improved the clock's accuracy.
Perhaps Knibb's most notable invention was his Roman notation strike system. Normally favoured with movements of month or three-month duration the Roman strike system was so-called because the Roman figures on the dial directly influenced the method of striking which used two bells of different tone. The method was to strike the smaller bell for the Roman I and larger bell for the V and twice on the larger bell for X. This system was particularly useful for long duration movements because using the normal system seventy-eight blows of the hammer are required in every 24 hours whereas under the Roman strike system only thirty blows are required thereby conserving a good deal of power and ensuring that the strike train did not run down before its going train. When employing his Roman strike, Knibb always used the conventional Roman IV on the chapter ring instead of the usual chapter IIII.
Joseph Knibb was one of the most innovative clockmakers of his time and quite apart from his standard domestic clocks his work included turret clocks, night clocks and lantern clocks (see lot 152). He specialised in movements of long duration (one or three months) and occasionally employed a 1¼ second beating pendulum, a variation that was little used owing to technical problems but theoretically improved the clock's accuracy.
Perhaps Knibb's most notable invention was his Roman notation strike system. Normally favoured with movements of month or three-month duration the Roman strike system was so-called because the Roman figures on the dial directly influenced the method of striking which used two bells of different tone. The method was to strike the smaller bell for the Roman I and larger bell for the V and twice on the larger bell for X. This system was particularly useful for long duration movements because using the normal system seventy-eight blows of the hammer are required in every 24 hours whereas under the Roman strike system only thirty blows are required thereby conserving a good deal of power and ensuring that the strike train did not run down before its going train. When employing his Roman strike, Knibb always used the conventional Roman IV on the chapter ring instead of the usual chapter IIII.