Turret clock
Category
Horology
Date
c. 1490
Materials
wrought iron mounted on oak
Measurements
115 cm (Height)
Place of origin
England
Order this imageCollection
Cotehele, Cornwall
NT 347888
Caption
Few houses in Britain can claim to measure time by a 15th-century clock, but Cotehele House in Cornwall enjoys that distinction. This rare timepiece, found in the medieval chapel, began ticking at the start of the Tudor period (1485). It has no face, dial or hands and simply strikes the hour on a connected bell in the roof. Remarkably, it has survived unaltered for more than 500 years because, unlike most early clocks, it has not been converted to use a pendulum. The design is a type of turret clock, so called because it was usually mounted high in a clock tower and consists of a wrought-iron frame and two trains of wheels. The clock has movable 40kg weights, one made of stone and the other iron, which help to adjust the timekeeping. The clock can run for 24 hours, but winding it requires considerable strength and agility. Until its restoration in the mid-20th century it had probably been left unwound – and silent – for centuries.
Summary
A wrought iron turret clock mounted on an oak beam, c. 1490. It is the oldest running, unaltered clock in Britain. It tells the time by striking the hours on a bell which hangs in the bell-cote over the clock mechanism. The wooden upright to which the clock is attached is relatively modern, suggesting that the clock has at some point been re-positioned. It is similar in style to a number of medieval church or monastic clocks, but no domestic examples are known, casting doubt on the assertion that it originated as a domestic clock. Instead of a pendulum it has a foliot-and-verge mechanism, which takes the form of a horizontal bar with weights at each end that swings from side-to-side. The hour wheel is turned by a rope and falling weight. It makes one turn in an hour and drives the escapement or ‘crown’ wheel. The escapement wheel is turned by the hour wheel and also gives impulse to the foliot-and-verge, which controls the ‘going train’ to keep time. Given a steady impulse the freely suspended foliot will oscillate at a constant frequency as long as the size and disposition of the weights is constant. The cam turns with the hour wheel to raise the lifting piece and therefore also the locking lever on the hour, to unlock the ‘striking train’. The flail (driven by the great wheel) is released. The great wheel turns when the striking train is unlocked, and it has eight ‘pins’ to actuate the bell lever. The count wheel is driven by the great wheel, and it determines the number of strikes. The flyvane steadies the speed of the striking train. The stop on the lifting piece arrests the striking train. To prevent the clock from striking, the flail is lifted and rested in the hanging hook.
Full description
A wrought iron turret clock mounted on an oak beam, c. 1490. It is the oldest running, unaltered clock in the country. The wooden upright to which the clock is attached is relatively modern, suggesting that the clock has at some point been re-positioned. It is similar in style to a number of medieval church or monastic clocks, but no domestic examples are known, casting doubt on the assertion that it originated as a domestic clock. Instead of a pendulum it has a foliot-and-verge mechanism, which takes the form of a horizontal bar with weights at each end that swings from side-to-side. The hour wheel is turned by a rope and falling weight. It makes one turn in an hour and drives the escapement or ‘crown’ wheel. The escapement wheel is turned by the hour wheel and also gives impulse to the foliot-and-verge, which controls the ‘going train’ to keep time. Given a steady impulse the freely suspended foliot will oscillate at a constant frequency as long as the size and disposition of the weights is constant. The cam turns with the hour wheel to raise the lifting piece and therefore also the locking lever on the hour, to unlock the ‘striking train’. The flail (driven by the great wheel) is released. The great wheel turns when the striking train is unlocked, and it has eight ‘pins’ to actuate the bell lever. The count wheel is driven by the great wheel, and it determines the number of strikes. The flyvane steadies the speed of the striking train. The stop on the lifting piece arrests the striking train. To prevent the clock from striking, the flail is lifted and rested in the hanging hook. Cecil Clutton described the clock as follows: “It can almost certainly claim to be the world’s oldest larger-than-domestic clock with its original verge and foliot escapement. It is also the oldest survivor of a type of English clock that continued into the early eighteenth century (that is, the type with the trains laid out in a single vertical line, between two pillars). The clock can be dated with considerable accuracy to the last decade of the fifteenth century, which is the date of the chapel. The clock stands in a niche resembling a contemporary fireplace, from which runs a shaft in the thickness of the wall to accommodate the ropes and weights, and connecting with a bellcote on the apex of the roof, where the bell is rung by the clock. There is no dial, nor ever was. The metal frame of the clock is fixed to a stout wooden post, which is fixed in turn to the wall at the back of the niche. The preservation of the clock, like so much else at Cotehele, must be attributed primarily to the care and conservatism of successive Mount Edgcumbes, for without the latter it would certainly have been scrapped or converted to pendulum long ago. Possibly this might still have happened, had it not been for the upside-down layout of the clock, with its escapement only a foot or so above the ground, which would make a pendulum conversion extremely difficult to effect” (Antiquarian Horology, September 1962). The traditional description of the clock as 'the oldest known pre-pendulum domestic clock, still in its original position' has often been called into question. The Reverend Byrth noted that 'over the west-end of the chapel, is a small turret, surmounted with battlements and pinnacles, and containing two apartments for bells' (‘The Plymouth Literary Magazine’, 19 November 1814). The Reverend Arundell wrote that 'the curious works of an ancient clock are under the bell tower' (Cothele on the Banks of the Tamar, ca 1840). He does not specify if the workings were assembled, nor does Venning, who refers to 'a clock said to be the oldest in Cornwall' (1887). It is also been described by Geoffrey Wills: 'Behind a door at the west end is the movement of a turret clock, which retains its original foliot balance, a device in use prior to the invention of the pendulum, and is the only such clock so far recorded in this original condition. It has suffered surprisingly little wear or damage during its lifetime of about five centuries. This may be accounted for, perhaps, by the fact that it has been in use only occasionally. It was not working in 1833, when seen by the correspondent of Gentleman's Magazine. It was never provided with a dial or hands, but struck hourly on a bell which is still in the bell-cote above it' (The Connoisseur Year Book, 1956).
Provenance
Until recently, it was thought that the clock was installed by Sir Richard Edgcumbe (d.1489) although there is no firm evidence to support this theory. More research is needed.
References
Clutton 1962: Cecil Clutton,’The 15th Century Clock at Cotehele House’ Antiquarian Horology (September 1962) pp. 362-364 Wills 1956, Geoffrey Wills, The Connoisseur Year Book ed. L. G. G. Ramsey (London 1956) Robinson 1953: T. R. Robinson, Horological Journal (Dec. 1953. Vol. 95) page 818