- Museum number
Astronomical calendar clock; eight-day movement with two trains, for going and striking, both with fusee; dead beat escapement with inverted crutch piece, pendulum suspended from vertical steel loop; striking-train with inside count-wheel; back plate engraved with foliate border, scrolling foliage, birds and a mask; dial constructed from several fixed sections of brass and copper, with idle subsidiary corner dials and a nest of rings at centre, some rotating, some fixed; give multiple astronomical indications, dates from the church calendar, equation of time and other information; all visible parts of dial are silvered and engraved with mixture of scenes; case of ebonised and ebony-veneered pine with a swivel base which allows the whole of the upper section to be turned to facilitate winding; mounts of gilded brass.
Also with the clock is an engraved print with instructions, which was probably supplied with the clock, beginning 'The Explanation March the first 1725/6".
- Production date
Height: 96.50 centimetres
- Curator's comments
- Text from 'Clocks', by David Thompson, London, 2004, pp.106-109.
Nantwich and London, c.1725
Height 84 cm, width 57.5 cm, depth 29.5 cm
The eighteenth century saw a resurgence in the fashion for clocks specially designed for owners who had an interest in all things astronomical. Clearly, the more impressive and complex the dial indications were, the more opportunity was afforded the owner to demonstrate his knowledge of the universe to his peers. Such clocks were not a new idea but had their origins as far back as the medieval period, when public clocks such as those in Strasbourg Cathedral or in the Old Town Square in Prague were intended to demonstrate the wonders of God's universe to the common people. In the sixteenth century a similar fashion existed in the princely 'Kunstkammer', where astronomical clocks on a grand scale by such eminent makers as Eberhard Baldewein and Jost Bürgi were clearly made to impress.
John Naylor came from Nantwich in Cheshire but very little is known of him beyond the existence of a small number of clocks; in particular two magnificent astronomical clocks, one in The British Museum collections and the other in Paris in the Musée des Arts et Métiers. Apart from the clock itself, there is also a large print published in 1726, intended to show the intricacies of the dial. An interesting alteration to the print has been made to accommodate the new Gregorian calendar adopted in England in 1752.
The large case is typically English, in ebony-veneered oak and with very little decoration. It does, however, have a turntable base to allow the clock to be rotated for winding and for access to the back without turning the whole clock - something of a necessity in such a large and heavy clock. The conventional eight-day movement has fusees and verge escapement with spring-suspended pendulum, but the complicated under-dial work is far from standard. One interesting feature is the support for the pendulum, which is a high-arched steel hoop designed to raise the pendulum in order to accommodate it within the case. The movement back plate is engraved with a fine border of wheat ears enclosing foliate scroll decoration with birds and a mask in the centre. The blued-steel hands are pierced and indicate against the inner ring with its unusual wavy hour numerals. The fixed outer ring is calibrated for minutes.
In the arch is a finely-engraved depiction of Apollo the sun-god in his chariot, crossing the sky, with the lion of the constellation of Leo in the background. Around the outside, in the spaces between the dials and the main chapter ring, are beautifully-executed depictions of the four elements: earth, air, fire and water. Two subsidiary dials at the top, one in the lower left corner and a small one on the central vertical bar, are set manually to give information relating to the solar and lunar cycles, to enable the two pointers to the left of the main chapter ring to be set to show the date of Easter in both Julian and Gregorian terms against the wide calendar ring. This calendar, engraved with saints' days, revolves once per year around the fixed minute ring. Joining the minute ring to the central hour ring are two curved horizons which pass over a celestial ring engraved with the constellations of the zodiac between the two tropics. This planispheric map of the heavens rotates once in a sidereal year (366 sidereal days, equivalent to 365 solar days). Moving over the celestial ring are sun and moon effigies which rotate once per day to show their times of rising and setting as they pass between the horizons, and also to show their positions in the zodiac throughout the year. In addition to this, a small semicircular aperture in the celestial ring gives the moon's apogees and perigees, the points at which the moon is furthest from or nearest to the earth. The fixed chapter ring, engraved with the hours, encloses a terrestrial planisphere centred on the north pole. Between the hour numerals XII and III and the map is a scale that shows the time of high tide at London Bridge.
Purchased in 1985.
- On display (G39/dc9)
- Exhibition history
1999 1 Dec-2000 24 Sep, London, The Queen’s House, The Story of Time
- Acquisition date
- Britain, Europe and Prehistory
- Registration number