Mahogany cased spring driven astronomical and musical clock [pedestal not original]

Description — British Museum

Movement: Massive 8-day, spring-driven, three-train movement, the back plate engraved with a foliate design with a basket of fruit, birds, shells and a Chinese pavilion. The time indication, the astronomical dial and the orrery are all driven by the going train. The clock strikes the hours and plays one of a selection of 12 tunes on 13 bells. Dead-beat escapement with later wood-rod pendulum. : DIALS The upper dial, is a heliocentric orrery consisting of six revolving concentric rings painted with gold stars against a dark blue background, each ring with a black and white sphere to represent one of the six planets known at the time [Mercury, Venus, Earth, Mars, Jupiter and Saturn]. Each with an engraved plate inscribed with the duration of its orbit. Around the outside, a fixed silvered-brass ring is engraved with the months, the date and the degrees and signs of the zodiac. The composite lower dial has an upper subsidiary dial with hours, minutes and centre-seconds. To the left a subsidiary dial shows the months and to the right a similar one shows the the time of high tide in a number of named locations. The lower main dial is a mechanical celestial planisphere which shows the relative positions of the earth, sun, moon and principal stars. : CASE Mahogany case with applied gilt-brass foliate mounts to the canted corners of the lower section and fluted canted corners with gilt-brass plinths and capitals on the upper section. The case has an inverted bell top with flaming-urn finials. Around the base of the top are cast gilt-brass panels decorated with putti and chariots in low relief. The upper side apertures [probably with pierced frets originally] are now filled with wood panels with applied, gilt-brass urns. The rear of the case with upper and lower glazed doors. On the right-hand side is a small silvered-brass setting dial engraved with the names of the tunes. The clock now stands on a purpose-built mahogany pedestal which utilizes the original gilt-brass feet and gilt-brass mounts taken from the clock case, the latter replaced with poor-quality copies cast from the originals.

Curator's comments — British Museum

There are three other clocks by Jenkins known to survive. 1. Solar/sidereal clock, National Maritime Museum. 2. Astronomical longcase clock, illustrated in Cescinsky & Webster, English Domestic Clocks, fig.242 3. Astronomical table clock, Cescinsky & Webster, English Domestic Clocks, fig.339. Text from 'Clocks', by David Thompson, London, 2004, p. 112. Henry Jenkins Astronomical clock London, 1778 In the second half of the eighteenth century interest in astronomy was perhaps at its height. The two transits of Venus in 1761 and 1769 had been earnestly followed by such august bodies as the Royal Society, and the work of astronomers such as James Ferguson had done much to popularize the subject among the large fraternity of gentlemen scientists. Astronomical clocks were understandably popular. Henry Jenkins was born and educated in Cornwall. At the age of ten he was apprenticed as a tailor, but he also acquired knowledge of clockmaking and astronomy. He first appears in London in about 1755 and in the following five years made at least four clocks of increasing complexity. In 1778 he published a small treatise entitled 'A Description of Several Astronomical and Geographical Clocks'. In the second edition of the treatise Jenkins described in some detail this particular clock, which he judged his most complicated. The illustration from the treatise (bottom) shows the original design of the case. The clock has astronomical indications on two large dials. The upper dial is in the form of an orrery with the six known planets, Mercury, Venus, Earth, Mars, Jupiter and Saturn, revolving around a fixed sun. It is possible that the Jupiter gearing, which provides an orbit of 4334.3 days, may be Jenkins's more accurate contribution (it is now calculated at 4332.595 days). The lower dial has a series of subsidiaries arranged around it. The large subsidiary dial at the top shows hours, minutes and centre-seconds. The smaller subsidiaries are a calendar to the left and a dial showing the time of high tide at various ports to the right. The main dial consists of a planisphere showing the positions of the sun, moon and the earth relative to the stars. The central, silvered disc is a plane projection of the heavens centred on the celestial north pole and revolving once in a sidereal year. It is engraved with all the major stars known at the time, with concentric circles for the equator and the two tropics, and the eccentric circle of the ecliptic. The movement of the clock is equally impressive, with a back plate engraved with the chinoiserie designs commonly found on clock plates in the third quarter of the eighteenth century. It is designed to go for eight days and is controlled by a pendulum. The clock also plays music: one of the tunes, entitled 'Air by Mudge', written by Richard Mudge (brother of the famous clockmaker), is not known by musicologists to exist in any other form. Purchased in 1992. View more about curator's comments Jenkins, Henry, A DESCRIPTION OF SEVERAL ASTRONOMICAL AND GEOGRAPHICAL CLOCKS, 2nd ed. London 1778. [A copy in the Guildhall Library] Barker & Co. Ltd., Kensington, London W., Sale catalogue [undated] Britten, F.J., OLD CLOCKS AND WATCHES AND THEIR MAKERS, 3rd Ed.London 1911, pp. 363-364. Cescinsky & Webster, ENGLISH DOMESTIC CLOCKS, 2nd Ed? King, H.C., GEARED TO THE STARS, Bristol 1978, pp.147-148. National Heritage Memorial Fund, ANNUAL REPORT, 1992-3, pp.37-38, illus.