Rock crystal cased verge watch with calendar

Description — British Museum

Movement frame: Circular gilt-brass plates with four pierced Egyptian pillars without decoration. Engraved foliage around the verge aperture. A hole in the pillar-plate for the foot of the potence. Mainspring &-up: Gilt-brass barrel with dovetailed cap and riveted steel hook. Ratchet and click set-up with a pierced blued-steel click and a large diameter blued steel ratchet wheel. Fusee & stop-work: Gilt-brass fusee with original chain and English stop-work. Train: Four wheel going train, the second and third wheels with turned gilt-brass collets, the contrate wheel probably a replacement. Escapement & balance: Verge escapement with a crown wheel running between a riveted potence with engraved decoration on the visible side and a screwed-on counter-potence. Pierced and engraved foliate balance cock screwed to the potence-plate. The verge and wide rimmed balance are not original. Dial and hands: Gilt-brass dial pinned to the pillar-plate and engraved all over with realistic flowers. At the top a double sector aperture showing the day of the week by its planetary sign, both in name and in picture. In the upper left an applied silver subsidiary chapter ring engraved 1-29 plus a hatched half division, for the age of the moon surrounding a rotating silver disc engraved with realistic flowers. An aperture in the disc shows the moon's phase and a pointer shows its age. To the right is another applied silver chapter ring engraved 1-30 for the date, the number 30 being hatched over. In the lower part of the dial a subsidiary silver chapter ring is engraved I-XII for the hours, with arrow-head half-hour marks and a circle of twelve dots at the hours. Within this chapter ring is a further aperture, beneath which rotates a gilt-brass disc engraved with the days of the week in Latin and some of the signs of the zodiac. The aperture and the disc below it do not appear to be original. To the left another aperture shows the four parts of the day, 'NOCTUS, ORORE, MEDIRIES [sic] and VESPERS' each with a pictorial representation. To the right a double sector aperture shows the months and the seasons, the latter also with a pictorial representation. The blued-steel date hand survives, but the hour hand is missing. CASE: The gilt-brass rims with hatched decoration survive but the original rock-crystal case has been replaced by a plain silver box. Gilt-brass pendant and finial, the pendant ring replaced. Case catch: The dial has four lugs in its edge which locate in four recesses in the case band. The case catch consists of a gilt-brass spring and steel catch mounted on the inside of the pillar-plate. The dial is hinged to the case at XII o'clock. Calendar work: Pinion of report [A] = 11 Dial wheel [B] = 22 - hour hand rotates once in12 hours. Pinion [C] (on arbor [B]) = 11 Pinion [D] (on arbor [B]) = 4 . Pinion [C] drives:- Wheel [E] = 22 - carries 1/4 day disc rotates once/day. Underneath wheel E an index operates a sprung lever to index a seven-point star wheel which carries the days of the week disc. Rotates once in 7 days. Pinion [D] drives:- Wheel [F] = 56 rotates once in 7 days. this disc is not original. Pinion [G] on wheel [F] = 14 rotates once in 7 days. Pinion [G] drives:- Wheel [H] = 59 - rotates once in 29.5 days, carries lunar disc. Wheel [I] = 60 - rotates once in 30 days carries date hand. On the underside of wheel [I] an index operates a sprung lever which advances a 12-point star wheel which carries the month disc and rotates once in 12 months.

Curator's comments — British Museum

Bibliography: Good, Richard, WATCHES IN COLOUR, Poole 1978, plate 4.