Complicated watch with two dials

Historical significance

• The gold case has two glazed bezels.
• The main dial is white enamel and has an hour chapter-ring at the centre painted with black Roman numerals from I to XII and red Arabic numerals from 13 to 24. The outer chapter-ring, which is divided into 300, indicates the fifths of a second with two slender blued steel hands: one, a direct-drive seconds hand and the other, a flyback hand activated by a pushpiece in the winding crown.
• The silvered metal dial on the reverse side has six indications: upper left, a blued steel hand indicates the start of each season: 21 March, spring; 21 June, summer; 23 September, autumn; and 22 December, winter. At the centre, the days of the week; below this, the position of the year in the four-year cycle. On the right, the phases and age of the moon; below this, the date and finally, lower left, the month.
• The tourbillon appears in a circular aperture on the left: the two-armed carriage rotates once a minute. It is supported by a three-armed polished steel bridge fitted at the centre with a screwed gold jewel-setting. The movement has a lever escapement, a compensation balance, and a blued steel balance spring with a Breguet overcoil.
• Complicated watches with a tourbillon are very rare. Abraham Louis Breguet, who invented the tourbillon regulator, made several with a state of winding indicator. At the beginning of the twentieth century, two English companies, Charles Frodsham and S. Smith & Son, produced a few tourbillon chronometers fitted with a split-seconds chronograph and a minute repeating.

Sources & references

1. Musée international d'horlogerie, online collection record, inv. I-250: https://collection.mih.ch/fr/collection/item/37658/

Where sources disagree, the disagreement is stated rather than resolved silently.