Tact watch

Historical significance

• The enamel painting on the case cover depicts rays of light bursting forth from a pansy, the symbol of remembrance, against the backdrop of a cloudy sky. On the rotating enamelled case-back, Cupid fires a gold arrow whose tip, set with brilliants, points to the hours engraved in Arabic numerals on the silver caseband. A tactile reading of the time is possible by means of the protruding buttons at 3, 6, and 9 o’clock.
• A small, silvered eccentric dial, engraved with the hours in Arabic numerals, can be seen through the pierced dome. Two blued steel “jumping” hands indicate the hours and minutes.
• The movement, with individual cocks, is fitted with a central hanging barrel, a ruby cylinder escapement with a twelve-toothed steel escape wheel, a brass three-armed balance, and a flat balance spring. The watch can be regulated through the dome by a pin affixed to the blued steel index.
• The International Watch Museum has two other à tact watches: one, bearing the number 3801 (Inv. I-473) and made by Breguet and Son, was sold in 1826 to Mr. Rigaud. It has a gold case with an engine-turned back and a movement fitted with a lever escapement. The other (Inv. I-1325) comes from the workshop of Basile-Charles Le Roy: based on the same principles as Breguet’s watches, it has an enamelled case and a movement with a virgule escapement.
• This kind of à tact watch was invented by A.-L. Breguet between 1796 and 1800. Not only could it be used to tell the time in the dark or, if one was in company, by discreetly touching the case-middle, it could also measure a period of time. When the à tact hand or case-back was turned until it met resistance, the watch would continue to function, while the à tact hand remained stationary.

Sources & references

1. Musée international d'horlogerie, online collection record, inv. I-493: https://collection.mih.ch/fr/collection/item/38837/

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