Montre à heures universelles (sphéromètre)

Historical significance

• The case has a silver caseband and is fitted with two bezels of rolled gold on silver which are chased with scrolls. The hands are set with a pushpiece.
• An illustration of the technical innovation of XIXth century timepieces. This watch has two dials: one for the universal hours, the other for the local time of the different cities whose names are printed on the dials. The hours and minutes are indicated on the exterior circle of the main dial, which is divided into twenty-four hours (two times twelve) and sixty minutes. The lower part, in grey enamel, shows the nocturnal hours. In the centre and turning with the hour hand, an enamel circle divided into twenty-four coloured sections gives the names of twenty-five cities. The universal time minute-dial, on the back, comprises an enamelled ring bearing the names of forty-three towns and cities, using the same colours as the main dial. The central minute-disc, divided from 1 to 60, makes one revolution per hour.
• The nickel silver movement has a straight line lever escapement with covered pallets, a balance with screws, and a flat steel balance spring. The centre wheel arbor is extended and carries the universal minute dial.
• This piece shows to what extent the region’s watchmakers followed the latest innovations. Indeed, in 1879, the engineer Sandford Fleming suggested dividing the world into 24 time zones, but it wasn’t until 1884 that his suggestion was implemented, with the Greenwich meridian recognised as the zero meridian.

Sources & references

1. Musée international d'horlogerie, online collection record, inv. I-1141: https://collection.mih.ch/fr/collection/item/38908/

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