I recently received an email from a visitor to Time Worn Watches, with questions about a pocket watch that had been passed down through the family. I immediately recognised the brand of the watch based on the somewhat peculiar layout of the dial. The watch in question was the Hebdomas Patent pocket watch shown below. The off-centre dial and exposed balance identify this watch as Hebdomas, a watch famous for its 8-day movement.
Hebdomas history
The Hebdomas 8-day movement was invented in 1888 in the Vallée de Joux in Switzerland, with the patent (no. 88) granted on January 10, 1889 to Iréné Aubry (1859 – 1936) of Saignelégier. The watch was then produced under licence by the firm, Graizely & Cie of La Ferrière. According to Mikrolisk the brand name “Hebdomas” was registered to Graizely & Cie in 1889. Arthur Graizely added more patents, including one for a power reserve indicator, a central winding pinion and digital time display.
Note: some sources suggest the firm Aubry, Graizely & Godat was formed to produce the watch, but there is no mention of such a firm in Mikrolisk. However, Aubry’s ongoing involvement with Arthur Graizely is consistent across multiple source. Therefore I think it is likely that Aubry was involved in the business until he retired in 1912.
At some point in the early 20th century (the dates differ across sources, 1900, 1906 or 1913) the peculiar-looking watch came to the attention of Otto Schild of Grenchen. Schild and Graizely entered into some form of partnership to produce the Hebdomas watches, most likely under the name of Graizely & Cie. In 1915, the Graizely name disappeared and the Hebdomas watch continued to be produced by Schild & Cie. The Hebdomas 8-day movement was produced through to the 1950s, although the Hebdomas brand played a lesser part in the activities of Schild & Cie. There was a pocket watch revival in the late 1960s and the Hebdomas brand was resurrected. The Hebdomas movement continued in production through the 1970s, sold mostly as a pocket watch. Schild & Cie survived as a business until the 1980s.
Hebdomas name
The “Hebdomas” name was chosen to reflect the traditional Latin and Greek name for the Holy Week. It highlighted the fact that this watch would only need to be wound just once a week. Although the term traditionally suggests seven days rather than eight, it was thought that the name would have more appeal to the buyers at the time. It is worth noting, that watches of the time would normally have a power reserve of a little more than 30 hours and therefore would require winding daily.
Hebdomas movement
These watches are notoriously unpredictable at timekeeping due to the length of the mainspring. The owner would be sacrificing accuracy for the convenience of only winding the watch once a week. If accurate timekeeping wasn’t important in the owner’s profession, it was probably a good trade-off.
The basic design of the Hebdomas watch included an open dial showing the balance mounted on a straight-across bridge. In addition, there was a full-diameter mainspring barrel using teeth around the circumference rather than a pivot at the centre. This technique, of driving the mainspring barrel directly using teeth and a ratchet around the circumference, would later become standard in most watches.
The hour and minute hands are set off-centre above the balance wheel. This gives Hebdomas-powered watches a distinctive haute horology look. This, combined with the engraved bridge and exposed balance, provides a look reminiscent of high-end complicated watches of yesteryear. However, the Hebdomas movement has always been a lower-priced offering. This is quite possibly due to the irregular timekeeping associated with the massive mainspring. Under no circumstances should the back cover be removed by an amateur. The massive mainspring could then escape and be difficult to replace correctly.
In the image above, as well as information regarding the watch movement, the barrel also has images of medals won for Hebdomas watches in Geneva, Paris, Chicago, Milan and Bruxelles.
Due to the small size (15 or 19 ligne) of the Hebdomas movement, it found its way into wristwatches quite early. Most examples are oriented with the crown at 3:00 and the exposed balance at 9:00.
Related content
Hebdomas at Watch Wiki.
The story of the 8-day pocket watch at Grail Watch.