Buren was quite an impressive watch company. They developed their own in house calibres – and made a lot of them. They were specifically good at making thin wrist watch movements. Founded in 1873 in the small town of Büren an der Aare they produced simple cylinder escapement pocket watches, manufacturing completely in house.37 Buren 41

From 1932 Buren started rolling out several new movements; 40, 45, 35, 60, 295, 350, 50, 356, 14, 370, 410, 380, 462, 30 and 565. The 462 movement being used in their contribution to the dirty dozen.

Buren was constantly on the pursuit for ever thinner movements. In 1960 they released the calibre 280. This was only 2.8 mm thick, featured a 49 hour power reserve and was remarkably accurate for the time. This movement was also used by Dugena, and later by Hamilton.

The calibre 525 produced from 1955 was a neat little bumper movement. Rather than using a full 360 degrees of rotation on an oscillating weight – this movement used a sort of pendulum that would swing back and forth as the wearer moved.

The crowning jewel of Buren movements was their patent from 1954. The calibre 1000 featured a very small rotor integrated within the movement that allowed for a very slim (4.2 mm) automatic watch.

This calibre 1000 is the grandfather to the first automatic chronograph – the caliber 11. Released in 1969 as a joint venture between Heuer, Breitling-Leonidas, Dubois-Depraz and Buren. The chronograph module 8510 from Dubois-Depraz and the Buren 1280 calibre combined to make one legendary combo. Easily identifiable with the crown on the left and the pushers on the right of the case.

During the development of this movement Hamilton acquired Buren in 1969 and transferred all production away from the US to Switzerland. Hamilton made great use of Buren movements in the Thin-O-Matic.

As with most watch journeys it ends badly – Buren-Hamilton partnership was dissolved in 1972. Following this the factory was liquidated from reduced interest in the brand. In 1974 the Hamilton brand was sold to SSIH.