Eduard Kummer Bettlach, later called Ed. Kummer SA, was a producer of ebauches and watches in Bettlach near Grenchen, Solothurn, Switzerland. The company was founded in 1888 by Eduard Kummer. The watchmaking division was added to ASUAG in 1931, with the movement production falling under Ebauches SA in 1932 and 1939 or 1940. Kummer's 1950s factory in Bettlach remains in use by ETA today but the original factory at the center of town was torn down.
Eduard Kummer was born in Bettlach in 1845 and returned to Grenchen to work as a watchmaker after studying in Charquemont in France and Reconvilier. In 1882, Kummer tried to take over the successful firm Obrecht & Cie. in nearby Grenchen but was unsuccessful. Recognizing the potential in Kummer's ideas, the community of Bettlach urged him to build a new factory there instead. In 1888, Eduard Kummer Bettlach was established, and soon a large factory was built to produce anchor, pin lever, and Roskopf movements.
The Ed. Kummer factory was successfully producing a wide variety of movements in the 1890s. Listed products included movements based on designs by Jules Jurgensen, Renversés, Roskopf, and Systéme Glashütte from 11.75 to 26 lignes. Kummer's fortunes rose and fell in the next decades, adding production of complete watches and building branches in Besançon in France and Como in Italy, though these were soon closed. Kummer began producing wristwatches in 1914, brought to market the first purely-Swiss alarm clock under the Inventic (I.A.C.) brand, and produced stopwatches under the Ariston name in the 1910s. Indeed, the company was called Ed. Kummer, A.G. Uhrenfabrik Ariston Inventic in Bettlach in the 1910s.
Financial difficulties soon hit, with the Russian market lost, leaving Kummer in debt of more than 2.5 million francs. A massive embezzlement scandal soon hit the company, costing it 500,000 francs and forcing Kummer's heirs to liquidate. The watchmaking operation was taken over by ASUAG on July 28, 1931, leaving the movement operations intact for a time. The anchor and cylinder clock manufacturing was absorbed into Ebauches SA in 1931 and the Roskopf movement factory was taken over in 1939 or 1940.
Under ASUAG, Kummer produced watches under the Atlantic brand in Bettlach, though the company maintained the Inventic and Ariston brands and also used Opus, Ancora, Ardua, Oreas, Vivax, Miracle, Times, Sailor, Mariner, Atlantis, and Integra.
In later years, Ebauches Bettlach produced mainly Roskopf movements under Ebauches SA. A modern factory was constructed in the 1950s to produce Roskopf ebauches, and this remains in use by ETA as their "W05" production site.