Certina

Adolf and Alfred Kurth opened a small workshop for watch parts and movements in Grenchen in 1888. The brothers later made complete watches, sold first under the name Grana (from Granacus, the Latin name of Grenchen) and, from 1939, as Certina, from the Latin certus, 'sure'.

In 1959 Certina introduced the DS ('Double Security') concept, a case and movement mounting designed to resist shocks and water, which became the basis of its sports watches; the company's turtle emblem dates from the same period. Certina joined the General Watch Co. of the ASUAG group in 1971 and became part of SMH, later the Swatch Group, in 1983.

How to recognise the work: early watches may be signed Grana or Kurth Frères rather than Certina. DS models from 1959 carry the DS name and, on the caseback, the turtle emblem chosen to stand for the case's protection; many 1960s and 1970s divers' and sports models, such as the DS-2 Super PH 1000m in the catalogue, are in this family.

The firm began in 1888 with three employees in a workshop joined to the family home, making movements and supplies for other firms before complete watches. It had 250 employees by its 50th anniversary in 1938, 500 by 1955, when it made about 1,000 watches a day, and 900 by 1972, when it made 600,000 a year. Its first wristwatches, in 1938, were mostly for women, because men still preferred pocket watches.

The DS concept was developed in 1959 by Hans and Edwin Kurth. After joining ASUAG's General Watch Co. in 1971 the company gave up making its own calibres as Japanese automatic and quartz watches took the market, and by the end of the 1970s its operations had moved to Biel/Bienne. In the Swatch Group it was later managed together with Mido and Tissot.