Among the best-known of the Danish clock makers is Green of Aabenraa, or 'Apenrade', as the signature is written on the clocks. The family can be traced back to the English clock maker Peter Green, who emigrated with his wife and children from Liverpool to Aabenraa, around 1745 and worked there until his death in 1795. He had two sons, William and Jonathan, who also became clock makers in Aabenraa and finally William had a son, Jakob, who continued making clocks until his death in 1847. The Green clocks span a period of more than a century, but only the clocks from the first 50–60 years are of a high standard. See D. Yde Andersen: Bornholmer og andre gamle ure, Borgens Forlag, 1974.