Lachenal &amp; Co.Lachenal &amp; Co. Lachenal & Co. Lachenal & Co. was a British firm producing concertinas from approximately 1850–1936. The firm was founded by Louis L. Lachenal (c. 1821–1861), a Swiss emigrant to the United Kingdom, who arrived there in 1839, and by 1844 was working in support of the famous Wheatstone concertina firm before founding a supporting contract firm and by 1858, an independent firm. Lachenal's innovations in concertina production led his company to become one of the most prolific concertina producers of the era. Lachenal & Co. Lachenal & Co. was a British firm producing concertinas from approximately 1850–1936. The firm was founded by Louis