Louis Lachenal, an apprentice watchmaker from Switzerland arrived in England and was employed by Charles Wheatstone as a screw maker for parts in the assembly of his new concertina. All parts were hand made.
Lachenal was also an engineer and began making tools to facilitate the making of concertinas. This made them cheaper and more consistently, but allegedly, only Lachenal knew how it worked so he really became the maker of Wheatstone concertinas.
Later, Lachenal had his own company and is credited with making the largest number of concertinas of any maker at that time.