Georges-Auguste Leschot (1800-1884), pioneered in the field of interchangeability in clockmaking by the invention of various machine tools. 1830 he designed an anchor escapement, which his student, Antoine Léchaud, later mass produced. 1839 he invented a pantograph allowing some degree of standardisation and interchangeability of parts on watches fitted with the same calibre.Watch manufacturing really changed from assembly in watchmaking shops to mass production with interchangeable parts, as from 1854, pioneered by the Waltham Watch Company, in Waltham, Massachusetts. in 1850, Roxbury, David Davis, Edward Howard and Aaron Lufkin Dennison formed together the company that would later become the Waltham Watch Company. The Waltham Watch Company, also known as the American Waltham Watch Co. and the American Watch Co., produced about 40 million high quality watches, clocks, speedometers, compasses, time fuses and other precision instruments between 1850 and 1957.
The Waltham Watch Company went out of business in 1957, but had founded a subsidiary in Switzerland in 1954, Waltham International SA. Waltham International SA continues to produce mechanical wrist watches and mechanical pocket watches under the "Waltham" brand and is a full-fledged member of the Federation of the Swiss Watch Industry FH.
