Historical Documents

Here you can see the authoritative history of SI in either English or French. The menu on the first page includes links to discussions of the evolution and definition of the meter (metre), the name "kilogram," temperature scales, and other topics.

Two pages of James R. Frysinger's SI Guide deal with the historical milestones in the evolution of the Système International (SI) from an American perspective. SI Background provides dates, events, descriptions and citations. SI History Headlines provides dates and events only. For other links to the SI Guide, see Guides to SI.

Dennis Brownridge, author of Metric in Minutes, has very kindly provided the SI Navigator site with a comprehensive table of non-SI units. Many of the units are, in fact, metric. However, they are not part of the simplified, coherent set of metric units known as the International System, or SI. Please note that there are notes clarifying the table headings and table content at the end of the page. Note, also, that the page is quite large and will take about 17 seconds to load at 50 kbit/s.  

Here are three pages, from an old German book, dealing with the non-metric units still in use, in 1932, in a number of countries.