Ligne, Charles Joseph, prince de, 1735-1814, Austrian field marshal. He belonged to an ancient princely family of Hainaut, in the Austrian Netherlands (now Belgium). He held high military and diplomatic posts, was an adviser of Holy Roman Emperor Joseph II, and won the favor of Catherine II of Russia while on a mission at her court. Though deprived of most of his estates by the French and sunk to relative obscurity, he remained active in European affairs. Ligne was celebrated for his cosmopolitanism and wit; his most famous remark, a reference to the Congress of Vienna, was Le congrès ne marche pas, il danse. [The congress does not walk (i.e., make progress), but it dances.] His selected letters and memoirs (tr. 1927) mirror his personal charm, polished gaiety, and unpretentious wisdom.

For the French river of the same name see River Ligne.

The ligne (from the French word meaning "line") is a unit of length that was in use prior to the French adoption of the metric system in the late 1700s, and is still used by French and Swiss wristwatch makers to measure the size of a watch movement. In this usage there are 12 ligne to one French inch (pouce). The standardized conversion for a ligne is 2.2558291 mm (1 mm = 0.443296 ligne), and it is abbreviated with the letter L or represented by the triple prime, ‴.

This is comparable in size to the British measurement called "line" (one twelfth of an imperial inch).

In the ninth century the term ligne came into use among German button makers, where it was used to measure the diameter of buttons. The consensus definition was that a ligne was the measurement of a round wick, folded flat. In this sense it measures of an inch, but not exactly, for there were several inches in the kingdoms and petty states of Germany at that time. Such a measurement became the American measurement called "line", being one fortieth of the US-customary inch. Its use was again to measure buttons, and was probably introduced by German immigrants.

See also

• Horology
• Line (length)