ligne

In Haiti, Mauritius and the Seychelles, 20^th century (UN, 1966, a unit of length, = 2.25 millimeters (about 0.0886 inches).

This is a colonial descendent of a pre-metric French unit, 1 ligne = ¹⁄₁₂ pouce, about 2.25583 millimeters (about 0.088814 inches).

In France and Britain, the ligne survived into the 20^th century in the jewelry and watch-making trades. Compare the U.S. unit line, used for buttons and watch glasses.

sources

LIGNE. A unit used in the measurement of watch movements. It is 1/12 French inch [i.e., a pouce] i.e., 2.256 mm. The size of a watch movement is referred to as “so many lignes,” e.g. 8¾′′′ lady’s size or 18′′′ gentleman’s pocket size, etc. The three small strokes (′′′) are the accepted symbol for ligne. [page 167]

GOLIATH. Refers to a large watch of 24 to 28 lignes and used as a clock. [page 140]

Donald de Carle, F.R.H.I.
Watch and Clock Encyclopedia.
New York: Bonanza Books, 1977.
This is a republication of the 1975 edition from the N.A.G. Press of London, who published the first edition in 1950.