For the equivalent French unit used in watchmaking and other industries, see ligne.
The line (abbreviated L or l or ‴ or lin.) was a small English unit of length, variously reckoned as 1⁄10, 1⁄12, 1⁄16, or 1⁄40 of an inch. It was not included among the units authorized as the British Imperial system in 1824.
Size
The line was not recognized by any statute of the English Parliament but was usually understood as 1⁄4 of a barleycorn,[1] (which itself was recognized by statute as 1⁄3 of an inch[2]) making it 1⁄12 of an inch, and 1⁄144 of a foot. The line was eventually decimalized as 1⁄10 of an inch, without recourse to barleycorns.[5]
The US button trade uses the same or a similar term but defined as one-fortieth of the US-customary inch (making a button-maker's line equal to 0.635 mm (0.0250 in)).[6][7]
In use
Botanists formerly used the units (usually as 1⁄12 inch) to measure the size of plant parts. Linnaeus's Philosophia botanica (1751) includes the Linea in its summary of units of measurements, defining it as Linea una Mensurae parisinae [lit.'One line of the Parisian measure']; Stearns gives its length as 2.25 mm (0.089 in). Even after metrication, British botanists continued to employ tools with gradations marked as linea (lines); the British line is approximately 2.1 mm (0.083 in) and the Paris line approximately 2.3 mm (0.091 in).[8]
Entomologists in the UK and other European countries in the 1800s used lines as a unit of measurement for insects, at least for the relatively large mantids and phasmids. Examples include Westwood,[9][10] in the UK, and de Haan[11] in the Netherlands.
^"Barleycorn". Oxford Dictionary of English (3rd ed.). Oxford University Press. a former unit of measurement (about a third of an inch) based on the length of a grain of barley
^The Metric System | Hearings Before a Subcommittee of the Committee on Manufactures, United States Senate, Sixty-seventh Congress, First and Second Sessions on S. 2267 a Bill to Fix the Metric System of Weights and Measures as the Single Standard of Weights and Measures for Certain Uses. By United States. Congress. Senate. Committee on Manufactures. 11 October 1921. p. 216.
^Stearn, W.T. (1992). Botanical Latin: History, grammar, syntax, terminology, and vocabulary (Fourth ed.). David and Charles.
^Westwood, J.O. (1859). Catalogue of the Orthopterous Insects in the Collection of British Museum. Part I: Phasmidae. British Museum, London.
^Westwood, J.O. (1889). Revisio Insectorum Familiae Mantidarum, speciebus novis aut minus cognitis descriptis et delineatis. – Revisio Mantidarum. Gurney & Jackson, London.
^Haan, W.de (1842). Bijdragen tot de Kennis Orthoptera. in C.J. Temminck, Verhandelingen over de natuurlijke Geschiedenis der Nederlandsche overzeesche Bezittingen. volume 2.
