Line (unit) explained

The line (abbreviated L or l or ‴ or lin.) was a small English unit of length, variously reckoned as,,, or 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 of a barleycorn,^[1] (which itself was recognized by statute as of an inch.^[2]) making it of an inch, and of a foot. The line was eventually decimalized as of an inch, without recourse to barleycorns.

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).^{[3] [4]}

In use

Botanists formerly used the units (usually as 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"; Stearns gives its length as 2.25 mm. Even after metrication, British botanists continued to employ tools with gradations marked as linea (lines); the British line is approx. 2.1 mm and the Paris line approx. 2.3 mm.^[5]

Entomologists, both in the UK and in other European countries, in the 1800s were using lines as a unit of measurement for insects, at least for the relatively large mantids and phasmids - examples include Westwood,^{[6] [7]} in the UK, and de Haan^[8] in the Netherlands.

Gunsmiths and armament companies also employed the -inch line (the "decimal line"), in part owing to the importance of the German and Russian arms industries. These are now given in terms of millimeters, but the seemingly arbitrary 7.62 mm caliber was originally understood as a 3-line caliber (as with the 1891 Mosin–Nagant rifle). The 12.7 mm caliber used by the M2 Browning machine gun was similarly a 5-line caliber.

Foreign units

Other similar small units called lines include:

• The Russian Russian: liniya (ли́ния), of the diuym which had been set precisely equal to an English inch by Peter the Great
• The French French: [[ligne]] or "Paris line", of the French inch (French: pouce), 2.256 mm and about 1.06 L.
• The Portuguese Portuguese: [[linha]], of the Portuguese inch or 12 "points" (Portuguese: pontos) or 2.29 mm
• The German German: linie was usually of the German inch but sometimes also German inch
• The Vienna line, of a Vienna inch.^{[9] [10]}

See also

• English units used prior to 1824
• Imperial units defined by the British Weights and Measures Act of 1824
• List of unusual units of measurement

References

Bibliography

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Notes and References

1. Oxford Dictionary of English . 3rd . Oxford University Press . Barelycorn . a former unit of measurement (about a third of an inch) based on the length of a grain of barley.
2. Book: Fowler, W. . Royal Institution of Chartered Surveyors . Transactions . On the ancient terms applicable to the measurement of land . https://archive.org/details/transactions04survgoog/page/n295/mode/2up . 1884 . XVI . 277.
3. Web site: An Easy Guide to Button Measurement and Sizing . 2019-06-19 . Sun Mei Button Enterprise Co., Ltd..
4. Book: 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.. 216 . October 11, 1921 . By United States. Congress. Senate. Committee on Manufactures.
5. Book: Stearn, W.T. . 1992 . Botanical Latin: History, grammar, syntax, terminology and vocabulary, Fourth edition . David and Charles.
6. Book: Westwood, J.O. . 1859 . Catalogue of the Orthopterous Insects in the Collection of British Museum. Part I: Phasmidae. . British Museum, London..
7. Book: Westwood, J.O. . 1889 . Revisio Insectorum Familiae Mantidarum, speciebus novis aut minus cognitis descriptis et delineatis. – Revisio Mantidarum. . Gurney & Jackson, London..
8. Book: Haan, W.de . 1842 . Bijdragen tot de Kennis Orthoptera. in C.J. Temminck, Verhandelingen over de natuurlijke Geschiedenis der Nederlandsche overzeesche Bezittingen. volume 2..
9. Albert Johannsen."Manual of petrographic methods".p. 623.
10. Karl Wilhelm Naegeli; Simon Schwendener."The Microscope in Theory and Practice".p. 294.