Hair's breadth

Definitions

This measurement is not precise because human hair varies in diameter, ranging anywhere from 17 μm to 181 μm [millionths of a metre] One nominal value often chosen is 75 μm, but this – like other measures based upon such highly variable natural objects, including the barleycorn – is subject to a fair degree of imprecision.

Such measures can be found in many cultures. The English "hair's breadth" has a direct analogue in the formal Burmese system of Long Measure. A "tshan khyee", the smallest unit in the system, is literally a "hair's breadth". 10 "tshan khyee" form a "hnan" (a Sesamum seed), 60 (6 hnan) form a mooyau (a species of grain), and 240 (4 mooyau) form an "atheet" (literally, a "finger's breadth").

Some formal definitions even existed in English. In several systems of English Long Measure, a "hair's breadth" has a formal definition. Samuel Maunder's Treasury of Knowledge and Library of Reference, published in 1855, states that a "hair's breadth" is one 48th of an inch (and thus one 16th of a barleycorn). John Lindley's An introduction to botany, published in 1839, and William Withering' An Arrangement of British Plants, published in 1818, states that a "hair's breadth" is one 12th of a line, which is one 144th of an inch or ~176 μm (a line itself being one 12th of an inch). Carl Linnaeus had earlier recommended, in place of Joseph Pitton de Tournefort's geometric scale for botanical measurements, a scale starting with a "hair's breadth" (capillus) which was one 12th of a line (linea), one 6th of a (finger) nail (unguis), and likewise 144th of a thumb (pollex); which itself was equal to a (Parisian) inch.

Other body part measurements

Winning a competition, such as a horse race, "by a whisker" (a short beard hair) is a narrower margin of victory than winning "by a nose." An even narrower anatomically-based margin might be described in the idiom "by the skin of my teeth," which is typically applied to a narrow escape from impending disaster. This is roughly analogous to the phrase "as small as the hairs on a gnat's bollock." Some German speakers similarly use “Muggeseggele,” literally “housefly’s scrotum,” as a small unit of measurement.

References

Notes

Citations

Sources

• {{cite book |author1-last=Maunder|author1-first=Samuel|author1-link=Samuel Maunder| year = 1855 | title = Treasury of Knowledge and Library of Reference | url = https://archive.org/details/treasuryknowled04maungoog | publisher=J. W. Bell | location = New York

References

1. (10 February 2011). "Hair's breadth (hare's breath)". [[Grammarist]].
2. "Hairs breadth". [[Oxford English Dictionary]].
3. "Hairs breadth". [[Macmillan English Dictionary for Advanced Learners.
4. "Hairs breadth". [[Cambridge Advanced Learner's Dictionary.
5. Ley, Brian. (1999). "Diameter of a human hair".
6. (2002). "Win by a nose". [[Houghton Mifflin Company]]/[[Dictionary.com]].
7. "By a nose". Free Dictionary.
8. "The meaning and origin of the expression: By the skin of your teeth". The phrase finder.
9. Sellner, Jan. (9 March 2009). "Schönstes schwäbisches Wort: Großer Vorsprung für Schwabens kleinste Einheit". [[Stuttgarter Nachrichten]].