Definition:Imperial/Length/Inch
Definition
The inch is an imperial and FPS unit of length.
Conversion Factors
| \(\ds \) | \(\) | \(\ds 1\) | inch | |||||||||||
| \(\ds \) | \(=\) | \(\ds \dfrac 1 {12}\) | foot | |||||||||||
| \(\ds \) | \(=\) | \(\ds 2 \cdotp 54\) | centimetres | \(\quad\) (exact) | ||||||||||
| \(\ds \) | \(=\) | \(\ds 0 \cdotp 0254\) | metres | \(\quad\) (exact) |
Symbol
The following symbols are in general use to denote an inch of linear measure:
Symbol: $\mathrm {in} $
- $\mathrm {in}$
The symbol for the inch is $\mathrm {in}$.
Its $\LaTeX$ code is \mathrm {in} .
Symbol: ${}^{\prime \prime}$
- ${}^{\prime \prime}$
One of the symbols in general use for the inch is ${}^{\prime \prime}$.
Thus, for example, $10$ inches is presented as:
- $10^{\prime \prime}$
The $\LaTeX$ code for \(10^{\prime \prime}\) is 10^{\prime \prime} or 10' '.
Linguistic Note
The word inch derives ultimately from the same root as ounce, that is, from the Latin word uncia, meaning $\dfrac 1 {12}$ part.
In this context, the inch is of course the $\dfrac 1 {12}$ part of a foot.
From the same root, the uncial letters of a mediaeval manuscript are letters which are an inch high.
Despite the gradual migration to the metric system, the word inch still lives on as a rhetorical flourish for a small distance, for example:
- Slowly and steadily they inched forward ...
Sources
- 1944: Alfred E. Holbrow: Geometrical Drawing (12th ed.) ... (previous) ... (next): Section $\text I$. Introduction
- 1969: J.C. Anderson, D.M. Hum, B.G. Neal and J.H. Whitelaw: Data and Formulae for Engineering Students (2nd ed.) ... (previous) ... (next): $1.$ Units and Abbreviations: $1.3$ British and other units
- 1986: David Wells: Curious and Interesting Numbers ... (previous) ... (next): $12$
- 1997: David Wells: Curious and Interesting Numbers (2nd ed.) ... (previous) ... (next): $12$
- 1998: David Nelson: The Penguin Dictionary of Mathematics (2nd ed.) ... (previous) ... (next): inch
- 2008: David Nelson: The Penguin Dictionary of Mathematics (4th ed.) ... (previous) ... (next): inch