![Briefwaage Lineal](https://upload.wikimedia.org/wikipedia/commons/4/47/Briefwaage_Lineal.jpg)
A ruler, sometimes called a rule, line gauge, or scale, is a device used in
geometry
Geometry (; ) is, with arithmetic, one of the oldest branches of mathematics. It is concerned with properties of space such as the distance, shape, size, and relative position of figures. A mathematician who works in the field of geometry is c ...
and
technical drawing
Technical drawing, drafting or drawing, is the act and Academic discipline, discipline of composing Plan (drawing), drawings that Visual communication, visually communicate how something functions or is constructed.
Technical drawing is essent ...
, as well as the engineering and construction industries, to
measure distances or draw straight lines.
Variants
![Bronze ruler](https://upload.wikimedia.org/wikipedia/commons/b/bd/Bronze_ruler._Han_Dynasty_206_BCE_to_CE_220._Excavated_in_Zichang_County..jpg)
Rulers have long been made from different materials and in multiple sizes. Some are wooden.
Plastics
Plastics are a wide range of synthetic polymers, synthetic or semi-synthetic materials that use polymers as a main ingredient. Their Plasticity (physics), plasticity makes it possible for plastics to be Injection moulding, moulded, Extrusion, e ...
have also been used since they were invented; they can be molded with length markings instead of being
scribed. Metal is used for more durable rulers for use in the workshop; sometimes a metal edge is embedded into a wooden desk ruler to preserve the edge when used for straight-line cutting. in length is useful for a ruler to be kept on a desk to help in drawing. Shorter rulers are convenient for keeping in a pocket. Longer rulers, e.g., , are necessary in some cases. Rigid wooden or plastic
yardsticks, 1 yard long, and
meter stick
A meterstick, metrestick, or yardstick is either a straightedge or foldable ruler used to measure length, and is especially common in the construction industry. They are often made of wood or plastic, and often have metal or plastic joints so ...
s, 1
meter long, are also used. Classically, long
measuring rods were used for larger projects, now superseded by
tape measure,
surveyor's wheel
A surveyor's wheel, also called a clickwheel, hodometer, waywiser, trundle wheel, measuring wheel or perambulator is a device for measuring distance.
Origin
The origins of the surveyor's wheel are connected to the origins of the odometer. Wh ...
or laser
rangefinders.
Desk rulers are used for three main purposes: to measure, to aid in drawing straight lines, and as a straight guide for cutting and scoring with a blade. Practical rulers have distance markings along their edges.
A line gauge is a type of ruler used in the printing industry. These may be made from a variety of materials, typically metal or clear plastic. Units of measurement on a basic line gauge usually include inches,
agate,
picas, and
points
Point or points may refer to:
Places
* Point, Lewis, a peninsula in the Outer Hebrides, Scotland
* Point, Texas, a city in Rains County, Texas, United States
* Point, the NE tip and a ferry terminal of Lismore, Inner Hebrides, Scotland
* Point ...
. More detailed line gauges may contain sample widths of lines, samples of common type in several point sizes, etc.
Measuring instruments similar in function to rulers are made portable by folding (carpenter's folding rule) or retracting into a coil (metal tape measure) when not in use. When extended for use, they are straight, like a ruler. The illustrations on this page show a carpenter's rule, which folds down to a length of to easily fit in a pocket, and a tape, which retracts into a small housing.
A flexible length-measuring instrument which is not necessarily straight in use is the tailor's fabric tape measure, a length of tape calibrated in inches and centimeters. It is used to measure around a solid body, e.g., for a person's
waist
The waist is the part of the abdomen between the rib cage and hips. On people with slim bodies, the waist is the narrowest part of the torso.
''Waistline'' refers to the horizontal line where the waist is narrowest, or to the general appearan ...
measurement, as well as for linear measurement, e.g., for the inside leg length. It is rolled up when not in use, taking up little space.
A ''ruler software program'' can be used to measure pixels on a computer screen or mobile phone. These programs are also known as screen rulers.
Ruler applications in geometry
In geometry, a ruler without any marks on it (a straightedge) may be used only for drawing straight lines between points. A straightedge is also used to help draw accurate graphs and tables.
A
ruler and compass construction
In geometry, straightedge-and-compass construction – also known as ruler-and-compass construction, Euclidean construction, or classical construction – is the construction of lengths, angles, and other geometric figures using only an ideali ...
refers to constructions using an unmarked ruler and a compass. It is possible to bisect an angle into two equal parts with a ruler and compass. It can be proved, though, that it is impossible to divide an angle into three equal parts using only a compass and straightedge — the problem of
angle trisection
Angle trisection is a classical problem of straightedge and compass construction of ancient Greek mathematics. It concerns construction of an angle equal to one third of a given arbitrary angle, using only two tools: an unmarked straightedge an ...
. However, should two marks be allowed on the ruler, the problem becomes solvable.
History
![MaryRose-carpentry tools1](https://upload.wikimedia.org/wikipedia/commons/d/db/MaryRose-carpentry_tools1.jpg)
In the
history of measurement
The earliest recorded systems of weights and measures originate in the 3rd or 4th millennium BC. Even the very earliest civilizations needed measurement for purposes of agriculture, construction and trade. Early standard units might only have ap ...
many distance units have been used which were based on human body parts such as the
cubit
The cubit is an ancient unit of length based on the distance from the elbow to the tip of the middle finger. It was primarily associated with the Sumerians, Egyptians, and Israelites. The term ''cubit'' is found in the Bible regarding No ...
,
hand
A hand is a prehensile, multi-fingered appendage located at the end of the forearm or forelimb of primates such as humans, chimpanzees, monkeys, and lemurs. A few other vertebrates such as the koala (which has two opposable thumbs on each "h ...
and
foot
The foot ( : feet) is an anatomical structure found in many vertebrates. It is the terminal portion of a limb which bears weight and allows locomotion. In many animals with feet, the foot is a separate organ at the terminal part of the leg made ...
and these units varied in length by era and location. In the late 18th century the
metric system
The metric system is a system of measurement that succeeded the Decimal, decimalised system based on the metre that had been introduced in French Revolution, France in the 1790s. The historical development of these systems culminated in the d ...
came into use and has been adopted to varying degrees in almost all countries in the world.
The oldest preserved measuring rod is a copper-alloy bar that dates from 2650 BCE and was found by the German Assyriologist
Eckhard Unger
Eckhard Unger (Landsberg an der Warthe, 11 April 1884 – 24 July 1966) was a German assyriologist.
Unger who was the curator of the Istanbul museum described the remains of Balawat Gates that are still in the Istanbul Museum. Unger was fully aw ...
while excavating at the
Sumerian city of
Nippur
Nippur (Sumerian language, Sumerian: ''Nibru'', often logogram, logographically recorded as , EN.LÍLKI, "Enlil City;"The Cambridge Ancient History: Prolegomena & Prehistory': Vol. 1, Part 1. Accessed 15 Dec 2010. Akkadian language, Akkadian: '' ...
(present day Iraq).
Rulers made of
ivory were in use by the
Indus Valley civilization
The Indus Valley Civilisation (IVC), also known as the Indus Civilisation was a Bronze Age civilisation in the northwestern regions of South Asia, lasting from 3300 BCE to 1300 BCE, and in its mature form 2600 BCE to 1900&n ...
period prior to 1500 BCE.
Excavations at
Lothal (2400 BCE) have yielded one such ruler calibrated to about .
[Whitelaw, p. 14.] Ian Whitelaw holds that the
Mohenjo-Daro ruler is divided into units corresponding to and these are marked out in decimal subdivisions with amazing accuracy, to within . Ancient bricks found throughout the region have dimensions that correspond to these units.
Anton Ullrich Johannes Anton Ullrich (1826–1895) was a German industrialist, inventor, and co-founder of the "Gebrüder Ullrich" in the Rhineland-Palatinate.
Life
Anton Ullrich was born on the 30 August 1826 in the small village of Maikammer, Germany. He ...
invented the folding ruler in 1851. Frank Hunt later made the flexible ruler in 1902.
Curved and flexible rulers
The equivalent of a ruler for drawing or reproducing a smooth curve, where it takes the form of a rigid template, is known as a
French curve. A flexible device that can be bent to the desired shape is known as a
flat spline, or (in its more modern incarnation) a ''flexible curve''. Historically, a flexible
lead
Lead is a chemical element with the symbol Pb (from the Latin ) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly cu ...
rule used by
masons
Mason may refer to:
Occupations
* Mason, brick mason, or bricklayer, a craftsman who lays bricks to construct brickwork, or who lays any combination of stones, bricks, cinder blocks, or similar pieces
* Stone mason, a craftsman in the stone-cutt ...
that could be bent to the curves of a
molding was known as a
lesbian rule
A lesbian rule was historically a flexible mason's rule made of lead that could be bent to the curves of a molding, and used to measure or reproduce irregular curves. Lesbian rules were originally constructed of a pliable kind of lead found on ...
.
[ ]
Philosophy
Ludwig Wittgenstein
Ludwig Josef Johann Wittgenstein ( ; ; 26 April 1889 – 29 April 1951) was an Austrian-British philosopher who worked primarily in logic, the philosophy of mathematics, the philosophy of mind, and the philosophy of language. He is considere ...
famously used rulers as an example in his discussion of
language games
A language game (also called a cant, secret language, ludling, or argot) is a system of manipulating spoken words to render them incomprehensible to an untrained listener. Language games are used primarily by groups attempting to conceal their c ...
in the ''
Philosophical Investigations''. He pointed out that the
standard meter bar in Paris was the criterion against which all other rulers were determined to be one meter long, but that there was no analytical way to demonstrate that the standard meter bar itself was one meter long. It could only be asserted as one meter as part of a language game.
See also
*
*
*
*
*
*
* Scales:
**
** and
**
*
*
References
Bibliography
* Cherry, Dan. "Collector's guide to rules", ''Furniture & Cabinetmaking'', no. 259, July 2017
ISSN 1365-4292 pp. 52–6
* Rees, Jane and Mark (2010). ''The Rule Book: Measuring for the Trades''. Lakeville, MN: Astragal Press
*
Russell, David R.; with photography by
James Austin James Austin may refer to:
Sports
* Jim Austin (baseball) (born 1963), former baseball pitcher
* Jim Austin (rugby league), New Zealand rugby league player
* James Austin (judoka) (born 1983), English judoka
* James Austin (American football) (19 ...
and foreword by
David Linley
David Albert Charles Armstrong-Jones, 2nd Earl of Snowdon (born 3 November 1961), styled as Viscount Linley until 2017 and known professionally as David Linley, is an English furniture maker, a former chairman of the auction house Christie's UK, ...
(2010). ''
Antique Woodworking Tools: Their Craftsmanship from the Earliest Times to the Twentieth Century'', Cambridge:
John Adamson , pp. 64–74
* Whitelaw, Ian (2007). ''A Measure of All Things: The Story of Man and Measurement''. Macmillan
{{Authority control
Length, distance, or range measuring devices
Metalworking measuring instruments
Stationery
Stonemasonry tools
Woodworking measuring instruments