![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 discipline of composing drawings that visually communicate how something functions or is constructed.
Technical drawing is essential for communicating ideas in industry and engineering ...
, 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 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
yardstick
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 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
The metre (British spelling) or meter (American spelling; see spelling differences) (from the French unit , from the Greek noun , "measure"), symbol m, is the primary unit of length in the International System of Units (SI), though its pref ...
long, are also used. Classically, long
measuring rod
A measuring rod is a tool used to physically measure lengths and survey areas of various sizes. Most measuring rods are round or square sectioned; however, they can also be flat boards. Some have markings at regular intervals. It is likely th ...
s were used for larger projects, now superseded by
tape measure
A tape measure or measuring tape is a flexible ruler used to measure length or distance.
It consists of a ribbon of cloth, plastic, fibre glass, or metal strip with linear measurement markings. It is a common measuring tool. Its design all ...
,
surveyor's wheel or laser
rangefinder
A rangefinder (also rangefinding telemeter, depending on the context) is a device used to measure distances to remote objects. Originally optical devices used in surveying, they soon found applications in other fields, such as photography an ...
s.
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
Agate () is a common rock formation, consisting of chalcedony and quartz as its primary components, with a wide variety of colors. Agates are primarily formed within volcanic and metamorphic rocks. The ornamental use of agate was common in Anci ...
,
picas, and
points. 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 appear ...
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 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. 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 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 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
Ivory is a hard, white material from the tusks (traditionally from elephants) and teeth of animals, that consists mainly of dentine, one of the physical structures of teeth and tusks. The chemical structure of the teeth and tusks of mammals is ...
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
Lothal () was one of the southernmost sites of the ancient Indus Valley civilisation, located in the Bhāl region of the modern state of Gujarāt. Construction of the city is believed to have begun around 2200 BCE.
Archaeological Survey of ...
(2400 BCE) have yielded one such ruler calibrated to about .
[Whitelaw, p. 14.] Ian Whitelaw holds that the
Mohenjo-Daro
Mohenjo-daro (; sd, موئن جو دڙو'', ''meaning 'Mound of the Dead Men';[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. H ...]
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 French curve is a template usually made from metal, wood or plastic composed of many different segments of the Euler spiral (aka the clothoid curve). It is used in manual drafting and in fashion design to draw smooth curves of varying radii. ...
. A flexible device that can be bent to the desired shape is known as a
flat spline
A spline consists of a long strip fixed in position at a number of points whose tension creates a smooth curve passing through those points, for the purpose of transferring that curve to another material.
Before computers were used for creating ...
, 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 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
''Philosophical Investigations'' (german: Philosophische Untersuchungen) is a work by the philosopher Ludwig Wittgenstein, published posthumously in 1953.
''Philosophical Investigations'' is divided into two parts, consisting of what Wittgens ...
''. 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 (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