A brief history of the Rule

3rd March 2020

A brief history of the rule


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		Rules are flat rods used for measurement and to aid with drawing, cutting or scoring straight lines. Tools used for these jobs have been around for a long time. They have been used to create standardised measurements and assist in human accuracy.
		Rules to measure
		Measurement is at least as old as language, and they have both influenced the development of civilisations. Tools resembling rules, used to measure, have been around since ancient times. Over the years, and within different civilisations, they have been calibrated to various measuring systems.

		Ancient measures didn’t need to be as precise as scientific measures are today. Builders and craftsmen could mark out spaces with strides or arm and hand lengths. They shaped materials with the best hand tools they had. As tools became more refined, objects could be produced with more precision.

		Various rule-type implements have been excavated from the Indus Valley Civilisations. One of the oldest known measuring rods dates from 2650BC and was made from a copper alloy. Ivory rules dating from around 2400BC have been found where the ancient city of Lothal was – these had calibrations relating closely to modern measurement systems. Rules, and similar tools, have developed alongside standardised measurements.

		The development of standardised measurement
		Different civilisations or groups created their own standards of measure, but there were variations locally, regionally, and nationally. They were usually based on the dimensions of the human body or related to daily activities. For early man precision wasn’t vital; spaces could be marked out with strides or arm and hand lengths. They shaped materials with the best hand tools they had. As tools became more refined, objects could be produced with more precision.

		Ancient Egypt One of the earliest measuring systems was believed to have been devised around 3,000 BC in Ancient Egypt. This was the ‘Egyptian cubit’, based on the length of an arm from an outstretched middle finger to the back of the elbow. Commonly used cubit rods, like rules, were made from wood and stone in Ancient Eygpt.

		This cubit was standardised around 2,500BC to the ‘royal master cubit’, represented as a black marble piece, resembling a rule. It was around 520mm (20.5″) long: this was the measurement from the Pharaoh’s elbow to his fingertips, plus the width of his palm. Cubit rods or rules used in Egypt at this time could be measured against this master on a regular basis.

		This royal cubit was subdivided in a surprisingly complicated way, but its accuracy is demonstrated in the dimensions of the Great Pyramid of Giza. Its sides vary from the average length by less than 0.05%, despite the fact that thousands of people were involved in building it. The original dimensions of the pyramid’s sides are thought to have been 440 x 440 royal cubits.

		The development of the imperial system Ancient Rome introduced its own standard linear measures, influenced by Egyptian and other civilisations. Measuring rods like rules were important to the Romans – their art often depicts surveyors using them. The Romans had ten-foot rule-like instruments they called a decempeda, usually made from wood with metal caps at each end. These were used for measurements in the construction of roads and buildings.



		Roman measurements were adapted by the Anglo-Saxons in Britain, eventually developing into imperial yards, feet and inches. It is thought that a standard measuring stick, representing a yard, was held by Saxon king, Elgar, in the 10th Century. King Edward I, who reigned from 1272-1307, instructed that a permanent iron ‘yardstick’, like an iron rule, be cast. This represented a standardised yard for the United Kingdom. This yardstick was equally divided; three feet or thirty-six inches go into a yard.

		This imperial system of weights and measures became globally significant with the spread of the British Empire. As the influence of the British Empire faded, so did the use of imperial system measurements. Although it is still in regular use in Britain it is not the official measurement system. America is the only country which still uses imperial measures as its official system, although they do not always correspond exactly to Britain’s imperial measurements.

		The development of the metric system The metric system was scientifically constructed, based on the measurements of the Earth. The original metre was developed in France in the late 1700s. It was meant to be one ten-millionth of a quarter of a meridian of the Earth, which is the distance between the north pole and the equator. Although the calculations used for this were slightly wrong, the length of the original metre remains the same.



		Due to the original miscalculation, the metre has been redefined by scientists a few times over the years. To be able to ensure that a standard metre can be reproduced all over the world accurately, an official definition was needed. The metre is now officially defined as the distance a light wave moves, in a vacuum, in 1/299,792,458 of a second.

		The metric system is now the official measurement system of every country in the world, apart from America, Liberia and Burma. In Britain, the change to metric began after a 1963 Act of Parliament, although some imperial measurements are still used in some official capacities today (we drink pints in pubs, drive miles in distance and weigh ourselves in stones and pounds). Many British rules and other measuring tools display both metric and imperial measurements.

		Rules to guide straight lines

		Nature does not have many forms which are completely straight. It is not clear how humans first thought to create a perfectly straight line, but it is likely that still bodies of water, or materials such as string pulled taut, may have been used to gauge straight lines. It is known that knotted rope was sometimes used in Ancient Egypt to gauge lines and rough distances. If the rope was pulled tight enough, it would create a straight line.

		Once humans were able to create straight lines, they could be replicated onto different materials. The original rules, made from ivory and wood, could be carved so they could guide straight lines, as well as measure. Ruled lines is the name given to marked straight lines, usually printed onto paper or similar materials.

		Ruled lines Ruled lines usually appear as guidelines used on paper, or in books. Often they consist of horizontal lines, to mark where text will sit, and vertical lines to mark out margins, and have been used to guide handwriting for centuries. You can also get sheets with variations of ruled lines such as sheet music and squared or graph paper.

		Today, visible ruled lines are not generally used for formal writing: they are considered untidy. This was not the case in the Middle Ages – the smarter the script, the more extravagant the ruled lines would be. They even recorded some standard measurements for how a manuscript should be correctly ruled for different texts.

		Unruled manuscripts from medieval times tended to be cheap or simple handmade transcripts. Even early printed manuscripts would have lines drawn around each line of text, probably because this was how people expected to view text.