Ruler
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A ruler is an instrument used to make length measurements, whereby a length is read from a series of markings called "rules" along an edge of the device. Alternatively, it is called a rule, scale, lin
A variety of rulers
Retractable flexible rule or tape measure
A closeup of a steel ruler
The Nippur cubit-rod, c. 2650 BC, in the Archeological Museum of Istanbul, Turkey
Scale ruler
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A scale ruler is a tool for measuring lengths and transferring measurements at a fixed ratio of length; two common examples are an architect's scale and engineer's scale. In scientific and engineering
Ruler
…Rolling ruler Scales: Architect's scale – Tool used for measuring at a fixed ratio Metric scale – Tool used for measuring at a fixed ratio and Engineer's scale – Tool used for measuring at a…
A flat scale ruler with multiple scales
A triangular architect's scale, made of brass
Boxed set of 1850s ivory engineer's scales presented to the railway civil engineer George Turnbull in India. 16 scales are engraved.