Rolling ruler

Rolling ruler

A rolling ruler is a ruler that contains a cylinder much like a rolling pin inside, thereby enabling it to "roll" along a sheet of paper or other surface where it is being used. A rolling ruler can draw straight, parallel lines, and also has other instruments included, enabling it to do the jobs of a protractor and compass.^[1][2]

References

1. Jack E. Ingels (2003). "Using Drawing Instruments". Landscaping: Principles and Practices. Cengage Learning. p. 11. ISBN 9781401834104.
2. Jim Tolpin (2007). "drawing techniques". Measure Twice, Cut Once. Popular Woodworking Books. p. 24. ISBN 9781558708099.