parallel rulers

plural noun

1. a pair of straightedges connected by two pivoted crosspieces of equal length so as to be parallel at all times, used for various navigational purposes, especially for transferring the bearing of a plotted course to a compass rose.

Word History and Origins

Origin of parallel rulers¹

First recorded in 1695–1705

Example Sentences

I pricked that place off on the chart with my dividers, and with my parallel rulers found that west-by-south was the true course.

From Project Gutenberg

Captain Ponsberry said no more, but threw down his parallel rulers and his pencil.

From Project Gutenberg

The parallel rulers need no explanation except for the way in which they are used on a chart.

From Project Gutenberg

It is just as accurate, too, if you lay the distances off carefully with the dividers and parallel rulers.

From Project Gutenberg

Hence we find him first making brass scales, parallel-rulers and quadrants.

From Project Gutenberg