parallel rulers

American  

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.

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Etymology

Origin of parallel rulers

First recorded in 1695–1705

Example Sentences

But he always remembered Elizabeth Boardman and the parallel rulers.

From "Carry On, Mr. Bowditch" by Jean Lee Latham

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

From Lectures in Navigation by Draper, Ernest Gallaudet

Now place the parallel rulers along that line and slide them over until the nearest edge intersects the center of the compass rose at the bottom or side of the chart.

From Lectures in Navigation by Draper, Ernest Gallaudet

I crossed the Channel on the 29th of July 1863, embarrassed by the possession of two ladders, each twelve feet long, which joined together like those used by firemen, and shut up like parallel rulers.

From The Ascent of the Matterhorn by Whymper, Edward

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

From At the Fall of Port Arthur Or, A Young American in the Japanese Navy by Stratemeyer, Edward