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

Then, with my parallel rulers, I laid down a course from the Snark's position to Port Resolution.

From The Cruise of the Snark by London, Jack

Then with the parallel rulers carry the bearing of one object from the chart compass card until you can intersect the object itself and draw a line through it.

From Lectures in Navigation by Draper, Ernest Gallaudet

There stood Mr. Pike, his sou’wester doffed, his oilskins streaming rivulets to the floor, while he, dividers and parallel rulers in hand, bent over the chart. 

From The Mutiny of the Elsinore by London, Jack