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

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

The Captain changed his frown for a smile as the situation dawned on him, then, snatching the parallel rulers from the chart-table he began to belabour the most accessible portion of his gurgling subordinate's anatomy.

From H.M.S. —— by Bower, John Graham

Fosterdyke, busy with parallel rulers and compass was bending over a chart.

From The Airship "Golden Hind" by Westerman, Percy F. (Percy Francis)

Writing; materials for writing; pens; inks; use of coloured inks for denoting numbers; polygraph; telegraph; geometrical instruments; rulers; compasses; flexible rulers; squares; triangular compasses; parallel rulers; Marquois's scales; pantograph; proportional compasses; sector.

From Heroes of Science: Physicists by Garnett, William