A description of a new instrument denominated the celestial or variation compass
A description of a new instrument called the celestial or variation compass, written and invented by George Graydon, an officer in the Corps of Royal Engineers, and published in London in 1826. The text is a technical account of a navigational instrument meant for sailors and surveyors who needed to find magnetic variation without relying on a magnetic needle alone. The three plates show the instrument's mechanical parts, which a designer might use as references for precision mechanical drawings with fine hatching and labelled plan views.
