This image is a derivative work of the following images: File:Marine_sextant_text.svg licensed with Cc-by-2.5, Cc-by-sa-3.0-migrated, GFDL 2006-11-11T09:58:32Z...
reflecting circle, a ninetinch quintant on a stand with counterpoises, and a sextant i with an artificial, horizon, two,barometers, a large protractor with...
