https://wellcomecollection.org/concepts/n76p43hm
Find books, manuscripts, paintings, illustrations, photos and unpublished archives about Cross-staffs (Navigation instruments), many of them with free online...
navigation instrumentswellcome collectioncrossstaffs
https://perso.madh.eu/dufour1800/dufour1800.aceboard.fr/325159-8045-0-Instruments-navigation.htm
Instruments de navigation Forum le site du dufour 1800
instrumentsdenavigation