Plane scale or logaritmic ruler from the wreck of the Dutch East Indiaman Hollandia

Tools and instruments, navigation, plane scale; ruler: oblong, straight, rectangular, flat, one longitudinal edge bevelled, different (logaritmic) scales inscribed on both sides, as well as a maker's mark [initials JVK, Jan van Keulen], small tubes inserted into certain points on the scales.

Plane scale or logaritmic ruler from the wreck of the Dutch East Indiaman Hollandia

Tools and instruments, navigation, plane scale; ruler: oblong, straight, rectangular, flat, one longitudinal edge bevelled, different (logaritmic) scales inscribed on both sides, as well as a maker's mark [initials JVK, Jan van Keulen], small tubes inserted into certain points on the scales.