Gunnery instrument - dividers

Gilt brass with steel hinged tips that pivot.
Folds flat to give four faces, each with an engraved scale.

[scale 1:] 1-100 non-linear
[scale 2:] 1-100 non-linear (shorter than 1)
[scale 3:] 1-50 non-linear
[scale 4:] 1-12 linear, each unit = 24 mm

Object Details

ID: NAV0539
Type: Gunnery instrument - dividers
Display location: Not on display
Creator: Unknown
Date made: 1597
Credit: National Maritime Museum, Greenwich, London
Measurements: 360 x 6 x 5 mm (unfolded); 185 x 11 x 5 mm (folded)