Name/Title
Gunner's calipersEntry/Object ID
2015.459.1Description
Boxwood gunner's calipers. Incised markings for iron guns on one arm and brass guns on the other. Each arm includes scales to measure the bore and shot diameters. Each arm also includes a "proof service" mark, which indicates that the tools was used by a formal military or government body to certify that the cannons were safe for combat.Inscription/Signature/Marks
Type
Makers MarkLocation
On hingeTranscription
Made by A. Lamb N. HavenMaterial/Technique
StampedInterpretative Labels
Label Type
Cultural/Historical ContextLabel
In the 18th and early 19th centuries, artillery crews relied heavily on precise measurements to hit their targets. Lightweight yet durable instruments like these boxwood calipers were essential tools for artillery officers and bombardiers to quickly evaluate weapons and ammunition in the field. By using the jaws, a gunner could accurately determine a cannonball's diameter or a barrel's bore to prevent dangerous misfires caused by ill-fitting cannonballs. The faces are stamped with mathematical scales, allowing crews to instantly calculate shot weight and the exact amount of gunpowder needed to safely fire different sizes of cannons.
