Flintlock swivel guns were commonly used on a wide variety of military and merchant vessels in the early 19th century and earlier and could be used both for fighting enemy personnel and for signaling. Others of this roughly same pattern with Cooper & Goodman marked locks are known. Joseph Rock Cooper and John D. Goodman were in partnership from 1857 to 1886. Given those dates, these swivel guns were likely manufactured for use by locals on boats in the Indian and Pacific. It has a 3 1/4 inch muzzle opening, "9" bore marking by the English proofs at the breech, "COOPER &/GOODMAN" on the lock, and plain brass furniture. The swivel mount is absent.