from The Century Dictionary.
- noun Nautical, a painted canvas cap fitted over the muzzle of a gun at sea, to keep out water.
Sorry, no etymologies found.
In using guns on shore, a canvas muzzle-bag, a soft wad, or a light stopper of wood, suggest themselves as means of security during the interval between loading and firing the gun.
Loaders put in the tompion and on muzzle-bag, and wipe off and re-lacquer the front pivot-bolt.
The Loader and Sponger haul up and secure the lower half-ports, put in tompion, and secure muzzle-bag.