tompion

• To this tompion is, or used to be, attached a large piece of wadding, what for I never rightly understood. —  Sketches From My Life
• There were the tompion (a lid that fitted over the muzzle of the gun to keep wind and weather out of the bore) and the lead cover for the vent; water buckets for the sponges and passing boxes for the powder; scrapers and tools for "searching" the bore to find dangerous cracks or holes; chocks for the wheels; blocks and rollers, lifting jacks, and gins for moving guns; and drills and augers for clearing the vent (figs. —  Artillery Through the Ages A Short Illustrated History of Cannon, Emphasizing Types Used in America
• He is to see that the tompion is put in securely, and the vent and all screw-holes stopped by a plug of soft wood, and puttied over 47. —  Ordnance Instructions for the United States Navy. 1866. Fourth edition.
• Each scuttle is to have a tompion or other means of closing it, so as to be water-tight when not in use, and to be so placed or regulated in height as not to interfere with the transportation of guns 192. —  Ordnance Instructions for the United States Navy. 1866. Fourth edition.
• In this case the breeching should be secured after alternate exercises right and left The Loader and Sponger haul up and secure the lower half-ports, put in tompion, and secure muzzle-bag. —  Ordnance Instructions for the United States Navy. 1866. Fourth edition.

Allen's Synonyms and Antonyms