Thanks for the replies. I will ask the guys at the Fort about those shells. I do know that they are on limited funding, and conservation may be low on the priority list. Those rooms are not environmentally controlled, and are subject to the high humidity, etc., so they will corrode. I did not go through the rooms and look at all the displays, as I was more interested in looking at the cannon, or rather the markings on the cannon. The IX Inch Dahlgren on the parapet is #116, made at the Tredgar Foundry in 1857. The one we have here at the Lab in #144, made by the Alger Company in Boston in 1858. Only 1,201 IX Inch Dahlgrens were made, with 53 surviving examples. #54 is on the CSS Georgia, and I have to wait until next year to see her! Arrgh!