I had the pleasure of attending, as a layman, a tour organized by Fort McHenry for a group of visiting scholars, held yesterday. The purpose of the tour was to gather input regarding what objects/displays should be included in the new (future) visitor's center. I was invited by Don Graves, a Canadian scholar and author with whom I've been in contact regarding artillery. I had the pleasure of meeting scholar and author Donald R. Hickey and some of the other distinguished gentlemen who attended.
One event Don Graves had set up in advance was the lifting of four particular "French Pattern" (hist terminology) iron field guns, to see if any had markings underneath. The Columbia Foundry in Washington DC is known to have marked some of their cast-iron cannons underneath, including two 6-pounder field guns on display at Fort Niagra, NY.
No marks were found on the undersides of the four cannons, but it was worth a try anyway.
I've linked a slideshow which is more or less random pictures of some objects at the fort, including one of my favorites, the extremely rare 13-inch carcass shell, recovered after the 1814 battle. A carcass is an early type of incendiary shell, filled with a violently-burning pyrotechnic composition that would shoot flames up to 3 feet long out of its 3 or 4 "exhaust holes."
I measured the exhaust holes and found them to be about 2.95 inches in diameter. The two "lifting ear" holes were shaped like keyholes, and measured 1.6 inches long and 0.9 inches wide,and were nearly an inch deep. I couldn't measure the wall thickness of the carcass due to glass ports installed to keep trash out, but it appeared to be about three inches thick all around. Many such shells are made thicker at the base, to better resist internal ballistic pressures.
One of the highlights of the "Ranger Tour" we got was a very detailed explanation of the origin Francis Scott Key's song "The Star Spangled Banner." This was explained in front of a large copy of the original handbill containing the original text, including the little-known fourth stanza. The details of the Fort's designation as the sole U.S. "National Monument and Historic Shrine" were also explained.
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