I suspect the author of the posts 'DE Graves' is none other than Donald E Graves - I do not recall if he is a member of CMH, but he is well respected in any case. Mr Graves is a Canadian historian who has written extensively (and very well) on the War of 1812, and who edited an edition of De Scheel's Treatise on Artillery which was published by the Museum Restoration Service (I think in 1984). For those interested, his website is here: http://www.ensigngroup.ca/
I seem to recall the same problem with a lack of concrete information when I was looking for information on Columbiads and the War of 1812 a few years ago. I seem to recall someone writing that there were 50- and 100-pound versions at the time of the war, but it was not first hand material, and all of the conjecture I've seen around the name Columbiad points to an origin at the Columbia foundry, but don't recall any hard evidence.
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