Yes it is 18th C. The capture inscription on muzzle reads "Taken by Earl Howe on June 1 1794." Boom and I have both made some posts about that famous battle. I have not yet found any documentation on this particular model of French swivel gun but I have one example with a different cascabel, and no capture inscription, then there's this one. These typically only had sparse trunnion marks, weight on one trunnion and serial or registry number on the other. I have not yet determined what "RM" on either trunnion means-perhaps initials for French words meaning "rimbase modified." If anyone speaks French, please see if that makes sense. The reason there aren't more of these I think is that when the French came out with the much heavier one-pounder swivel gun M1786, they threw these little guys in the pot to get some of the bronze required. But obviously they were still in use to some extent in 1794.
I would bet a considerable sum of money that a certain English dealer I know beat me out of this on a phone bid, since it was a phone bid that got it. The piece would be worth a lot more in the UK with that capture inscription than it would be in the US. In the UK having that inscription is like a cannon here having an inscription "Taken by Gen. _____ on July 3, 1863." I have no doubt that once he gets that to the UK he'll be able to sell it for at least a few times what he has in it. He deals with the upper crust of collectors on that side of the pond.
I've made something of a study of French bronze swivels, the "Cannon-appearing" type that is, and have documented two distinct types in addition to the already-well-documented M1786.
Again, Gilkerson's book is a good ref for swivels, but like all 20th C. authors of works on naval ordnance, he has missed two of the three principal French swivel cannon models. The modern author everyone uses for reference on this subject is Jean Boudriot, whose books are only in French and cost hundreds if you can find one. He also missed the two earlier, smaller models of French bronze swivel cannon, probably because the documentation on them was lost during the French Revolution. All we have left to go on, until someone finds some mention of them in some old French ordnance book, is a very few surviving examples, which (may I say "until I came along?") were not recognized as French swivels.
If you're interested, here's a link to my brief dissertation on the larger French M1756 bronze swivel. I recently spotted another one in the "Brown Catalog" and that info is in the CMH board post following the one linked here:
http://gs19.inmotionhosting.com/~milita8/cmh/member/member.cgi/read/3955
