A fine, complete original example of a classic British Brown Bess Bayonet Rev. War through 1812. The blade is 17" long and 1 -1/8 " wide (at the blade base) and the socket 4" long. Proper 2 step lug slot with no indication of the later style "keeper spring", and expected circumference to take a 75 cal Brown Bess barrel. The three sided triangular blade is fluted on two sides and the "flat" is marked with what appears to be a "Crowned 9" inspector's mark, and a partial MAKER'S MARK (which seems to read something like "S. Chambers"?????? Below the maker's mark is an intriguing "2" or "Z" looking symbol which may even be a partial "Broad Arrow" mark???? I don't know. (see pictures).
Small Roman numeral marks also appear on the flat end of the socket ring....(ie..."XII" and on the opposite side an "I")
Perhaps it's greatest asset (as evidence that it was used in accordance with the British Army Regimental marking system) is the "fraction" style engraving on the socket itself. There, it displays a "D" (thought to be for "Company D") and a "26" (thought to be the "weapon number" and originally corresponding to a certain issued musket of that same number).
These marks are otherwise what one would expect to see on these things even though further research is constantly being done to understand the evolution of the mysterious British Weapons marking system (see "The Socket Bayonet in the British Army 1687 -1783" by Eric Goldstein)