British India Pattern 1808 Socket Bayonet measuring 21" overall, 4" socket, and with a triangular blade of 16.75" with a inside socket diameter of .925".   Ricasso stamped,  "OSBORN & GUNBY" Shows age patina, scattered spotting/pitting. These were used with the .75 Caliber India Pattern Brown Bess Flintlock Musket during the Napoleonic Wars.   This See photos for further details.