Prosser died in 1838, which dtes this sword ca. 1827-1838. It is mounted with a curved pipe-back blade on a massive, well-cast hilt. Blade is 71 cm long, and has acquired a nice uniform patina, with several minor spots of pitting and several light nicks on the edge. Blade is extensively decorated in Royal regalia and naval symbols, and is prominently maker-marked.
The sword still has part of its scabbard, a small but important part - the top locket with 2 rings with a bit of leather still inside, marked with the retailer's name - FISKE of High Street in Portsmouth. Fiske was a known naval officers' outfitter. The two-ring suspension indicates that the sword was last carried in the period spanning 1847-1856. Light-weight, with a smaller and narrower blade than would be expected? indicates this was either a midshipman's first sword, or a levee sword of commissioned officer. Being that the sword was originally produced ca.1827-1838, and was still in service ca.1847, tilts it towards being a midshipman's sword at first, then relegated to the levee occasions of a commissioned officer.