Inscription: Engraved on underside: BT
Marking:  Leopard's head crowned (London assay office mark);
 F (London date letter for 1683–84);
 Lion passant (English quality mark for sterling);
 B.M., two pellets above, star below in heart-shaped outline (maker's mark)
Location of marks:
All marks struck on underside of base.
Notes on marks:
The third pellet in the maker's mark is part of a second similar mark otherwise obliterated.