the view on the right shows the depression where tallow was placed to pick up sea-bed sediments to aid navigation
sounding lead
Navigational sounding weight, called a lead, or sounding lead. Made of cast lead, weight 7lb. Length 8", 1 1/2" square, eyehole in top for attachment of rope.
curator's notes
Lead and line, a method of depth sounding used on boats and ships.
BRXHM reference: 5378.1