What is "sounding lead"

Sounding \Sound"ing\, n.

1. The act of one who, or that which, sounds (in any of the senses of the several verbs).

2. (Naut.) [From Sound to fathom.]

   1. measurement by sounding; also, the depth so ascertained.

   2. Any place or part of the ocean, or other water, where a sounding line will reach the bottom; -- usually in the plural.

   3. The sand, shells, or the like, that are brought up by the sounding lead when it has touched bottom.

      Sounding lead, the plummet at the end of a sounding line.

      Sounding line, a line having a plummet at the end, used in making soundings.

      Sounding post (Mus.), a small post in a violin, violoncello, or similar instrument, set under the bridge as a support, for propagating the sounds to the body of the instrument; -- called also sound post.

      Sounding rod (Naut.), a rod used to ascertain the depth of water in a ship's hold.

      In soundings, within the eighty-fathom line.
      --Ham. Nav. Encyc.

n. a metal bob at the end of a sounding line