Sounding Weights

These weights (1), which varied in shape and size, are among the oldest known nautical instruments. They were tied to a rope and thrown over the side of a ship. When the weight hit the seafloor, sailors used the rope to measure the depth beneath the ship’s hull (2). The bottom of some weights had a layer of tallow, a soft substance that would pick up fragments, such as pebbles and sand, from the seafloor. When the weight was retrieved, these fragments would be brought to the surface for the sailors to inspect. Though various materials were used, sounding weights were typically made of lead. Appropriately, the Greek verb for “to sound the depth; to make a sounding” used at Ac 27:28 literally means “to heave the lead.”

1. Sounding weight

2. Rope