Strata: What Is It?

A. Byzantine bell

B. Stone anchor

C. Roman pendant

D. Lead sounding weight

E. Christmas ornament

F. Pedestal

Answer: (D) Sounding weight

In the proverbial toolbox of every ancient seaman, there would have been a sounding weight among a variety of fishing gear. Sounding weights were used to find the depth of bodies of water. Usually they were made of lead and shaped like a bullet. The lead sounding weight pictured here has a cross incised on it. Found in the Mediterranean Sea, it has been dated to the sixth–seventh centuries A.D.

A sounding weight would have been tied to a rope and dropped over the edge of the ship. It was an important navigation tool since it allowed seamen to figure out their position—even when land and sky marks were not visible. The data collected from these soundings were used to map the floors of bodies of water.

Sounding weights could also determine what the sea bottom was like. By attaching sticky material (tallow) to the sounding weight—often to its base—the weight was able to bring up a sample of the sea floor, which helped seamen locate fishing grounds.