Sailors' biscuits made from flour, water and salt were baked until rock-hard. Some surviving pieces from the 1800s are still intact in museums.

Crews softened them in coffee or stew, and weevils were part of the deal. It is a good reminder that durable food used to be a matter of survival.

Why it is in the vault: it is the kind of find worth coming back to. Add sources, corrections and related links in the discussion thread.