Hydrometer in a wooden case with key. The hydrometer is glass with mercury in the bulb; paper scale in the top of the hydrometer tube runs 0-100. The box also contains 6 differently sized brass parts, each punched with a number from 2 to 7; one missing (no. 1). Brass parts 2 and 5 are washers, parts 1, 3, 5, and 4 are plugs. Felt lined recess.