A 2 1/2 inch, pear-shaped shell of copper-alloy filled with lead, and ending in a ring at the top was among the artifacts recovered from the <i>Mary Rose</i>. Comparison with similar objects indicated this is a medieval steelyard (i.e. unequal-armed balance for wool, etc.) weight whose alloy composition is detailed. Since the use of steelyards for official purposes was forbidden in 1350, these weights may have been put to other uses, such as sounding-line weights on board ship for ballast. Marine archaeologists should be aware of this possibility when excavating late medieval or even later period wrecks. This weight predates most other artifacts on the <i>Mary Rose</i> by at least two centuries. -- AATA