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prettygoodwordsteelyard (STEEL-yahrd, STIL-yerd) - n., a balance with unequal arms, where the object to be weighed is attached to the shorter arm and a movable counterbalance is slid along the longer one.
Also called a steelyard balance and a Roman balance -- though it well predates the examples found in Pompeii -- and still used today:
Thanks, WikiMedia!
The mechanism takes advantage of the law of levers (developed by Archimedes from observing their use) so that the counterweight doesn't have to equal the unknown weight, which is useful when you're weighing really heavy things like loads of iron or steel -- thence the name (from the early 1600s), where the -yard part is in the sense of a rod/pole, as in the yardarm that holds the sail of a ship.
---L.
Also called a steelyard balance and a Roman balance -- though it well predates the examples found in Pompeii -- and still used today:
Thanks, WikiMedia!
The mechanism takes advantage of the law of levers (developed by Archimedes from observing their use) so that the counterweight doesn't have to equal the unknown weight, which is useful when you're weighing really heavy things like loads of iron or steel -- thence the name (from the early 1600s), where the -yard part is in the sense of a rod/pole, as in the yardarm that holds the sail of a ship.
---L.
