STEELYARD
steelyard, lever scale, beam scale
(noun) a portable balance consisting of a pivoted bar with arms of unequal length
Source: WordNet® 3.1
Etymology
Noun
steelyard (plural steelyards)
A transportable balance with unequal arm lengths.
A place where steel (and possibly other metals as well) is stored and sold.
Source: Wiktionary
Steel"yard, n. Etym: [So named from a place in London called the
Steelyard, which was a yard in which steel was sold.]
Definition: A form of balance in which the body to be weighed is suspended
from the shorter arm of a lever, which turns on a fulcrum, and a
counterpoise is caused to slide upon the longer arm to produce
equilibrium, its place upon this arm (which is notched or graduated)
indicating the weight; a Roman balance; -- very commonly used also in
the plural form, steelyards.
Source: Webster’s Unabridged Dictionary 1913 Edition