- A permanent system of weights mounted, for example, on a theatre stage to balance curtains, scenery, or lighting equipment.
- A system for raising and lowering scenery by means of an arrangement of lines and weights. A theater so equipped (sometimes called a counterweight house) does not require a fly floor (see flies).
The most spectacular counterweight system was that devised in 1641 byGiacomo Torelli for La festa teatrale della finta pazzia atVenice's Teatro Novissimo. Counterweights were connected to eight pairs ofwings that could be changed simultaneously by one person. A similar systemcan still be seen at the Drottningholm Theatre and Museum, Sweden. seealso hand-worked house.