Demos by PIRA

  4A30.10Bimetallic strip: Brass/invar strip curves when heated.
  4A30.11Bimetallic switch: Change in temperature lights cold/hot lamps.
  4A30.21Ring and ball: Ball fits through ring only after ring is heated.
  4A30.30Heated steel rod expands, raises pointer,breaks pin on cooling.
  4A30.60Heated horizontal nichrome wire stretches, weight sags.
  4A30.61Heated iron wire stretches, rotates pointer.