To verify the laws of triangle, parallelogram and polygon of forces. Compressed with 12mm thick wooden board 30cm dia. disc accurately turned and graduated in degrees. It is provided with 4 frictionless adjustable pulleys having pivots of hardened steel, cords from central ring carries hangers for slotted weights. Pulley clamps have an index to show direction of forces. The base is of heavy cast iron with leveling screws and vertical rod is nicely polished supplied complete with 4 mass hangers and 12 masses (2 x 10 g, 2 x 20 g, 4 x 50 g, 4 x 100 gm).
1. Two metal frames are connected by a pivoted link which also carries a spirit level.
2. A micrometer head reading to 0.01mm is provided to re-adjust the spirit level.
3. With two self-centering wire pin chucks, a ceiling bracket also with two pin chucks, a counterpoise weight & supply of suitable wires but without slotted masses.