Wave from Helix

Simple type model, it comprises a wooden board 700 x 90 mm (L x W) on four feet, fitted with two steel wires about 0.3mm x 1m (dia x length). At one end of base there are two 50 N spring balances with hooks and at the other end are two wrest pins, supplied complete with three bridges, one large, to span both wires and two small bridges for individual wires, two steel wires 0.3 mm dia. x 1 meter long.

Three Tuning forks are mounted on three wooden resonance boxes dimensions of which are compatible with frequency of the forks to produce a strong sustained tone. Forks are nickel plated with shanks to screw in the bushes on the top of the boxes. Each set supplied with rubber headed hammer.