Physics

Hollow wooden-sounding box 1290 x 130 x 110 mm, with mm scale, has two fixed bridges 72 cm apart over which wires are stretched. To one wire is fitted a spring balance reading to 100N x 5N and its tension can be adjusted by a winged nut and measured. Another wire passes over a pulley and can be loaded as desired. A third wire, for comparison, can have its tension adjusted by a wrest pin. With 3 movable bridges, wrest-pin key, spring balance, and set of four wires of different diameters, each 1.5 meter long, without masses.

4 precision aluminium alloy tuning forks to sound the major chords (C-256, E-320, G-384, and C-512). Frequency and note are stamped on each fork.

Six precision aluminium alloy tuning forks. Set consists of 125 Hz; 250 Hz; 500 Hz; 1,000 Hz; 2,000 Hz; and 4,000 Hz.

Threaded shanks, mounted on a common resonance box and having frequencies of C1 (256), E (320), G (384) and C2 (512) Hz. Size of box 285 x 115 x 63 mm approx., complete with hammer.

Set of two resonance boxes with extra heavy aluminium forks having double the duration of audible vibration than the ordinary forks. One fork is weighted and can be adjusted over range of about 30 Hz. forks are of different lengths 19.4 cm and 17.5 cm approx.

Improved type, to show effects of vibrations in a stretched cord and to investigate relation between frequency, tension and density. Comprising an adjustable length of thin steel rod mounted in a pair of socket terminals near one end and passing through an A.C. energising coil and a permanent magnet. The other end of the wire has a small boss with clamping screw for attaching to cord. Two adjustable contacts are also fixed on either side of the armature connected to terminal sockets to provide a quick changeover switch in capacitor charge/discharge experiments etc.