An electric bell 3-6 volts ac/dc suspended in a bell jar, fitted with rubber bung & connector terminals.

For use with ripple tank, simple form. A disc of 250 mm diam. with 12 equispaced slots and a finger hole, rotating on its axis, with handle.

4 ohm moving coil speaker, mounted in sheet metal frame for vertical or horizontal position, with two 4 mm sockets.

Improved type, to show effects of vibrations in a stretched cord & to investigate relation between requency, tension & 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 change-over switch in capacitor charge/discharge experiments etc.

General purpose piezzo-electric crystal microphone, frequency response 60 to 10,000 Hz. Complete with 1.4 m screened lead, terminals and jack plug.

Simple open form, polished wood, air column 40 cm. Size 520 x 50 x 50 mm

As above, but with graduated sliding rod, overall length 540 mm when closed.

For use with ripple tank, to operate both the rippler motor and the illuminant. Output 12 V a.c. max 24 W for illuminant and 0 to 6 V d.c. variable for rippler motor. Operates from 240 V a.c. mains.

Consists of a chrome plated brass resonance tube 100 cm long, brass reservoir 250 ml and a metre scale mounted on a metallic stand. With rubber tubing.
 

For measuring the resonant length of an air column driven by a tuning fork. Comprises a brass tube 292x27 mm diameter fixed to a base with a sliding inner tube 305 mm long which allows the length of the air column to be varied from 350 to 530 mm.
 

Glass tube of approx. 840 x 25 mm size mounted on a retort stand with clamp and boss is connected by rubber tubing to a 500 ml glass bulb supported on rubber covered split iron ring, with a spring clip for rubber tubing.

Transparent acrylic plastic ripple tank, supported in a sturdy plastic frame which has recesses to hold four legs with levelling feet. The tank edges are shaped to minimise undesired reflections. Tank has a drain hole closed by a rubber stopper.
With two light alloy uprights to carry a horizontal rippler support rod which is adjustable for height. The ripple assembly, elastically suspended from the support rod, consists of a 4-6 V d.c. motor mounted on a wooden beam. The motor has an eccentric weight which causes the beam to oscillate. Two point sources are provided by two plastic spheres, each mounted on a right angled rod. A metal rod is fixed centrally into a socket in one short side of the frame to afford support to the illuminant.
Overall size of the tank 580 x 500 x 80 mm, window area 370 x 280 mm, height of tank above bench level (with legs attached) approx 375 mm.
Complete with following accessories:-
2 Straight obstacles of aluminium alloy length 130mm; 1 Straight obstacle length 40mm;1 curved reflector radius 200 mm.;1 trapezoidal plastic plate for refraction;1 wood hand wave roller;1 water dropper;1 pkt rubber bands;1 foam plastic sponge; one illuminant with a 12 V,24 W lamp mounted in a lamphouse and provided with a long supporting rod which can be attached to a retort stand, with instructions.
 

Set of four toothed wheels,75 mm diam on a common spindle, having 40, 50, 60 & 80 teeth respectively.

As above, with stand
 

A 300 mm metal disc with eight concentric rings of 48, 45, 40, 36, 32, 30, 27 & 24 holes respectively.