Optically worked for Spectrometer, Equilateral, two faces polished 32x32mm ht.

Prisms also available in sizes 25 x 25 mm and 38 x 38 mm.

20 cm. long, straight form, with side electrodes and 50 mm. long fine capillary in the middle. Filled with Oxygen, Neon, Helium, Air Nitrogen, Argon. Ammonia Vapours, Alcohal Vapuours, Carbon Dioxide, Hydrogen, Lodine Vapour, Sulpher Water Vapurs.

Rectangular plastic body, metal scale, with zeroadjuster, suspension ring and load hook.

Copper, cylinderical vessel 280 x 115 mm overall height x diameter, capacity 1.5 liters, neck 23 mm dia. With riffled side tube 9.5 mm maximum outer dia and water gauge.

Cylinderical copper vessel 180 x 115 mm height x diameter, with filling tube, steam vent and vertical tube terminating the chute passing through side of vessel. Brass tube, a sliding fit in the central tube, to carry thermometer. Lower end cut at an angle to seal the chute.

The bakelite ring or bobbin. 162.5 mm overall diameter wound with three coils of insulated copper wire with 2, 50 and 500 turns mounted on black bakelite moulded platform fitted with 4 terminals, rotating on a tripod non-magnetic metal base, supported by brass levelling screws. Complete with compass box(Magnetometer) mounted at the centre of the ring. Compass box(Magnetometer) spare for tangent galvonometer.

Set of two vertical units, each unit consists of a microphone, a receiver, bell and transformer, with visible wiring connections. Workable with 4-6 V d.c.

Set of two units. Each unit is fitted with one morse key, one sounder and on/off switch for battery, with two battery and two line terminals.All connections are visible. Each unit is workable on 4-6 volts d.c.

Cylinderical copper rod about 300 mm length 25 mm diameter, one end containing a steam chamber connected to inlet and outlet tubes, other end of copper rod has cavity connected via thermometer pockets to water inlet and outlet tubes. Through two thermometers supports tubes 75 mm apart are inserted in the rod for finding the temperature at two points. Fitted in teakwood polished case packed with felt with removable front, without thermometers.

One each wires copper and constantan approximately 305 mm long, twisted and brazed together.

To demonstrate generation of electricity when the junction of two unlike metal is heated.

It consists of 12 pairs of Bismuth and Antimony bars joined together in series with insulation between them. The couples thus arranged are enclosed in a brass frame having two terminals connected to the Bismuth and Antimony poles. Complete with nickel-plated brass cone and mounted on an adjustable stand.

Working on 12 V d.c. supply. Provides dots at 1/50 second intervals.

For ticker tape timer No. P10551, input 220-240 V, output 12 V a.c. 1 amp.

To explain the principle of triode.

On sturdy streamlined base with provision for horizontal or vertical use. Forks is manufactured from selected steel. Prong is 10x25x300 mm. Accurate frequency adjustment chrome plated, vibrations rate 60 per seconds. Electromagnet can work on 6 volts. The amplitude of vibration can vary by sliding the electromagnet inside prongs. Complete with stylet, mirror and counterpoise.

On sturdy streamlined base with provision for horizontal or vertical use. Forks is manufactured from selected steel. Prong is 10 x 25 x 300 mm. Accurate frequency adjustment, chrome plated, vibrations rate 60 per seconds. Electromagnet can work on 6 volts. The amplitude of vibration can vary by sliding ther electromagnet inside prongs. Complete with stylet, mirror and counterpoise.

For demonstrating the production of beat frequencies. Comprises two nickel plated forks A (426.6) mounted on individual boxes. One fork is provided with adjustable mass by means of which frequency may be shifted from the nominal 426.6. When both forks are sounded a clearly audible 'beat' is produced, its rate depending upon the difference in frequency between the forks.

Best quality nickel-plated, plain shanks, with frequency marked, C (256), D (288), E (320), F (341), G (384), A (426), B (480), C (512). Complete set of EIGHT tuning forks, supplied in velvet case.

Represents internal structure and operating principles of an air-cooled two stroke engine. All parts in aluminium alloy. Ignition is shown by means of a mainature bulb. Carburetter and fuel supply also sectioned. Mounted on base, with printed diagram showing working.

Low voltage, double pole double throw, may be used as changeover switch with appropriate connections, moulded base with plated spring metal contacts and screw connectors.

With three brass blocks, each with a 4mm insulated terminal and two standard tapered plugs to fit the two holes between the blocks.

Size 50 x 10 x 5 mm, per pair with plastic cover.

For demonstrating that white light may be composed from all the spectral colours by rotation of multi-colored disc. Comprising a multi-coloured metal disc 150mm. diameter mounted on metal stand and driven by belt with the help of driving wheel, fitted with a handle, individually packed.

As above, with coloured disc 150mm dia & mounted on light metal base for schools.

With charge indicating system 2 volts 45 AH on 20 Hrs rate in plastic container.

Moving coil for D.C. measurements, Any single range 0-1, 1.5, 3, 5, 10 Amps.