ELECTROLYSIS CELL 1628
Comprises a glass cylinder, 75x25mm diameter, fitted with a rubber bung carrying two carbon electrodes separated by an insulating strip. Two gas collection tubes, 75 x 10mm diameter, are suspended over the electrodes. Supplied with two crocodile clips.

DOUBLE ‘C’ CORE AND CLIP 1629
Laminated core to form a roughly rectangular core 92 x 56 x 20 mm approx. With a cross section of 20 x 12 mm & is cut across the middle to produce 2 equal ‘C’s. A strong spring steel strip is provided to hold the two halves together.

THERMOCOUPLE, COPPER-CONSTANTAN 1630
A simple junction of soldered wires, one each of copper and constantan, 0.5mm diameter x 500mm long. Watch wire coiled for convenience.

THERMOCOUPLE, BISMUTH-ANTIMONY 1631
Bars of bismuth and antimony each 20x3x3mm are soldered together and carrying connecting leads, 500mm x 0.5mm diameter, neatly coiled.

THERMO-PILE, COPPER-CONSTANTAN 1632
Approx. 150 junctions in a small area, the 'hot' face being exposed at the end of short tube 30mm x 30mm dia. A metal heat-collecting cone is attached at this end, the rear end carrying two 4mm socket terminals. Mounted on 13mm aluminium alloy rod 150mm long.

CONTACT KEY SINGLE 1635
A Phosphor bronze spring arm with press knob and two 4mm socket terminals. All mounted on a bakelite base 80x55mm. connected through stainless steel strip underneath.

CONTACT KEY DOUBLE 1636
A contact arm and three metal studs mounted on a bakelite base with three brass terminals. The centre terminal is common a connection to arm and the two other terminals are connected to other studs.

PLUG KEY, ONE WAY 1638
Two brass blocks 9mm thick with brass terminals mounted on a bakelite base 80 x 55mm. Accurately tapered plug with bakelite moulded top is fitted into the hole between the blocks.

PLUG KEY COMMUTATOR, 4 WAYS 1640
Circular, all brass parts on bakelite base.

KNIFE SWITCH SINGLE 1641
Single pole, double throw, mounted on bakelite base, with screw holes for bench fixing, etc. 3 pairs of connecting terminals. Dimension: 100 x15x30mm.

KNIFE SWITCH DOUBLE 1642
Double pole, double throw, mounted on insulating base with screw holes for bench fixing, etc. Dimensions: 100 x 38 x 30mm.

REVERSING SWITCH 1644
Rotary brush type switch with phosphor bronze contacts. Screw terminals. Maximum current 1 Amps. Mounted on an insulating base. Dimensions: 100 x100 x70 mm.

MORSE KEY 1645
Mounted on a wooden base it has adjustable pivots variable spring tension and variable movement. Three terminal posts are provided for make and break operation.

MORSE SOUNDER 1646
An open construction on wooden base with twin coils. Adjustment is provided on armature spring tension and movement, two terminals are provided for connection.

MORSE KEY AND SOUNDER (TELEGRAPH MODEL)1647
A combined version of above Morse key and Morse sounder.

RESISTANCE COILS 1650
Non-inductivity wound on plastic bobbin in transparent plastic tube with two screw terminals adjusted to + 0.2% rating Iw. Resistance in ohms:
(a) 0.1, (b) 0.5, (c) 1, (d) 2, (e) 5, (g) 10, (h) 20, (i) 50, (j) 100.