SOUND AND WAVES ORGAN PIPE A) Wooden, well polished, open or closed. B) Wooden, well polished open type with graduated sliding rod.     RESONANCE APPARATUS Comprises glass tube , mounted on retort stand with clamp and boss ; with 500 ml glass tube, connecting tubing and spring clip supported on split iron ring .   RESONANCE TUBES Comprising of two glass tubes, one 300 x 32 mm and other 300 x 25 mm. The smaller tube slides inside the wider tube in foam plastic collars, allowing the air column length to be varied from 300 to 530 mm.   RESONANCE BOXES Wooden, fitted with holders for tuning forks. For 1 / 2 / 3 / or 4 forks.   SONOMETER 700 x 90 mm wooden baseboard mounted on four feet. Two spring balances 50 N with hooks are provided at one end. At the other end are two wrestpins. Supplied with three bridges, two steel wires and one wrest-pin key.    RIPPLE TANK Comprises robust power supply, legs with levelling screws. Legs, other supporting rods and stroboscope made of Aluminium. Moulded detachable ripple tank tray.   WAVE MOTION APPARATUS For demonstrating longitudinal and transverse wave motion. Consists of 18 accentric aluminium discs supporting a  series of metal rods on revolving the handle, transverse waves are obtained with bent. Straight rods on wooden box. SLINKY SPRING Flat section tempered steel wire in helical coil, about 3 cm dia x 12 cm length closed size. Extended 5 meters.   TUNING FORK Nickel plated or blued steel, with plain or screwed shanks, frequency marked, single piece of any frequency or  set of 8 in box. Frequencies  a) b) c) d) e) f) g) h) C D E F G A B C 256 288 320 341.3 384 426.6 480 512   TUNING FORK MOUNTED Pair of nickel plated tuning forks A (426.6). One fitted with slidin g weight fitted on resonance box. The other plain tuning fork also fitted on individual resonance box. Complete with hammer.